<?php

namespace App\Services;

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

/**
 * Image enhancement via Replicate free-tier models.
 *
 * Supported models (Try-for-Free):
 *   - topazlabs/image-upscale   — professional upscaling (2x/4x/6x)
 *   - sczhou/codeformer         — face restoration for old/AI photos
 *
 * Polls synchronously (upscaling typically takes 10-40s).
 */
class ReplicateEnhanceService
{
    private string $apiKey;
    private string $baseUrl;

    public function __construct()
    {
        $this->apiKey  = (string) config('services.replicate.api_key', '');
        $this->baseUrl = (string) config('services.replicate.base_url', 'https://api.replicate.com/v1');
    }

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

    /**
     * Upscale image using topazlabs/image-upscale.
     * @param  string $imageUrl  Absolute https:// URL
     * @param  int    $factor    2, 4, or 6
     * @return string  Output image URL from Replicate CDN
     */
    public function upscaleImage(string $imageUrl, int $factor = 2): string
    {
        $normalizedFactor = match ($factor) {
            4 => '4x',
            6 => '6x',
            default => '2x',
        };

        return $this->runModel('topazlabs/image-upscale', [
            'image'          => $imageUrl,
            'upscale_factor' => $normalizedFactor,
            'output_format'  => 'png',
        ]);
    }

    /**
     * Restore faces using sczhou/codeformer.
     * @param  string $imageUrl    Absolute https:// URL
     * @param  float  $fidelity    0.0 (restore more) – 1.0 (preserve original)
     * @return string  Output image URL from Replicate CDN
     */
    public function restoreFace(string $imageUrl, float $fidelity = 0.7): string
    {
        return $this->runModel('sczhou/codeformer', [
            'image'               => $imageUrl,
            'codeformer_fidelity' => round($fidelity, 2),
            'background_enhance'  => true,
            'face_upsample'       => true,
            'upscale'             => 2,
        ]);
    }

    public function portraitEnhance(string $imageUrl, int $factor = 2, float $fidelity = 0.7): string
    {
        $upscaledUrl = $this->upscaleImage($imageUrl, $factor);

        return $this->restoreFace($upscaledUrl, $fidelity);
    }

    // ─── Internal ──────────────────────────────────────────────────────────

    private function runModel(string $model, array $input): string
    {
        if (! $this->isAvailable()) {
            throw new RuntimeException('REPLICATE_API_KEY belum diset.');
        }

        // Ensure image URL is absolute
        if (! str_starts_with($input['image'] ?? '', 'http')) {
            $input['image'] = rtrim((string) config('app.url', ''), '/') . '/' . ltrim($input['image'], '/');
        }

        $endpoint = rtrim($this->baseUrl, '/') . '/models/' . $model . '/predictions';
        $payload  = ['input' => $input];

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

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

        return $this->pollForUrl($id, $model);
    }

    private function pollForUrl(string $id, string $model): string
    {
        $maxWait  = 120;
        $interval = 3;
        $elapsed  = 0;
        $endpoint = rtrim($this->baseUrl, '/') . '/predictions/' . $id;

        while ($elapsed < $maxWait) {
            sleep($interval);
            $elapsed += $interval;

            $r = Http::withToken($this->apiKey)->timeout(15)->get($endpoint);
            if ($r->failed()) {
                continue;
            }

            $status = $r->json('status');

            if ($status === 'succeeded') {
                $output = $r->json('output');
                $url    = is_array($output) ? ($output[0] ?? '') : (string) ($output ?? '');
                if (filled($url)) {
                    return $url;
                }
                throw new RuntimeException('Replicate enhance: output URL kosong.');
            }

            if (in_array($status, ['failed', 'canceled'], true)) {
                $err = $r->json('error') ?? 'Unknown error';
                Log::warning('ReplicateEnhanceService: failed', ['id' => $id, 'model' => $model, 'error' => $err]);
                throw new RuntimeException('Replicate enhance gagal: ' . Str::limit($err, 150));
            }
        }

        throw new RuntimeException('Replicate enhance timeout (>2 menit). Coba lagi.');
    }
}