OMG.PSUtilities.AI

1.0.10

Public/Invoke-PSUPromptOnGeminiAi.ps1

function Invoke-PSUPromptOnGeminiAi {
    <#
.SYNOPSIS
    Sends a text prompt to the Google Gemini 2.0 Flash AI model and returns the generated response.
 
.DESCRIPTION
    This function interacts with Google's Generative Language API (Gemini 2.0 Flash model) to perform fast and
    lightweight AI content generation.
 
    How to get started:
    ----------------------
    1. Visit: https://makersuite.google.com/app/apikey
    2. Sign in with your Google account
    3. Click **"Create API Key"**
    4. Copy the key and save it using:
 
        Set-PSUUserEnvironmentVariable -Name "API_KEY_GEMINI" -Value "<your-api-key>"
 
    You're now ready to call `Invoke-PSUPromptOnGeminiAi` with your prompt!
 
.PARAMETER Prompt
    (Mandatory) The text you want Gemini AI to process and respond to.
 
.PARAMETER ApiKey
    (Optional) The API key for Google Gemini AI service.
    Default value is $env:API_KEY_GEMINI. Set using: Set-PSUUserEnvironmentVariable -Name "API_KEY_GEMINI" -Value "your-api-key"
 
.PARAMETER ReturnJsonResponse
    (Optional) Switch parameter to return only valid JSON object from the response.
 
.EXAMPLE
    Invoke-PSUPromptOnGeminiAi -Prompt "Generate a PowerShell script to get system uptime"
 
.EXAMPLE
    Invoke-PSUPromptOnGeminiAi -Prompt "Summarize cloud computing in one line"
 
    .NOTES
        Author: Lakshmanachari Panuganti
        Date: 2025-07-03
        Model: Gemini 2.0 Flash (Generative Language API).LINK
    https://github.com/lakshmanachari-panuganti/OMG.PSUtilities/tree/main/OMG.PSUtilities.AI
    https://www.linkedin.com/in/lakshmanachari-panuganti/
    https://www.powershellgallery.com/packages/OMG.PSUtilities.AI
    https://ai.google.dev/gemini-api/docs
 
#>
    [CmdletBinding()]
    [Diagnostics.CodeAnalysis.SuppressMessageAttribute(
        'PSAvoidUsingWriteHost',
        '',
        Justification = 'This is intended for this function to display formatted output to the user on the console'
    )]
    param(
        [Parameter(Mandatory)]
        [string]$Prompt,

        [Parameter()]
        [string]$ApiKey = $env:API_KEY_GEMINI,

        [Parameter()]
        [switch]$ReturnJsonResponse
    )

    #----------[Validating the 'ApiKey' inside the function body (instead of in the parameter block) is for clearer error messaging and better formatting]----------

    if ([string]::IsNullOrWhiteSpace($ApiKey)) {
        Write-Host " Please provide a valid Google Gemini API Key" -ForegroundColor Red
        Write-Host "" -ForegroundColor Red
        Write-Host " If you are using it first time:" -ForegroundColor Yellow
        Write-Host " -------------------------------" -ForegroundColor Yellow
        Write-Host @"
   1. Visit: https://makersuite.google.com/app/apikey
   2. Sign in with your Google account
   3. Click **"Create API Key"**
   4. Copy the key and save it using:
 
       Set-PSUUserEnvironmentVariable -Name "API_KEY_GEMINI" -Value "YOUR_API_KEY_VALUE"
 
"@ -ForegroundColor Cyan
        return
    }

    if ($ReturnJsonResponse.IsPresent) {
        $Prompt += "`nReturn only a valid JSON object. Exclude any additional text, explanations, or formatting such as triple backticks. The output must be raw JSON with appropriate properties."
        $Prompt += "`nExample 1: { ""scriptName"": ""Backup-Logs.ps1"", ""author"": ""adminUser"", ""lastModified"": ""2025-07-15T10:45:00Z"", ""parameters"": [""sourcePath"", ""destinationPath""] }"
        $Prompt += "`nExample 2: { ""planet"": ""Mars"", ""distanceFromSun_km"": 227943824, ""hasAtmosphere"": true, ""moons"": 2 }"
        $Prompt += "`nExample 3: { ""fullName"": ""Asha Verma"", ""age"": 34, ""city"": ""Pune"", ""interests"": [""traveling"", ""reading"", ""music""] }"
    }
    
    $uri = "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent?key=$ApiKey"
    $body = @{ contents = @(@{ parts = @(@{ text = $Prompt }) }) } | ConvertTo-Json -Depth 10

    try {
        Write-Host "🧠 Thinking..." -ForegroundColor Cyan
        $response = Invoke-RestMethod -Method Post -Uri $uri -Body $body -ContentType 'application/json'

        if ($response.candidates.Count -eq 0 -or -not $response.candidates[0].content.parts[0].text) {
            throw "No content received from Gemini API."
        }

        $rawText = $response.candidates[0].content.parts[0].text

        if ($ReturnJsonResponse.IsPresent) {
            $jsonBlock = ''

            # Match fenced JSON block
            if ($rawText -match '(?s)```json\s*(\[.*?\]|\{.*?\})\s*```') {
                $jsonBlock = $matches[1]
                $jsonBlock = $jsonBlock -replace '```json\s*|\s*```', ''
                return $jsonBlock
            }

            # Match raw JSON array or object
            elseif ($rawText -match '(\[.*?\]|\{.*?\})') {
                return $matches[1]
            }

            else {
                Write-Warning "Could not find a JSON object in the response."
                return $rawText
            }
        }
        else {
            return $rawText
        }

    }
    catch {
        Write-Error "Failed to get response from Gemini:`n$($_.Exception.Message)"
    }  
}