Classes/OpenAiChat.psm1
|
using module "..\Private\OutHelper.psm1" using namespace System using namespace System.Text using namespace System.IO using namespace System.Net.Http using namespace System.Net.Http.Formatting using namespace System.Net.Http.Headers using namespace System.Web using namespace System.Web.Extensions class OpenAiChatMessage { [string]$Role [string]$Content OpenAiChatMessage([string]$role, [string]$content) { $this.Role = $role $this.Content = $content } static [OpenAiChatMessage] ToAssistant([string]$message) { return [OpenAiChatMessage]::new("user", $message) } static [OpenAiChatMessage] FromAssistant([string]$message) { return [OpenAiChatMessage]::new("assistant", $message) } } class OpenAiChat { [string]$AuthToken [string]$Model = "gpt-3.5-turbo" [decimal]$Temperature [decimal]$Top_p [int]$N [HttpClient]$httpClient [string]$httpContentType = "application/json" [bool]$_debug = $false [string]$Baseurl = "https://api.openai.com/v1/" OpenAiChat([string]$authToken) { $this.AuthToken = $authToken if(!$this.AuthToken) { throw "OpenAiChat requires an auth token (authToken argument on constructor)" } } # messages is an array of objects with 'role' and 'content' properties # 'content' is url encoded before sending to the API [object] ChatCompletion([object]$messages, [bool]$useStream, [Func[HttpResponseMessage, object]]$success) { $encoded = @() $messages | ForEach-Object { $encoded += @{ "role" = $_.role; "content" = $_.content; } } # construct body $body = @{ "model" = $this.Model "messages" = $encoded } # set optional parameters for the request if($this.Temperature) { $body.temperature = $this.Temperature } if($this.Top_p) { $body.top_p = $this.Top_p } if($this.N) { $body.n = $this.N } if($useStream) { $body.stream=$true } return $this.InvokeRequestObject("chat/completions", $body, $useStream, $success) } # call the api, requestObject is a object/hashtable with the full request body [object] InvokeRequestObject($url, [object]$requestBody, [bool]$useStream, [Func[HttpResponseMessage, object]]$success) { # $useStream = $true $url = "$($this.Baseurl)$url" $headers = @{ "Authorization" = "Bearer $($this.AuthToken)" } $body = $requestBody | ConvertTo-Json -Depth 10 $response = $null try { if($this._debug) { Write-Debug "Request:`n$body" } if(!$this.httpClient) { $this.httpClient = [HttpClient]::new() } # create an HTTP request with a range header to receive only a specific chunk of data $request = [HttpRequestMessage]::new([HttpMethod]::Post, [Uri]::new($url)) foreach($key in $headers.Keys) { $request.Headers.Add($key, $headers[$key]) } if($useStream) { $request.Headers.Range = [RangeHeaderValue]::new(0, 1024) } $request.Content = [StringContent]::new($body, [Encoding]::UTF8, $this.httpContentType) # send the HTTP request and get the response $response = $this.httpClient.SendAsync($request, [HttpCompletionOption]::ResponseHeadersRead).Result if(!$response.IsSuccessStatusCode) { throw "An error occurred: $($response.StatusCode)" } if($success) { if($this._debug) { Write-Debug "Response:`n$($response | ConvertTo-Json -Depth 10)" } return $success.Invoke($response) } } catch { # [OutHelper]::NonCriticalError("$($_.Exception)") $failureBody = $response.Content.ReadAsStringAsync().Result [OutHelper]::NonCriticalError("$($_)") [OutHelper]::NonCriticalError("Request:`n$body") [OutHelper]::NonCriticalError("Response:`n$($failureBody | ConvertTo-Json -Depth 10)") } return $null } # calls the api and streams the response as it comes in [object] ReadAndStreamResponse($response) { $choices = @{} [OutHelper]::GptDelta("", $true) # writes GPT: $streamReader = [StreamReader]::new($response.Content.ReadAsStreamAsync().Result) try { # read the response content as a stream of JSON data $dataPrefix = "data: " while (!$streamReader.EndOfStream) { # each line will begin with "data: ", the final line will be "data: [DONE]" $line = $streamReader.ReadLine() if (!$line.StartsWith($dataPrefix)) { continue } $line = $line.Substring($dataPrefix.Length) if($line -eq "[DONE]") { break } # [OutHelper]::Gpt($line) if($this._debug) { Write-Host "($line)" -ForegroundColor DarkGray -NoNewLine } $chunk = $line | ConvertFrom-Json if(!$chunk.choices -or $chunk.choices.Count -ne 1) { continue } # update the choices array with the new choice $delta = $chunk.choices[0].delta # {"content":" you"} $index = "i$($chunk.choices[0].index)" # 0 if(!$choices[$index]) { $choices[$index] = @{} } # merge the delta into the choices array $initalValue = $false foreach($nameValue in $delta.PSObject.Properties) { $key = $nameValue.Name $value = $nameValue.Value if(!$choices[$index].$key) { $choices[$index].$key = $value $initalValue = $true } else { $choices[$index].$key += $value } # output new content (delta) to user if($index -eq "i0" -and $key -eq "content") { if($initalValue) { $value = $value.TrimStart() } # $value = [HttpUtility]::UrlDecode($value) [OutHelper]::GptDelta($value, $false) } } } } finally { $streamReader.Dispose() } [OutHelper]::GptDelta("`n", $false) # convert the choices hashtable to an array of answers (strings) $answers = @() foreach($choice in $choices.Values) { $answers += [HttpUtility]::UrlDecode($choice.content.Trim()) } return $answers } [string] Ask([string]$message) { return $this.GetAnswer(@([OpenAiChatMessage]::ToAssistant($message)), $false) } [object] ReadResponseAsObject([HttpResponseMessage]$response) { return $response.Content.ReadAsStringAsync().Result | ConvertFrom-Json -AsHashtable } [object] ReadChoices([HttpResponseMessage]$response) { $res = $this.ReadResponseAsObject($response) if($null -eq $res) { return $null } return $res.choices | ForEach-Object { $_.message.content.Trim() } } [object] GetAnswer([object]$messages) { return $this.GetAnswer($messages, $false) } [object] GetAnswer([object]$messages, $useStream) { $response = if($useStream) { $this.ChatCompletion($messages, $true, $this.ReadAndStreamResponse) } else { $this.ChatCompletion($messages, $false, $this.ReadChoices) } if($null -ne $response) { if($response.Length -gt 1) { return $response } else { return $response[0] } } return $null } } |