<?php
/**
 * IP 归属地查询（腾讯 / 高德 / 太平洋 / 轮询）。
 *
 * @package AKSRT
 */

namespace AKSRT\Extensions;

defined('ABSPATH') || exit;

class IPGeo {

    private static $instance = null;

    public static function get_instance(): self {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    /**
     * 查询 IP 归属地。
     *
     * @param string $ip    IPv4 / IPv6
     * @param bool   $force 管理端测试：跳过启用开关与缓存；仍拒绝私有 IP
     * @return array{country:string,province:string,city:string,raw:array,reason?:string,provider?:string,http_code?:int,detail?:string}
     */
    public function lookup(string $ip, bool $force = false): array {
        $config = $this->get_config();
        $ip     = trim($ip);

        if (!$force && empty($config['ip_geo_enabled'])) {
            return $this->empty_result('disabled');
        }

        if ($ip === '' || !filter_var($ip, FILTER_VALIDATE_IP)) {
            return $this->empty_result('invalid_ip');
        }

        if ($this->is_private_ip($ip)) {
            return $this->empty_result('private_ip');
        }

        $cache_key = 'aksrt_ip_geo_' . md5($ip);
        $ttl       = max(3600, (int) ($config['ip_geo_cache_ttl'] ?? 86400));
        if (!$force) {
            $cached = get_transient($cache_key);
            if ($cached !== false && is_array($cached)) {
                return $cached;
            }
        }

        $provider = sanitize_key((string) ($config['ip_addr_sdk'] ?? 'null'));
        $result   = $this->query_provider($provider, $ip, $config);

        if ($this->has_location($result)) {
            if (!$force) {
                set_transient($cache_key, $result, $ttl);
            }
            return $result;
        }

        if (empty($result['reason'])) {
            $result['reason'] = 'provider_empty';
        }

        return $result;
    }

    public function get_status(): array {
        $config   = $this->get_config();
        $provider = sanitize_key((string) ($config['ip_addr_sdk'] ?? 'null'));
        $enabled  = !empty($config['ip_geo_enabled']);

        $missing = [];
        if ($enabled && $provider === 'qq') {
            if (empty($config['ip_addr_sdk_qq_appkey'])) {
                $missing[] = 'ip_addr_sdk_qq_appkey';
            }
        }
        if ($enabled && $provider === 'amap') {
            if (empty($config['ip_addr_sdk_amap_appkey'])) {
                $missing[] = 'ip_addr_sdk_amap_appkey';
            }
        }

        return [
            'enabled'        => $enabled,
            'provider'       => $provider,
            'configured'     => $enabled && empty($missing),
            'available'      => $enabled,
            'verified'       => !empty($config['ip_geo_verified']),
            'transport'      => 'http_api',
            'missing_fields' => $missing,
            'cache_ttl'      => (int) ($config['ip_geo_cache_ttl'] ?? 86400),
            'display'        => (array) ($config['ip_geo_display'] ?? ['comment', 'user_home', 'user_center', 'post']),
            'format'         => (string) ($config['ip_geo_format'] ?? 'province_city'),
        ];
    }

    public function format(array $geo, string $format = ''): string {
        if ($format === '') {
            $config = $this->get_config();
            $format = (string) ($config['ip_geo_format'] ?? 'province_city');
        }

        $country  = $this->string_field($geo['country'] ?? '');
        $province = $this->string_field($geo['province'] ?? '');
        $city     = $this->string_field($geo['city'] ?? '');

        switch ($format) {
            case 'province':
                return $province !== '' ? $province : $city;
            case 'country_province':
                return trim($country . ' ' . $province);
            case 'province_city':
            default:
                $parts = array_filter([$province, $city]);
                return $parts ? implode(' ', $parts) : $country;
        }
    }

    private function get_config(): array {
        if (class_exists('\AKSRT\Settings\Settings')) {
            return \AKSRT\Settings\Settings::get_ip_geo_settings();
        }
        return ['ip_geo_enabled' => false];
    }

    private function query_provider(string $provider, string $ip, array $config): array {
        switch ($provider) {
            case 'qq':
                return $this->query_qq($ip, $config);
            case 'amap':
                $amap = $this->query_amap($ip, $config);
                if ($this->has_location($amap)) {
                    return $amap;
                }
                // Credential / platform mismatch: free path so front still works.
                if ($this->should_fallback_free($amap)) {
                    $free = $this->query_pconline($ip);
                    if ($this->has_location($free)) {
                        $free['detail'] = 'amap_failed_fallback_free:' . (string) ($amap['detail'] ?? $amap['reason'] ?? '');
                        return $free;
                    }
                }
                return $amap;
            case 'polling':
                $last = $this->empty_result('provider_empty');
                foreach (['qq', 'amap', 'null'] as $fallback) {
                    if ($fallback === 'qq' && empty($config['ip_addr_sdk_qq_appkey'])) {
                        continue;
                    }
                    if ($fallback === 'amap' && empty($config['ip_addr_sdk_amap_appkey'])) {
                        continue;
                    }
                    // Avoid re-entering amap→free→… recursion: call leaf methods.
                    if ($fallback === 'amap') {
                        $result = $this->query_amap($ip, $config);
                    } elseif ($fallback === 'qq') {
                        $result = $this->query_qq($ip, $config);
                    } else {
                        $result = $this->query_pconline($ip);
                    }
                    if ($this->has_location($result)) {
                        return $result;
                    }
                    $last = $result;
                }
                // Last resort free path.
                $free = $this->query_pconline($ip);
                return $this->has_location($free) ? $free : $last;
            case 'null':
            default:
                // Admin label「太平洋公共接口」: pconline, with ip-api if blocked.
                return $this->query_pconline($ip);
        }
    }

    /**
     * Whether a paid-provider failure should fall back to free IP lookup.
     */
    private function should_fallback_free(array $result): bool {
        $reason = (string) ($result['reason'] ?? '');
        if (in_array($reason, ['missing_key', 'http_error'], true)) {
            return true;
        }
        if ($reason !== 'provider_error') {
            return false;
        }
        $detail = strtoupper((string) ($result['detail'] ?? ''));
        foreach (['USERKEY_PLAT_NOMATCH', 'INVALID_USER_KEY', 'INVALID_USER_SCODE', 'DAILY_QUERY_OVER_LIMIT', 'ACCESS_TOO_FREQUENT', 'CUQPS_HAS_EXCEEDED_THE_LIMIT'] as $code) {
            if (str_contains($detail, $code)) {
                return true;
            }
        }
        return false;
    }

    private function query_qq(string $ip, array $config): array {
        $appkey    = trim((string) ($config['ip_addr_sdk_qq_appkey'] ?? ''));
        $secretkey = trim((string) ($config['ip_addr_sdk_qq_secretkey'] ?? ''));
        if ($appkey === '') {
            return $this->empty_result('missing_key', ['provider' => 'qq', 'detail' => 'missing appkey']);
        }

        // Path used for Tencent signature (zibll parity).
        $path  = '/ws/location/v1/ip';
        $query = 'ip=' . rawurlencode($ip) . '&key=' . rawurlencode($appkey);
        $url   = 'https://apis.map.qq.com' . $path . '?' . $query;
        if ($secretkey !== '') {
            $url .= '&sig=' . md5($path . '?' . $query . $secretkey);
        }

        $http = $this->http_get($url, 8);
        if (!$http['ok']) {
            return $this->empty_result('http_error', [
                'provider'  => 'qq',
                'http_code' => $http['code'],
                'detail'    => $http['error'],
                'raw'       => $http['body_raw'] !== '' ? ['body' => $http['body_raw']] : [],
            ]);
        }

        $data = $http['json'];
        if (!is_array($data) || (int) ($data['status'] ?? 1) !== 0) {
            $msg = is_array($data) ? (string) ($data['message'] ?? 'status_error') : 'invalid_json';
            return $this->empty_result('provider_error', [
                'provider'  => 'qq',
                'http_code' => $http['code'],
                'detail'    => $msg,
                'raw'       => is_array($data) ? $data : [],
            ]);
        }

        $info = is_array($data['result']['ad_info'] ?? null) ? $data['result']['ad_info'] : [];
        return [
            'country'  => $this->string_field($info['nation'] ?? '中国'),
            'province' => $this->string_field($info['province'] ?? ''),
            'city'     => $this->string_field($info['city'] ?? ''),
            'raw'      => $data,
            'provider' => 'qq',
        ];
    }

    private function query_amap(string $ip, array $config): array {
        $appkey    = trim((string) ($config['ip_addr_sdk_amap_appkey'] ?? ''));
        $secretkey = trim((string) ($config['ip_addr_sdk_amap_secretkey'] ?? ''));
        if ($appkey === '') {
            return $this->empty_result('missing_key', [
                'provider' => 'amap',
                'detail'   => 'missing appkey',
            ]);
        }

        // Amap sign: md5(sorted query without sig + secret) — zibll uses ip=&key= order.
        $base_query = 'ip=' . $ip . '&key=' . $appkey;
        $url        = 'https://restapi.amap.com/v3/ip?' . $base_query;
        if ($secretkey !== '') {
            $url .= '&sig=' . md5($base_query . $secretkey);
        }

        $http = $this->http_get($url, 8);
        if (!$http['ok']) {
            return $this->empty_result('http_error', [
                'provider'  => 'amap',
                'http_code' => $http['code'],
                'detail'    => $http['error'],
                'raw'       => $http['body_raw'] !== '' ? ['body' => $http['body_raw']] : [],
            ]);
        }

        $data = $http['json'];
        if (!is_array($data) || (string) ($data['status'] ?? '0') !== '1') {
            $info = is_array($data) ? (string) ($data['info'] ?? 'status_error') : 'invalid_json';
            // Common: INVALID_USER_KEY / DAILY_QUERY_OVER_LIMIT / USERKEY_PLAT_NOMATCH
            return $this->empty_result('provider_error', [
                'provider'  => 'amap',
                'http_code' => $http['code'],
                'detail'    => $info,
                'raw'       => is_array($data) ? $data : [],
            ]);
        }

        // Amap returns empty arrays for province/city on some IPs / overseas.
        $province = $this->string_field($data['province'] ?? '');
        $city     = $this->string_field($data['city'] ?? '');
        $country  = '中国';
        if ($province === '' && $city === '') {
            return $this->empty_result('provider_empty', [
                'provider' => 'amap',
                'detail'   => 'empty province/city',
                'raw'      => $data,
            ]);
        }

        return [
            'country'  => $country,
            'province' => $province,
            'city'     => $city,
            'raw'      => $data,
            'provider' => 'amap',
        ];
    }

    /**
     * 太平洋网络 whois（GB2312 正文）。
     */
    private function query_pconline(string $ip): array {
        $url  = 'http://whois.pconline.com.cn/ipJson.jsp?json=true&ip=' . rawurlencode($ip);
        $http = $this->http_get($url, 8, [
            'Accept'          => '*/*',
            'Accept-Language' => 'zh-CN,zh;q=0.9',
            'User-Agent'      => 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
            'Referer'         => 'https://www.pconline.com.cn/',
        ]);

        if (!$http['ok']) {
            // Fallback: ip-api only when pconline network fails (not dual storage — runtime failover).
            $fallback = $this->query_ip_api($ip);
            if ($this->has_location($fallback)) {
                $fallback['provider'] = 'ip-api';
                $fallback['detail']   = 'pconline_failed_fallback_ip_api';
                return $fallback;
            }
            return $this->empty_result('http_error', [
                'provider'  => 'pconline',
                'http_code' => $http['code'],
                'detail'    => $http['error'] !== '' ? $http['error'] : 'pconline blocked or unreachable',
                'raw'       => $http['body_raw'] !== '' ? ['body' => mb_substr($http['body_raw'], 0, 500)] : [],
            ]);
        }

        $body = $http['body_raw'];
        // pconline often serves GBK/GB2312.
        if (function_exists('mb_convert_encoding')) {
            $converted = @mb_convert_encoding($body, 'UTF-8', 'GBK,GB2312,UTF-8');
            if (is_string($converted) && $converted !== '') {
                $body = $converted;
            }
        }

        $json = json_decode($body, true);
        if (is_array($json)) {
            $province = $this->string_field($json['pro'] ?? $json['province'] ?? '');
            $city     = $this->string_field($json['city'] ?? '');
            $region   = $this->string_field($json['region'] ?? '');
            $addr     = $this->string_field($json['addr'] ?? '');
            $country  = '';
            if ($addr !== '' && preg_match('/^(\S+)/u', $addr, $m)) {
                $country = $m[1];
            }
            if ($province !== '' || $city !== '') {
                return [
                    'country'  => $country !== '' ? $country : '中国',
                    'province' => $province,
                    'city'     => $city !== '' ? $city : $region,
                    'raw'      => $json,
                    'provider' => 'pconline',
                ];
            }
        }

        // Regex fallback (zibll).
        preg_match('/"pro":"(.*?)"/u', $body, $pro);
        preg_match('/"city":"(.*?)"/u', $body, $city);
        preg_match('/"region":"(.*?)"/u', $body, $region);
        preg_match('/"addr":"(.*?)(\s)(.*?)"/u', $body, $addr);

        $province = $this->string_field($pro[1] ?? '');
        $city_s   = $this->string_field($city[1] ?? '');
        $country  = $this->string_field($addr[1] ?? '');

        if ($province === '' && $city_s === '') {
            return $this->empty_result('provider_empty', [
                'provider' => 'pconline',
                'detail'   => 'parse_failed',
                'raw'      => ['body' => mb_substr($body, 0, 500)],
            ]);
        }

        return [
            'country'  => $country !== '' ? $country : '中国',
            'province' => $province,
            'city'     => $city_s !== '' ? $city_s : $this->string_field($region[1] ?? ''),
            'raw'      => ['body' => $body],
            'provider' => 'pconline',
        ];
    }

    private function query_ip_api(string $ip): array {
        $url  = 'http://ip-api.com/json/' . rawurlencode($ip) . '?lang=zh-CN&fields=status,message,country,regionName,city,query';
        $http = $this->http_get($url, 6);
        if (!$http['ok']) {
            return $this->empty_result('http_error', [
                'provider'  => 'ip-api',
                'http_code' => $http['code'],
                'detail'    => $http['error'],
            ]);
        }
        $data = $http['json'];
        if (!is_array($data) || ($data['status'] ?? '') !== 'success') {
            return $this->empty_result('provider_error', [
                'provider' => 'ip-api',
                'detail'   => is_array($data) ? (string) ($data['message'] ?? 'fail') : 'invalid_json',
                'raw'      => is_array($data) ? $data : [],
            ]);
        }
        return [
            'country'  => $this->string_field($data['country'] ?? ''),
            'province' => $this->string_field($data['regionName'] ?? ''),
            'city'     => $this->string_field($data['city'] ?? ''),
            'raw'      => $data,
            'provider' => 'ip-api',
        ];
    }

    /**
     * @param array<string,string> $extra_headers
     * @return array{ok:bool,code:int,error:string,json:?array,body_raw:string}
     */
    private function http_get(string $url, int $timeout = 8, array $extra_headers = []): array {
        $headers = array_merge([
            'Accept'     => 'application/json,text/plain,*/*',
            'User-Agent' => 'AKSRT-IPGeo/3.4 (+WordPress)',
        ], $extra_headers);

        $response = wp_remote_get($url, [
            'timeout'     => $timeout,
            'redirection' => 3,
            'sslverify'   => true,
            'headers'     => $headers,
        ]);

        if (is_wp_error($response)) {
            return [
                'ok'       => false,
                'code'     => 0,
                'error'    => $response->get_error_message(),
                'json'     => null,
                'body_raw' => '',
            ];
        }

        $code = (int) wp_remote_retrieve_response_code($response);
        $body = (string) wp_remote_retrieve_body($response);
        if ($code < 200 || $code >= 300) {
            return [
                'ok'       => false,
                'code'     => $code,
                'error'    => 'HTTP ' . $code,
                'json'     => null,
                'body_raw' => $body,
            ];
        }

        $json = json_decode($body, true);

        return [
            'ok'       => true,
            'code'     => $code,
            'error'    => '',
            'json'     => is_array($json) ? $json : null,
            'body_raw' => $body,
        ];
    }

    private function is_private_ip(string $ip): bool {
        return !filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE);
    }

    private function has_location(array $result): bool {
        return $this->string_field($result['province'] ?? '') !== ''
            || $this->string_field($result['city'] ?? '') !== ''
            || $this->string_field($result['country'] ?? '') !== '';
    }

    /**
     * Amap may return [] for empty province/city.
     *
     * @param mixed $value Raw field.
     */
    private function string_field($value): string {
        if (is_array($value)) {
            if ($value === []) {
                return '';
            }
            $value = reset($value);
        }
        if (!is_scalar($value) && $value !== null) {
            return '';
        }
        return trim((string) $value);
    }

    /**
     * @param array<string,mixed> $extra Extra fields.
     * @return array{country:string,province:string,city:string,raw:array,reason?:string}
     */
    private function empty_result(string $reason = '', array $extra = []): array {
        $out = [
            'country'  => '',
            'province' => '',
            'city'     => '',
            'raw'      => is_array($extra['raw'] ?? null) ? $extra['raw'] : [],
        ];
        if ($reason !== '') {
            $out['reason'] = $reason;
        }
        foreach (['provider', 'http_code', 'detail'] as $k) {
            if (array_key_exists($k, $extra)) {
                $out[$k] = $extra[$k];
            }
        }
        return $out;
    }
}