<?php

namespace App\Services;

use App\Models\Event;
use App\Models\EventMedia;
use Illuminate\Http\UploadedFile;
use Illuminate\Support\Facades\Storage;
use Illuminate\Support\Str;

/**
 * Stores a file as event media and creates the row.
 *
 * Images get an original, a preview and a thumbnail. Videos keep their
 * original file and get a poster frame (preview + thumbnail) when ffmpeg is
 * available. Voice notes are transcoded to AAC in an MP4 container when
 * ffmpeg is available, because browser recordings (WebM/Opus) lack duration
 * and index data and do not play in Safari at all. An event can carry any
 * number of voice notes. The key image points the event at the new
 * thumbnail. Shared by the API upload and the lifeline importer.
 */
class EventMediaStore
{
    public const TYPE_IMAGE = 'image';

    public const TYPE_VIDEO = 'video';

    public const TYPE_AUDIO = 'audio';

    public function __construct(
        private readonly EventMediaImageProcessor $processor,
        private readonly EventMediaProbe $probe,
        private readonly MediaCleaner $mediaCleaner,
    ) {}

    public function store(Event $event, UploadedFile $file, string $collection = 'gallery', ?string $caption = null): EventMedia
    {
        $type = $this->typeFor($file, $collection);
        $uuid = (string) Str::uuid();
        $directory = "event-media/{$event->user_id}/{$event->client_id}";

        $attributes = match ($type) {
            self::TYPE_IMAGE => $this->storeImage($file, $directory, $uuid),
            self::TYPE_VIDEO => $this->storeVideo($file, $directory, $uuid),
            default => $this->storeAudio($file, $directory, $uuid),
        };

        if ($collection === 'key_image') {
            $this->deleteExistingInCollection($event, 'key_image');
        }

        $media = $event->media()->create([
            'uuid' => $uuid,
            'user_id' => $event->user_id,
            'collection' => $collection,
            'type' => $type,
            'caption' => $caption !== null && $caption !== '' ? $caption : null,
            'name' => $file->getClientOriginalName(),
            'disk' => 'local',
            ...$attributes,
        ]);

        if ($collection === 'key_image') {
            $event->update(['image' => "/event-media/{$media->id}/thumb"]);
        }

        return $media;
    }

    public function typeFor(UploadedFile $file, string $collection): string
    {
        if ($collection === 'voice_note') {
            return self::TYPE_AUDIO;
        }

        $mime = (string) ($file->getMimeType() ?: $file->getClientMimeType());

        return str_starts_with($mime, 'video/') ? self::TYPE_VIDEO : self::TYPE_IMAGE;
    }

    /**
     * @return array<string, mixed>
     */
    private function storeImage(UploadedFile $file, string $directory, string $uuid): array
    {
        $processed = $this->processor->process($file);
        $path = "{$directory}/{$uuid}.jpg";
        $previewPath = "{$directory}/{$uuid}_preview.jpg";
        $thumbnailPath = "{$directory}/{$uuid}_thumb.jpg";

        Storage::disk('local')->put($path, $processed['original']);
        Storage::disk('local')->put($previewPath, $processed['preview']);
        Storage::disk('local')->put($thumbnailPath, $processed['thumbnail']);

        return [
            'mime_type' => $processed['mime_type'],
            'path' => $path,
            'thumbnail_path' => $thumbnailPath,
            'preview_path' => $previewPath,
            'size' => $processed['size'],
            'duration_ms' => null,
            'width' => $processed['width'],
            'height' => $processed['height'],
            'thumbnail_width' => $processed['thumbnail_width'],
            'thumbnail_height' => $processed['thumbnail_height'],
            'preview_width' => $processed['preview_width'],
            'preview_height' => $processed['preview_height'],
        ];
    }

    /**
     * @return array<string, mixed>
     */
    private function storeVideo(UploadedFile $file, string $directory, string $uuid): array
    {
        $extension = $this->extensionFor($file, 'mp4');
        $path = "{$directory}/{$uuid}.{$extension}";
        $realPath = (string) $file->getRealPath();

        Storage::disk('local')->putFileAs($directory, $file, "{$uuid}.{$extension}");

        $durationMs = $this->probe->durationMs($realPath);
        $poster = $this->posterFor($realPath, $durationMs);

        $attributes = [
            'mime_type' => $file->getMimeType() ?: ($file->getClientMimeType() ?: 'video/mp4'),
            'path' => $path,
            'thumbnail_path' => null,
            'preview_path' => null,
            'size' => $file->getSize(),
            'duration_ms' => $durationMs,
            'width' => null,
            'height' => null,
            'thumbnail_width' => null,
            'thumbnail_height' => null,
            'preview_width' => null,
            'preview_height' => null,
        ];

        if ($poster !== null) {
            $previewPath = "{$directory}/{$uuid}_preview.jpg";
            $thumbnailPath = "{$directory}/{$uuid}_thumb.jpg";

            Storage::disk('local')->put($previewPath, $poster['preview']);
            Storage::disk('local')->put($thumbnailPath, $poster['thumbnail']);

            $attributes = [
                ...$attributes,
                'thumbnail_path' => $thumbnailPath,
                'preview_path' => $previewPath,
                'width' => $poster['width'],
                'height' => $poster['height'],
                'thumbnail_width' => $poster['thumbnail_width'],
                'thumbnail_height' => $poster['thumbnail_height'],
                'preview_width' => $poster['preview_width'],
                'preview_height' => $poster['preview_height'],
            ];
        }

        return $attributes;
    }

    /**
     * @return array<string, mixed>
     */
    private function storeAudio(UploadedFile $file, string $directory, string $uuid): array
    {
        $transcoded = $this->transcodedAudio($file);

        if ($transcoded !== null) {
            $path = "{$directory}/{$uuid}.m4a";
            Storage::disk('local')->put($path, (string) file_get_contents($transcoded));
            $durationMs = $this->probe->durationMs($transcoded);
            $size = (int) filesize($transcoded);
            @unlink($transcoded);

            return $this->audioAttributes($path, 'audio/mp4', $size, $durationMs);
        }

        // Without ffmpeg the recording is kept as delivered.
        $extension = $this->extensionFor($file, 'webm');
        $path = "{$directory}/{$uuid}.{$extension}";

        Storage::disk('local')->putFileAs($directory, $file, "{$uuid}.{$extension}");

        // Browsers record audio into containers libmagic reports as video
        // (WebM, MP4). The client's own type is the honest one here.
        $clientMime = (string) $file->getClientMimeType();
        $mime = str_starts_with($clientMime, 'audio/')
            ? $clientMime
            : ($file->getMimeType() ?: 'audio/webm');

        return $this->audioAttributes(
            $path,
            $mime,
            (int) $file->getSize(),
            $this->probe->durationMs((string) $file->getRealPath()),
        );
    }

    /**
     * Path of a temporary AAC/MP4 rendition of the upload, or null when
     * ffmpeg is unavailable or the input could not be decoded.
     */
    private function transcodedAudio(UploadedFile $file): ?string
    {
        $target = tempnam(sys_get_temp_dir(), 'voice_').'.m4a';

        if ($this->probe->transcodeAudioToM4a((string) $file->getRealPath(), $target)) {
            @unlink(substr($target, 0, -4));

            return $target;
        }

        @unlink($target);
        @unlink(substr($target, 0, -4));

        return null;
    }

    /**
     * @return array<string, mixed>
     */
    private function audioAttributes(string $path, string $mime, int $size, ?int $durationMs): array
    {
        return [
            'mime_type' => $mime,
            'path' => $path,
            'thumbnail_path' => null,
            'preview_path' => null,
            'size' => $size,
            'duration_ms' => $durationMs,
            'width' => null,
            'height' => null,
            'thumbnail_width' => null,
            'thumbnail_height' => null,
            'preview_width' => null,
            'preview_height' => null,
        ];
    }

    /**
     * Poster frame of a video, run through the image pipeline so it gets the
     * same preview and thumbnail sizes as an uploaded photo.
     *
     * @return array<string, mixed>|null
     */
    private function posterFor(string $videoPath, ?int $durationMs): ?array
    {
        $posterPath = tempnam(sys_get_temp_dir(), 'poster_').'.jpg';

        try {
            if (! $this->probe->posterFrame($videoPath, $posterPath, $durationMs)) {
                return null;
            }

            $poster = new UploadedFile($posterPath, 'poster.jpg', 'image/jpeg', null, true);

            return $this->processor->process($poster);
        } catch (\Throwable) {
            return null;
        } finally {
            @unlink($posterPath);
            @unlink(substr($posterPath, 0, -4));
        }
    }

    private function extensionFor(UploadedFile $file, string $fallback): string
    {
        $extension = strtolower((string) ($file->getClientOriginalExtension() ?: $file->guessExtension()));
        $extension = preg_replace('/[^a-z0-9]/', '', $extension) ?? '';

        return $extension !== '' ? $extension : $fallback;
    }

    private function deleteExistingInCollection(Event $event, string $collection): void
    {
        foreach ($event->media()->where('collection', $collection)->get() as $media) {
            $this->mediaCleaner->purgeMedia($media);
            $media->delete();
        }
    }
}