<?php

namespace App\Services;

use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Storage;
use Illuminate\Support\Str;
use RuntimeException;
use function extension_loaded;
use function escapeshellarg;
use function escapeshellcmd;
use function shell_exec;
use function imagecreatefromstring;
use function imagecreatefrompng;
use function imagecreatefromjpeg;
use function imagecreatefromwebp;
use function imagejpeg;
use function imagedestroy;
use function tempnam;
use function sys_get_temp_dir;
use function file_put_contents;
use function unlink;

class MotionVideoService
{
    public function __construct(private ?HuggingFaceMediaStorageService $hfMediaStorage = null)
    {
    }

    public function createFromImageUrl(string $imageUrl, string $prompt, array $options = []): array
    {
        if (! $this->canUseShellExec()) {
            throw new RuntimeException('Server memblokir shell_exec, jadi render video lokal belum bisa dijalankan. Gunakan provider video remote seperti Replicate atau aktifkan shell_exec + ffmpeg di server.');
        }

        $ffmpeg = trim((string) $this->runShellCommand('command -v ffmpeg 2>/dev/null'));
        if ($ffmpeg === '') {
            throw new RuntimeException('FFmpeg belum tersedia di server, jadi generate video 9:16 belum bisa dijalankan.');
        }

        $workingDir = Storage::disk('public')->path('media-lab');
        if (! is_dir($workingDir) && ! @mkdir($workingDir, 0775, true) && ! is_dir($workingDir)) {
            throw new RuntimeException('Gagal menyiapkan folder kerja media lab.');
        }

        $sourceFrame = $this->normalizeImageFrame($imageUrl, $workingDir);
        $relativeOutput = 'videos/story_'.now()->format('Ymd_His').'_'.Str::lower(Str::random(8)).'.mp4';
        $outputPath = Storage::disk('public')->path($relativeOutput);
        $outputDirectory = dirname($outputPath);

        if (! is_dir($outputDirectory) && ! @mkdir($outputDirectory, 0775, true) && ! is_dir($outputDirectory)) {
            throw new RuntimeException('Gagal menyiapkan folder output video.');
        }

        if (! is_writable($outputDirectory)) {
            throw new RuntimeException('Folder output video belum writable untuk proses web.');
        }

        $aspectRatio = (string) ($options['aspect_ratio'] ?? '9:16');
        $videoQuality = (string) ($options['video_quality'] ?? '1080p');
        $videoDuration = (string) ($options['video_duration'] ?? '4s');
        $durationSeconds = match ($videoDuration) {
            '4s', '5s' => 4,
            '6s' => 6,
            default => 8,
        };
        $fps = 24;
        $frameCount = $durationSeconds * $fps;

        $dimensions = $this->resolveVideoDimensions($aspectRatio, $videoQuality);
        $outputWidth = $dimensions['output_width'];
        $outputHeight = $dimensions['output_height'];
        $sourceWidth = $dimensions['source_width'];
        $sourceHeight = $dimensions['source_height'];
        $fadeOutStart = max(0.3, $durationSeconds - 0.7);

        // ── Choose motion preset based on prompt keywords (Ken Burns style) ──────
        $lowerPrompt = strtolower($prompt);

        $zoompanPresets = [
            // 0 — slow zoom in toward center
            "zoompan=z='zoom+0.001':x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':d={$frameCount}:s={$outputWidth}x{$outputHeight}:fps={$fps}",
            // 1 — start zoomed in, slowly pull out
            "zoompan=z='1.25-on*0.002':x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':d={$frameCount}:s={$outputWidth}x{$outputHeight}:fps={$fps}",
            // 2 — pan left to right (fixed zoom 1.15)
            "zoompan=z=1.15:x='(iw-iw/zoom)*on/{$frameCount}':y='ih/2-(ih/zoom/2)':d={$frameCount}:s={$outputWidth}x{$outputHeight}:fps={$fps}",
            // 3 — pan right to left
            "zoompan=z=1.15:x='(iw-iw/zoom)*(1-on/{$frameCount})':y='ih/2-(ih/zoom/2)':d={$frameCount}:s={$outputWidth}x{$outputHeight}:fps={$fps}",
            // 4 — tilt up (pan bottom to top)
            "zoompan=z=1.15:x='iw/2-(iw/zoom/2)':y='(ih-ih/zoom)*(1-on/{$frameCount})':d={$frameCount}:s={$outputWidth}x{$outputHeight}:fps={$fps}",
        ];

        if (str_contains($lowerPrompt, 'aerial') || str_contains($lowerPrompt, 'drone') || str_contains($lowerPrompt, 'zoom out') || str_contains($lowerPrompt, 'pull back')) {
            $motionIdx = 1;
        } elseif (str_contains($lowerPrompt, 'pan') || str_contains($lowerPrompt, 'tracking shot') || str_contains($lowerPrompt, 'follow')) {
            $motionIdx = 2;
        } elseif (str_contains($lowerPrompt, 'tilt') || str_contains($lowerPrompt, 'reveal') || str_contains($lowerPrompt, 'rise')) {
            $motionIdx = 4;
        } elseif (str_contains($lowerPrompt, 'push in') || str_contains($lowerPrompt, 'close up') || str_contains($lowerPrompt, 'zoom in')) {
            $motionIdx = 0;
        } else {
            $motionIdx = abs((int) crc32($prompt)) % 5;
        }

        $zoompanFilter = $zoompanPresets[$motionIdx];
        $baseScale     = "scale={$sourceWidth}:{$sourceHeight}:force_original_aspect_ratio=increase,crop={$sourceWidth}:{$sourceHeight}";
        $fades         = "fade=t=in:st=0:d=0.3,fade=t=out:st={$fadeOutStart}:d=0.7,format=yuv420p";
        $motionFilter  = $baseScale . ',' . $zoompanFilter . ',' . $fades;

        // Bump PHP execution limit for this request only (video encoding can take 60-90s)
        @set_time_limit(180);

        $command = sprintf(
            '%s -y -loop 1 -i %s -vf %s -t %d -r %d -c:v libx264 -preset ultrafast -crf %d -pix_fmt yuv420p -movflags +faststart %s 2>&1',
            escapeshellcmd($ffmpeg),
            escapeshellarg($sourceFrame),
            escapeshellarg($motionFilter),
            $durationSeconds,
            $fps,
            $videoQuality === '720p' ? 28 : 23,
            escapeshellarg($outputPath)
        );

        $output = $this->runShellCommand($command);

        // Fallback A: zoompan unavailable — try simple static fade (no motion but at least a video)
        if (! is_file($outputPath) || filesize($outputPath) < 1024) {
            $staticFilter = "scale={$outputWidth}:{$outputHeight}:force_original_aspect_ratio=increase,crop={$outputWidth}:{$outputHeight},fade=t=in:st=0:d=0.3,fade=t=out:st={$fadeOutStart}:d=0.7,format=yuv420p";
            $fallbackCmd  = sprintf(
                '%s -y -loop 1 -i %s -vf %s -t %d -r %d -c:v libx264 -preset ultrafast -crf %d -pix_fmt yuv420p -movflags +faststart %s 2>&1',
                escapeshellcmd($ffmpeg),
                escapeshellarg($sourceFrame),
                escapeshellarg($staticFilter),
                $durationSeconds,
                $fps,
                $videoQuality === '720p' ? 30 : 25,
                escapeshellarg($outputPath)
            );
            $output = $this->runShellCommand($fallbackCmd);
        }

        if (! is_file($outputPath) || filesize($outputPath) < 1024) {
            throw new RuntimeException('Generate video gagal dijalankan. Detail: '.Str::limit(trim((string) $output), 240));
        }

        return [
            'url' => $this->offloadPublicPath($relativeOutput),
            'provider' => 'motion-video',
            'aspect' => $aspectRatio,
            'prompt' => $prompt,
            'duration_seconds' => $durationSeconds,
            'applied_settings' => [
                'aspect_ratio' => $aspectRatio,
                'video_quality' => $videoQuality,
                'video_duration' => $durationSeconds.'s',
                'veo_variant' => 'local-fallback',
                'video_audio' => 'off',
            ],
        ];
    }

    private function resolveVideoDimensions(string $aspectRatio, string $videoQuality): array
    {
        $quality = $videoQuality === '720p' ? '720p' : '1080p';

        return match ($aspectRatio) {
            '16:9' => $quality === '720p'
                ? ['output_width' => 1280, 'output_height' => 720, 'source_width' => 2560, 'source_height' => 1440]
                : ['output_width' => 1920, 'output_height' => 1080, 'source_width' => 2880, 'source_height' => 1620],
            default => $quality === '720p'
                ? ['output_width' => 720, 'output_height' => 1280, 'source_width' => 1440, 'source_height' => 2560]
                : ['output_width' => 1080, 'output_height' => 1920, 'source_width' => 1620, 'source_height' => 2880],
        };
    }

    private function normalizeImageFrame(string $imageUrl, string $workingDir): string
    {
        if (! \extension_loaded('gd')) {
            throw new RuntimeException('GD extension belum aktif, jadi gambar sumber video belum bisa diproses.');
        }

        $binary = $this->loadImageBinary($imageUrl);

        // Detect SVG — GD cannot rasterize vector formats
        $sniff = \ltrim(\substr($binary, 0, 100));
        if (
            \str_starts_with($sniff, '<svg') ||
            \str_starts_with($sniff, '<?xml') ||
            \str_contains(\strtolower(\substr($binary, 0, 256)), '<svg')
        ) {
            throw new RuntimeException(
                'Format SVG tidak bisa digunakan sebagai sumber video. '
                .'Generate gambar terlebih dahulu menggunakan provider OpenAI, HuggingFace, atau Pollinations, lalu klik "Buat Video".'
            );
        }

        // Detect HTML error page
        if (\str_starts_with($sniff, '<!DOCTYPE') || \str_starts_with($sniff, '<html')) {
            throw new RuntimeException('URL gambar mengembalikan halaman HTML bukan file gambar. Coba generate ulang gambar sumbernya.');
        }

        $resource = @\imagecreatefromstring($binary);

        if ($resource === false) {
            // Try format-specific fallbacks
            $tmpFile = \tempnam(\sys_get_temp_dir(), 'mvframe_');
            \file_put_contents($tmpFile, $binary);
            
            if (\function_exists('\imagecreatefrompng')) {
                $resource = @\imagecreatefrompng($tmpFile);
            }
            
            if ($resource === false && \function_exists('\imagecreatefromjpeg')) {
                $resource = @\imagecreatefromjpeg($tmpFile);
            }
            
            if ($resource === false && \function_exists('\imagecreatefromwebp')) {
                $resource = @\imagecreatefromwebp($tmpFile);
            }
            
            @\unlink($tmpFile);
        }

        if ($resource === false) {
            throw new RuntimeException(
                'Gambar sumber video tidak bisa diproses (format tidak support atau data korup). '
                .'Coba generate ulang gambar dengan provider yang berbeda.'
            );
        }

        $framePath = $workingDir.'/frame_'.now()->format('Ymd_His').'_'.Str::lower(Str::random(8));
        
        // Try JPEG first, then WebP, then PNG
        if (\function_exists('\imagejpeg')) {
            $framePath .= '.jpg';
            $saved = @\imagejpeg($resource, $framePath, 92);
        } elseif (\function_exists('\imagewebp')) {
            $framePath .= '.webp';
            $saved = @\imagewebp($resource, $framePath, 85);
        } else {
            $framePath .= '.png';
            $saved = @\imagepng($resource, $framePath, 6);
        }

        if (! $saved) {
            \imagedestroy($resource);
            throw new RuntimeException('Gagal menyimpan frame sementara untuk video. GD JPEG/WebP/PNG might be broken.');
        }

        \imagedestroy($resource);

        return $framePath;
    }

    private function loadImageBinary(string $imageUrl): string
    {
        $path = parse_url($imageUrl, PHP_URL_PATH) ?: $imageUrl;

        if (is_string($path) && str_starts_with($path, '/storage/')) {
            $relative = ltrim(substr($path, strlen('/storage/')), '/');
            if (Storage::disk('public')->exists($relative)) {
                $binary = Storage::disk('public')->get($relative);
                if ($binary !== '') {
                    return $binary;
                }
            }
        }

        $response = Http::timeout(60)->get($imageUrl);
        if (! $response->successful()) {
            throw new RuntimeException('Gagal mengambil gambar sumber untuk video dari URL publik (HTTP '.$response->status().').');
        }

        $contentType = strtolower((string) $response->header('Content-Type'));
        if ($contentType !== '' && ! str_starts_with($contentType, 'image/')) {
            // SVG from API may come as image/svg+xml
            if (str_contains($contentType, 'svg')) {
                throw new RuntimeException(
                    'Format SVG tidak bisa digunakan sebagai sumber video. '
                    .'Generate gambar terlebih dahulu menggunakan provider OpenAI, HuggingFace, atau Pollinations, lalu klik "Buat Video".'
                );
            }
            throw new RuntimeException(
                'URL gambar mengembalikan konten bukan gambar (Content-Type: '.$contentType.'). Coba generate ulang gambar sumbernya.'
            );
        }

        return (string) $response->body();
    }

    private function offloadPublicPath(string $relativePath): string
    {
        try {
            return $this->hfMedia()->offloadPublicRelativePath($relativePath);
        } catch (\Throwable) {
            return Storage::url($relativePath);
        }
    }

    private function canUseShellExec(): bool
    {
        return \function_exists('shell_exec');
    }

    private function runShellCommand(string $command): string
    {
        if (! $this->canUseShellExec()) {
            return '';
        }

        return (string) @shell_exec($command);
    }

    private function hfMedia(): HuggingFaceMediaStorageService
    {
        if ($this->hfMediaStorage instanceof HuggingFaceMediaStorageService) {
            return $this->hfMediaStorage;
        }

        $service = app(HuggingFaceMediaStorageService::class);
        if (! $service instanceof HuggingFaceMediaStorageService) {
            throw new RuntimeException('Service HuggingFaceMediaStorageService tidak tersedia.');
        }

        $this->hfMediaStorage = $service;

        return $this->hfMediaStorage;
    }
}