param(
    [string]$Destination
)

$ErrorActionPreference = 'Stop'
$repoRoot = (Resolve-Path (Join-Path $PSScriptRoot '..\..')).Path
if ([string]::IsNullOrWhiteSpace($Destination)) {
    $Destination = Join-Path $repoRoot 'build\ffmpeg-sdk'
}
$manifest = Get-Content -LiteralPath (Join-Path $PSScriptRoot 'dependency-win64.json') -Raw | ConvertFrom-Json
$downloadDir = Join-Path $repoRoot 'build\downloads'
$archivePath = Join-Path $downloadDir $manifest.archive
$extractRoot = Join-Path $Destination ([IO.Path]::GetFileNameWithoutExtension($manifest.archive))
New-Item -ItemType Directory -Force -Path $downloadDir | Out-Null

if (-not (Test-Path -LiteralPath $archivePath)) {
    Invoke-WebRequest -Uri $manifest.url -OutFile $archivePath
}
$actualHash = (Get-FileHash -Algorithm SHA256 -LiteralPath $archivePath).Hash.ToLowerInvariant()
if ($actualHash -ne $manifest.sha256) {
    throw "FFmpeg archive SHA-256 mismatch: expected $($manifest.sha256), got $actualHash"
}
if (-not (Test-Path -LiteralPath $extractRoot)) {
    Expand-Archive -LiteralPath $archivePath -DestinationPath $Destination
}
$sdkRoot = Get-ChildItem -LiteralPath $Destination -Directory |
    Where-Object { Test-Path -LiteralPath (Join-Path $_.FullName 'include\libavformat\avformat.h') } |
    Select-Object -First 1 -ExpandProperty FullName
if (-not $sdkRoot) { throw "FFmpeg SDK was not found under $Destination" }
$reported = & (Join-Path $sdkRoot 'bin\ffmpeg.exe') -version | Select-Object -First 1
$expectedVersion = $manifest.ffmpeg_version -replace '-20260721$', ''
if ($reported -notlike "*$expectedVersion*" ) {
    throw "Unexpected FFmpeg build: $reported"
}
Write-Output $sdkRoot