#requires -Version 5.1

<#
Конвертация всех FLAC-файлов в CD-качество:
16 бит / 44,1 кГц / стерео.

Скрипт:
- рекурсивно ищет все *.flac;
- пропускает файлы, которые уже 16 бит / 44100 Гц / стерео;
- сохраняет теги и встроенную обложку;
- проверяет результат через ffprobe;
- после успешной проверки заменяет исходный файл;
- показывает прогресс;
- в конце выводит список файлов с ошибками.
#>

$ProjectRoot = Split-Path -Parent $PSScriptRoot
$ToolsFolder = Join-Path $ProjectRoot "tools"
$RootFolder = Join-Path $ProjectRoot "downloads"

$ErrorActionPreference = "Stop"

function Find-Tool {
    param(
        [Parameter(Mandatory = $true)]
        [string]$CommandName,

        [Parameter(Mandatory = $true)]
        [string[]]$LocalNames
    )

    foreach ($LocalName in $LocalNames) {
        $LocalPath = Join-Path $ToolsFolder $LocalName
        if (Test-Path -LiteralPath $LocalPath -PathType Leaf) {
            return (Resolve-Path -LiteralPath $LocalPath).Path
        }
    }

    $Command = Get-Command $CommandName -ErrorAction SilentlyContinue
    if ($Command) {
        return $Command.Source
    }

    return $null
}

$FfmpegPath = Find-Tool -CommandName "ffmpeg.exe" -LocalNames @("ffmpeg.exe")
$FfprobePath = Find-Tool -CommandName "ffprobe.exe" -LocalNames @("ffprobe.exe")


try {
    $Host.UI.RawUI.WindowTitle = "FLAC -> CD quality"
}
catch {
}

function Wait-BeforeExit {
    Write-Host ""
    [void](Read-Host "Нажмите Enter для выхода")
}

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

    $probeOutput = & $FfprobePath `
        -v error `
        -select_streams a:0 `
        -show_entries "stream=codec_name,sample_rate,channels,bits_per_sample,bits_per_raw_sample,sample_fmt" `
        -of json `
        -- `
        $Path 2>&1

    if ($LASTEXITCODE -ne 0) {
        throw "ffprobe не смог прочитать файл:`n$probeOutput"
    }

    $probeData = $probeOutput | ConvertFrom-Json

    if (
        -not $probeData.streams -or
        $probeData.streams.Count -lt 1
    ) {
        throw "Аудиопоток не найден."
    }

    $stream = $probeData.streams[0]
    $bitDepth = 0

    if (
        $null -ne $stream.bits_per_raw_sample -and
        [string]$stream.bits_per_raw_sample -ne "" -and
        [int]$stream.bits_per_raw_sample -gt 0
    ) {
        $bitDepth = [int]$stream.bits_per_raw_sample
    }
    elseif (
        $null -ne $stream.bits_per_sample -and
        [string]$stream.bits_per_sample -ne "" -and
        [int]$stream.bits_per_sample -gt 0
    ) {
        $bitDepth = [int]$stream.bits_per_sample
    }
    elseif ([string]$stream.sample_fmt -match "s16") {
        $bitDepth = 16
    }
    elseif ([string]$stream.sample_fmt -match "s32") {
        $bitDepth = 24
    }

    [PSCustomObject]@{
        Codec      = [string]$stream.codec_name
        SampleRate = [int]$stream.sample_rate
        Channels   = [int]$stream.channels
        BitDepth   = [int]$bitDepth
        SampleFmt  = [string]$stream.sample_fmt
    }
}

Clear-Host

Write-Host "FLAC -> CD quality" -ForegroundColor Cyan
Write-Host "16 бит / 44,1 кГц / стерео"
Write-Host "Папка: $RootFolder"
Write-Host ""

if (
    -not (
        Test-Path `
            -LiteralPath $RootFolder `
            -PathType Container
    )
) {
    Write-Host "ОШИБКА: папка не найдена:" -ForegroundColor Red
    Write-Host $RootFolder -ForegroundColor Red

    Wait-BeforeExit
    exit 1
}

if (-not $FfmpegPath) {
    Write-Host "ОШИБКА: ffmpeg.exe не найден." -ForegroundColor Red
    Write-Host "Проверены папка tools и системный PATH."
    Wait-BeforeExit
    exit 1
}

if (-not $FfprobePath) {
    Write-Host "ОШИБКА: ffprobe.exe не найден." -ForegroundColor Red
    Write-Host "Проверены папка tools и системный PATH."
    Wait-BeforeExit
    exit 1
}

$files = @(
    Get-ChildItem `
        -LiteralPath $RootFolder `
        -Filter "*.flac" `
        -File `
        -Recurse |
    Where-Object {
        $_.Name -notlike "*.__cd_temp__.flac"
    } |
    Sort-Object FullName
)

$total = $files.Count

if ($total -eq 0) {
    Write-Host "FLAC-файлы не найдены." `
        -ForegroundColor Yellow

    Wait-BeforeExit
    exit 0
}

$converted = 0
$skipped = 0
$failed = 0
$index = 0
$startTime = Get-Date

$failedFiles = [System.Collections.Generic.List[object]]::new()

foreach ($file in $files) {
    $index++

    $percent = [int][Math]::Floor(
        (($index - 1) / $total) * 100
    )

    Write-Progress `
        -Activity "Конвертация FLAC в CD-качество" `
        -Status (
            "Файл {0} из {1}: {2}" -f `
                $index,
                $total,
                $file.Name
        ) `
        -CurrentOperation $file.DirectoryName `
        -PercentComplete $percent

    Write-Host ""

    Write-Host (
        "[{0}/{1}] {2}" -f `
            $index,
            $total,
            $file.FullName
    ) -ForegroundColor White

    $tempFile = Join-Path `
        -Path $file.DirectoryName `
        -ChildPath (
            $file.BaseName +
            ".__cd_temp__.flac"
        )

    $backupFile = Join-Path `
        -Path $file.DirectoryName `
        -ChildPath (
            $file.Name +
            ".__original_backup__"
        )

    try {
        if (Test-Path -LiteralPath $tempFile) {
            Remove-Item `
                -LiteralPath $tempFile `
                -Force
        }

        if (Test-Path -LiteralPath $backupFile) {
            Remove-Item `
                -LiteralPath $backupFile `
                -Force
        }

        $sourceInfo = Get-FlacAudioInfo `
            -Path $file.FullName

        Write-Host (
            "Исходник: {0} бит, {1} Гц, {2} канал(а)" -f `
                $sourceInfo.BitDepth,
                $sourceInfo.SampleRate,
                $sourceInfo.Channels
        )

        $alreadyCdQuality = (
            $sourceInfo.BitDepth -eq 16 -and
            $sourceInfo.SampleRate -eq 44100 -and
            $sourceInfo.Channels -eq 2
        )

        if ($alreadyCdQuality) {
            $skipped++

            Write-Host `
                "Уже CD-качество — пропущено." `
                -ForegroundColor Green

            continue
        }

        Write-Host "Конвертация..." `
            -ForegroundColor Yellow

        $ffmpegOutput = & $FfmpegPath `
            -hide_banner `
            -loglevel error `
            -y `
            -i `
            $file.FullName `
            -map 0:a:0 `
            -map "0:v?" `
            -map_metadata 0 `
            -c:a flac `
            -sample_fmt s16 `
            -ar 44100 `
            -ac 2 `
            -compression_level 8 `
            -c:v copy `
            -- `
            $tempFile 2>&1

        if ($LASTEXITCODE -ne 0) {
            throw "ffmpeg завершился с ошибкой:`n$ffmpegOutput"
        }

        if (
            -not (
                Test-Path `
                    -LiteralPath $tempFile `
                    -PathType Leaf
            )
        ) {
            throw "Временный файл не был создан."
        }

        $tempFileInfo = Get-Item `
            -LiteralPath $tempFile

        if ($tempFileInfo.Length -le 0) {
            throw "Создан пустой временный файл."
        }

        $resultInfo = Get-FlacAudioInfo `
            -Path $tempFile

        $validResult = (
            $resultInfo.BitDepth -eq 16 -and
            $resultInfo.SampleRate -eq 44100 -and
            $resultInfo.Channels -eq 2
        )

        if (-not $validResult) {
            throw (
                "Проверка результата не пройдена. " +
                "Получено: {0} бит, {1} Гц, " +
                "{2} канал(а)." -f `
                    $resultInfo.BitDepth,
                    $resultInfo.SampleRate,
                    $resultInfo.Channels
            )
        }

        $originalCreationTime = $file.CreationTime
        $originalLastWriteTime = $file.LastWriteTime

        Move-Item `
            -LiteralPath $file.FullName `
            -Destination $backupFile

        try {
            Move-Item `
                -LiteralPath $tempFile `
                -Destination $file.FullName

            $newFile = Get-Item `
                -LiteralPath $file.FullName

            $newFile.CreationTime = $originalCreationTime
            $newFile.LastWriteTime = $originalLastWriteTime

            Remove-Item `
                -LiteralPath $backupFile `
                -Force
        }
        catch {
            if (
                Test-Path `
                    -LiteralPath $file.FullName
            ) {
                Remove-Item `
                    -LiteralPath $file.FullName `
                    -Force `
                    -ErrorAction SilentlyContinue
            }

            if (
                Test-Path `
                    -LiteralPath $backupFile
            ) {
                Move-Item `
                    -LiteralPath $backupFile `
                    -Destination $file.FullName `
                    -ErrorAction SilentlyContinue
            }

            throw
        }

        $converted++

        Write-Host `
            "Готово — исходный файл заменён." `
            -ForegroundColor Cyan
    }
    catch {
        $failed++

        $errorMessage = $_.Exception.Message

        $failedFiles.Add(
            [PSCustomObject]@{
                Name      = $file.BaseName
                FileName  = $file.Name
                FullName  = $file.FullName
                Directory = $file.DirectoryName
                Error     = $errorMessage
            }
        )

        Write-Host "ОШИБКА:" `
            -ForegroundColor Red

        Write-Host $errorMessage `
            -ForegroundColor Red

        if (
            Test-Path `
                -LiteralPath $tempFile
        ) {
            Remove-Item `
                -LiteralPath $tempFile `
                -Force `
                -ErrorAction SilentlyContinue
        }

        if (
            (Test-Path -LiteralPath $backupFile) -and
            -not (
                Test-Path `
                    -LiteralPath $file.FullName
            )
        ) {
            Move-Item `
                -LiteralPath $backupFile `
                -Destination $file.FullName `
                -ErrorAction SilentlyContinue
        }
    }
}

Write-Progress `
    -Activity "Конвертация FLAC в CD-качество" `
    -Completed

$elapsed = (Get-Date) - $startTime

Write-Host ""
Write-Host "========================================" `
    -ForegroundColor DarkGray

Write-Host "Обработка завершена" `
    -ForegroundColor Cyan

Write-Host (
    "Всего файлов:       {0}" -f $total
)

Write-Host (
    "Конвертировано:     {0}" -f $converted
) -ForegroundColor Cyan

Write-Host (
    "Пропущено (уже CD): {0}" -f $skipped
) -ForegroundColor Green

if ($failed -gt 0) {
    Write-Host (
        "Ошибок:             {0}" -f $failed
    ) -ForegroundColor Red
}
else {
    Write-Host "Ошибок:             0" `
        -ForegroundColor Gray
}

Write-Host (
    "Время:              {0:hh\:mm\:ss}" -f $elapsed
)

Write-Host "========================================" `
    -ForegroundColor DarkGray

if ($failedFiles.Count -gt 0) {
    Write-Host ""
    Write-Host "ТРЕКИ С ОШИБКАМИ:" `
        -ForegroundColor Red

    Write-Host "========================================" `
        -ForegroundColor DarkGray

    $failedNumber = 0

    foreach ($failedFile in $failedFiles) {
        $failedNumber++

        Write-Host (
            "{0}. {1}" -f `
                $failedNumber,
                $failedFile.Name
        ) -ForegroundColor Red

        Write-Host (
            "   Файл:   {0}" -f `
                $failedFile.FullName
        ) -ForegroundColor DarkGray

        Write-Host (
            "   Ошибка: {0}" -f `
                $failedFile.Error
        ) -ForegroundColor DarkYellow

        Write-Host ""
    }

    Write-Host "========================================" `
        -ForegroundColor DarkGray
}
else {
    Write-Host ""
    Write-Host "Все файлы обработаны без ошибок." `
        -ForegroundColor Green
}

Wait-BeforeExit