param(
    [switch]$InstallDeps,
    [switch]$BuildFrontend,
    [string]$HostAddress = "0.0.0.0",
    [int]$BackendPort = 8080
)

$ErrorActionPreference = "Stop"

$Base = Split-Path -Parent $MyInvocation.MyCommand.Path
$BackendDir = Join-Path $Base "backend"
$RuntimeDir = Join-Path $Base "runtime"
$HlsDir = Join-Path $RuntimeDir "hls"
$ReplayDir = Join-Path $RuntimeDir "replay"
$LogDir = Join-Path $RuntimeDir "logs"

New-Item -ItemType Directory -Force -Path $RuntimeDir, $HlsDir, $ReplayDir, $LogDir | Out-Null
if (-not $env:LS_HLS_RUNTIME_DIR) { $env:LS_HLS_RUNTIME_DIR = $HlsDir }
if (-not $env:LS_REPLAY_MEDIA_DIR) { $env:LS_REPLAY_MEDIA_DIR = $ReplayDir }

function Resolve-Python {
    $candidates = @(
        (Join-Path $BackendDir ".venv\Scripts\python.exe"),
        (Join-Path $BackendDir "venv\Scripts\python.exe"),
        "python",
        "py"
    )
    foreach ($candidate in $candidates) {
        if (Test-Path $candidate) { return $candidate }
        $cmd = Get-Command $candidate -ErrorAction SilentlyContinue
        if ($cmd) { return $cmd.Source }
    }
    throw "Python not found. Install Python 3.11+ or create backend\.venv."
}

$Python = Resolve-Python

if ($InstallDeps) {
    Write-Host "[StreamCore] Installing backend dependencies..."
    Push-Location $BackendDir
    & $Python -m pip install -r requirements.txt
    Pop-Location
}

# The frontend is built once and then served by the backend, so Node is only
# needed here — production never runs npm. Done automatically on a first start so
# a fresh checkout does not come up as a 503 with no obvious cause.
$FrontendDir = Join-Path $Base "frontend"
$DistDir = Join-Path $FrontendDir "dist"
if ($BuildFrontend -or -not (Test-Path (Join-Path $DistDir "index.html"))) {
    if (Get-Command "npm" -ErrorAction SilentlyContinue) {
        Write-Host "[StreamCore] Building frontend..."
        Push-Location $FrontendDir
        if (-not (Test-Path "node_modules")) { npm install }
        npm run build
        Pop-Location
    } else {
        Write-Warning "npm not found and frontend\dist is missing; the site will return 503."
        Write-Warning "Install Node.js and run: cd frontend; npm install; npm run build"
    }
}

# MediaMTX, the transcoders and the HLS tree are managed by the backend itself:
# it starts the media origin at boot, supervises ffmpeg, and restarts either if it
# dies. This launcher only has to bring up the process that owns all of that.
Write-Host "[StreamCore] Starting backend on ${HostAddress}:${BackendPort} ..."
Write-Host "[StreamCore] Frontend, MediaMTX, transcoders and HLS are served by the backend."

$backendArgs = @("-m", "uvicorn", "main:app", "--host", $HostAddress, "--port", "$BackendPort")
& $Python @backendArgs