[CmdletBinding()]
param(
    [string]$SourceScript,
    [string]$OutputDir,
    [string]$BuildDir,
    [string]$ExeName = 'PortableCaffeine.exe',
    [switch]$ConsoleTarget,
    [switch]$KeepExtractedSource
)

Set-StrictMode -Version Latest
$ErrorActionPreference = 'Stop'

# In Windows PowerShell 5.1, $PSScriptRoot may be empty during param default evaluation.
# Resolve script-relative defaults after the param block for compatibility.
$scriptRoot = if (-not [string]::IsNullOrWhiteSpace($PSScriptRoot)) {
    $PSScriptRoot
} elseif ($MyInvocation.MyCommand.Path) {
    Split-Path -Parent $MyInvocation.MyCommand.Path
} else {
    (Get-Location).Path
}

if ([string]::IsNullOrWhiteSpace($SourceScript)) {
    $SourceScript = Join-Path $scriptRoot 'caffeine.ps1'
}
if ([string]::IsNullOrWhiteSpace($OutputDir)) {
    $OutputDir = Join-Path $scriptRoot 'dist'
}
if ([string]::IsNullOrWhiteSpace($BuildDir)) {
    $BuildDir = Join-Path $scriptRoot 'build'
}

function Get-CSharpFromCaffeineScript {
    param(
        [Parameter(Mandatory = $true)]
        [string]$Path
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        throw "Source script not found: $Path"
    }

    $raw = Get-Content -LiteralPath $Path -Raw -Encoding UTF8

    $pattern = '(?s)\$csharp\s*=\s*@''\r?\n(?<code>.*?)\r?\n''@'
    $match = [regex]::Match($raw, $pattern)
    if (-not $match.Success) {
        throw "Could not locate embedded C# here-string (`$csharp = @' ... '@) in $Path"
    }

    return $match.Groups['code'].Value
}

function Get-CscPath {
    $candidates = @(
        (Join-Path $env:WINDIR 'Microsoft.NET\Framework64\v4.0.30319\csc.exe'),
        (Join-Path $env:WINDIR 'Microsoft.NET\Framework\v4.0.30319\csc.exe')
    )

    foreach ($candidate in $candidates) {
        if ($candidate -and (Test-Path -LiteralPath $candidate)) {
            return $candidate
        }
    }

    $cmd = Get-Command csc.exe -ErrorAction SilentlyContinue
    if ($cmd) {
        return $cmd.Source
    }

    throw "csc.exe not found. Install .NET Framework build tools (or run on Windows with .NET Framework 4.x)."
}

if ([Environment]::OSVersion.Platform -ne [PlatformID]::Win32NT) {
    throw "This build script is intended for Windows because it compiles WinForms code against .NET Framework (csc.exe)."
}

New-Item -ItemType Directory -Force -Path $OutputDir | Out-Null
New-Item -ItemType Directory -Force -Path $BuildDir | Out-Null

$csharpSource = Get-CSharpFromCaffeineScript -Path $SourceScript
$generatedCsPath = Join-Path $BuildDir 'PortableCaffeine.generated.cs'
$outExePath = Join-Path $OutputDir $ExeName
$targetKind = if ($ConsoleTarget) { 'exe' } else { 'winexe' }
$cscPath = Get-CscPath

[System.IO.File]::WriteAllText($generatedCsPath, $csharpSource, (New-Object System.Text.UTF8Encoding($false)))

$arguments = @(
    '/nologo'
    "/target:$targetKind"
    '/optimize+'
    '/platform:anycpu'
    "/out:$outExePath"
    '/r:System.dll'
    '/r:System.Windows.Forms.dll'
    '/r:System.Drawing.dll'
    $generatedCsPath
)

Write-Host "Compiling with: $cscPath"
Write-Host "Target: $targetKind"
Write-Host "Output: $outExePath"

& $cscPath @arguments
$exitCode = $LASTEXITCODE
if ($exitCode -ne 0) {
    throw "csc.exe failed with exit code $exitCode"
}

if (-not $KeepExtractedSource) {
    Remove-Item -LiteralPath $generatedCsPath -Force -ErrorAction SilentlyContinue
}

Write-Host ""
Write-Host "Build succeeded."
Write-Host "EXE: $outExePath"
if ($KeepExtractedSource) {
    Write-Host "Extracted source kept at: $generatedCsPath"
}