<?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;

class GeminiVideoService
{
    private string $apiKey;
    private string $baseUrl;
    private string $defaultModel;
    private string $fastModel;

    public function __construct(private ?HuggingFaceMediaStorageService $hfMediaStorage = null)
    {
        $this->apiKey = (string) config('services.gemini.api_key', '');
        $this->baseUrl = rtrim((string) config('services.gemini.base_url', 'https://generativelanguage.googleapis.com/v1beta'), '/');
        $this->defaultModel = (string) config('services.gemini.veo_model', 'veo-3.1-generate-preview');
        $this->fastModel = (string) config('services.gemini.veo_fast_model', 'veo-3.1-fast-generate-preview');
    }

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

    public function submit(?string $imageUrl, string $prompt, array $options = []): array
    {
        if (! $this->isAvailable()) {
            throw new RuntimeException('GEMINI_API_KEY belum diset.');
        }

        $payload = $this->buildPayload($imageUrl, $prompt, $options);
        $endpoint = sprintf('%s/models/%s:predictLongRunning', $this->baseUrl, $payload['model']);

        $response = Http::withHeaders([
            'x-goog-api-key' => $this->apiKey,
            'Content-Type' => 'application/json',
        ])->timeout((int) config('services.gemini.timeout', 180))
            ->post($endpoint, $payload['body']);

        if ($response->failed()) {
            $message = $response->json('error.message')
                ?? $response->json('error.status')
                ?? $response->body();

            throw new RuntimeException('Gemini submit gagal: ' . Str::limit((string) $message, 240));
        }

        $operationName = (string) $response->json('name', '');
        if ($operationName === '') {
            throw new RuntimeException('Gemini tidak mengembalikan operation name.');
        }

        Log::info('GeminiVideoService: submitted', [
            'operation' => $operationName,
            'model' => $payload['model'],
        ]);

        return [
            'prediction_id' => $operationName,
            'applied_settings' => $payload['applied_settings'],
        ];
    }

    public function checkStatus(string $operationName): array
    {
        if (! $this->isAvailable()) {
            return ['status' => 'failed', 'error' => 'GEMINI_API_KEY belum diset.'];
        }

        $response = Http::withHeaders([
            'x-goog-api-key' => $this->apiKey,
        ])->timeout(30)->get(sprintf('%s/%s', $this->baseUrl, ltrim($operationName, '/')));

        if ($response->failed()) {
            $message = $response->json('error.message')
                ?? $response->json('error.status')
                ?? 'Gagal mengambil status dari Gemini.';

            return ['status' => 'failed', 'error' => Str::limit((string) $message, 240)];
        }

        $data = $response->json();
        if (! (bool) ($data['done'] ?? false)) {
            return ['status' => 'processing'];
        }

        $operationError = data_get($data, 'error.message')
            ?? data_get($data, 'error.status');

        if ($operationError) {
            return ['status' => 'failed', 'error' => Str::limit((string) $operationError, 240)];
        }

        $videoUri = (string) data_get($data, 'response.generateVideoResponse.generatedSamples.0.video.uri', '');
        if ($videoUri === '') {
            return ['status' => 'failed', 'error' => 'Gemini selesai tetapi URI video kosong.'];
        }

        try {
            $localUrl = $this->downloadVideo($videoUri);

            return [
                'status' => 'succeeded',
                'url' => $localUrl,
                'remote_url' => $videoUri,
                'provider' => 'gemini-veo',
            ];
        } catch (\Throwable $e) {
            return ['status' => 'failed', 'error' => $e->getMessage()];
        }
    }

    private function buildPayload(?string $imageUrl, string $prompt, array $options): array
    {
        $instance = [
            'prompt' => trim($prompt),
        ];

        $hasImageInput = false;

        if ($imageUrl !== null && trim($imageUrl) !== '') {
            $instance['image'] = $this->toImageObject($imageUrl);
            $hasImageInput = true;
        }

        $endFrameUrl = trim((string) ($options['end_frame_url'] ?? ''));
        if ($endFrameUrl !== '' && $hasImageInput) {
            $instance['lastFrame'] = $this->toImageObject($endFrameUrl);
        }

        $parameters = [
            'sampleCount' => 1,
            'aspectRatio' => $this->normalizeAspectRatio((string) ($options['aspect_ratio'] ?? '16:9')),
            'resolution' => $this->normalizeResolution((string) ($options['video_quality'] ?? '1080p')),
        ];

        $effectiveDuration = $this->resolveDurationSeconds($parameters['resolution'], $hasImageInput, $endFrameUrl !== '', (string) ($options['video_duration'] ?? '8s'));
        if ($effectiveDuration !== null) {
            $parameters['durationSeconds'] = $effectiveDuration;
        }

        $negativePrompt = trim((string) ($options['video_negative_prompt'] ?? ''));
        if ($negativePrompt !== '') {
            $parameters['negativePrompt'] = $negativePrompt;
        }

        $model = $this->resolveModelCode((string) ($options['veo_variant'] ?? 'veo-3-fast'));
        $audioSetting = str_contains($model, 'veo-3.1') ? 'on' : 'off';

        return [
            'model' => $model,
            'body' => [
                'instances' => [$instance],
                'parameters' => $parameters,
            ],
            'applied_settings' => [
                'aspect_ratio' => $parameters['aspectRatio'],
                'video_quality' => $parameters['resolution'],
                'video_duration' => ($effectiveDuration ?? 8) . 's',
                'veo_variant' => $model === $this->defaultModel ? 'veo-3' : 'veo-3-fast',
                'video_audio' => $audioSetting,
                'gemini_model' => $model,
            ],
        ];
    }

    private function resolveModelCode(string $variant): string
    {
        return trim($variant) === 'veo-3' ? $this->defaultModel : $this->fastModel;
    }

    private function resolveDurationSeconds(string $resolution, bool $hasImageInput, bool $hasLastFrame, string $requestedDuration): ?int
    {
        if ($resolution === '1080p' || $hasLastFrame) {
            return 8;
        }

        if (! $hasImageInput && $requestedDuration === '5s') {
            return 6;
        }

        return $requestedDuration === '5s' ? 6 : 8;
    }

    private function normalizeAspectRatio(string $aspectRatio): string
    {
        return trim($aspectRatio) === '9:16' ? '9:16' : '16:9';
    }

    private function normalizeResolution(string $resolution): string
    {
        return trim($resolution) === '720p' ? '720p' : '1080p';
    }

    private function toImageObject(string $url): array
    {
        [$binary, $mimeType] = $this->loadBinaryAndMimeType($url);

        if (! str_starts_with($mimeType, 'image/')) {
            throw new RuntimeException('Gemini hanya menerima input image untuk mode image-to-video ini.');
        }

        return [
            'bytesBase64Encoded' => base64_encode($binary),
            'mimeType' => $mimeType,
        ];
    }

    private function loadBinaryAndMimeType(string $url): array
    {
        $path = parse_url($url, PHP_URL_PATH) ?: $url;

        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, $this->detectMimeType($binary, $relative)];
                }
            }
        }

        $response = Http::timeout(90)->get($url);
        if ($response->failed()) {
            throw new RuntimeException('Gagal mengambil image source untuk Gemini video (HTTP ' . $response->status() . ').');
        }

        $binary = (string) $response->body();
        $mimeType = trim((string) $response->header('Content-Type'));

        return [$binary, $this->normalizeMimeType($mimeType !== '' ? $mimeType : $this->detectMimeType($binary, $path))];
    }

    private function detectMimeType(string $binary, string $pathHint = ''): string
    {
        $mimeType = '';

        if (class_exists('finfo')) {
            $finfo = new \finfo(FILEINFO_MIME_TYPE);
            $mimeType = (string) $finfo->buffer($binary);
        }

        if ($mimeType === '' && $pathHint !== '') {
            $extension = strtolower((string) pathinfo($pathHint, PATHINFO_EXTENSION));
            $mimeType = match ($extension) {
                'jpg', 'jpeg' => 'image/jpeg',
                'png' => 'image/png',
                'webp' => 'image/webp',
                default => '',
            };
        }

        return $this->normalizeMimeType($mimeType);
    }

    private function normalizeMimeType(string $mimeType): string
    {
        $normalized = strtolower(trim(explode(';', $mimeType)[0] ?? ''));

        return match ($normalized) {
            'image/jpg' => 'image/jpeg',
            'image/jpeg', 'image/png', 'image/webp' => $normalized,
            default => $normalized !== '' ? $normalized : 'image/png',
        };
    }

    private function downloadVideo(string $remoteUrl): string
    {
        $response = Http::withHeaders([
            'x-goog-api-key' => $this->apiKey,
        ])->timeout(180)->get($remoteUrl);

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

        $relPath = 'videos/gemini_' . 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 Gemini.');
        }

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

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

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

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