param(
	[string]$OutDir = "build/frontend/dist",
	[string]$Version = "0.0.0-dev"
)

$ErrorActionPreference = "Stop"

$repoRoot = (Resolve-Path (Join-Path $PSScriptRoot "..")).Path
$webRoot = Join-Path $repoRoot "web"

function Resolve-RepoPath {
	param(
		[Parameter(Mandatory = $true)]
		[string]$Path
	)

	if ([System.IO.Path]::IsPathRooted($Path)) {
		return [System.IO.Path]::GetFullPath($Path)
	}

	return [System.IO.Path]::GetFullPath((Join-Path $repoRoot $Path))
}

if (-not (Test-Path (Join-Path $webRoot "package.json"))) {
	throw ("frontend package.json not found: {0}" -f (Join-Path $webRoot "package.json"))
}

if (-not (Test-Path (Join-Path $webRoot "bun.lock"))) {
	throw ("frontend lockfile not found: {0}" -f (Join-Path $webRoot "bun.lock"))
}

$bun = Get-Command bun -ErrorAction SilentlyContinue
if (-not $bun) {
	throw "bun is required to build the frontend"
}

$outPath = Resolve-RepoPath $OutDir
$buildVersion = $Version.Trim()
if ([string]::IsNullOrWhiteSpace($buildVersion)) {
	throw "frontend build version must not be empty"
}
$outParent = Split-Path -Parent $outPath
if (-not (Test-Path $outParent)) {
	New-Item -ItemType Directory -Path $outParent -Force | Out-Null
}

$previousBuildVersion = [Environment]::GetEnvironmentVariable("DASH_BUILD_VERSION", "Process")
try {
	$env:DASH_BUILD_VERSION = $buildVersion
	Push-Location $webRoot
	try {
		& $bun.Source install --frozen-lockfile
		if ($LASTEXITCODE -ne 0) {
			throw ("bun install failed (exit {0})" -f $LASTEXITCODE)
		}

		& $bun.Source run build -- --outDir $outPath --emptyOutDir
		if ($LASTEXITCODE -ne 0) {
			throw ("vite build failed (exit {0})" -f $LASTEXITCODE)
		}
	} finally {
		Pop-Location
	}
} finally {
	if ($null -eq $previousBuildVersion) {
		Remove-Item Env:DASH_BUILD_VERSION -ErrorAction SilentlyContinue
	} else {
		$env:DASH_BUILD_VERSION = $previousBuildVersion
	}
}

foreach ($asset in @("index.html", "theme-bootstrap.js")) {
	$assetPath = Join-Path $outPath $asset
	if (-not (Test-Path $assetPath -PathType Leaf) -or (Get-Item $assetPath).Length -eq 0) {
		throw ("frontend build is missing required runtime asset: {0}" -f $assetPath)
	}
}

Write-Host ("frontend built: {0}" -f $outPath)