GroupsAndTeams.ps1

#see also Get-MsolGroup ; Get-MsolGroupMember ; add-MsolGroupMember; Remove-MsolGroupMember
function Get-GraphGroupList {
    <#
      .Synopsis
        Gets a list of groups
      .Description
        The list of groups returned can be filtered by name (the beginning of the displayname and mail
        address are checked) or with a custom filter string. Or it can be sorted, Or specific fields can
        be selected. However there is a limitation in the graph API which prevent these being combined.
        Requires consent to use the Group.Read.All scope.
      .Example
        >Get-GraphGroupList | format-table -autosize Displayname, SecurityEnabled, Mailenabled, Mail, ID
        Displays a table of groups in the current tennant
      .Example
        >(Get-GraphGroupList -Name consult | Get-GraphTeam -Site).weburl
        Gets any group whose name begins "Consult" , finds its sharepoint site, and returns the site's URL
    #>

    [Cmdletbinding(DefaultparameterSetName="None")]
    param (
        #if specified limits the groups returned to those with names begining...
        [Parameter(Mandatory=$true, parameterSetName='FilterByName')]
        [string]$Name,
        #Field(s) to select: ID and displayname are always included;
        #The following are only available when getting a single group:
        #'allowExternalSenders','autoSubscribeNewMembers','isSubscribedByMail' 'unseenCount',
        [ValidateSet( 'assignedLicenses', 'classification', 'createdDateTime', 'description', 'groupTypes',
                    'licenseProcessingState', 'mail', 'mailEnabled', 'mailNickname', 'onPremisesLastSyncDateTime',
                    'onPremisesProvisioningErrors', 'onPremisesSecurityIdentifier', 'onPremisesSyncEnabled',
                    'preferredDataLocation', 'proxyAddresses', 'renewedDateTime', 'securityEnabled', 'visibility')]
        [Parameter(Mandatory=$true, parameterSetName='SelectFields')]
        [string[]]$Select,
        #An oData order by string
        [Parameter(Mandatory=$true, parameterSetName='Sort')]
        [string]$OrderBy,
        #An oData filter string; there is a graph limitation that you can't filter by description or Visibility.
        [Parameter(Mandatory=$true, parameterSetName='FilterByString')]
        [string]$Filter
    )
    #investigate '?$filter=groupTypes/any(c:c+eq+''Unified'')'

    Connect-MSGraph

    $webparams    = @{'Method'  = "Get"
                      'Headers' = $Script:DefaultHeader
    }
    $uri          = 'https://graph.microsoft.com/v1.0/Groups/'

    if     ($Select)  {$uri += '?$select='  + ((@('id','displayName') + $Select) -join ',')}
    elseif ($OrderBy) {$uri += '?$OrderBy=' + $OrderBy}
    elseif ($Filter)  {$uri += '?$Filter='  + $Filter }
    elseif ($Name)    {
        #for once we don't need to fix case.If * is specified , remove it.
        if ($Name -match '\*') {$Name = $Name -replace "\*",""}
        $uri      += ("?`$filter=startswith(displayName,'{0}') or startswith(mail,'{0}')" -f $Name )
    }

    Write-progress -Activity "Finding Groups"
    $groups = (Invoke-RestMethod @webparams -Uri $uri ).value
    #If Selecting fields, don't set a type to display fields we probably do not have.
    if (-not $Select) {
         foreach ($g in $groups) {$g.pstypenames.Add("GraphGroup") }
    }
    Write-progress -Activity "Finding Groups" -Completed

    $groups
}

function New-GraphGroup {
    <#
      .Synopsis
        Adds a new group/team
      .Description
        Every team is also a group, but not every group is team enabled.
        This Command has an alias of New-GraphTeam so you call it as team or group
        By default it creates the group as a team UNLESS you specify -NoTeam.
        A non-Teams enabled group can be teams enabled with Set-GraphGroup -EnableTeam
        Creating and modifying groups requires consent to use the Group.ReadWrite.All scope
    #>

    [Cmdletbinding(SupportsShouldprocess=$true)]
    [Alias("New-GraphTeam")]
    param(
        #The Name of the group / team
        [Parameter(Mandatory=$true, Position=0)]
        [string]$Name,
        #The group/team's mail nickname
        [string]$MailNickName,
        #A description for the group
        [string]$Description,
        #The visibility of the group, Public by default, it can be 'private' or 'hidden membership'
        [ValidateSet('private', 'public', 'hiddenmembership')]
        [string]$Visibility = 'public',
        #Ordinary Members of the group - assumed to be users, given by their User Principal Name or ID or as objects
        $Members,
        #Owners of the group - assumed to be users, given by their User Principal Name or ID or as objects
        $Owners,
        #By default the group is configured as a team unless -NoTeam is specified
        [Switch]$NoTeam,
        #if specified group will be added without prompting
        [Switch]$Force
    )
    Connect-MSGraph
    if (-not $Script:WorkOrSchool) {Write-Warning   -Message "This command only works when you are logged in with a work or school account." ; return    }

    $webparams = @{ Headers     = $Script:DefaultHeader  }
    if ( (Invoke-RestMethod -Method Get @webparams -Uri "https://graph.microsoft.com/v1.0/groups?`$filter=displayname eq '$Name'" ).value) {
        throw "There is already a group with the display name '$Name'." ; return
    }
    #Server-side is case-sensitive for [most] JSON so make sure hashtable names and constants have the right case!
    if (-not $MailNickName) {$MailNickName = $Name -replace "\W",'' }
    $settings = @{  'displayName'          = $Name ;
                    'mailNickname'         = $MailNickName;
                    'mailEnabled'          = $true;
                    'securityEnabled'      = $false;
                    'visibility'           = $Visibility.ToLower() ;
                    'groupTypes'           = @("Unified") ;
    }
    if ($Description) {
                  $settings['description'] = $Description
    }
    #if we got owners or users with no ID, fix them at the end, if they have an ID add them now
    if ($Members) {
        $settings['members@odata.bind']= @();
        foreach ($m in $Members) {
            if  ($m.id) {$settings['members@odata.bind'] += "https://graph.microsoft.com/v1.0/users/$($m.id)"}
            else        {$settings['members@odata.bind'] += "https://graph.microsoft.com/v1.0/users/$m"}
        }
    }
    #If we make someone else the owner of the group, we can't make it a team, so only set owners here if we are not making a team.
    if ($noTeam -and $Owners) {
        $settings['owners@odata.bind']= @()
        foreach    ($o in $Owners)  {
            if     ($o.id) {$settings['owners@odata.bind']  += "https://graph.microsoft.com/v1.0/users/$($o.id)"}
            else{           $settings['owners@odata.bind']  += "https://graph.microsoft.com/v1.0/users/$o"}
        }
    }
    $webparams["contentType"] = 'application/json'
    #Don't add URI or body to web params as we are going to make two calls ...
    $uri       = "https://graph.microsoft.com/v1.0/groups"
    $json = ConvertTo-Json $settings
    Write-Debug $json

    if ($Force -or $PSCmdlet.shouldprocess($Name,"Add new Group")) {
        Write-Progress -Activity 'Creating Group/Team' -CurrentOperation "Adding Group $Name"
        $group = Invoke-RestMethod @webparams -Method Post -uri $uri -body $json
        foreach ($m in $group.members) {if ($m.'@odata.type' -match "user") {$m.pstypenames.add("GraphUser")}}
        if ($NoTeam) {
            $group.pstypenames.Add("GraphGroup")
            Write-Progress -Activity 'Creating Group/Team' -Completed
            return $group
        }
        else {
            $uri = $uri + "/" + $group.id + "/team"
            Write-Progress -Activity 'Creating Group/Team' -CurrentOperation "Team-enabling Group $Name"
            $team   = Invoke-RestMethod @webparams -Method Put -uri $uri -Body "{ }"
            $team.pstypenames.Add("GraphTeam")
            Add-Member -InputObject $team -MemberType NoteProperty -Name DisplayName -Value $group.displayName
            Add-Member -InputObject $team -MemberType NoteProperty -Name Description -Value $group.description
            Add-Member -InputObject $team -MemberType NoteProperty -Name Members     -Value $group.members
            Add-Member -InputObject $team -MemberType NoteProperty -Name Mail        -Value $group.Mail
            Add-Member -InputObject $team -MemberType NoteProperty -Name visibility  -Value $group.visibility
            Write-Progress -Activity 'Creating Group/Team' -CurrentOperation "Setting Group ownership on $Name"
            if ($Owners) {
                $Owners | Add-GraphGroupMember -Group $group -AsOwner -Force
            }
            Write-Progress -Activity 'Creating Group/Team' -Completed

            $team
        }
    }
}
<#
See also https://docs.microsoft.com/en-gb/graph/api/team-post?view=graph-rest-beta
 
POST https://graph.microsoft.com/beta/teams
Content-Type: application/json
{
 "template@odata.bind": "https://graph.microsoft.com/beta/teamsTemplates/standard",
 "displayName": "My Sample Team",
 "description": "My Sample Team’s Description",
}
#>


function Set-GraphGroup {
    <#
      .Synopsis
        Sets options on a group
      .Description
        Allows or blocks external senders, changes visibility or description and enables the group as a team.
        Other options for a team are set via Set-GraphTeam.
        Requires consent to use the Group.ReadWrite.All scope.
      .Example
       Get-GraphGroupList -Name consult | Set-GraphGroup -Description "People who do consulting work" -Force
       Finds the group(s) with a name which matches Consult* and sets the description without a confirmation prompt.
    #>

    [Cmdletbinding(SupportsShouldprocess=$true,ConfirmImpact='High')]
    param (
        [Parameter(Mandatory=$true, ValueFromPipeline=$true,Position=0)]
        $Group ,
        #If specified, the group can receive external email; the option can be disabled with -AllowExternalSenders:$false.
        [switch]$AllowExternalSenders,
        #A new description for the group
        [string]$Description,
        #The visibility of the group; groups are created as public by default, it can be 'private' or 'hidden membership'
        [ValidateSet('private', 'public', 'hiddenmembership')]
        [string]$Visibility,
        #Enables team functionality on a group which does not yet have it enabled
        [switch]$EnableTeam,
        #If specified the group will be updated without prompting for confirmation.
        [switch]$Force
    )
    Connect-MSGraph

    if     ($Group.Id)            {$uri = "https://graph.microsoft.com/v1.0/groups/$($Group.ID)"}
    elseif ($Group -is [string])  {$uri = "https://graph.microsoft.com/v1.0/groups/$Group"}
    else   {Write-Warning -Message 'Could not process group paramaeter' ; return}
    $webparams = @{'uri'         = $uri
                   'Headers'     = $Script:DefaultHeader
                   'ContentType' = 'application/json'
    }

    $settings = @{}
    if ($Visibility)        {$settings['visibility']            = $Visibility.ToLower()}
    if ($Description)       {$settings['description']           = $Description}
    if ($PSBoundparameters.ContainsKey('AllowExternalSenders')) {
                             $settings['allowExternalSenders']  = [bool]$AllowExternalSenders
    }
    $json = ConvertTo-Json $settings
    Write-Debug $json
    if (($settings.Count -or $EnableTeam) -and
        ($Force -or $PSCmdlet.Shouldprocess($group.displayname,'Update Group'))) {
        if ($settings.Count) {
                  Invoke-RestMethod @webparams -Method Patch -Body $json | Out-Null
        }
        if ($EnableTeam)     {
            $g  = Invoke-RestMethod @webparams -Method Get
            if ($g.resourceProvisioningOptions -notcontains 'Team') {
                  $webparams['uri'] +=  "/team"
                  Invoke-RestMethod @webparams -Method Put -Body "{ }"   | Out-Null
            }
            elseif ($EnableTeam) {Write-Warning  "Group $($g.displayName) is already team-enabled." }
        }
    }
}

function Remove-GraphGroup {
    <#
      .Synopsis
        Removes a group/team
      .Description
        Requires consent to use the Group.ReadWrite.All scope.
        The group may remain visible for a short time.
    #>

    [Cmdletbinding(SupportsShouldprocess=$true,ConfirmImpact='High')]
    [Alias("Remove-GraphTeam")]
    param(
        #The ID of the Group / team
        [Parameter(Mandatory=$true, Position=0,ValueFromPipeline=$true )]
        [Alias("Team")]
        $Group,
        #If specified the group will be removed without prompting
        $Force
    )
    begin   {
        Connect-MSGraph
    }
    process {
        if     (-not $Script:WorkOrSchool) {Write-Warning   -Message "This command only works when you are logged in with a work or school account." ; return    }
        if     ($Group.displayName)  {$displayName = $Group.DisplayName}
        if     ($Group.ID)           {$groupID     = $Group.ID}
        elseif ($Group -is [String]) {$groupID     = $Group   }
        else   {Write-Warning -Message 'Could not process Group parameter.'; return }

        $webparams = @{'Headers' = $Script:DefaultHeader
                       'uri'     = "https://graph.microsoft.com/v1.0/groups/$groupID/"
        }
        if (-not $displayName){
            try   {  $g  = Invoke-RestMethod -Method Get @webparams }
            catch        {throw "Could not get the group to delete"; return}
            if (-not $g) {throw "Could not get the group to delete"; return}
            else         {$displayName = $g.displayname}
        }
        if ($PSCmdlet.Shouldprocess($DisplayName,"Delete Group")) {
            Invoke-RestMethod -Method Delete  @webparams
        }
    }
}

# Groups in the recycle bin (irm -Method Get -headers $Script:DefaultHeader -Uri "https://graph.microsoft.com/v1.0/directory/deletedItems/microsoft.graph.group").value
# DELETE /directory/deletedItems/{id} permanent delete
# POST /directory/deletedItems/{id}/restore restore item

function Add-GraphGroupMember {
    <#
      .Synopsis
        Adds a user (or group) to a group/team as either a member or owner.
      .Description
        Because the group may be a team the this command has alias of Add-GraphTeamMember
        requires consent to use the Group.ReadWrite.All, Directory.ReadWrite.All, or
        Directory.AccessAsUser.All scope.
      .Example
        >
        >$newGroup = New-GraphGroup -Name Test99
        >Get-GraphUserList -Filter "Department eq 'Accounts'" | Add-GraphGroupMember -Group $g
        Creates a new group; then gets a list of users and adds them to the group.
      .Example
        >Add-GraphTeamMember -Team $Newteam -Member alex@contoso.com -AsOwner
        Adds an owner to a team, using aliases for both the command and the group parameter
    #>

    [Cmdletbinding(SupportsShouldprocess=$true)]
    [Alias("Add-GraphTeamMember")]
    param   (
        #The group / team either as an ID or a group/team object with an IDn
        [Parameter(Mandatory=$true, Position=0)]
        [Alias("Team")]
        $Group,
        #The user or nested-group to add, either as a UPN or ID or as a object with an ID
        [Parameter(Mandatory=$true, Position=1, ValueFromPipeline=$true)]
        $Member,
        #If specified the user will be added as an owner, otherwise they will be a standard member
        [switch]$AsOwner,
        #If specified group member will be added without prompting
        [Switch]$Force
    )
    begin   {
        Connect-MSGraph
        if     ($Group.ID)           {$groupID  = $Group.ID}
        elseif ($Group -is [String]) {$groupID  = $Group   }
        else   {Write-Warning -Message 'Could not process Group parameter.'; return }

        if ($AsOwner) {$uri   = "https://graph.microsoft.com/v1.0/groups/$groupID/owners/`$ref" }
        else          {$uri   = "https://graph.microsoft.com/v1.0/groups/$groupID/members/`$ref"}

        $webparams = @{'Method'      = 'Post'
                       'uri'         = $uri
                       'Headers'     = $Script:DefaultHeader
                       'ContentType' = 'application/json'
        }
    }
    process {
        if   (-not $Script:WorkOrSchool) {Write-Warning   -Message "This command only works when you are logged in with a work or school account." ; return    }
        #if we weren't passed as a user as a an object, resolve what we did get ...
        if   ($Member.id)          {$memberID     = $Member.id}
        else {
            try   {
                $Member     = Get-GraphUser -User $Member
                $memberid   = $Member.id
            }
            catch {throw "Could not get a user matching $Member"; return }
            if (-not $Member) {throw "Could not get a member ID"; return }
        }

        $settings  = @{'@odata.id' = "https://graph.microsoft.com/v1.0/directoryObjects/$memberID"   }
        $json      = ConvertTo-Json $settings
        Write-Debug $json
        if ($Force -or $PSCmdlet.shouldprocess($Member.displayname,"Add to Group")) {
            Invoke-RestMethod @webparams -Body $json
        }
    }
}

function Remove-GraphGroupMember {
    <#
      .Synopsis
        Removes a user (or group) from a group/team
      .Description
        Because the group may be a team the command has an alias of Remove-GraphTeamMember.
        It requires consent to use the Group.ReadWrite.All, Directory.ReadWrite.All, or
        Directory.AccessAsUser.All scope.
      .Example
        Remove-GraphGroupMember -Group $g -FromOwners -Member alex@contoso.com -Force
        Remmvoes a user from the owners of a group without prompting for confirmation.
      .Example
        Get-GraphUserList -Filter "Department eq 'Accounts'" | Remove-GraphGroupMember -Group $g
        Gets a list of users and removes them from from a group.
    #>

    [Cmdletbinding(SupportsShouldprocess=$true,ConfirmImpact='High')]
    [Alias("Remove-GraphTeamMember")]
    param   (
        #The ID of the Group / team
        [Parameter(Mandatory=$true, Position=0)]
        [Alias("Team")]
        $Group,
        #A group object with an ID field, or a user object, user ID or UPN
        [Parameter(Mandatory=$true, Position=1, ValueFromPipeline=$true)]
        $Member,
        #If specified the member will be removed from the owners rather than members
        [switch]$FromOwners,
        #If specified the member will be removed without prompting for confirmation
        [switch]$Force
    )
    begin   {
        Connect-MSGraph
    }
    process {
        if     (-not $Script:WorkOrSchool) {
                Write-Warning -Message "This command only works when you are logged in with a work or school account."
                return
        }
        if     ($Group.id)           {$groupid = $Group.id}
        elseif ($Group -is [string]) {$groupId = $Group }
        else   {Write-Warning -Message "Could not resolve the group parameter."; return}
        if     ($Member.id) {
                $memberid = $Member.id
        }
        else {
            try {
                $Member   = Get-GraphUser -User $Member
                $memberid = $Member.id
            }
            catch {throw "Could not get a user matching $Member";  return}
            if (-not $Memberid) {throw "Could not get a member ID" ; return}
        }

        $webparams = @{'Method'      = 'Delete'
                       'Headers'     =  $Script:DefaultHeader
                       'contentType' = 'application/json'
        }
        if ($FromOwners) {
                $webparams['URI']    = "https://graph.microsoft.com/v1.0/groups/$groupid/owners/$memberid/`$ref"
        }
        else {
                $webparams['URI']    = "https://graph.microsoft.com/v1.0/groups/$groupid/members/$memberid/`$ref"
        }
        if ($Force -or $PSCmdlet.Shouldprocess($member.displayName,"Remove from Group")) {
            Invoke-RestMethod @webparams
        }
    }
}

function Get-GraphTeam {
    <#
      .Synopsis
        Gets information about a group and associated office 365 team
      .Description
        Takes a a team ID or team object as a parameter and gets information about the team
        The teams Apps, Calendar, Channels, Drive, Members or Planners can be requested.
        Depending on which aspect of the group are queried, may need access to the following
        Scopes Group.Read.All, Files.Read, Sites.Read.All, Notes.Create, Notes.Read,
      .Example
        >get-graphuser -teams | get-graphteam -Plans | select -last 1 | get-graphplan -FullTasks | ft PlanTitle,Bucketname,Title,DueDateTime,PercentComplete,Assignees
         Gets the current user's Teams, and gets the plans for each; selects just
         the last one, and gets its task details, showing the result as a table.
      .Example
        >(Get-GraphTeam -Site).lists | where name -match document
        Gets team(s) for the current user and returns the associated site(s).
        Site objects include a lists property, which holds a collection of lists
        this command will fiter the lists down to those where name matches "document"
      .Example
        >(Get-GraphTeam -Drive).root.children.where({$_.folder}) | Select name, weburl, id,@{n="drive";e={$_.parentReference.driveId}}
        Gets team(s) for the current user and returns the associated drive(s)
        Drive objects include a root property, which holds an object describing the root folder;
        this in turn has a children property which contains files and folder objects in the root folder.
        This command filters the children collection to folders and returns their name,
        WebURl and the item ID and Drive ID needed to access them from one
      .Example
        >Get-GraphTeam -Notebooks | select -ExpandProperty sections | where "Displayname" -eq "General_Notes"
        Gets team(s) for the current user and returns the associated notebooks(s)
        Notebook objects include a Sections property, which holds a collection of OneNote sections in the notebook;
        This command gets returns any section in a team notebook which has the name "General_Notes"
      .Example
        > Get-GraphTeam -threads | where {[datetime]$_.lastDeliveredDateTime -gt [datetime]::Now.AddDays(-7) }
        Gets the teams conversation threads which have been updated in the last 7 days.
    #>

    [Cmdletbinding(DefaultparameterSetName="None")]
    [Alias("Get-GraphGroup")]
    param   (
        #The name of a team.
        #One more Team IDs or team objects containing and ID. If omitted the current user's teams will be used.
        [Parameter(ValueFromPipeline=$true, Position=0)]
        [Alias("ID","Group")]
        $Team ,
        #If specified the Team parameter is treated as a name not an ID
        [Switch]$ByName,
        #If specified returns the teams Apps
        [Parameter(parameterSetName='Apps')]
        [switch]$Apps,
        #If specified gets the team's Calendar (a team only has one)
        [Parameter(Mandatory=$true, parameterSetName='Calendar')]
        [switch]$Calendar,
        #If specified gets the team's channels
        [Parameter(parameterSetName='Channels')]
        [switch]$Channels,
        #If Specified, retrun team's conversations (usually better to use threads)
        [Parameter(Mandatory=$true, parameterSetName='Conversations' )]
        [switch]$Conversations,
        #If specified gets the Team's one drive
        [Parameter(Mandatory=$true, parameterSetName='Drive')]
        [switch]$Drive,
        #If specified returns the members of the team
        [Parameter(Mandatory=$true, parameterSetName='Members')]
        [switch]$Members,
        #If specified returns the Owners of the team
        [Parameter(Mandatory=$true, parameterSetName='Owners')]
        [switch]$Owners,
        #If specified returns the team's notebook(s)
        [Parameter(Mandatory=$true, parameterSetName='Notebooks')]
        [switch]$Notebooks,
        #if Specified, returns the teams Planners.
        [Parameter(Mandatory=$true, parameterSetName='Planners')]
        [switch]$Plans,
        #If Specified, retrun team's threads
        [Parameter(Mandatory=$true, parameterSetName='Threads' )]
        [switch]$Threads,
        #if Specified, returns the teams site.
        [Parameter(Mandatory=$true, parameterSetName='Site')]
        [switch]$Site,
        #limits searches for appsby name.
        [Parameter(parameterSetName='Apps')]
        [String]$AppName,
        #limits searches for channels by name. Other's cant be filtered by name ... perhaps notebooks can but a group only has one.
        [Parameter(parameterSetName='Channels')]
        [String]$ChannelName,
         #Field(s) to select: ID and displayname are always included
        #The following are only available when getting a single group:
        [ValidateSet('allowExternalSenders','autoSubscribeNewMembers','isSubscribedByMail', 'unseenCount',
                     'assignedLicenses', 'classification', 'createdDateTime', 'description', 'groupTypes',
                     'licenseProcessingState', 'mail', 'mailEnabled', 'mailNickname', 'onPremisesLastSyncDateTime',
                     'onPremisesProvisioningErrors', 'onPremisesSecurityIdentifier', 'onPremisesSyncEnabled',
                     'preferredDataLocation', 'proxyAddresses', 'renewedDateTime', 'securityEnabled', 'visibility')]
        [Parameter(Mandatory=$true, parameterSetName='SelectFields')]
        [string[]]$Select

    )
    begin   {
        Connect-MSGraph
        $webparams = @{Method = "Get"
                       Headers = $Script:DefaultHeader
        }
    }
    process {
        if     (-not $Script:WorkOrSchool)          {Write-Warning   -Message "This command only works when you are logged in with a work or school account." ; return    }
        if     ($ByName -and $Team -isnot [string]) {Write-Warning 'The team parameter does not look like a name'; return}
        elseif ($ByName)    {$Team = Get-GraphGroupList -Name $Team}
        elseif (-not $Team) {$Team = Get-GraphUser      -Teams }
        if     (-not $Team) {Write-Warning 'Could not Get a team from the parameters provided' ; return}
        foreach ($t in   $Team) {
            if  ($t.id) {$teamid = $t.id}
            else        {$teamid = $t }
            $groupURI = "https://graph.microsoft.com/v1.0/groups/$teamid"
            $teamURI  = "https://graph.microsoft.com/v1.0/teams/$teamid"
            try   {
                #For each of the switches get the data from /groups{id}/whatever or /teams/{id}.whatever
                #Add a type to PS Type names so we can format it, and add any properties we expect to want later.
                if     ($Site)          {
                    Write-Progress -Activity 'Getting Group Site Information'
                    $result  =  Invoke-RestMethod  @webparams -Uri ("$groupURI/sites/root"  + '?expand=drives,sites,lists(expand=columns,contenttypes,drive)')
                    foreach ($s in $result) {
                        $s.pstypenames.Add("GraphSite")
                        foreach ($l in $s.lists) {
                            $l.pstypenames.add('GraphList')
                            Add-Member -InputObject $l -MemberType NoteProperty   -Name SiteID    -Value  $s.id
                            Add-Member -InputObject $l -MemberType NoteProperty   -Name ParentUrl -Value  $s.weburl
                            Add-Member -InputObject $l -MemberType ScriptProperty -Name Template  -Value {$this.list.template}
                            $l.columns | ForEach-Object {$_.pstypenames.add('GraphColumn')}
                        }
                        $s.drives      | ForEach-Object {$_.pstypenames.add('GraphDrive') }
                    }
                    Write-Progress -Activity 'Getting Group Site Information' -Completed
                    $result
                }
                elseif ($Calendar)      {
                    Write-Progress -Activity 'Getting Group Calendar'
                    $result = Invoke-RestMethod  @webparams -Uri  "$groupURI/calendar"
                    $result.pstypenames.Add("GraphCalendar")
                    Add-Member -InputObject $result -MemberType NoteProperty -Name GroupID      -Value $teamid
                    Add-Member -InputObject $result -MemberType NoteProperty -Name CalendarPath -Value "groups/$teamid/Calendar"
                    Write-Progress -Activity 'Getting Group Calendar' -Completed
                    $result
                }
                elseif ($Drive)         {
                    Write-Progress -Activity 'Getting Group Drive information'
                    $result = Invoke-RestMethod  @webparams -Uri ("$groupURI/drive" + '?$expand=root($expand=children)' )
                    $result.pstypenames.Add("GraphDrive")
                    Write-Progress -Activity 'Getting Group Drive information' -Completed
                    $result
                }
                elseif ($Members)       {
                    Write-Progress -Activity 'Getting Group Members'
                    $result = (Invoke-RestMethod  @webparams -Uri  "$groupURI/members")
                    $users  = $result.value  #do we need a while ($result.'@odata.nextLink') { irm nextlink, add value to users} ??
                    foreach ($u in $users) {
                         if ($u.'@odata.type'  -match 'user') {$u.psTypenames.Add("GraphUser")}
                    }
                    Write-Progress -Activity 'Getting Group Members' -Completed
                    $users
                }  #can do group ?$expand=Memebers, the others don't expand
                elseif ($Owners)        {
                    Write-Progress -Activity 'Getting Group Owners'
                    $result = (Invoke-RestMethod  @webparams -Uri  "$groupURI/Owners")
                    $users  = $result.value  #do we need a while ($result.'@odata.nextLink') { irm nextlink, add value to users} ??
                    foreach ($u in $users) {
                         if ($u.'@odata.type'  -match 'user') {$u.psTypenames.Add("GraphUser")}
                    }
                    Write-Progress -Activity 'Getting Group Owners' -Completed
                    $users
                }  #can do group ?$expand=Memebers, the others don't expand
                elseif ($Notebooks)     {
                    Write-Progress -Activity 'Getting Group OneNote Notebooks'
                    #if groups can have more than onebook , then add if name ... uri = blah + "?`$expand=sections&`$filter=startswith(tolower(displayname),'$name')"
                    $results = (Invoke-RestMethod  @webparams -Uri ("$groupURI/onenote/notebooks" + '?$expand=sections'  ) )
                    $books   = $results.value
                    foreach ($b in $books) {
                        $b.pstypenames.add("GraphOneNoteBook")
                        #Section fetched this way won't have parentNotebook, so make sure it is available when needed
                        $bookobj =new-object -TypeName psobject -Property @{'id'=$b.id; 'displayname'=$b.displayName; 'Self'=$b.self}
                        foreach ($s in $b.sections) {
                            Add-Member -InputObject $s -MemberType NoteProperty -Name ParentNotebook   -Value $bookobj
                            $s.pstypeNames.add("GraphOneNoteSection")
                        }
                    }
                    Write-Progress -Activity 'Getting Group OneNote Notebooks' -Completed
                    $books
                }
                elseIf ($Plans)         {
                    Write-Progress -Activity 'Getting Group Planner Plans'
                    $result   = Invoke-RestMethod  @webparams -Uri  "$groupURI/planner/plans" #would like to have expand details here but it only works with a single plan.
                    $planList = $result.value
                    while ($result.'@odata.nextLink') {
                        $result = Invoke-RestMethod  @webparams -Uri $result.'@odata.nextLink'
                        $planList += $result.value
                    }
                    if (-not $planList) {
                        Write-Host "The team $($Team.DisplayName) has not created any plans"
                        return
                    }
                    $dirObjectsHash = @{}
                    if ($t.displayName) {$dirObjectsHash[$teamId] = $t.displayName}
                    @() + $planList.owner + $planList.createdby.user.id  |ForEach-Object  {
                        if (-not $dirObjectsHash[$_]) {
                            $dirObjectsHash[$_] = (Invoke-RestMethod  @webparams -Uri "https://graph.microsoft.com/v1.0/directoryobjects/$_").displayname
                        }
                    }
                    foreach ($p in $planList) {
                        $p.pstypenames.add("GraphPlan")
                        Add-Member -InputObject $P -MemberType NoteProperty -Name OwnerName   -Value $dirObjectsHash[$p.owner]
                        Add-Member -InputObject $P -MemberType NoteProperty -Name CreatorName -Value $dirObjectsHash[$p.createdBy.user.id]
                    }
                    Write-Progress -Activity 'Getting Group Planner Plans' -Completed
                    $planList
                }
                elseif ($Threads)       {
                    Write-Progress -Activity 'Getting Group Conversation threads'
                    $results = (Invoke-RestMethod  @webparams -Uri  "$groupURI/threads")
                    $threadList = $results.value #do we need a while ($result.'@odata.nextLink') { irm nextlink, add value to threads} ??
                    foreach ($t in $threadList) {
                        $t.pstypenames.add("GraphThread")
                        Add-Member -InputObject $t -MemberType NoteProperty -Name Group -Value $teamid
                    }
                    Write-Progress -Activity 'Getting Group Conversation threads' -Completed
                    $threadList
                }
                elseif ($Conversations) {
                    Write-Progress -Activity 'Getting Group Conversations'
                    $results  = (Invoke-RestMethod  @webparams -Uri ("$groupURI/conversations" +'?$expand=Threads')  )
                    $convList = $results.value #do we need a while ($result.'@odata.nextLink') { irm nextlink, add value to convList} ??
                    foreach ($c in $convList) {
                        $c.pstypenames.add("GraphConversation")
                        Add-Member -InputObject $c -MemberType NoteProperty -Name Group -Value $teamid
                        foreach ($t in $c.threads) {
                            $t.pstypenames.add("GraphThread")
                            Add-Member -InputObject $t -MemberType NoteProperty -Name Group -Value $teamid
                        }
                    }
                    Write-Progress -Activity 'Getting Group Conversations' -Completed
                    $convList
                }
                elseif ($Channels -or
                        $ChannelName)   {
                    if ($ChannelName) {
                        $uri =  "$teamURI/channels?`$filter=startswith(tolower(displayname), '$($ChannelName.ToLower())')"
                    }
                    else {
                        $uri =  "$teamURI/channels"
                    }
                    Write-Progress -Activity 'Getting Team Channels'
                    $results  = (Invoke-RestMethod  @webparams -Uri $uri)
                    $chanList = $results.value
                    foreach ($c in $chanList) {
                         $c.pstypenames.add("GraphChannel")
                         Add-Member -InputObject $c -MemberType NoteProperty -Name Team -Value $teamid
                    }
                    Write-Progress -Activity 'Getting Team Channels' -Completed
                    $chanList
                }
                elseif ($Apps -or
                        $AppName)       {
                    Write-Progress -Activity 'Getting Team Apps'
                    if ($AppName) {
                        $uri = "$teamURI/installedApps" +
                                    '?$expand=teamsAppDefinition&$filter=' +
                                    "startswith(tolower(teamsappdefinition/displayname),'$($AppName.ToLower())')"
                    }
                    else {
                        $uri = ("$teamURI/installedApps" + '?$expand=teamsAppDefinition')
                    }
                    $results  = (Invoke-RestMethod  @webparams -Uri $uri)
                    $appsList = $results.value
                    foreach ($a in $appsList) {
                        $a.pstypenames.add("GraphApp")
                        Add-Member -InputObject $a -MemberType NoteProperty -Name Team -Value $teamid
                    }
                    Write-Progress -Activity 'Getting Team Apps' -Completed
                    $appsList
                }
                elseif ($Select)        {
                    $SelectList = (@('id','displayName') + $Select ) -join','
                    Invoke-RestMethod  @webparams -Uri ($groupuri + '?$Select=' + $SelectList)
                }
                else                    {
                    Write-Progress -Activity 'Getting Group/Team information'
                    $g =  Invoke-RestMethod  @webparams -Uri "$groupuri`?`$expand=members"
                    if ($g.resourceProvisioningOptions -contains 'Team') {
                        $t = Invoke-RestMethod  @webparams -Uri  "$teamURI"
                        $t.pstypenames.Add("GraphTeam")
                        $memberList = $g.members | Select-Object id,department,displayname,mail,UserPrincipalName,usertype,businessPhones,MobilePhone,OfficeLocation
                        foreach ($m in $memberList) {if ($m.'@odata.type' -match "user") {$m.pstypenames.add("GraphUser")}}
                        Add-Member -InputObject $t -MemberType NoteProperty -Name DisplayName -Value $g.displayName
                        Add-Member -InputObject $t -MemberType NoteProperty -Name Description -Value $g.description
                        Add-Member -InputObject $t -MemberType NoteProperty -Name Members     -Value $memberList
                        Add-Member -InputObject $t -MemberType NoteProperty -Name Mail        -Value $g.Mail
                        Add-Member -InputObject $t -MemberType NoteProperty -Name visibility  -Value $g.visibility
                        Write-Progress -Activity 'Getting Group/Team information' -Completed
                        $t
                    }
                    else {
                        $g.pstypenames.Add("GraphGroup")
                        Write-Progress -Activity 'Getting Group/Team information' -Completed
                        $g
                    }
                }
            }
            catch {
                if ($_.exception -match"403\) Forbidden") {
                    Write-warning -Message "Server returned a 403 (Forbidden) error; you must be a memeber of the team $($t.displayname) to view some things [admin does not give access]. "
                }
                else {throw $_  }
            }
        }
    }
}
#>(irm -Method Get -headers $Script:DefaultHeader -Uri "https://graph.microsoft.com/v1.0/groupsettings/$($team.id)") ##may be empty

function Set-GraphTeam {
    <#
      .Synopsis
        Updates the settings for a team
      .Description
        Requires consent to use the Group.ReadWrite.All scope
      .Example
        >Get-GraphTeam -byname accounts | Set-GraphTeam -AllowGiphy:$false
        Gets a the team(s) with a name that begins with accounts, and turns off Giphy content
        Note the use of -SwitchName:$false.
    #>

    [Cmdletbinding()]
    param (
        #The team to update either as an ID or a team object with and ID.
        [Parameter(ValueFromPipeline=$true,Position=0)]
        $Team ,
        #Allow members to add or remove apps
        [switch]$AllowMemberAddRemoveApps,
        #Allow members to create update or remove connectors
        [switch]$AllowMemberCreateUpdateRemoveConnectors,
        #Allow members to create update or remove Tabs
        [switch]$AllowMemberCreateUpdateRemoveTabs,
        #Allow members to create or update Channels
        [switch]$AllowMemberCreateUpdateChannels,
        #Allow members to delete Channels
        [switch]$AllowMemberDeleteChannels,
        #Allow guests to create or update Channels
        [switch]$AllowGuestCreateUpdateChannels,
        #Allow guests to delete Channels
        [switch]$AllowGuestDeleteChannels,
        #Allow members to edit their own messages
        [switch]$AllowUserEditMessages,
        #Allow members to delete their own messages
        [switch]$AllowUserDeleteMessages,
        #Allow owners to delete mssages
        [switch]$AllowOwnerDeleteMessages,
        #Allow mentions of teams in messages
        [switch]$AllowTeamMentions,
        #Allow mentions of channels in messages
        [switch]$AllowChannelMentions,
        #Allow giphy graphics
        [switch]$AllowGiphy,
        #Rating for giphy graphics; either moderate or strict
        [ValidateSet('moderate', 'strict')]
        [string]$GiphyContentRating,
        #Allow stickers and memes
        [switch]$AllowStickersAndMemes,
        #Allow Custom memes
        [switch]$AllowCustomMemes
    )
    Connect-MSGraph
    $webparams = @{Method      =  'PATCH'
                  ContentType  =  'application/json'
                  Headers      =  $Script:DefaultHeader }

    if     ($Team.id)           {$webparams['Uri'] = "https://graph.microsoft.com/v1.0/teams/$($Team.id)"}
    elseif ($Team -is [string]) {$webparams['Uri'] = "https://graph.microsoft.com/v1.0/teams/$Team"}
    else   {Write-Warning -Message 'Could not resolve the team'; return}

    $settings          = @{}
    $memberSettings    = @{}
    $guestSettings     = @{}
    $messagingSettings = @{}
    $funSettings       = @{}

    if ($PSBoundparameters.ContainsKey('AllowMemberAddRemoveApps'))                {$memberSettings.allowAddRemoveApps                = [Bool]$AllowMemberAddRemoveApps}
    if ($PSBoundparameters.ContainsKey('AllowMemberCreateUpdateChannels'))         {$memberSettings.allowCreateUpdateChannels         = [Bool]$AllowMemberCreateUpdateChannels}
    if ($PSBoundparameters.ContainsKey('AllowMemberCreateUpdateRemoveConnectors')) {$memberSettings.allowCreateUpdateRemoveConnectors = [Bool]$AllowMemberCreateUpdateRemoveConnectors}
    if ($PSBoundparameters.ContainsKey('AllowMemberCreateUpdateRemoveTabs'))       {$memberSettings.allowCreateUpdateRemoveTabs       = [Bool]$AllowMemberCreateUpdateRemoveTabs}
    if ($PSBoundparameters.ContainsKey('AllowMemberDeleteChannels'))               {$memberSettings.allowDeleteChannels               = [Bool]$AllowMemberDeleteChannels}
    if ($PSBoundparameters.ContainsKey('AllowGuestCreateUpdateChannels'))          {$guestSettings.allowCreateUpdateChannels          = [Bool]$AllowGuestCreateUpdateChannels}
    if ($PSBoundparameters.ContainsKey('AllowGuestDeleteChannels'))                {$guestSettings.allowDeleteChannels                = [Bool]$AllowGuestDeleteChannels}
    if ($PSBoundparameters.ContainsKey('AllowUserEditMessages'))                   {$messagingSettings.allowUserEditMessages          = [Bool]$AllowUserEditMessages}
    if ($PSBoundparameters.ContainsKey('AllowUserDeleteMessages'))                 {$messagingSettings.allowUserDeleteMessages        = [Bool]$AllowUserDeleteMessages}
    if ($PSBoundparameters.ContainsKey('AllowOwnerDeleteMessages'))                {$messagingSettings.allowOwnerDeleteMessages       = [Bool]$AllowOwnerDeleteMessages}
    if ($PSBoundparameters.ContainsKey('AllowTeamMentions'))                       {$messagingSettings.allowTeamMentions              = [Bool]$AllowTeamMentions}
    if ($PSBoundparameters.ContainsKey('AllowChannelMentions'))                    {$messagingSettings.allowChannelMentions           = [Bool]$AllowChannelMentions}
    if ($PSBoundparameters.ContainsKey('AllowGiphy'))                              {$funSettings.allowGiphy                           = [Bool]$AllowGiphy}
` if ($PSBoundparameters.ContainsKey('GiphyContentRating'))                      {$funSettings.giphyContentRating                   = [Bool]$GiphyContentRating}
    if ($PSBoundparameters.ContainsKey('AllowStickersAndMemes'))                   {$funSettings.allowStickersAndMemes                = [Bool]$AllowStickersAndMemes}
    if ($PSBoundparameters.ContainsKey('AllowCustomMemes'))                        {$funSettings.allowCustomMemes                     = [Bool]$AllowCustomMemes}

    if ($memberSettings.Count)    {$settings['memberSettings']    = $memberSettings}
    if ($guestSettings.Count )    {$settings['guestSettings']     = $guestSettings}
    if ($messagingSettings.Count) {$settings['messagingSettings'] = $messagingSettings}
    if ($funSettings.Count)       {$settings['funSettings']       = $funSettings}

    if ($settings.Count) {
        $json = ConvertTo-Json $settings -Depth 10
        Write-Debug $json

        Invoke-RestMethod @webparams -Body $json
    }
    else {Write-Warning -Message "Nothing to set"}
}

function Get-GraphGroupConversation {
    <#
      .Synopsis
        Gets details of group converstation from outlook, or its threads.
      .Description
        Requires consent to use the Group.Read.All scope
      .Example
        Get-GraphGroupList -Name consult | Get-GraphGroup -Conversations | Get-GraphGroupConversation -Threads
        Gets group(s) matching the name "consult*" , finds their conversations and for each one gets the threads in the conversation
        Note, unless you are dealing with conversations which have multiple threads, it is easier to do Get-GraphGroup -Threads
    #>

    [Cmdletbinding()]
    [Alias("Get-GraphTeamConversation","Get-GraphConversation")]  #Strictly Conversations belong to a group in Outlook, not a Team in Microsoft teams, but let either name be used.
    param(
        #The Conversation, either as an ID or an object.
        [Parameter(ValueFromPipeline=$true, Mandatory=$true, Position=0, ParameterSetName='OneConversation')]
        $Conversation,
        #The group where the conversation is found, either as an ID or as an object, if it can't be found from the conversation
        [Parameter(ParameterSetName='AllInTeam', Mandatory=$true )]
        [Parameter(ParameterSetName='OneConversation', Position=1)]
        [Alias("Team")]
        $Group,
        #If specified selects the conversation's threads, otherwise an object representing the conversation itself is returned.
        [Parameter(ParameterSetName='OneConversation', Position=1)]
        [Switch]$Threads
    )
    begin   {
        Connect-MSGraph
        $webparams = @{Method  = "Get"
                       Headers = $Script:DefaultHeader
        }

    }
    process {
        if ($Group  -and -not $Conversation) {
            Get-GraphGroup -Group $Group -Conversations
            return
        }
        if     (-not $Script:WorkOrSchool) {Write-Warning   -Message "This command only works when you are logged in with a work or school account." ; return    }
        if     ($Conversation.Group)       {$groupID = $Conversation.Group}
        elseif ($Group.id)                 {$groupId = $Group.ID}
        elseif ($Group -is [String])       {$groupid = $Group}
        else   {Write-Warning 'Could not resolve the group - please specify the group explicitly' ; return}
        if     ($Conversation.id)          {$Conversation = $Conversation.id}

        if ($Threads) {
            $uri    = "https://graph.microsoft.com/v1.0/groups/$groupID/conversations/$conversation/Threads"
            $result = Invoke-RestMethod @webparams -Uri $uri
            foreach ($thread in $result.value) {
                $thread.pstypenames.add("GraphThread")
                Add-Member -InputObject $thread -MemberType NoteProperty -Name Group        -Value $GroupID
                Add-Member -InputObject $thread -MemberType NoteProperty -Name Conversation -Value $Conversation
            }
            return $result.value
        }
        else     {
            $c = (Invoke-RestMethod @webparams -Uri ("https://graph.microsoft.com/v1.0/groups/$groupID/conversations/$conversation"  +'?$expand=Threads'))
            $c.pstypenames.add("GraphConversation")
            Add-Member -PassThru -InputObject $c -MemberType NoteProperty -Name Group -Value $GroupID
        }
    }
}

function Get-GraphGroupThread {
    <#
      .Synopsis
        Gets a thread in a Group conversation in outlook, or its posts
      .Description
        Requires consent to use the Group.Read.All scope
      .Example
        >Get-GraphUser -Teams | Get-GraphGroup -Threads | Get-GraphGroupThread -Posts |
             ft -a -Wrap @{n="from";e={$_.from.emailaddress.name}},CreatedDateTime,Topic,@{n="Body";e={$_.body.content}}
        Gets a users teams, for each one gets their threads, and for each thread gets the outlook posts
        Displays the result as a table showing from, message date, thread topic and message body
        Note this uses Get-GraphGroup as an alias for Get-GraphTeams
    #>

    [Cmdletbinding()]
    [Alias("Get-GraphTeamThread")]
    param   (
        #The group thread, either as an ID or as a thread object (which may have the team/group as property)
        [Parameter(ParameterSetName='SingleThread', Position=0, ValueFromPipeline=$true, Mandatory=$true)]
        $Thread,
        #The group holding the thread, if it can't be found drm -thread
        [Alias("Team")]
        [Parameter(ParameterSetName='AllGroupThreads', Mandatory=$true)]
        [Parameter(ParameterSetName='SingleThread', Position=1)]
        $Group,
        #If specified, returns the posts in the thread
        [Parameter(ParameterSetName='SingleThread')]
        [Switch]$Posts
    )
    begin   {
        Connect-MSGraph
        $webparams = @{Method  = "Get"
                       Headers = @{Authorization = $Script:AuthHeader ; "Prefer" ='outlook.body-content-type="text"' }
        }
    }
    process {
        if (-not $Script:WorkOrSchool) {Write-Warning   -Message "This command only works when you are logged in with a work or school account." ; return    }
        if     ($Group -and -not $Thread) {
            Get-GraphGroup -Group $Group -Threads
            return
        }
        if     ($Thread.Group)         {$groupid  = $Thread.group}
        elseif ($Group.id)             {$groupid  = $Group.ID}
        elseif ($Group -is [string])   {$groupid  = $Group}
        else   {Write-Warning -Message 'Could not resolve group ID'; return}

        if     ($Thread.id)            {$threadID = $Thread.id}
        elseif ($Thread -is [string])  {$threadID = $Thread}
        else   {Write-Warning -Message 'Could not resolve thread ID'; return}

        $t = Invoke-RestMethod @webparams -Uri "https://graph.microsoft.com/v1.0/groups/$Groupid/Threads/$threadID`?`$expand=Posts"
        $t.pstypenames.Add("GraphThread")
        Add-Member     -InputObject $t    -MemberType NoteProperty -Name Group -Value $Groupid
        foreach  ($post in $t.posts) {
            $Post.pstypenames.add("GraphPost")
            Add-Member -InputObject $post -MemberType NoteProperty -Name Group  -Value $Groupid
            Add-Member -InputObject $post -MemberType NoteProperty -Name Thread -Value $t.ID
            Add-Member -InputObject $post -MemberType NoteProperty -Name Topic  -Value $t.Topic
        }
        if ($Posts) {$t.posts}
        else        {$t}
    }
}

function Add-GraphGroupThread {
    <#
      .Synopsis
        Starts a new thread in a group in outlook.
      .Description
        Requires consent to use the Group.ReadWrite.All scope
      .Example
        >
        >$G = Get-GraphGroup -ByName consultants
        >Add-GraphGroupThread -Group $G -Subject "Running tests.." -Content "We will be running a full test pass this afternoon"
        Gets a group by name and creates a new thread with a message using a plain text body.
      .Example
        >$thread = Add-GraphGroupThread -passthru -Group $G -Subject "Ruuning tests.." -ContentType HTML -Content "<b><i>Drum-Roll...</i>A full test pass is running... Watch this space</i>"
        Uses the group from the previous example, and creates a thread with an HTML body, and keeps a reference to it.
      .link
        Send-GraphGroupReply
    #>

    [Cmdletbinding(SupportsShouldprocess=$true, ConfirmImpact='Low')]
    param (
        #The group where the thread will be added
        [Parameter(Mandatory=$true,Position=0)]
        [Alias("Team")]
        $Group,
        #The subject line for the thread
        [Parameter(Mandatory=$true, Position=1)]
        [Alias("Subject")]
        $ThreadTopic,
        #The Message body - text by default, specify -contentType if using HTML
        [Parameter(Mandatory=$true, Position=2)]
        [String]$Content,
        #The content type, (Text by default) or HTML
        [ValidateSet("Text","HTML")]
        [String]$ContentType = "Text",
        #if Specified the message will be created without prompting; this is the default, unless $confirm preference has been changed
        [switch]$Force,
        #if Specified an object containing the Thread ID will be returned
        [switch]$PassThru
    )

    Connect-MSGraph
    if (-not $Script:WorkOrSchool) {Write-Warning   -Message "This command only works when you are logged in with a work or school account." ; return    }

    if     ($Group.ID)           {$groupID  = $Group.ID}
    elseif ($Group -is [String]) {$groupID  = $Group   }
    else   {Write-Warning -Message 'Could not process Group parameter.'; return }

    $webparams = @{ 'uri'         = "https://graph.microsoft.com/v1.0/groups/$groupID/threads/"
                    'method'      = 'Post'
                    'contentType' = 'application/json'
                    'Headers'     = $Script:DefaultHeader
    }
    $Settings  = @{ 'topic'       = $ThreadTopic
                    'posts'       = @( @{body= @{'content'     = $Content
                                                 'contentType' = $ContentType}})
    }
    $json      = ConvertTo-Json $settings -Depth 5

    if ($force -or $PSCmdlet.Shouldprocess($ThreadTopic,"Create New thread")) {
        $t = Invoke-RestMethod  @webparams -Body $json
        if ($PassThru) {
            Start-Sleep -Seconds 2
            Get-GraphGroupThread -Group $Group -Thread $t.id
        }
    }
}

function Remove-GraphGroupThread {
    <#
      .Synopsis
        Removes a thread from a group in outlook
      .Example
        Get-GraphGroup -ByName consultants -Threads | where topic -eq "Today's tests..." | Remove-GraphGroupThread
        Finds the threads for a named group; isolates one by topic name, and removes it.
    #>

    [Cmdletbinding(SupportsShouldprocess=$true, ConfirmImpact='High')]
    param (
        #The thread to remove, either as an ID or a thread object containing an ID, and possibly a group ID
        [Parameter(Mandatory=$true,Position=0,ValueFromPipeline=$true)]
        $Thread,
        #The group from which the thread is to be removed, either as an ID or a group object containing an ID
        [Alias("Team")]
        $Group,
        #if Specified the thread will be deleted without prompting.
        [switch]$Force
    )
    process {
        Connect-MSGraph
        if (-not $Script:WorkOrSchool) {Write-Warning   -Message "This command only works when you are logged in with a work or school account." ; return    }

        if     ($Thread.group)        {$groupid  = $Thread.group}
        elseif ($Group.ID)            {$groupid  = $Group.ID}
        elseif ($Group -is [string])  {$groupid  = $Group}
        else   {Write-Warning 'Could not resolve the group ID' ; return}

        if     ($Thread.ID)           {$threadid = $Thread.id  }
        elseif ($Thread -is [string]) {$threadid = $Thread.id  }
        else   {Write-Warning 'Could not resolve the group ID' ; return}


        $webparams = @{'Headers' = $Script:DefaultHeader
                       'uri'    =  "https://graph.microsoft.com/v1.0/groups/$GroupID/threads/$threadID"
        }
        Write-Progress -Activity "Deleting thread" -Status "Checking existing thread"
        try   {$thread  = Invoke-RestMethod -Method Get @webparams }
        catch {
            if ($_.exception.response.statuscode.value__ -eq 404) {
                Write-warning 'Thread not found, it may have been deleted already'
                return
            }
            else {
                throw $_ ;
                return
            }
        }
        if (-not $thread) {throw "Could not get the thread to delete"; return}
        Write-Progress -Activity "Deleting thread" -Completed
        if ($Force -or $PSCmdlet.Shouldprocess($thread.topic,"Delete thread")) {
            Write-Progress -Activity "Deleting thread" -Status "Sending delete instruction"
            Invoke-RestMethod -Method Delete  @webparams
            Write-Progress -Activity "Deleting thread" -Completed
        }
    }
}

function Send-GraphGroupReply {
    <#
      .Synopsis
        Replies to a group's post in outlook.
      .Example
        >$thread.posts[0] | Send-GraphGroupReply -content '<b><font color="green">Success!!</font> Go team!</b>' -ContentType HTML
        One of the examples for Add-GraphGroupThread left the result of a creating a new thread in $thread
        This takes the only post in the new thread and creates a reply to it with the content in HTML format.
      .Example
        >
        >$post = Get-GraphGroup -ByName consultants -Threads | where topic -eq "Today's tests..." | Get-GraphGroupThread -Posts | select -last 1
        >Send-GraphGroupReply $post -Content "Please join a celebration of the successful test at 4PM"
        This example finds threads for the consultants group, Isolates the one with the topic of
        "Today's Tests..." and finds the last post in the thread. It then posts are reply with the content as plain text.
      .link
        Add-GraphGroupThread
    #>

    [Cmdletbinding(SupportsShouldprocess=$true, ConfirmImpact='Low')]
    param (
        #The Post being replied to, either as an ID or a post object containing an ID which may identify the thread and group
        [Parameter(Mandatory=$true,Position=0,ValueFromPipeline=$true)]
        $Post,
        #The thread containing the post (if not embedded in the post itself), as an ID or object, which may identify the group
        $Thread,
        #The group containing the thread (if not embedded in the Post or thread) as an ID or object
        [Alias("Team")]
        $Group,
        #The Message body - text by default, specify -contentType if using HTML
        [Parameter(Mandatory=$true)]
        [String]$Content,
        #The type of content, text by default or HTML
        [ValidateSet("Text","HTML")]
        [String]$ContentType = "Text",
        #if Specified the message will be created without prompting.
        [switch]$Force
    )
    Connect-MSGraph
    if (-not $Script:WorkOrSchool) {Write-Warning   -Message "This command only works when you are logged in with a work or school account." ; return    }

    if     ($Post.Group)          {$groupID  = $Post.group}
    elseif ($Thread.Group)        {$groupID  = $Thread.group}
    elseif ($Group.ID)            {$groupID  = $Group.ID}
    elseif ($Group -is [string])  {$groupID  = $Group}
    else   {Write-warning -Message 'Could not resolve the group ID.' ; return}

    if     ($Post.Thread)         {$threadID = $Post.Thread}
    elseif ($Thread.ID)           {$threadID = $Thread.id  }
    elseif ($Thread -is [String]) {$threadID = $Thread.id  }
    else   {Write-warning -Message 'Could not resolve the Thread ID.' ; return}

    if     ($Post.ID)             {$PostID   = $Post.ID}
    elseif ($Post -is [String])   {$PostID = $Post  }
    else   {Write-warning -Message 'Could not resolve the Post ID.' ; return}

    if (-not ($PostID -and $threadID -and $groupID)) {throw "Could not find Group, Thread and Post IDs from supplied parameters."; Return}

    $webparams = @{Headers = $Script:DefaultHeader }
    $uri       =  "https://graph.microsoft.com/v1.0/groups/$groupID/threads/$threadID/posts/$postid"
    Write-Progress -Activity 'Posting reply to thread' -Status 'Checking parent message'
    try   {   $p  = Invoke-RestMethod -Method Get -uri $uri @webparams }
    catch {       throw "Could not get the post to reply to"; return}
    if (-not $p) {throw "Could not get the post to reply to"; return}

    $Settings  = @{ 'Post' = @{'body'= @{'content'=$Content; 'contentType'=$ContentType}}}
    $Json      = ConvertTo-Json $settings
    Write-Debug $Json

    if ($Force -or $PSCmdlet.Shouldprocess($thread.topic,"Reply to thread")) {
        $uri     += "/Reply"
        Write-Progress -Activity 'Posting reply to thread' -Status 'sending reply'
        Invoke-RestMethod -Method Post -Uri $URI  @webparams -Body $Json -ContentType "application/json"
        Write-Progress -Activity 'Posting reply to thread' -Completed
    }
}

Function Get-ChannelMessagesByURI {
    <#
      .synopsis
        Helper function to add get and expand messages or replies to messages
    #>

    param (
        [parameter(Position=0,ValueFromPipeline=$true)]
        $URI
    )
    begin   {
        Connect-MSGraph
        $webparams = @{Method = "Get"
                        Headers = $Script:DefaultHeader
        }
    }
    process {

        Write-progress -Activity 'Getting messages' -Status "Reading $($ch.displayname) Messages"
        $result   = Invoke-RestMethod @webparams -Uri $uri
        $msgList  = @() + $result.value
        while ($result.'@odata.nextLink' -and $result.'@odata.count' -gt 0 ) {
            Write-Verbose  $result.'@odata.count'
            Write-progress -Activity 'Getting messages' -Status "Reading $($ch.displayname) Messages" -CurrentOperation "$($msglist.count) so far"
            $result   = Invoke-RestMethod  @webparams -Uri $result.'@odata.nextLink'
            $msgList += $result.value
        }
        $userHash = @{}
        Write-progress -Activity 'Getting messages' -Status "Expanding User information"
        $msglist.from.user.id | Sort-Object -Unique | foreach-object {
            $userHash[$_] = ( Invoke-RestMethod @webparams -Uri  "https://graph.microsoft.com/v1.0/directoryObjects/$_").displayName
        }
        Write-progress -Activity 'Getting messages' -Completed
        foreach ($msg in $msgList) {
            $msg.pstypeNames.add("GraphTeamMsg")
            if ($msg.from.user.id) {
                Add-Member -InputObject $msg -MemberType NoteProperty -Name FromUserName -Value $userHash[$msg.from.user.id]
            }
            Add-Member     -InputObject $msg -MemberType NoteProperty -Name Created      -Value ([datetime]$msg.createdDateTime)
            Add-Member     -InputObject $msg -MemberType NoteProperty -Name team         -Value $teamID
            Add-Member     -InputObject $msg -MemberType NoteProperty -Name channel      -Value $channelID
        }

        $msgList | sort-object -Property Created
    }
}

function Get-GraphChannel {
    <#
      .Synopsis
        Gets details of a channel, or its Tabs or messages shown in Teams
      .Example
        >Get-GraphTeam -ByName consultants -ChannelName general | Get-GraphChannel -Tabs
        Gets channels for the team(s) with a name beginning 'Consultants' and selects channel(s)
        with a name beginning "general"; then gets the tabs shown in Teams for this channel
      .Example
        >Get-GraphTeam -ByName consultants -ChannelName general | Get-GraphChannel -Messages
        This follows the same method for getting the Teams but this time returns messaes in the channel
      .Example
        >Get-GraphChannel -Team $c -ByName general -Messages
        This is a variation on the previous example - here $c holds an object describing
        the consultants Team and the channel and its messages are retieved using a single command.
      .Example
        >Get-GraphChannel -Team $c -ByName -channel ""
        This previous example didn't explictly specify the channel parameter when using the
        ByName switch; this version does and specifies and empty string so it will return all
        channels (channel is a required parameter, but it can be an empty string)
    #>

    [Cmdletbinding(DefaultparameterSetName="None")]
    [Alias("Get-GraphTeamChannel")]
    param(
        #The channel either as an ID or as a channel object (which may contain the team as a property)
        [Parameter(Mandatory=$true, ValueFromPipeline=$true, Position=0)]
        $Channel,
        #If Channnel is string it is treated as an ID unless -ByName is specified
        [switch]$ByName,
        #The ID of the team if it is not in the channel object.
        $Team,
        #If specified gets the channel's Tabs
        [Parameter(parameterSetName="Tabs", Mandatory=$true)]
        [switch]$Tabs,
        #if Specified uses the beta api to get the channel's messages.
        [Parameter(parameterSetName="Msgs")]
        [Alias("Msgs")]
        [switch]$Messages,
        #If specified, returns the top n messages, otherwise the command will attempt to get all messages. The server may return more than the specified number.
        [Parameter(parameterSetName="Msgs")]
        $Top
    )
    begin   {
        Connect-MSGraph
        $webparams = @{Method = "Get"
                       Headers = $Script:DefaultHeader
        }
    }
    process {
        if (-not $Script:WorkOrSchool) {Write-Warning   -Message "This command only works when you are logged in with a work or school account." ; return    }
        if ($ByName) {
            $Channel = Get-GraphTeam -Team $Team -Channels -ChannelName $channel
        }
        #ByName might return multiple channels. Support -channel being given an array of channels.
        foreach ($ch in $channel) {
            if     ($ch.Team)           {$teamID    = $ch.team }
            elseif ($Team.ID)           {$teamID    = $Team.ID }
            elseif ($Team -is [string]) {$teamID    = $Team    }
            else   {Write-Warning -Message 'Could not resolve the team for this channel'; return}
            if     ($ch.id  )           {$channelID = $ch.ID   }
            elseif ($ch -is [string])   {$channelID = $ch      }
            else   {Write-Warning -Message 'Could not resolve the channel ID'; return}
            if (-not ($teamid -and $channelID)) {Write-warning -Message "You need to provide a team ID and a Channel ID"; return}
            elseif   ($Messages -or $Top) {
                $uri      =  "https://graph.microsoft.com/beta/teams/$teamID/channels/$channelID/messages"
                if ($Top) {$uri += '?$top=' + $Top }
                Get-ChannelMessagesByURI -URI $uri
                return
            }
            elseif   ($Tabs)     {
                $results = Invoke-RestMethod @webparams -Uri  "https://graph.microsoft.com/v1.0/teams/$teamID/channels/$channelID/tabs?`$expand=teamsApp"
                $t       = $results.value
                foreach ($tab in $t) {
                    $tab.pstypeNames.add('GraphTab')
                    #newly created tabs have a teamsAppId property. Existing apps have to look at the teamsApp and its ID. Make them the same!
                    Add-Member -InputObject $tab -MemberType ScriptProperty -Name teamsAppId   -Value {$this.teamsApp.ID}
                    Add-Member -InputObject $tab -MemberType ScriptProperty -Name teamsAppName -Value {$this.teamsApp.displayName}
                }
                return $t
            }
            elseif   ($ByName)   {
                #Have already fetched the channel once so don't fetch it again
                $ch
            }
            else                 {
                $result = Invoke-RestMethod @webparams -Uri  "https://graph.microsoft.com/v1.0/teams/$teamID/channels/$channelId"
                $result.pstypeNames.add("GraphChannel")
                Add-Member -InputObject $result -MemberType NoteProperty -Name Team -Value $teamID

                $result
            }
        }
    }
}

function New-GraphChannel {
    <#
      .Synopsis
        Adds a channel to a team
      .Description
        This requires the Group.ReadWrite.All scope.
      .Example
       >$newChannel = New-GraphChannel -Team $newTeam -Name $newProjectName -Description "For anything about project $newProjectName"
       $newTeam holds the result of creating a team with New-GraphTeam...
       $newProjectName holds the name of a project the team will be working on.
       This command creates a new channel in Teams, and stores the result in a variable
       which can then be used to post messages to the channel, or add tabs to it.
    #>

    [Cmdletbinding(SupportsShouldprocess=$true)]
    [Alias("Add-GraphTeamChannel")]
    param(
        #The team where the channel will be added, either as an ID or a team object
        [Parameter( Mandatory=$true, Position=0)]
        $Team,
        #Display name for the new channel
        [Parameter(Mandatory=$true, Position=1, ValueFromPipeline=$true)]
        [Alias("DisplayName")]
        [String]$Name,
        #Description for the new channel
        [String]$Description
    )
    begin  {
        if ($Team.id) {$Team = $Team.id}
        Connect-MSGraph
    }
    process {
        if (-not $Script:WorkOrSchool) {Write-Warning   -Message "This command only works when you are logged in with a work or school account." ; return    }
        if (Get-GraphTeam -Channels $team | Where-Object -property displayname -eq $Name) {
            Write-warning -Message "Channel $Name already exists in this team"
        }
        $webparams = @{Method = "POST"
                    Headers = $Script:DefaultHeader
                    URI    = "https://graph.microsoft.com/v1.0/teams/$Team/channels"
                    ContentType = "application/json"
        }
        $Settings  = @{"displayName" = $Name}
        if ($Description) {$settings["description"] = $Description}
        if ($PSCmdlet.Shouldprocess($Name,"Create channel")) {
            $channel =  Invoke-RestMethod @webparams -body (ConvertTo-Json $settings)
            $channel.psTypenames.add('GraphChannel')
            Add-Member -InputObject $channel -MemberType NoteProperty -Name Team -Value $Team

            $channel
        }
    }
}

function Remove-GraphChannel {
    <#
      .Synopsis
        Removes a channel from a team
      .Description
        This requires the Group.ReadWrite.All scope.
      .Example
        >Get-GraphTeam -ByName Developers -ChannelName "Project Firebird" | Remove-GraphChannel
        Finds a channel by name from a named team , and removes it.
    #>

    [Cmdletbinding(SupportsShouldprocess=$true, ConfirmImpact='High')]
    param(
        #The channel to delete; either as an ID, or a channel object
        [Parameter(Mandatory=$true, ValueFromPipeline=$true)]
        $Channel,
        #A team object or the ID of the team, if it can't be derived from the channel.
        $Team,
        #if Specified the channel will be deleted without prompting
        [switch]$Force
    )
    process {

        if ($Channel.Team) { $Team    = $Channel.team }
        elseif  ($Team.id) { $Team    = $Team.ID}
        if ($Channel.id  ) { $Channel = $Channel.ID   }

        try {
            $c = Get-GraphChannel -Channel $Channel -Team $Team
        }
        Catch {
            throw "Could not get the channel" ; return
        }
        if (-not $c)  {throw "Could not get the channel" ; return }
        if ($force -or $PSCmdlet.Shouldprocess($c.displayname, "Delete Channel")) {
            Connect-MSGraph
            Invoke-RestMethod -Method "Delete" -Headers $Script:DefaultHeader -Uri "https://graph.microsoft.com/v1.0/teams/$Team/channels/$Channel"
            }
        }
}

function Add-GraphChannelThread {
    <#
      .Synopsis
        Adds a new thread in a channel in Teams.
      .Description
        This uses BETA functionality.
      .Example
        >
        >$General = Get-GraphTeam $newTeam -ChannelName "General"
        >Add-GraphChannelThread -Channel $General -Content "Project Firebird now has its own channel."
        This adds a message t
    #>

    [Cmdletbinding(SupportsShouldprocess=$true, ConfirmImpact='Low')]
    param(
        #The channel to post to either as an ID or a channel object.
        [Parameter(Mandatory=$true, ValueFromPipeline=$true)]
        $Channel,
        #A team object or the ID of the team, if it can't be derived from the channel.
        $Team,
        #The Message body - text by default, specify -contentType if using HTML
        [Parameter(Mandatory=$true)]
        [String]$Content,
        #The format of the content, text by default , or HTML
        [ValidateSet("Text","HTML")]
        [String]$ContentType = "Text",
        #Normally the message is added 'silently'. If passthru is specified, the new message will be returned.
        [Alias('PT')]
        [switch]$Passthru,
        #if Specified the message will be created without prompting.
        [switch]$Force
    )
    process {
        if     ($Channel.Team)      {$teamID    = $Channel.team }
        elseif ($Team.id)           {$teamID    = $Team.ID}
        elseif ($Team -is [string]) {$teamID    = $Team}
        else   {Write-Warning -Message 'Could not determine the team ID'; return}

        if     ($Channel.id)           {$channelID = $Channel.ID   }
        elseif ($Channel -is [string]) {$channelID = $channel  }
        else   {Write-Warning -Message 'Could not determine the channel ID'; return}

        try {$c = Get-GraphChannel -Channel $channelID -Team $teamID }
        Catch         {throw "Could not get the channel" ; return}
        if (-not $c)  {throw "Could not get the channel" ; return }
        $webparams = @{ 'Method'      = 'POST'
                        'Headers'     = $Script:DefaultHeader
                        'URI'         = "https://graph.microsoft.com/beta/teams/$teamID/channels/$channelID/chatThreads"
                        'ContentType' = 'application/json'
        }
        $Settings = @{ rootMessage = @{body= @{content=$Content;}}}
        if ($ContentType -eq 'HTML') {$settings.rootMessage.body['contentType'] = 1}
        else                         {$settings.rootMessage.body['contentType'] = 2}
        $json =  (ConvertTo-Json $settings)
        Write-Debug $json
        if ($force -or $PSCmdlet.Shouldprocess("Create Message")) {
            $result = Invoke-RestMethod @webparams  -Body $json
            If ($Passthru) {
                $URI    = "https://graph.microsoft.com/beta/teams/$teamid/channels/$channelid/Messages/$($result.id)"
                $msg    = Invoke-RestMethod -Uri $uri -Method Get -Header $Script:DefaultHeader
                $msg.pstypenames.add('GraphTeammsg')

                $msg
            }
        }
    }
}

# can get replies in a thread , but can't send a reply, delete or update a thread

function Get-GraphChannelReply {
    <#
      .Synopsis
        Returns replies to messages in Teams channels
      .Description
        Access to channel messages is currently in the BETA API
        It is possible to start a new thread, but not to reply to the thread.
      .Example
        >Get-GraphChannel $General -Messages | Get-GraphChannelReply -PassThru
        The GraphAPI does not return replies when requesting messages
        from a channel in Teams. By piping the messages to Get-GraphChannelReply
        it is possible to get the replies; and if -Passthru is specified
        the messages will returned, followed by their replies.
        So if $General is a channel object, the first message and the its first
        reply might be output like this.
 
        From Created Isreply Deleted Importance Content
        ---- ------- ------- ------- ---------- -------
        James O'Neill 17/02/2019 11:42 False False normal Project Firebird now has its own channel.
        James O'Neill 17/02/2019 13:06 True False normal And the channel has its own planner
 
    #>

    [Cmdletbinding()]
    param (
        #The Message to reply to as an ID or a message object containing an ID (and possibly the team and channel ID)
        [Parameter(Position=0,ValueFromPipeline)]
        $Message,
        #If the Message does not contain the channel, the channel either as an ID or an object containing an ID and possibly the team ID
        $Channel,
        #If the message or channel parameters don't included the team ID, the team either as an ID or an objec containing the ID
        $Team,
        #If specified returns the message, followed by its replies. (Otherwise , only the replies are returned)
        [switch]$PassThru
    )
    #Is the team ID in the message, channel or team parameter ? Is the channel in the message parameter, and is message an object or ID?
    if     ($Message.team)         {$teamid    = $Message.team}
    elseif ($Channel.team)         {$teamid    = $Channel.team}
    elseif ($Team.id)              {$teamid    = $team.id}
    elseif ($Team -is [string])    {$teamid    = $team}
    else   {Write-Warning 'Could not determine the team ID for the message.'; return}
    if     ($Message.channel)      {$channelid = $Message.channel}
    elseif ($Channel.id)           {$channelid = $channel.id}
    elseif ($Channel -is [string]) {$channelid = $Channel}
    else   {Write-Warning 'Could not determine the Channel ID for the message.'; return}
    if     ($Message.ID)           {$msgID     = $Message.ID}
    elseif ($Message -is [string]) {$msgID     = $Message }
    else   {Write-Warning 'Could not determine the ID for the message.'; return}

    if ($PassThru) {$Message}
    Get-ChannelMessagesByURI -URI "https://graph.microsoft.com/beta/teams/$teamid/channels/$channelid/Messages/$msgID/replies"
}

#code for send reply is included here but not exported in the PSD1 file. It is described at
#https://docs.microsoft.com/en-us/graph/api/channel-post-messagereply?view=graph-rest-beta
#but calling it gives (501) Not Implemented.
function Send-GraphChannelReply {
    <#
      .Synopsis
        Posts a reply to a message in a Teams channel
    #>

    [Cmdletbinding(SupportsShouldProcess=$true)]
    param (
        #The Message to reply to as an ID or a message object containing an ID (and possibly the team and channel ID)
        $Message,
        #If the Message does not contain the channel, the channel either as an ID or an object containing an ID and possibly the team ID
        $Channel,
        #If the message or channel parameters don't included the team ID, the team either as an ID or an objec containing the ID
        $Team,
        #The Message body - text by default, specify -contentType if using HTML
        [Parameter(Mandatory=$true)]
        [String]$Content,
        #The format of the content, text by default , or HTML
        [ValidateSet("Text","HTML")]
        [String]$ContentType = "Text",
        #Normally the reply is added 'silently'. If passthru is specified, the new message will be returned.
        [Alias('PT')]
        [switch]$Passthru,
        #if Specified the message will be created without prompting.
        [switch]$Force
    )
    if     ($Message.team)         {$teamid    = $Message.team}
    elseif ($Channel.team)         {$teamid    = $Channel.team}
    elseif ($Team.id)              {$teamid    = $team.id}
    elseif ($Team -is [string])    {$teamid    = $team}
    else   {Write-Warning 'Could not determine the team ID for the message.'; return}
    if     ($Message.channel)      {$channelid = $Message.channel}
    elseif ($Channel.id)           {$channelid = $channel.id}
    elseif ($Channel -is [string]) {$channelid = $Channel}
    else   {Write-Warning 'Could not determine the Channel ID for the message.'; return}
    if     ($Message.ID)           {$msgID     = $Message.ID}
    elseif ($Message -is [string]) {$msgID     = $Message }
    else   {Write-Warning 'Could not determine the ID for the message.'; return}

    $uri =  "https://graph.microsoft.com/beta/teams/$teamid/channels/$channelid/Messages/$msgID"
    try   {$null = Invoke-RestMethod -Method Get -Headers $DefaultHeader -Uri $uri }
    catch {Write-Warning -Message 'Those parameters did correspond to a message. Cannot Continue.'; return}

    $Settings =  @{body= @{content=$Content;}}
    if ($ContentType -eq 'HTML') {$settings.body['contentType'] = 1}
    else                         {$settings.body['contentType'] = 2}
    $json =  (ConvertTo-Json $settings)
    Write-Debug $json
    if ($force -or $PSCmdlet.Shouldprocess("Post Reply")) {
        Invoke-RestMethod -Method 'POST' -Header $Script:DefaultHeader -Uri "$uri/replies" -ContentType 'application/json' -Body $json
    }
}

function Add-GraphWikiTab {
    <#
      .Synopsis
        Adds a wiki tab to a channel in teams
      .Example
        >Add-GraphWikiTab -Channel $Channel -TabLabel Wiki
        Channel contains an object representing a channel in teams,
        this adds a Wiki to it. The Wiki will need to be initialized
        when the tab is first opened
    #>

    [CmdletBinding(SupportsShouldprocess=$true)]
    param(
        #An ID or Channel object which may contain the team ID
        [Parameter(Mandatory=$true, ValueFromPipeline=$true)]
        $Channel,
        #A team ID, or a team object if the team can't be found from the the channel
        $Team,
        #The label for the tab
        $TabLabel = "Wiki",
        #If specified the tab will be added without prompting for confirmation
        [switch]$Force,
        #Normally the tab is added 'silently'. If passthru is specified, an object describing the new tab will be returned.
        [Alias('PT')]
        [switch]$PassThru
    )
    Connect-MSGraph
    if (-not $Script:WorkOrSchool) {Write-Warning   -Message "This command only works when you are logged in with a work or school account." ; return    }
    if     ($Channel.Team)         {$teamID  = $Channel.Team }
    elseif ($Team.id)              {$teamID  = $Team.id      }
    elseif ($Team -is [String])    {$teamID  = $Team}
    else   {Write-Warning -Message 'Could not determine the team from the channel. Please Specify the team explicitly.'; return}
    if     ($Channel.id)           {$channelID = $Channel.id }
    elseif ($Channel -is [string]) {$channelID = $Channel    }
    else   {Write-Warning -Message 'Could not determine the channel ID.'; return}
    $webparams = @{'Method'      = 'Post'
                   'Uri'         = "https://graph.microsoft.com/beta/teams/$teamID/channels/$channelID/tabs"
                   'Headers'     =  $Script:DefaultHeader
                   'ContentType' = 'application/json'
    }
    $json = ConvertTo-Json ([ordered]@{
                    'name'       = $TabLabel
                    'TeamsAppId' = 'com.microsoft.teamspace.tab.wiki'
            })
    Write-Debug $json
    if ($Force -or $PSCmdlet.Shouldprocess($TabLabel,"Create wiki tab")) {
        $result = Invoke-RestMethod @webparams -body $json
        if ($PassThru) {
            $result.pstypeNames.add('GraphTab')
            #Giving a type name formats things nicely, but need to set the name to be used when the tab is displayed
            Add-Member -InputObject $result -MemberType NoteProperty -Name teamsAppName -Value 'Wiki'

            $result
        }
    }
}
# Adding tab https://docs.microsoft.com/en-us/graph/api/teamstab-add?view=graph-rest-1.0
# https://products.office.com/en-us/microsoft-teams/appDefinitions.xml