<?php

namespace App\Services\Video;

use Illuminate\Support\Facades\Log;

class VideoAssemblyService
{
    /**
     * 영상 클립 결합 (concat)
     *
     * @param  array  $clipPaths  클립 파일 경로 배열
     * @return string|null 결합된 영상 경로
     */
    public function concatClips(array $clipPaths, string $outputPath): ?string
    {
        if (empty($clipPaths)) {
            return null;
        }

        // 클립이 1개면 그대로 복사
        if (count($clipPaths) === 1) {
            copy($clipPaths[0], $outputPath);

            return $outputPath;
        }

        $dir = dirname($outputPath);
        if (! is_dir($dir)) {
            mkdir($dir, 0755, true);
        }

        // concat용 파일 리스트 생성
        $listFile = "{$dir}/concat_list.txt";
        $listContent = '';

        foreach ($clipPaths as $path) {
            $listContent .= "file " . escapeshellarg($path) . "\n";
        }

        file_put_contents($listFile, $listContent);

        // 모든 클립을 동일 형식으로 재인코딩 후 concat
        $scaledPaths = [];
        foreach ($clipPaths as $i => $path) {
            $scaledPath = "{$dir}/scaled_{$i}.mp4";
            $scaleCmd = sprintf(
                'ffmpeg -y -i %s -vf "scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2,setsar=1" -r 30 -c:v libx264 -preset fast -crf 23 -an %s 2>&1',
                escapeshellarg($path),
                escapeshellarg($scaledPath)
            );
            exec($scaleCmd, $output, $returnCode);

            if ($returnCode !== 0) {
                Log::error('VideoAssemblyService: 클립 스케일링 실패', [
                    'clip' => $path,
                    'output' => implode("\n", $output),
                ]);

                return null;
            }

            $scaledPaths[] = $scaledPath;
        }

        // 스케일된 클립 리스트
        $scaledListFile = "{$dir}/scaled_list.txt";
        $scaledListContent = '';
        foreach ($scaledPaths as $path) {
            $scaledListContent .= "file " . escapeshellarg($path) . "\n";
        }
        file_put_contents($scaledListFile, $scaledListContent);

        $cmd = sprintf(
            'ffmpeg -y -f concat -safe 0 -i %s -c copy %s 2>&1',
            escapeshellarg($scaledListFile),
            escapeshellarg($outputPath)
        );

        exec($cmd, $output, $returnCode);

        // 임시 파일 정리
        @unlink($listFile);
        @unlink($scaledListFile);
        foreach ($scaledPaths as $path) {
            @unlink($path);
        }

        if ($returnCode !== 0) {
            Log::error('VideoAssemblyService: 클립 결합 실패', [
                'output' => implode("\n", $output),
            ]);

            return null;
        }

        return $outputPath;
    }

    /**
     * 나레이션 오디오 파일들을 하나로 합치기
     *
     * @param  array  $audioPaths  [scene_number => file_path]
     * @param  array  $scenes  시나리오 장면 정보 (duration 사용)
     */
    public function concatNarrations(array $audioPaths, array $scenes, string $outputPath): ?string
    {
        if (empty($audioPaths)) {
            return null;
        }

        $dir = dirname($outputPath);
        if (! is_dir($dir)) {
            mkdir($dir, 0755, true);
        }

        // 각 나레이션에 패딩(무음)을 추가해서 장면 길이에 맞춤
        $paddedPaths = [];
        foreach ($scenes as $scene) {
            $sceneNum = $scene['scene_number'];
            $duration = $scene['duration'] ?? 8;

            if (isset($audioPaths[$sceneNum])) {
                $paddedPath = "{$dir}/narration_padded_{$sceneNum}.mp3";
                // 나레이션을 장면 길이에 맞춰 패딩
                $cmd = sprintf(
                    'ffmpeg -y -i %s -af "apad=whole_dur=%d" -c:a libmp3lame -q:a 2 %s 2>&1',
                    escapeshellarg($audioPaths[$sceneNum]),
                    $duration,
                    escapeshellarg($paddedPath)
                );
                exec($cmd, $output, $returnCode);

                if ($returnCode === 0) {
                    $paddedPaths[] = $paddedPath;
                } else {
                    $paddedPaths[] = $audioPaths[$sceneNum];
                }
            }
        }

        if (empty($paddedPaths)) {
            return null;
        }

        // 나레이션 결합
        if (count($paddedPaths) === 1) {
            copy($paddedPaths[0], $outputPath);
        } else {
            $listFile = "{$dir}/narration_list.txt";
            $listContent = '';
            foreach ($paddedPaths as $path) {
                $listContent .= "file " . escapeshellarg($path) . "\n";
            }
            file_put_contents($listFile, $listContent);

            $cmd = sprintf(
                'ffmpeg -y -f concat -safe 0 -i %s -c:a libmp3lame -q:a 2 %s 2>&1',
                escapeshellarg($listFile),
                escapeshellarg($outputPath)
            );

            exec($cmd, $output, $returnCode);
            @unlink($listFile);

            if ($returnCode !== 0) {
                Log::error('VideoAssemblyService: 나레이션 결합 실패', [
                    'output' => implode("\n", $output),
                ]);

                return null;
            }
        }

        // 임시 패딩 파일 정리
        foreach ($paddedPaths as $path) {
            if (str_contains($path, 'narration_padded_')) {
                @unlink($path);
            }
        }

        return $outputPath;
    }

    /**
     * ASS 자막 파일 생성
     *
     * @param  array  $scenes  [{scene_number, narration, duration}, ...]
     */
    public function generateAssSubtitle(array $scenes, string $outputPath): string
    {
        $dir = dirname($outputPath);
        if (! is_dir($dir)) {
            mkdir($dir, 0755, true);
        }

        $ass = "[Script Info]\n";
        $ass .= "ScriptType: v4.00+\n";
        $ass .= "PlayResX: 1080\n";
        $ass .= "PlayResY: 1920\n";
        $ass .= "WrapStyle: 0\n\n";

        $ass .= "[V4+ Styles]\n";
        $ass .= "Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding\n";
        $ass .= "Style: Default,NanumGothic,48,&H00FFFFFF,&H000000FF,&H00000000,&H80000000,-1,0,0,0,100,100,0,0,1,3,1,2,40,40,200,1\n\n";

        $ass .= "[Events]\n";
        $ass .= "Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\n";

        $currentTime = 0;

        foreach ($scenes as $scene) {
            $duration = $scene['duration'] ?? 8;
            $narration = $scene['narration'] ?? '';

            if (empty($narration)) {
                $currentTime += $duration;

                continue;
            }

            $startTime = $this->formatAssTime($currentTime);
            $endTime = $this->formatAssTime($currentTime + $duration);

            // 긴 텍스트는 줄바꿈
            $text = $this->wrapText($narration, 18);
            $text = str_replace("\n", "\\N", $text);

            $ass .= "Dialogue: 0,{$startTime},{$endTime},Default,,0,0,0,,{$text}\n";

            $currentTime += $duration;
        }

        file_put_contents($outputPath, $ass);

        return $outputPath;
    }

    /**
     * 최종 합성: 영상 + 나레이션 + BGM + 자막
     */
    public function assemble(
        string $videoPath,
        ?string $narrationPath,
        ?string $bgmPath,
        string $subtitlePath,
        string $outputPath
    ): ?string {
        $dir = dirname($outputPath);
        if (! is_dir($dir)) {
            mkdir($dir, 0755, true);
        }

        $inputs = ['-i ' . escapeshellarg($videoPath)];
        $filterParts = [];
        $mapParts = ['-map 0:v'];
        $audioIndex = 1;

        // 나레이션 추가
        if ($narrationPath && file_exists($narrationPath)) {
            $inputs[] = '-i ' . escapeshellarg($narrationPath);
            $filterParts[] = "[{$audioIndex}:a]volume=1.0[nar]";
            $audioIndex++;
        }

        // BGM 추가
        if ($bgmPath && file_exists($bgmPath)) {
            $inputs[] = '-i ' . escapeshellarg($bgmPath);
            $filterParts[] = "[{$audioIndex}:a]volume=0.15[bgm]";
            $audioIndex++;
        }

        // 오디오 믹싱 필터
        if (count($filterParts) === 2) {
            // 나레이션 + BGM
            $filterComplex = implode(';', $filterParts) . ';[nar][bgm]amix=inputs=2:duration=first[a]';
            $mapParts[] = '-map "[a]"';
        } elseif (count($filterParts) === 1) {
            // 나레이션 또는 BGM 중 하나만
            $streamName = $narrationPath ? 'nar' : 'bgm';
            $filterComplex = $filterParts[0];
            $mapParts[] = '-map "[' . $streamName . ']"';
        } else {
            $filterComplex = null;
        }

        // 자막 비디오 필터
        $vf = sprintf("subtitles=%s", escapeshellarg($subtitlePath));

        // FFmpeg 명령 조립
        $cmd = 'ffmpeg -y ' . implode(' ', $inputs);

        if ($filterComplex) {
            $cmd .= ' -filter_complex "' . $filterComplex . '"';
        }

        $cmd .= ' ' . implode(' ', $mapParts);
        $cmd .= ' -vf ' . escapeshellarg($vf);
        $cmd .= ' -c:v libx264 -preset fast -crf 23 -r 30';
        $cmd .= ' -c:a aac -b:a 192k';
        $cmd .= ' -shortest';
        $cmd .= ' ' . escapeshellarg($outputPath);
        $cmd .= ' 2>&1';

        Log::info('VideoAssemblyService: 최종 합성 시작', ['cmd' => $cmd]);

        exec($cmd, $output, $returnCode);

        if ($returnCode !== 0) {
            Log::error('VideoAssemblyService: 최종 합성 실패', [
                'return_code' => $returnCode,
                'output' => implode("\n", array_slice($output, -20)),
            ]);

            return null;
        }

        Log::info('VideoAssemblyService: 최종 합성 완료', [
            'output' => $outputPath,
            'size' => file_exists($outputPath) ? filesize($outputPath) : 0,
        ]);

        return $outputPath;
    }

    /**
     * ASS 시간 형식 (H:MM:SS.cs)
     */
    private function formatAssTime(float $seconds): string
    {
        $hours = floor($seconds / 3600);
        $minutes = floor(($seconds % 3600) / 60);
        $secs = floor($seconds % 60);
        $centiseconds = round(($seconds - floor($seconds)) * 100);

        return sprintf('%d:%02d:%02d.%02d', $hours, $minutes, $secs, $centiseconds);
    }

    /**
     * 긴 텍스트를 일정 글자수로 줄바꿈
     */
    private function wrapText(string $text, int $maxCharsPerLine): string
    {
        if (mb_strlen($text) <= $maxCharsPerLine) {
            return $text;
        }

        $lines = [];
        $words = preg_split('/\s+/', $text);
        $currentLine = '';

        foreach ($words as $word) {
            if (mb_strlen($currentLine . ' ' . $word) > $maxCharsPerLine && $currentLine !== '') {
                $lines[] = trim($currentLine);
                $currentLine = $word;
            } else {
                $currentLine .= ($currentLine ? ' ' : '') . $word;
            }
        }

        if ($currentLine !== '') {
            $lines[] = trim($currentLine);
        }

        return implode("\n", $lines);
    }

    /**
     * 작업 디렉토리 정리
     */
    public function cleanup(string $workDir): void
    {
        if (! is_dir($workDir)) {
            return;
        }

        $files = glob("{$workDir}/*");
        foreach ($files as $file) {
            if (is_file($file) && ! str_contains($file, 'final_')) {
                @unlink($file);
            }
        }
    }
}