<?php

namespace App\Services;

use App\Models\DisplayMedia;
use Illuminate\Http\UploadedFile;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Storage;
use Illuminate\Support\Str;
use Symfony\Component\Process\Process;

class DisplayMediaService
{
    /**
     * Store an uploaded file and create a DisplayMedia record.
     */
    public function storeUpload(UploadedFile $file, ?string $collection = null): DisplayMedia
    {
        $filename = $file->getClientOriginalName();
        $extension = strtolower($file->getClientOriginalExtension());
        $storageName = Str::uuid().'.'.$extension;
        $datePath = now()->format('Y/m');
        $relativePath = "display-media/{$datePath}/{$storageName}";

        Storage::disk('public')->putFileAs("display-media/{$datePath}", $file, $storageName);

        $type = in_array($extension, ['mp4', 'webm', 'mov']) ? 'video' : 'image';

        $metadata = [];
        if ($type === 'image') {
            $dimensions = @getimagesize($file->getRealPath());
            if ($dimensions) {
                $metadata['width'] = $dimensions[0];
                $metadata['height'] = $dimensions[1];
            }
        }

        $media = DisplayMedia::create([
            'filename' => $filename,
            'disk' => 'public',
            'path' => $relativePath,
            'source_type' => 'upload',
            'type' => $type,
            'mime_type' => $file->getMimeType(),
            'file_size' => $file->getSize(),
            'collection' => $collection,
            'metadata' => ! empty($metadata) ? $metadata : null,
        ]);

        if ($type === 'video') {
            $thumbnailPath = $this->generateVideoThumbnail($media);

            if ($thumbnailPath !== null) {
                $media->update(['thumbnail_path' => $thumbnailPath]);
            }
        }

        return $media;
    }

    /**
     * Generate a poster frame for an uploaded video using ffmpeg.
     *
     * Returns the relative thumbnail path on the media's disk, or null when
     * generation is not possible (e.g. ffmpeg missing or an unreadable file).
     */
    public function generateVideoThumbnail(DisplayMedia $media): ?string
    {
        if (! $media->isVideo() || ! $media->isUpload() || ! $media->path) {
            return null;
        }

        $disk = Storage::disk($media->disk);
        $videoPath = $disk->path($media->path);

        if (! is_file($videoPath)) {
            return null;
        }

        $thumbnailRelativePath = preg_replace('/\.[^.\/]+$/', '', $media->path).'-poster.jpg';
        $thumbnailPath = $disk->path($thumbnailRelativePath);

        if (! is_dir(dirname($thumbnailPath))) {
            @mkdir(dirname($thumbnailPath), 0755, true);
        }

        // Try a frame ~1s in first (avoids black intro frames); fall back to
        // the very first frame for clips shorter than one second.
        foreach (['1', '0'] as $seekSeconds) {
            if ($this->extractFrame($videoPath, $thumbnailPath, $seekSeconds) && filesize($thumbnailPath) > 0) {
                return $thumbnailRelativePath;
            }
        }

        if (is_file($thumbnailPath)) {
            @unlink($thumbnailPath);
        }

        return null;
    }

    private function extractFrame(string $videoPath, string $thumbnailPath, string $seekSeconds): bool
    {
        $process = new Process([
            'ffmpeg',
            '-y',
            '-ss', $seekSeconds,
            '-i', $videoPath,
            '-frames:v', '1',
            '-vf', 'scale=640:-2',
            '-q:v', '3',
            $thumbnailPath,
        ]);
        $process->setTimeout(60);

        try {
            $process->run();
        } catch (\Throwable) {
            return false;
        }

        return $process->isSuccessful() && is_file($thumbnailPath);
    }

    /**
     * Create a DisplayMedia record from an external URL.
     */
    public function createFromUrl(string $url, string $type = 'video', ?string $title = null, ?string $collection = null): DisplayMedia
    {
        $filename = $title ?: $this->extractFilenameFromUrl($url);

        return DisplayMedia::create([
            'filename' => $filename,
            'disk' => 'public',
            'path' => null,
            'external_url' => $url,
            'source_type' => 'external',
            'type' => $type,
            'mime_type' => null,
            'file_size' => 0,
            'title' => $title,
            'collection' => $collection,
        ]);
    }

    /**
     * Validate that an external URL is accessible.
     */
    public function validateExternalUrl(string $url): bool
    {
        try {
            $response = Http::timeout(10)
                ->withOptions(['allow_redirects' => true])
                ->head($url);

            return $response->successful() || $response->status() === 302 || $response->status() === 301;
        } catch (\Throwable) {
            // Some services block HEAD requests, try GET with stream
            try {
                $response = Http::timeout(10)
                    ->withOptions(['allow_redirects' => true, 'stream' => true])
                    ->get($url);

                return $response->successful();
            } catch (\Throwable) {
                return false;
            }
        }
    }

    /**
     * Delete a DisplayMedia record and its associated files.
     */
    public function delete(DisplayMedia $media): void
    {
        if ($media->isUpload() && $media->path) {
            Storage::disk($media->disk)->delete($media->path);
        }

        if ($media->thumbnail_path) {
            Storage::disk($media->disk)->delete($media->thumbnail_path);
        }

        $media->delete();
    }

    private function extractFilenameFromUrl(string $url): string
    {
        $parsed = parse_url($url, PHP_URL_PATH);
        $basename = $parsed ? basename($parsed) : 'external-media';

        return Str::limit($basename, 100);
    }
}