param(
  [string]$FFmpegSource = ""
)

$ErrorActionPreference = "Stop"
$ROOT_DIR = Split-Path -Parent (Split-Path -Parent $PSCommandPath)
$VENDOR_DIR = Join-Path $ROOT_DIR "src-tauri\vendor\ffmpeg\windows-x86_64"
$BIN_DIR = Join-Path $VENDOR_DIR "bin"
$FFMPEG_URL = "https://www.gyan.dev/ffmpeg/builds/ffmpeg-release-essentials.7z"

# Ensure target directory exists
if (-not (Test-Path $BIN_DIR)) {
  New-Item -ItemType Directory -Path $BIN_DIR -Force | Out-Null
}

# Strategy 1: if -FFmpegSource explicitly provided, use it
if ($FFmpegSource) {
  if (-not (Test-Path $FFmpegSource)) {
    Write-Host "ffmpeg not found at: $FFmpegSource" -ForegroundColor Red
    exit 1
  }
  Write-Host "Copying ffmpeg from: $FFmpegSource"
  Copy-Item -Path $FFmpegSource -Destination (Join-Path $BIN_DIR "ffmpeg.exe") -Force
  Write-Host "ffmpeg bundled at: $BIN_DIR\ffmpeg.exe" -ForegroundColor Green
  exit 0
}

# Strategy 2: download Gyan Essentials build via 7-Zip
$sevenZipPaths = @(
  "${env:ProgramFiles}\7-Zip\7z.exe",
  "${env:ProgramFiles(x86)}\7-Zip\7z.exe",
  "${env:LOCALAPPDATA}\Programs\7-Zip\7z.exe"
)
$sevenZip = $sevenZipPaths | Where-Object { Test-Path $_ } | Select-Object -First 1

if ($sevenZip) {
  $tempDir = Join-Path $env:TEMP "ffmpeg-essentials"
  $archivePath = Join-Path $tempDir "ffmpeg.7z"

  try {
    Remove-Item -Path $tempDir -Recurse -Force -ErrorAction SilentlyContinue
    New-Item -ItemType Directory -Path $tempDir -Force | Out-Null

    Write-Host "Downloading ffmpeg essentials from: $FFMPEG_URL" -ForegroundColor Cyan
    Invoke-WebRequest -Uri $FFMPEG_URL -OutFile $archivePath -UseBasicParsing

    Write-Host "Extracting..." -ForegroundColor Cyan
    & $sevenZip x $archivePath -o"$tempDir\out" -y -bso0 | Out-Null

    $extractedExe = Get-ChildItem -Path "$tempDir\out" -Recurse -Filter "ffmpeg.exe" | Select-Object -First 1 -ExpandProperty FullName
    if (-not $extractedExe) {
      throw "ffmpeg.exe not found in extracted archive"
    }

    Copy-Item -Path $extractedExe -Destination (Join-Path $BIN_DIR "ffmpeg.exe") -Force
    Remove-Item -Path $tempDir -Recurse -Force -ErrorAction SilentlyContinue

    $size = (Get-Item (Join-Path $BIN_DIR "ffmpeg.exe")).Length / 1MB
    Write-Host "ffmpeg essentials bundled at: $BIN_DIR\ffmpeg.exe ($([math]::Round($size)) MB)" -ForegroundColor Green
    exit 0
  }
  catch {
    Write-Host "Download/extraction failed: $_" -ForegroundColor Yellow
    Remove-Item -Path $tempDir -Recurse -Force -ErrorAction SilentlyContinue
  }
}
else {
  Write-Host "7-Zip not found, recommend installing it for automatic download." -ForegroundColor Yellow
  Write-Host "Download manually from: $FFMPEG_URL and extract ffmpeg.exe to $BIN_DIR" -ForegroundColor Yellow
}

# Strategy 3: fall back to copying system ffmpeg
$systemFFmpeg = (Get-Command ffmpeg -ErrorAction SilentlyContinue).Source
if ($systemFFmpeg) {
  Write-Host "Falling back to system ffmpeg: $systemFFmpeg" -ForegroundColor Cyan
  Copy-Item -Path $systemFFmpeg -Destination (Join-Path $BIN_DIR "ffmpeg.exe") -Force
  $size = (Get-Item (Join-Path $BIN_DIR "ffmpeg.exe")).Length / 1MB
  Write-Host "ffmpeg bundled at: $BIN_DIR\ffmpeg.exe ($([math]::Round($size)) MB)" -ForegroundColor Green
  exit 0
}

Write-Host "ERROR: No ffmpeg found. Install ffmpeg or specify path via -FFmpegSource." -ForegroundColor Red
exit 1