Get data from OpenAI deployment/model

# A PowerShell script to extract invoice details using Azure OCR and OpenAI.

# Path to your config file
$configFilePath = "Settings-Agreements.json"
if (-not (Test-Path $configFilePath)) {
    throw "Configuration file not found at $configFilePath"
}

# Load configuration from JSON file
$Config = Get-Content -Path $configFilePath | ConvertFrom-Json

# Extract Values from Config
$OpenAI_Key = $Config.APIKeys.OpenAI
$OCR_Key = $Config.APIKeys.DocumentIntelligence
$OCR_Endpoint = $Config.Endpoints.DocumentIntelligence
$OpenAI_Endpoint = $Config.Endpoints.OpenAI
$OCR_Version = $Config.OCRVersion
$FilePath = $Config.FilePath
$Base64String = $Config.Base64String

# Function to Extract Text from PDF/Image Using Azure OCR
function Get-TextFromDocument($Base64String) {
    # Convert Base64 to binary
    $BinaryData = [Convert]::FromBase64String($Base64String)

    # Set OCR request headers
    $Headers = @{
        "Ocp-Apim-Subscription-Key" = $OCR_Key
        "Content-Type" = "application/pdf"  # Change to "image/jpeg" for images
    }

    # Send file to Azure Document Intelligence OCR API
    Invoke-RestMethod -Uri "$OCR_Endpoint/documentintelligence/documentModels/prebuilt-read:analyze?api-version=$OCR_Version" `
                      -Headers $Headers -Method Post -ResponseHeadersVariable HeaderInfo -Body $BinaryData

    if (-not $HeaderInfo) {
        throw "Failed to start OCR process."
    }

    # Extract operation URL
    $OperationUrl = ($HeaderInfo."Operation-Location")[0]
    
    # Poll for result
    Start-Sleep -Seconds 5  # Wait before checking status
    do {
        $Result = Invoke-RestMethod -Uri $OperationUrl -Headers @{ "Ocp-Apim-Subscription-Key" = $OCR_Key }
        $Status = $Result.status
        Start-Sleep -Seconds 2
    } while ($Status -ne "succeeded")

    # Extract recognized text
    $ExtractedText = ($Result.analyzeResult.pages.lines.content) -join " "
    return $ExtractedText
}

# Function to Extract Names Using Azure OpenAI
function Get-Inputs($ExtractedText) {
    # OpenAI Request Payload
    $OpenAI_Request = @{
        messages = @(
            @{ role = "system"; content = "Extract Invoice No, Sales Person, Date Of Invoice, SubTotal, Tax and Total and return in plain json format" }
            @{ role = "user"; content = "Text: $ExtractedText" }
        )
    } | ConvertTo-Json -Depth 3

    # OpenAI Headers
    $OpenAI_Headers = @{
        "api-key" = $OpenAI_Key
        "Content-Type" = "application/json"
    }

    # Call OpenAI API
    $OpenAI_Response = Invoke-RestMethod -Uri "$OpenAI_Endpoint" `
                                         -Method Post -Headers $OpenAI_Headers -Body $OpenAI_Request

    # Extract Names from Response
    $responseContent = $OpenAI_Response.choices[0].message.content 
    # Remove leading and trailing triple backticks and 'json' label
    $jsonString = $responseContent -replace '^```json\s*', '' -replace '\s*```$', ''
    return $jsonString
}

# Function to Process Base64 Document Input
function Get-Data($Base64String) {
    try {
        # Step 1: Extract text using OCR
        $ExtractedText = Get-TextFromDocument -Base64String $Base64String

        # Step 2: Extract Names using OpenAI
        $Names = Get-Inputs -ExtractedText $ExtractedText

        # Step 3: Return as JSON
        return $Names
    }
    catch {
        return @{ "error" = $_.Exception.Message } | ConvertTo-Json
    }
}

# Function to convert file to Base64 string
function Convert-Base64String($path) {
    $Base64Input = [Convert]::ToBase64String([IO.File]::ReadAllBytes($path))
    return $Base64Input
}


# Example Usage: Provide a Base64 String of a PDF or Image
$Base64Input = Convert-Base64String $FilePath

# Call the Function
$Result = Get-Data -Base64String $Base64Input
Write-Output $Result