<?php

namespace app\support;

use support\Request;

class PublicAssetUrlService
{
    public function buildUrl(Request $request, string $relativePath): string
    {
        $relativePath = ltrim($relativePath, '/');
        $publicPath = $this->configService()->isOss()
            ? $this->configService()->objectKey($relativePath)
            : $relativePath;

        return $this->resolveBaseUrl($request) . '/' . ltrim($publicPath, '/');
    }

    public function normalizeUrl(string $value, Request $request): string
    {
        $value = trim($value);
        if ($value === '') {
            return '';
        }

        $parts = parse_url($value);
        $path = (string)($parts['path'] ?? '');
        $query = (string)($parts['query'] ?? '');
        $fragment = (string)($parts['fragment'] ?? '');
        $host = strtolower((string)($parts['host'] ?? ''));
        $scheme = (string)($parts['scheme'] ?? '');

        if ($scheme === '' && $host === '') {
            return $this->appendQueryAndFragment(
                $this->buildUrl($request, $path !== '' ? $path : $value),
                $query,
                $fragment
            );
        }

        if ($path !== '' && $this->shouldRewriteHost($host)) {
            return $this->appendQueryAndFragment(
                $this->buildUrl($request, $path),
                $query,
                $fragment
            );
        }

        return $value;
    }

    public function storagePath(string $value): string
    {
        $value = trim($value);
        if ($value === '') {
            return '';
        }

        $path = parse_url($value, PHP_URL_PATH);
        if (!is_string($path) || $path === '') {
            $path = ltrim($value, '/');
            return $this->configService()->isOss() ? $this->configService()->removePathPrefix($path) : $path;
        }

        $path = ltrim($path, '/');
        return $this->configService()->isOss() ? $this->configService()->removePathPrefix($path) : $path;
    }

    private function resolveBaseUrl(Request $request): string
    {
        $configured = $this->configService()->publicBaseUrl();
        if ($configured !== '') {
            return $configured;
        }

        $configured = trim((string)($_ENV['PUBLIC_FILE_BASE_URL'] ?? ($_ENV['APP_PUBLIC_BASE_URL'] ?? '')));
        if ($configured !== '') {
            return $this->normalizeBaseUrl($configured);
        }

        $scheme = trim((string)($request->header('x-forwarded-proto') ?: 'http'));
        $host = trim((string)($request->header('x-forwarded-host') ?: $request->header('host') ?: $request->host()));
        if (($commaPos = strpos($host, ',')) !== false) {
            $host = trim(substr($host, 0, $commaPos));
        }

        $port = trim((string)($request->header('x-forwarded-port') ?: ''));
        if ($port !== '' && strpos($host, ':') === false) {
            if (!(($scheme === 'http' && $port === '80') || ($scheme === 'https' && $port === '443'))) {
                $host .= ':' . $port;
            }
        }

        return $this->normalizeBaseUrl($scheme . '://' . $host);
    }

    private function normalizeBaseUrl(string $baseUrl): string
    {
        $baseUrl = trim($baseUrl);
        if ($baseUrl === '') {
            return '';
        }

        if (!preg_match('/^https?:\/\//i', $baseUrl)) {
            $baseUrl = 'https://' . ltrim($baseUrl, '/');
        }

        return rtrim($baseUrl, '/');
    }

    private function configService(): FileStorageConfigService
    {
        return new FileStorageConfigService();
    }

    private function shouldRewriteHost(string $host): bool
    {
        if ($host === '') {
            return false;
        }

        if (in_array($host, ['localhost', '127.0.0.1', '0.0.0.0', 'host.docker.internal'], true)) {
            return true;
        }

        return preg_match('/^(10\.|192\.168\.|172\.(1[6-9]|2\d|3[0-1])\.)/', $host) === 1;
    }

    private function appendQueryAndFragment(string $url, string $query, string $fragment): string
    {
        if ($query !== '') {
            $url .= '?' . $query;
        }
        if ($fragment !== '') {
            $url .= '#' . $fragment;
        }

        return $url;
    }
}