Public/Threads/Add-ThreadMessage.ps1

function Add-ThreadMessage {
    [CmdletBinding()]
    [OutputType([pscustomobject])]
    param (
        [Parameter(Mandatory = $true, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true)]
        [Alias('thread_id')]
        [Alias('Thread')]
        [ValidateScript({
            ($_ -is [string] -and $_.StartsWith('thread_')) -or `
                ($_.id -is [string] -and $_.id.StartsWith('thread_')) -or `
                ($_.thread_id -is [string] -and $_.thread_id.StartsWith('thread_'))
            })]
        [Object]$InputObject,

        [Parameter(Mandatory = $true, Position = 0)]
        [Alias('Text')]
        [Alias('Content')]
        [ValidateNotNullOrEmpty()]
        [string]$Message,

        [Parameter()]
        [string][LowerCaseTransformation()]$Role = 'user',

        [Parameter()]
        [Alias('file_ids')]
        [ValidateRange(0, 10)]
        [string[]]$FileId,

        [Parameter()]
        [System.Collections.IDictionary]$MetaData,

        [Parameter()]
        [int]$TimeoutSec = 0,

        [Parameter()]
        [ValidateRange(0, 100)]
        [int]$MaxRetryCount = 0,

        [Parameter(DontShow = $true)]
        [OpenAIApiType]$ApiType = [OpenAIApiType]::OpenAI,

        [Parameter()]
        [System.Uri]$ApiBase,

        [Parameter(DontShow = $true)]
        [string]$ApiVersion,

        [Parameter(DontShow = $true)]
        [string]$AuthType = 'openai',

        [Parameter()]
        [securestring][SecureStringTransformation()]$ApiKey,

        [Parameter()]
        [Alias('OrgId')]
        [string]$Organization,

        [Parameter()]
        [switch]$PassThru
    )

    begin {
        # Initialize API Key
        [securestring]$SecureToken = Initialize-APIKey -ApiKey $ApiKey

        # Initialize API Base
        $ApiBase = Initialize-APIBase -ApiBase $ApiBase -ApiType $ApiType

        # Initialize Organization ID
        $Organization = Initialize-OrganizationID -OrgId $Organization

        # Get API endpoint
        if ($ApiType -eq [OpenAIApiType]::Azure) {
            $OpenAIParameter = Get-AzureOpenAIAPIEndpoint -EndpointName 'Threads' -Engine $Model -ApiBase $ApiBase -ApiVersion $ApiVersion
        }
        else {
            $OpenAIParameter = Get-OpenAIAPIEndpoint -EndpointName 'Threads' -ApiBase $ApiBase
        }

        # Parse Common params
        $CommonParams = ParseCommonParams $PSBoundParameters
    }

    process {
        # Get thread_id
        [string][UrlEncodeTransformation()]$ThreadID = ''
        if ($InputObject -is [string]) {
            $ThreadID = $InputObject
        }
        elseif ($InputObject.id -is [string] -and $InputObject.id.StartsWith('thread_')) {
            $ThreadID = $InputObject.id
        }
        elseif ($InputObject.thread_id -is [string] -and $InputObject.thread_id.StartsWith('thread_')) {
            $ThreadID = $InputObject.thread_id
        }
        if (-not $ThreadID) {
            Write-Error -Exception ([System.ArgumentException]::new('Could not retrieve Thread ID.'))
            return
        }

        $QueryUri = $OpenAIParameter.Uri.ToString() + "/$ThreadID/messages"

        #region Construct parameters for API request
        $PostBody = [System.Collections.Specialized.OrderedDictionary]::new()
        $PostBody.role = $Role
        $PostBody.content = $Message
        if ($PSBoundParameters.ContainsKey('FileId')) {
            $PostBody.file_ids = $FileId
        }
        if ($PSBoundParameters.ContainsKey('Metadata')) {
            $PostBody.metadata = $Metadata
        }
        #endregion

        #region Send API Request
        $Response = Invoke-OpenAIAPIRequest `
            -Method $OpenAIParameter.Method `
            -Uri $QueryUri `
            -ContentType $OpenAIParameter.ContentType `
            -TimeoutSec $TimeoutSec `
            -MaxRetryCount $MaxRetryCount `
            -ApiKey $SecureToken `
            -AuthType $AuthType `
            -Organization $Organization `
            -Headers (@{'OpenAI-Beta' = 'assistants=v1' }) `
            -Body $PostBody

        # error check
        if ($null -eq $Response) {
            return
        }
        #endregion

        #region Output
        # Output thread object only when the PassThru switch is specified.
        if ($PassThru) {
            PSOpenAI\Get-Thread -InputObject $ThreadID @CommonParams
        }
        #endregion
    }

    end {

    }
}