<?php

namespace App\Services;

use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\Storage;
use Illuminate\Support\Str;
use RuntimeException;

/**
 * Image-to-Video via Replicate API — ASYNC design.
 *
 * Step A (fast, <2s):  submit()       — POST /predictions → returns prediction_id
 * Step B (poll):       checkStatus()  — GET  /predictions/{id} → called by AJAX endpoint
 */
class ReplicateVideoService
{
    private const WAVESPEED_WAN_MODEL = 'wavespeedai/wan-2.1-i2v-480p';

    private string $apiKey;
    private string $baseUrl;
    private string $i2vModel;

    public function __construct(private ?HuggingFaceMediaStorageService $hfMediaStorage = null)
    {
        $this->apiKey   = (string) config('services.replicate.api_key', '');
        $this->baseUrl  = (string) config('services.replicate.base_url', 'https://api.replicate.com/v1');
        $this->i2vModel = (string) config('services.replicate.i2v_model', self::WAVESPEED_WAN_MODEL);
    }

    public function isAvailable(): bool
    {
        return $this->apiKey !== '';
    }

    /**
     * STEP A — submit prediction job, returns prediction_id immediately (<2s).
     *
     * @throws RuntimeException
     */
    public function submit(string $imageUrl, string $prompt, array $options = []): array
    {
        if (! $this->isAvailable()) {
            throw new RuntimeException('REPLICATE_API_KEY belum diset.');
        }

        // Replicate requires a fully-qualified https:// URI — convert relative paths.
        if (! str_starts_with($imageUrl, 'http://') && ! str_starts_with($imageUrl, 'https://')) {
            $imageUrl = rtrim((string) config('app.url', ''), '/') . '/' . ltrim($imageUrl, '/');
        }

        $endpoint = rtrim($this->baseUrl, '/') . '/models/' . $this->i2vModel . '/predictions';

        $payload = $this->buildImageToVideoPayload($imageUrl, $prompt, $options);
        $requestBody = [
            'input' => $payload['input'] ?? [],
        ];

        $response = Http::withToken($this->apiKey)->timeout(30)->post($endpoint, $requestBody);

        // Retry once after 3s on rate-limit (burst=1 on low-credit accounts)
        if ($response->status() === 429) {
            Log::info('ReplicateVideoService: rate-limited, retrying in 3s…');
            sleep(3);
            $response = Http::withToken($this->apiKey)->timeout(30)->post($endpoint, $requestBody);
        }

        if ($response->failed()) {
            $status = $response->status();
            $detail = $response->json('detail') ?? $response->body();
            if ($status === 429) {
                throw new RuntimeException('Replicate sedang sibuk (rate limit). Tunggu beberapa detik lalu coba lagi.');
            }
            throw new RuntimeException('Replicate submit gagal: ' . Str::limit((string) $detail, 200));
        }

        $id = $response->json('id');
        if (blank($id)) {
            throw new RuntimeException('Replicate: prediction ID tidak ada di response.');
        }

        Log::info('ReplicateVideoService: submitted', ['id' => $id]);

        return [
            'prediction_id' => (string) $id,
            'applied_settings' => $payload['applied_settings'],
        ];
    }

    private function buildImageToVideoPayload(string $imageUrl, string $prompt, array $options): array
    {
        $model = $this->resolveRequestedModel($options);
        $aspectRatio = $this->normalizeAspectRatio((string) ($options['aspect_ratio'] ?? '16:9'));
        $audioEnabled = ((string) ($options['video_audio'] ?? 'off')) === 'on';
        $negativePrompt = trim((string) ($options['video_negative_prompt'] ?? ''));

        if ($model === self::WAVESPEED_WAN_MODEL) {
            [$numFrames, $fps, $durationLabel] = $this->resolveWanFrameSettings((string) ($options['video_duration'] ?? '4s'));

            $input = [
                'prompt' => $prompt,
                'image' => $imageUrl,
                'aspect_ratio' => $aspectRatio,
                'frames_per_second' => $fps,
                'num_frames' => $numFrames,
            ];

            if ($negativePrompt !== '') {
                $input['negative_prompt'] = $negativePrompt;
            }

            return [
                'input' => $input,
                'applied_settings' => [
                    'aspect_ratio' => $aspectRatio,
                    'video_duration' => $durationLabel,
                    'video_quality' => '480p',
                    'video_audio' => 'off',
                    'veo_variant' => 'wan-2.1-i2v-480p',
                    'replicate_i2v_model' => $model,
                ],
            ];
        }

        if ($model === 'google/veo-3-fast' || $model === 'google/veo-3') {
            $duration = $this->normalizeVeoDuration((string) ($options['video_duration'] ?? '4s'));
            $resolution = ((string) ($options['video_quality'] ?? '1080p')) === '720p' ? '720p' : '1080p';

            $input = [
                'prompt' => $prompt,
                'image' => $imageUrl,
                'duration' => $duration,
                'resolution' => $resolution,
                'aspect_ratio' => $aspectRatio,
                'generate_audio' => $audioEnabled,
            ];

            if ($negativePrompt !== '') {
                $input['negative_prompt'] = $negativePrompt;
            }

            return [
                'input' => $input,
                'applied_settings' => [
                    'aspect_ratio' => $aspectRatio,
                    'video_duration' => $duration.'s',
                    'video_quality' => $resolution,
                    'video_audio' => $audioEnabled ? 'on' : 'off',
                    'veo_variant' => $model === 'google/veo-3' ? 'veo-3' : 'veo-3-fast',
                    'replicate_i2v_model' => $model,
                ],
            ];
        }

        if ($model === 'google/veo-2') {
            $duration = ((string) ($options['video_duration'] ?? '8s')) === '5s' ? 5 : 8;

            return [
                'input' => [
                    'prompt' => $prompt,
                    'image' => $imageUrl,
                    'duration' => $duration,
                    'aspect_ratio' => $aspectRatio,
                ],
                'applied_settings' => [
                    'aspect_ratio' => $aspectRatio,
                    'video_duration' => $duration.'s',
                    'video_quality' => '720p',
                    'video_audio' => 'off',
                    'veo_variant' => 'veo-2',
                    'replicate_i2v_model' => $model,
                ],
            ];
        }

        if ($model === 'luma/ray-2-720p') {
            $duration = ((string) ($options['video_duration'] ?? '8s')) === '5s' ? 5 : 9;

            return [
                'input' => [
                    'prompt' => $prompt,
                    'start_image' => $imageUrl,
                    'duration' => $duration,
                    'aspect_ratio' => $aspectRatio,
                ],
                'applied_settings' => [
                    'aspect_ratio' => $aspectRatio,
                    'video_duration' => $duration.'s',
                    'video_quality' => '720p',
                    'video_audio' => 'off',
                    'veo_variant' => 'luma-ray-2',
                    'replicate_i2v_model' => $model,
                ],
            ];
        }

        if ($model === 'kwaivgi/kling-v1.6-pro') {
            $duration = ((string) ($options['video_duration'] ?? '8s')) === '5s' ? 5 : 10;

            return [
                'input' => [
                    'prompt' => $prompt,
                    'start_image' => $imageUrl,
                    'duration' => $duration,
                    'aspect_ratio' => $aspectRatio,
                ],
                'applied_settings' => [
                    'aspect_ratio' => $aspectRatio,
                    'video_duration' => $duration.'s',
                    'video_quality' => '1080p',
                    'video_audio' => 'off',
                    'veo_variant' => 'kling-v1.6-pro',
                    'replicate_i2v_model' => $model,
                ],
            ];
        }

        return [
            'input' => [
                'prompt' => $prompt,
                'first_frame_image' => $imageUrl,
                'prompt_optimizer' => true,
            ],
            'applied_settings' => [
                'aspect_ratio' => $aspectRatio,
                'video_duration' => '6s',
                'video_quality' => '720p',
                'video_audio' => 'off',
                'veo_variant' => 'legacy-replicate',
                'replicate_i2v_model' => $model,
            ],
        ];
    }

    private function resolveRequestedModel(array $options): string
    {
        $requestedProvider = trim((string) ($options['video_provider'] ?? ''));
        $requestedModel = trim((string) ($options['replicate_i2v_model'] ?? ''));

        if ($requestedProvider === 'replicate') {
            return $requestedModel !== '' ? $requestedModel : trim($this->i2vModel);
        }

        $requestedVariant = trim((string) ($options['veo_variant'] ?? ''));

        return match ($requestedVariant) {
            'veo-3' => 'google/veo-3',
            'veo-3-fast' => 'google/veo-3-fast',
            default => trim($this->i2vModel),
        };
    }

    private function normalizeAspectRatio(string $aspectRatio): string
    {
        return match (trim($aspectRatio)) {
            '9:16', '16:9' => trim($aspectRatio),
            default => '16:9',
        };
    }

    private function normalizeVeoDuration(string $duration): int
    {
        return match (trim($duration)) {
            '4s', '5s' => 4,
            '6s' => 6,
            default => 8,
        };
    }

    private function resolveWanFrameSettings(string $duration): array
    {
        return match (trim($duration)) {
            '6s' => [72, 12, '6s'],
            '8s' => [96, 12, '8s'],
            default => [48, 12, '4s'],
        };
    }

    /**
     * STEP B — called from polling AJAX endpoint every ~5s.
     * Returns status array. When succeeded, downloads and stores the video.
     *
     * @return array{status: string, url?: string, error?: string}
     */
    public function checkStatus(string $predictionId): array
    {
        $endpoint = rtrim($this->baseUrl, '/') . '/predictions/' . $predictionId;

        $response = Http::withToken($this->apiKey)
            ->timeout(15)
            ->get($endpoint);

        if ($response->failed()) {
            return ['status' => 'failed', 'error' => 'Gagal mengambil status dari Replicate.'];
        }

        $status = (string) $response->json('status');

        if ($status === 'succeeded') {
            $output    = $response->json('output');
            $remoteUrl = is_array($output) ? ($output[0] ?? null) : $output;

            if (blank($remoteUrl)) {
                return ['status' => 'failed', 'error' => 'Output URL kosong.'];
            }

            try {
                $localUrl = $this->downloadVideo((string) $remoteUrl);
                return ['status' => 'succeeded', 'url' => $localUrl, 'remote_url' => (string) $remoteUrl];
            } catch (\Throwable $e) {
                return ['status' => 'failed', 'error' => $e->getMessage()];
            }
        }

        if ($status === 'failed' || $status === 'canceled') {
            $error = $response->json('error') ?? $status;
            return ['status' => 'failed', 'error' => Str::limit((string) $error, 200)];
        }

        // starting | processing
        return ['status' => $status];
    }

    // ─────────────────────────────────────────────────────────────────────────

    /**
     * Submit a luma/reframe-video prediction.
     * Reframes (reaspects) an existing video to the target aspect ratio.
     *
     * @param  string $videoUrl     Absolute URL to the source video
     * @param  string $aspectRatio  Target ratio: "9:16" | "16:9" | "1:1" | "4:5"
     * @return string  prediction_id
     */
    public function submitReframe(string $videoUrl, string $aspectRatio = '9:16'): string
    {
        if (! $this->isAvailable()) {
            throw new RuntimeException('REPLICATE_API_KEY belum diset.');
        }

        if (! str_starts_with($videoUrl, 'http')) {
            $videoUrl = rtrim((string) config('app.url', ''), '/') . '/' . ltrim($videoUrl, '/');
        }

        $endpoint = rtrim($this->baseUrl, '/') . '/models/luma/reframe-video/predictions';

        $payload = [
            'input' => [
                'video_url'    => $videoUrl,
                'aspect_ratio' => $aspectRatio,
            ],
        ];

        $response = Http::withToken($this->apiKey)->timeout(30)->post($endpoint, $payload);

        if ($response->status() === 429) {
            sleep(3);
            $response = Http::withToken($this->apiKey)->timeout(30)->post($endpoint, $payload);
        }

        if ($response->failed()) {
            $detail = $response->json('detail') ?? $response->body();
            if ($response->status() === 429) {
                throw new RuntimeException('Replicate sibuk (rate limit). Coba beberapa detik lagi.');
            }
            throw new RuntimeException('Luma reframe submit gagal: ' . Str::limit((string) $detail, 200));
        }

        $id = $response->json('id');
        if (blank($id)) {
            throw new RuntimeException('Replicate: prediction ID tidak ada di response.');
        }

        Log::info('ReplicateVideoService(luma/reframe): submitted', ['id' => $id]);
        return (string) $id;
    }

    /**
     * Submit a topazlabs/video-upscale prediction.
     * Enhances and upscales a low-resolution video.
     *
     * @param  string $videoUrl  Absolute URL to the source video
     * @return string  prediction_id
     */
    public function submitVideoUpscale(string $videoUrl): string
    {
        if (! $this->isAvailable()) {
            throw new RuntimeException('REPLICATE_API_KEY belum diset.');
        }

        if (! str_starts_with($videoUrl, 'http')) {
            $videoUrl = rtrim((string) config('app.url', ''), '/') . '/' . ltrim($videoUrl, '/');
        }

        $endpoint = rtrim($this->baseUrl, '/') . '/models/topazlabs/video-upscale/predictions';

        $payload = [
            'input' => [
                'video' => $videoUrl,
            ],
        ];

        $response = Http::withToken($this->apiKey)->timeout(30)->post($endpoint, $payload);

        if ($response->status() === 429) {
            sleep(3);
            $response = Http::withToken($this->apiKey)->timeout(30)->post($endpoint, $payload);
        }

        if ($response->failed()) {
            $detail = $response->json('detail') ?? $response->body();
            if ($response->status() === 429) {
                throw new RuntimeException('Replicate sibuk (rate limit). Coba beberapa detik lagi.');
            }
            throw new RuntimeException('Topaz video-upscale submit gagal: ' . Str::limit((string) $detail, 200));
        }

        $id = $response->json('id');
        if (blank($id)) {
            throw new RuntimeException('Replicate: prediction ID tidak ada di response.');
        }

        Log::info('ReplicateVideoService(topaz/video-upscale): submitted', ['id' => $id]);
        return (string) $id;
    }

    // ─────────────────────────────────────────────────────────────────────────

    private function downloadVideo(string $remoteUrl): string
    {
        $response = Http::withOptions(['stream' => false])
            ->timeout(60)
            ->get($remoteUrl);

        if ($response->failed()) {
            throw new RuntimeException('Gagal download video dari Replicate: ' . $remoteUrl);
        }

        $relPath   = 'videos/replicate_' . now()->format('Ymd_His') . '_' . Str::lower(Str::random(8)) . '.mp4';
        $absPath   = Storage::disk('public')->path($relPath);
        $outputDir = dirname($absPath);

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

        file_put_contents($absPath, $response->body());

        if (! is_file($absPath) || filesize($absPath) < 1024) {
            throw new RuntimeException('File video Replicate kosong atau rusak setelah download.');
        }

        if ($this->hfMediaStorage !== null) {
            try {
                return $this->hfMediaStorage->offloadPublicRelativePath($relPath);
            } catch (\Throwable $e) {
                Log::warning('ReplicateVideoService: HF offload failed', ['error' => $e->getMessage()]);
            }
        }

        return Storage::disk('public')->url($relPath);
    }
}