<?php
/**
 * Adjust / MMP 归因 URL 合并：宏占位符替换与安全 query 重建
 */
class AttributionUrlMerger
{
    /** @var string[] */
    private static $adjustHostSuffixes = [
        'adjust.com',
        'go.link',
        'aindl.com',
    ];

    /** @var string[] 广告平台 click ID，透传到 DB_FP 落地页供 Adjust JS 读取 */
    private static $passthroughKeys = [
        'fbclid',
        'gclid',
        'wbraid',
        'gbraid',
        'ttclid',
    ];

    /** @var string[] cloak 内部参数，不进入最终 Adjust URL */
    private static $stripKeys = [
        'ad_spm_id',
        'time',
        'utm_source',
        'utm_medium',
        'utm_campaign',
        'utm_term',
        'utm_content',
        'site_source',
        'placement',
        'campaign_id',
        'adgroup_id',
        'network',
    ];

    /** @var array<string,string> Adjust 默认 p1–p6 → Facebook 宏 */
    private static $defaultMacroParams = [
        'p1' => '{{campaign.name}}',
        'p2' => '{{campaign.id}}',
        'p3' => '{{adset.name}}',
        'p4' => '{{adset.id}}',
        'p5' => '{{ad.name}}',
        'p6' => '{{ad.id}}',
    ];

    /**
     * 目标 URL 是否需要归因宏合并
     */
    public static function needsAttributionMerge($targetUrl)
    {
        $targetUrl = trim((string) $targetUrl);
        if ($targetUrl === '') {
            return false;
        }

        if (stripos($targetUrl, '%7B%7B') !== false || stripos($targetUrl, '%7D%7D') !== false) {
            return true;
        }
        if (preg_match('/\{\{[a-zA-Z0-9_.]+\}\}/', $targetUrl)) {
            return true;
        }

        $parts = parse_url($targetUrl);
        $host  = strtolower((string) ($parts['host'] ?? ''));

        return self::isAdjustHost($host);
    }

    /**
     * 从 DB_FP URL 解析需追加到广告链接的宏参数（键名 => Facebook 宏模板）
     *
     * @return array<string,string>
     */
    public static function parseAdjustMacroKeys($targetUrl)
    {
        $targetUrl = trim((string) $targetUrl);
        if ($targetUrl === '') {
            return [];
        }

        $parts = parse_url($targetUrl);
        $query = [];
        if (!empty($parts['query'])) {
            parse_str($parts['query'], $query);
        }

        $keys = [];
        foreach ($query as $key => $value) {
            if (!self::isMacroPlaceholder($value)) {
                continue;
            }
            $macro = self::extractMacroTemplate($value);
            if ($macro !== '') {
                $keys[(string) $key] = $macro;
            }
        }

        if (empty($keys) && self::isAdjustHost(strtolower((string) ($parts['host'] ?? '')))) {
            return self::$defaultMacroParams;
        }

        return $keys;
    }

    /**
     * 将落地页 query 合并进目标 URL，替换宏占位符
     *
     * @param array<string,mixed> $incomingQuery
     */
    public static function merge($targetUrl, array $incomingQuery)
    {
        $targetUrl = trim((string) $targetUrl);
        if ($targetUrl === '') {
            return '';
        }

        $parts = parse_url($targetUrl);
        if ($parts === false) {
            return $targetUrl;
        }

        $targetQuery = [];
        if (!empty($parts['query'])) {
            parse_str($parts['query'], $targetQuery);
        }

        $merged = [];
        foreach ($targetQuery as $key => $value) {
            $key   = (string) $key;
            $value = (string) $value;

            if (self::isMacroPlaceholder($value) && self::hasIncomingValue($incomingQuery, $key)) {
                $merged[$key] = (string) $incomingQuery[$key];
                continue;
            }

            if (!self::isMacroPlaceholder($value)) {
                $merged[$key] = $value;
            }
        }

        foreach (self::$passthroughKeys as $ptKey) {
            if (!self::hasIncomingValue($incomingQuery, $ptKey)) {
                continue;
            }
            $merged[$ptKey] = (string) $incomingQuery[$ptKey];
        }

        return self::buildUrl($parts, $merged);
    }

    /**
     * @param array<string,mixed> $query
     */
    private static function buildUrl(array $parts, array $query)
    {
        $scheme = $parts['scheme'] ?? 'https';
        $host   = $parts['host'] ?? '';
        $port   = isset($parts['port']) ? ':' . $parts['port'] : '';
        $path   = $parts['path'] ?? '';
        $frag   = isset($parts['fragment']) ? '#' . $parts['fragment'] : '';

        $pairs = [];
        foreach ($query as $key => $value) {
            if (in_array((string) $key, self::$stripKeys, true)) {
                continue;
            }
            $pairs[] = rawurlencode((string) $key) . '=' . rawurlencode((string) $value);
        }

        $queryStr = implode('&', $pairs);
        $url      = $scheme . '://' . $host . $port . $path;
        if ($queryStr !== '') {
            $url .= '?' . $queryStr;
        }

        return $url . $frag;
    }

    /**
     * @param mixed $value
     */
    public static function isMacroPlaceholder($value)
    {
        $value = trim((string) $value);
        if ($value === '') {
            return false;
        }

        if (preg_match('/^\{\{[a-zA-Z0-9_.]+\}\}$/', $value)) {
            return true;
        }

        $decoded = rawurldecode($value);
        if ($decoded !== $value && preg_match('/^\{\{[a-zA-Z0-9_.]+\}\}$/', $decoded)) {
            return true;
        }

        return (bool) preg_match('/^%7B%7B[a-zA-Z0-9_.]+%7D%7D$/i', $value);
    }

    /**
     * @param mixed $value
     */
    public static function extractMacroTemplate($value)
    {
        $value = trim((string) $value);
        if ($value === '') {
            return '';
        }

        if (preg_match('/^\{\{([a-zA-Z0-9_.]+)\}\}$/', $value, $m)) {
            return '{{' . $m[1] . '}}';
        }

        $decoded = rawurldecode($value);
        if (preg_match('/^\{\{([a-zA-Z0-9_.]+)\}\}$/', $decoded, $m)) {
            return '{{' . $m[1] . '}}';
        }

        if (preg_match('/^%7B%7B([a-zA-Z0-9_.]+)%7D%7D$/i', $value, $m)) {
            return '{{' . $m[1] . '}}';
        }

        return '';
    }

    /**
     * @param array<string,mixed> $incomingQuery
     */
    private static function hasIncomingValue(array $incomingQuery, $key)
    {
        if (!array_key_exists($key, $incomingQuery)) {
            return false;
        }
        $value = $incomingQuery[$key];
        if ($value === null || $value === '') {
            return false;
        }
        if (is_array($value)) {
            return false;
        }
        if (self::isMacroPlaceholder($value)) {
            return false;
        }

        return true;
    }

    private static function isAdjustHost($host)
    {
        if ($host === '') {
            return false;
        }
        foreach (self::$adjustHostSuffixes as $suffix) {
            if ($host === $suffix || substr($host, -strlen('.' . $suffix)) === '.' . $suffix) {
                return true;
            }
        }

        return false;
    }
}