param(
    [string]$Target
)

$ErrorActionPreference = "Stop"

Write-Host "===================================="
Write-Host " Unity CI Build (Windows Agent)"
Write-Host " Target: $Target"
Write-Host "===================================="

try {

    # -----------------------------
    # Load toolchain config
    # -----------------------------
    $config = Get-Content ".\ci\toolchain.json" | ConvertFrom-Json

    $unityVersion = $config.unityVersion
    $unityRoot = $config.windows.unityRoot

    $hubExe = "${env:ProgramFiles}\Unity Hub\Unity Hub.exe"

    if (!(Test-Path $hubExe)) {
        throw "Unity Hub not found at: $hubExe"
    }

    # -----------------------------
    # Ensure Unity is installed
    # -----------------------------
    $unityEditorPath = Join-Path $unityRoot "$unityVersion\Editor\Unity.exe"

    if (!(Test-Path $unityEditorPath)) {

        Write-Host "Unity $unityVersion not found. Installing via Unity Hub..."

        # Install Unity Editor
        & $hubExe -- --headless install `
            --version $unityVersion

        if ($LASTEXITCODE -ne 0) {
            throw "Failed to install Unity $unityVersion"
        }
    }

    Write-Host "Unity found: $unityEditorPath"

    # -----------------------------
    # Ensure required modules
    # -----------------------------
    # NOTE:
    # Unity Hub CLI installs modules per version.
    # These are cached per editor version, not reinstalled each build.

    $modules = $config.windows.modules

    Write-Host "Ensuring Unity modules: $($modules -join ', ')"

    foreach ($module in $modules) {

        Write-Host "Checking module: $module"

        # Check installed modules via Unity Hub
        $installed = & $hubExe -- --headless editors --installed

        if ($installed -notmatch "$unityVersion.*$module") {

            Write-Host "Installing module: $module"

            & $hubExe -- --headless install-modules `
                --version $unityVersion `
                --module $module

            if ($LASTEXITCODE -ne 0) {
                throw "Failed to install module: $module"
            }
        }
        else {
            Write-Host "Module already installed: $module"
        }
    }

    # -----------------------------
    # Resolve Unity build method
    # -----------------------------
    if (!$Target) {
        Write-Host "No Target Provided"
        exit
    }
    else {
        $method = switch ($Target) {
            "Windows" { "BuildScript.Windows" }
            "Android" { "BuildScript.Android" }
        }

        Write-Host "Using Unity method: $method"

        Write-Host "===================================================================="
        Write-Host "===================== Starting Unity Build ========================="
        Write-Host "===================================================================="

        # 1. Define arguments cleanly using an array
        $logFile = "$PWD/unity_build.log"
        $unityArgs = @(
            "-batchmode",
            "-nographics",
            "-quit",
            "-projectPath", "$PWD",
            "-executeMethod", "$method",
            "-logFile", "$logFile"
        )

        # 2. Start the Unity process in the background
        $process = Start-Process -FilePath $unityEditorPath -ArgumentList $unityArgs -PassThru -NoNewWindow

        # 3. Wait for the log file to be created by Unity
        while (!(Test-Path $logFile) -and !$process.HasExited) {
            Start-Sleep -Milliseconds 100
        }

        # 4. Stream the log live into the TeamCity console
        if (Test-Path $logFile) {
            # Get-Content -Wait streams the file until the process kills it
            $logJob = Start-Job -ScriptBlock { Get-Content $using:logFile -Wait }
            
            # Wait for Unity to completely finish building
            $process.WaitForExit()
            
            # Stop streaming and clean up
            Stop-Job $logJob
            Receive-Job $logJob
            Remove-Job $logJob
            Remove-Item $logFile -Force
        }

        # 5. Bubble up the exit code so TeamCity catches errors
        if ($process.ExitCode -ne 0) {
            Write-Error "Unity build failed with exit code $($process.ExitCode)"
            exit $process.ExitCode
        }

        Write-Host "===================================="
        Write-Host " BUILD SUCCESS: $Target"
        Write-Host "===================================="
    }
}
catch {
    throw
} 
finally {
    Write-Host "Cleaning Up"
    # Stop-Process -Name "Unity", "Unity Hub" -Force
}