<?php

namespace app\common\service\article;

use think\Response;

class ArticleImageProxyService
{
    private const SOURCE_HOSTS = [
        'hkjc_racingnews' => [
            'res.hkjc.com',
            'racingnews.hkjc.com',
        ],
        'taiwan_lottery' => [
            'cdn.taiwanlottery.com.tw',
            'www.taiwanlottery.com',
            'taiwanlottery.com',
        ],
    ];

    private const SOURCE_REFERERS = [
        'hkjc_racingnews' => 'https://racingnews.hkjc.com/',
        'taiwan_lottery' => 'https://www.taiwanlottery.com/',
    ];

    public static function rewriteArticlePayload(array $article): array
    {
        $ext = self::decodeExt($article['ext'] ?? []);
        if (!self::shouldRewrite($ext)) {
            return $article;
        }

        if (!empty($article['image'])) {
            $article['image'] = self::buildProxyUrl((string) $article['image'], $ext);
        }

        if (!empty($article['content'])) {
            $article['content'] = preg_replace_callback(
                '/(<img\b[^>]*\bsrc=["\'])([^"\']+)(["\'][^>]*>)/i',
                static function (array $matches) use ($ext) {
                    $proxyUrl = self::buildProxyUrl($matches[2] ?? '', $ext);
                    if ($proxyUrl === '' || $proxyUrl === ($matches[2] ?? '')) {
                        return $matches[0];
                    }
                    return $matches[1]
                        . htmlspecialchars($proxyUrl, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8')
                        . $matches[3];
                },
                (string) $article['content']
            );
        }

        return $article;
    }

    public static function proxyRemoteImage(string $url): Response
    {
        $normalizedUrl = self::normalizeUrl($url);
        if ($normalizedUrl === '' || !self::isAllowedRemoteUrl($normalizedUrl)) {
            return response('image not found', 404)->header([
                'Content-Type' => 'text/plain; charset=utf-8',
                'Cache-Control' => 'public, max-age=300',
            ]);
        }

        $source = self::detectSourceByUrl($normalizedUrl);
        $headers = [
            'Accept: image/avif,image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8',
            'User-Agent: Mozilla/5.0 (compatible; SportEra/1.0)',
        ];
        $referer = self::SOURCE_REFERERS[$source] ?? '';
        if ($referer !== '') {
            $headers[] = 'Referer: ' . $referer;
        }

        $ch = curl_init($normalizedUrl);
        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_MAXREDIRS => 3,
            CURLOPT_CONNECTTIMEOUT => 10,
            CURLOPT_TIMEOUT => 20,
            CURLOPT_ENCODING => '',
            CURLOPT_HTTPHEADER => $headers,
        ]);

        $body = curl_exec($ch);
        $httpCode = (int) curl_getinfo($ch, CURLINFO_RESPONSE_CODE);
        $contentType = (string) curl_getinfo($ch, CURLINFO_CONTENT_TYPE);
        $effectiveUrl = (string) curl_getinfo($ch, CURLINFO_EFFECTIVE_URL);
        $curlError = curl_error($ch);
        curl_close($ch);

        if ($body === false || $curlError !== '' || $httpCode < 200 || $httpCode >= 300) {
            return response('image not found', 404)->header([
                'Content-Type' => 'text/plain; charset=utf-8',
                'Cache-Control' => 'public, max-age=300',
            ]);
        }

        $effectiveUrl = $effectiveUrl !== '' ? $effectiveUrl : $normalizedUrl;
        if (!self::isAllowedRemoteUrl($effectiveUrl)) {
            return response('image not found', 404)->header([
                'Content-Type' => 'text/plain; charset=utf-8',
                'Cache-Control' => 'public, max-age=300',
            ]);
        }

        $contentType = self::normalizeContentType($contentType, $effectiveUrl);
        if (!str_starts_with($contentType, 'image/')) {
            return response('image not found', 404)->header([
                'Content-Type' => 'text/plain; charset=utf-8',
                'Cache-Control' => 'public, max-age=300',
            ]);
        }

        return response($body, 200)->header([
            'Content-Type' => $contentType,
            'Cache-Control' => 'public, max-age=86400',
            'Access-Control-Allow-Origin' => '*',
        ]);
    }

    private static function shouldRewrite(array $ext): bool
    {
        $source = (string) ($ext['source'] ?? '');
        return isset(self::SOURCE_HOSTS[$source]);
    }

    private static function buildProxyUrl(string $url, array $ext = []): string
    {
        $normalizedUrl = self::normalizeUrl($url);
        if ($normalizedUrl === '' || self::isLocalProxyUrl($normalizedUrl)) {
            return $url;
        }

        if (!self::isAllowedRemoteUrl($normalizedUrl, $ext)) {
            return $url;
        }

        $path = '/api/article/imageProxy?url=' . rawurlencode($normalizedUrl);
        $domain = rtrim((string) request()->domain(), '/');
        return $domain !== '' ? $domain . $path : $path;
    }

    private static function normalizeUrl(string $url): string
    {
        $url = trim(html_entity_decode($url, ENT_QUOTES | ENT_HTML5, 'UTF-8'));
        if ($url === '') {
            return '';
        }
        if (str_starts_with($url, '//')) {
            return 'https:' . $url;
        }
        return $url;
    }

    private static function isAllowedRemoteUrl(string $url, array $ext = []): bool
    {
        $parts = parse_url($url);
        $scheme = strtolower((string) ($parts['scheme'] ?? ''));
        $host = strtolower((string) ($parts['host'] ?? ''));
        if ($host === '' || !in_array($scheme, ['http', 'https'], true)) {
            return false;
        }

        $allowedHosts = self::getAllowedHosts($ext);
        foreach ($allowedHosts as $allowedHost) {
            $allowedHost = strtolower($allowedHost);
            if ($host === $allowedHost || str_ends_with($host, '.' . $allowedHost)) {
                return true;
            }
        }

        return false;
    }

    private static function getAllowedHosts(array $ext = []): array
    {
        $source = (string) ($ext['source'] ?? '');
        if ($source !== '' && isset(self::SOURCE_HOSTS[$source])) {
            return self::SOURCE_HOSTS[$source];
        }

        $allHosts = [];
        foreach (self::SOURCE_HOSTS as $hosts) {
            $allHosts = array_merge($allHosts, $hosts);
        }
        return array_values(array_unique($allHosts));
    }

    private static function detectSourceByUrl(string $url): string
    {
        $parts = parse_url($url);
        $host = strtolower((string) ($parts['host'] ?? ''));
        foreach (self::SOURCE_HOSTS as $source => $hosts) {
            foreach ($hosts as $allowedHost) {
                $allowedHost = strtolower($allowedHost);
                if ($host === $allowedHost || str_ends_with($host, '.' . $allowedHost)) {
                    return $source;
                }
            }
        }
        return '';
    }

    private static function isLocalProxyUrl(string $url): bool
    {
        return str_contains($url, '/api/article/imageProxy?');
    }

    private static function normalizeContentType(string $contentType, string $url): string
    {
        $contentType = strtolower(trim(explode(';', $contentType)[0] ?? ''));
        if (str_starts_with($contentType, 'image/')) {
            return $contentType;
        }

        $path = strtolower((string) parse_url($url, PHP_URL_PATH));
        return match (pathinfo($path, PATHINFO_EXTENSION)) {
            'jpg', 'jpeg' => 'image/jpeg',
            'png' => 'image/png',
            'gif' => 'image/gif',
            'webp' => 'image/webp',
            'svg' => 'image/svg+xml',
            default => 'application/octet-stream',
        };
    }

    private static function decodeExt($ext): array
    {
        if (is_array($ext)) {
            return $ext;
        }
        if (is_string($ext) && $ext !== '') {
            $decoded = json_decode($ext, true);
            return is_array($decoded) ? $decoded : [];
        }
        return [];
    }
}