Public/Request-ImageGeneration.ps1

function Request-ImageGeneration {
    [CmdletBinding(DefaultParameterSetName = 'Format')]
    param (
        [Parameter(Mandatory, Position = 0, ValueFromPipeline)]
        [ValidateNotNullOrEmpty()]
        [string]$Prompt,

        [Parameter()]
        [Completions(
            'dall-e-2',
            'dall-e-3'
        )]
        [string][LowerCaseTransformation()]$Model = 'dall-e-2',

        [Parameter()]
        [ValidateRange(1, 10)]
        [Alias('n')]
        [uint16]$NumberOfImages = 1,

        [Parameter()]
        [ValidateSet('256', '512', '1024', '256x256', '512x512', '1024x1024', '1792x1024', '1024x1792')]
        [string]$Size = '1024x1024',

        [Parameter()]
        [ValidateSet('standard', 'hd')]
        [string][LowerCaseTransformation()]$Quality = 'standard',

        [Parameter()]
        [ValidateSet('vivid', 'natural')]
        [string][LowerCaseTransformation()]$Style = 'vivid',

        [Parameter(ParameterSetName = 'Format')]
        [Alias('response_format')]
        [ValidateSet('url', 'base64', 'byte', 'raw_response')]
        [string]$Format = 'url',

        [Parameter(ParameterSetName = 'OutFile', Mandatory)]
        [ValidateNotNullOrEmpty()]
        [string]$OutFile,

        [Parameter()]
        [string]$User,

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

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

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

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

        [Parameter()]
        [ValidateSet('openai', 'azure', 'azure_ad')]
        [string]$AuthType = 'openai',

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

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

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

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

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

        [Parameter()]
        [object]$AdditionalBody
    )

    begin {
        # Get API context
        $OpenAIParameter = Get-OpenAIAPIParameter -EndpointName 'Image.Generation' -Parameters $PSBoundParameters -Engine $Model -ErrorAction Stop
    }

    process {
        if ($NumberOfImages -gt 1) {
            if ($PSCmdlet.ParameterSetName -eq 'OutFile') {
                $NumberOfImages = 1
            }
            elseif ($Format -eq 'byte') {
                Write-Error -Message "When the format is specified as $Format, NumberOfImages should be 1."
                return
            }
        }

        # Parse Size property
        if ($PSBoundParameters.ContainsKey('Size') -and ($num = $Size -as [int])) {
            $Size = ('{0}x{0}' -f $num)
        }

        #region Construct parameters for API request
        $PostBody = [System.Collections.Specialized.OrderedDictionary]::new()
        $PostBody.prompt = $Prompt
        if ($NumberOfImages -ge 1) {
            $PostBody.n = $NumberOfImages
        }
        if ($null -ne $Size) {
            $PostBody.size = $Size
        }
        switch ($Format) {
            { $PSCmdlet.ParameterSetName -eq 'OutFile' } {
                $PostBody.response_format = 'url'
                break
            }
            'url' {
                $PostBody.response_format = 'url'
                break
            }
            'base64' {
                $PostBody.response_format = 'b64_json'
                break
            }
            'byte' {
                $PostBody.response_format = 'b64_json'
                break
            }
        }
        if ($OpenAIParameter.ApiType -eq [OpenAIApiType]::OpenAI) {
            if ($PSBoundParameters.ContainsKey('Model')) {
                $PostBody.model = $Model
            }
        }
        if ($PSBoundParameters.ContainsKey('Quality')) {
            $PostBody.quality = $Quality
        }
        if ($PSBoundParameters.ContainsKey('Style')) {
            $PostBody.style = $Style
        }
        #endregion

        #region Send API Request
        $splat = @{
            Method            = $OpenAIParameter.Method
            Uri               = $OpenAIParameter.Uri
            ContentType       = $OpenAIParameter.ContentType
            TimeoutSec        = $OpenAIParameter.TimeoutSec
            MaxRetryCount     = $OpenAIParameter.MaxRetryCount
            ApiKey            = $OpenAIParameter.ApiKey
            AuthType          = $OpenAIParameter.AuthType
            Organization      = $OpenAIParameter.Organization
            Body              = $PostBody
            AdditionalQuery   = $AdditionalQuery
            AdditionalHeaders = $AdditionalHeaders
            AdditionalBody    = $AdditionalBody
        }
        $Response = Invoke-OpenAIAPIRequest @splat

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

        #region Parse response object
        if ($Format -eq 'raw_response') {
            Write-Output $Response
            return
        }
        try {
            $Response = $Response | ConvertFrom-Json -ErrorAction Stop
        }
        catch {
            Write-Error -Exception $_.Exception
        }
        if ($null -ne $Response.data) {
            $ResponseContent = $Response.data
        }
        #endregion

        #region Output
        if ($PSCmdlet.ParameterSetName -eq 'OutFile') {
            $AbsoluteOutFile = New-ParentFolder -File $OutFile

            # Download image
            $ResponseContent | Select-Object -ExpandProperty 'url' | Select-Object -First 1 | ForEach-Object {
                Write-Verbose ('Downloading image to {0}' -f $AbsoluteOutFile)
                $splat = @{
                    Uri             = $_
                    Method          = 'Get'
                    OutFile         = $AbsoluteOutFile
                    UseBasicParsing = $true
                }
                Microsoft.PowerShell.Utility\Invoke-WebRequest @splat
            }
        }
        elseif ($Format -eq 'url') {
            Write-Output ($ResponseContent | Select-Object -ExpandProperty 'url')
        }
        elseif ($Format -eq 'base64') {
            Write-Output ($ResponseContent | Select-Object -ExpandProperty 'b64_json')
        }
        elseif ($Format -eq 'byte') {
            [byte[]]$b = [Convert]::FromBase64String(($ResponseContent | Select-Object -ExpandProperty 'b64_json' | Select-Object -First 1))
            Write-Output (, $b)
        }
        #endregion
    }

    end {

    }
}