<?php

namespace App\Utils;

use GuzzleHttp\Client;
use Exception;

class ImageDownloader
{
    private Client $httpClient;
    private string $basePath;

    public function __construct(string $basePath = 'storage/images', ?string $apiKey = null)
    {
        $headers = [
            'User-Agent' => 'MediaCollector/1.0'
        ];

        if ($apiKey) {
            $headers['ApiKey'] = $apiKey;
        }

        $this->httpClient = new Client([
            'timeout' => 30,
            'headers' => $headers,
            'verify' => false // Disable SSL verification for problematic servers
        ]);

        // Convert relative path to absolute path
        if (strpos($basePath, '/') !== 0) {
            $this->basePath = __DIR__ . '/../' . $basePath;
        } else {
            $this->basePath = $basePath;
        }
    }

    /**
     * Download an image from URL and save it locally
     */
    public function downloadImage(string $url, string $filename, string $subfolder = ''): ?string
    {
        if (empty($url) || !filter_var($url, FILTER_VALIDATE_URL)) {
            error_log("Invalid URL provided: {$url}");
            return null;
        }

        $maxRetries = 3;
        $retryDelay = 2; // seconds

        for ($attempt = 1; $attempt <= $maxRetries; $attempt++) {
            try {
                error_log("Downloading image (attempt {$attempt}/{$maxRetries}): {$url}");

                $response = $this->httpClient->get($url, [
                    'timeout' => 60, // Longer timeout for large images
                    'connect_timeout' => 30,
                    'headers' => [
                        'User-Agent' => 'MediaCollector/1.0',
                        'Referer' => parse_url($url, PHP_URL_HOST)
                    ]
                ]);

                if ($response->getStatusCode() !== 200) {
                    error_log("HTTP {$response->getStatusCode()} for {$url}");
                    if ($attempt === $maxRetries) {
                        return null;
                    }
                    sleep($retryDelay);
                    continue;
                }

                $imageData = $response->getBody()->getContents();
                if (empty($imageData)) {
                    error_log("Empty response for {$url}");
                    if ($attempt === $maxRetries) {
                        return null;
                    }
                    sleep($retryDelay);
                    continue;
                }

                // Validate image data
                if (!$this->isValidImage($imageData)) {
                    error_log("Invalid image data for {$url}");
                    if ($attempt === $maxRetries) {
                        return null;
                    }
                    sleep($retryDelay);
                    continue;
                }

                return $this->saveImage($imageData, $filename, $subfolder);

            } catch (Exception $e) {
                error_log("Error downloading {$url} (attempt {$attempt}): " . $e->getMessage());

                if ($attempt === $maxRetries) {
                    error_log("Failed to download {$url} after {$maxRetries} attempts");
                    return null;
                }

                sleep($retryDelay);
            }
        }

        return null;
    }

    private function isValidImage(string $data): bool
    {
        // Check for common image signatures
        $imageTypes = [
            'image/jpeg' => "\xFF\xD8\xFF",
            'image/png' => "\x89PNG",
            'image/gif' => "GIF",
            'image/webp' => "RIFF"
        ];

        foreach ($imageTypes as $type => $signature) {
            if (strpos($data, $signature) === 0) {
                return true;
            }
        }

        return false; // Not a valid image type
    }

    public function saveImage(string $imageData, string $filename, string $subfolder = ''): ?string
    {
        try {
            // Create subfolder if it doesn't exist
            $fullPath = $this->basePath;
            if (!empty($subfolder)) {
                $fullPath .= '/' . trim($subfolder, '/');
            }

            if (!is_dir($fullPath)) {
                mkdir($fullPath, 0755, true);
            }

            $filePath = $fullPath . '/' . $filename;

            // Write image data to file
            $bytesWritten = file_put_contents($filePath, $imageData);
            if ($bytesWritten === false || $bytesWritten === 0) {
                error_log("Failed to write image data to {$filePath}");
                return null;
            }

            return $filePath;

        } catch (Exception $e) {
            error_log("Error saving image {$filename}: " . $e->getMessage());
            return null;
        }
    }
    public function generateFilename(string $url, string $prefix = ''): string
    {
        $extension = pathinfo(parse_url($url, PHP_URL_PATH), PATHINFO_EXTENSION);
        if (empty($extension)) {
            $extension = 'jpg'; // Default fallback
        }

        $hash = substr(md5($url . time()), 0, 8);

        return ($prefix ? $prefix . '_' : '') . $hash . '.' . $extension;
    }

    /**
     * Get the public URL for a local image
     */
    public function getPublicUrl(string $localPath): ?string
    {
        if (empty($localPath) || !file_exists($localPath)) {
            return null;
        }

        // Remove the absolute basePath prefix to get the relative path
        $relativePath = str_replace($this->basePath . '/', '', $localPath);

        return '/images/' . $relativePath;
    }
}