<?php

namespace app\common\library;

use addons\shopro\model\Area;

/**
 * 天地图逆地理编码。
 * 微信选点返回 GCJ-02，天地图使用 CGCS2000，请求前先转换。
 */
class Tianditu
{
    public static function reverse($longitude, $latitude)
    {
        $key = self::key();
        if ($key === '') {
            throw new \Exception('未配置天地图密钥');
        }

        list($lon, $lat) = self::gcj02ToWgs84((float)$longitude, (float)$latitude);
        $result = self::request($lon, $lat, $key);
        $component = isset($result['addressComponent']) && is_array($result['addressComponent'])
            ? $result['addressComponent']
            : [];
        $area = self::matchArea($component);
        $address = self::detailAddress($result, $component);
        $province = $area['province'];
        $city = $area['city'] === $province ? '' : $area['city'];

        return [
            'area_text' => $area['province'] . '-' . $area['city'] . '-' . $area['district'],
            'address' => $address,
            'formatted_address' => $province . $city . $area['district'] . $address,
        ];
    }

    protected static function key()
    {
        $key = function_exists('config') ? config('tianditu.key') : '';
        if (!$key) {
            $file = dirname(__DIR__, 2) . '/extra/tianditu.php';
            $config = is_file($file) ? include $file : [];
            $key = is_array($config) && !empty($config['key']) ? $config['key'] : '';
        }
        return trim((string)$key);
    }

    protected static function request($longitude, $latitude, $key)
    {
        $postStr = json_encode([
            'lon' => round($longitude, 6),
            'lat' => round($latitude, 6),
            'ver' => 1,
        ], JSON_UNESCAPED_UNICODE);
        $url = 'https://api.tianditu.gov.cn/geocoder?postStr=' . rawurlencode($postStr) . '&type=geocode&tk=' . rawurlencode($key);

        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 5);
        curl_setopt($ch, CURLOPT_TIMEOUT, 8);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
        curl_setopt($ch, CURLOPT_USERAGENT, 'chufang-server/1.0');
        $body = curl_exec($ch);
        $errno = curl_errno($ch);
        curl_close($ch);

        if ($errno || $body === false || $body === '') {
            throw new \Exception('地址解析失败，请稍后重试');
        }

        $json = json_decode($body, true);
        if (!is_array($json) || !isset($json['status']) || (string)$json['status'] !== '0' || empty($json['result']) || !is_array($json['result'])) {
            $message = is_array($json) && !empty($json['msg']) ? $json['msg'] : '地址解析失败';
            throw new \Exception($message);
        }

        return $json['result'];
    }

    protected static function matchArea(array $component)
    {
        $district = self::findDistrict($component);
        if (!$district) {
            throw new \Exception('未能匹配区县，请手动选择所在地区');
        }

        $city = Area::where('id', $district['pid'])->find();
        $province = $city ? Area::where('id', $city['pid'])->find() : null;
        if (!$city || !$province || (int)$city['level'] !== 2 || (int)$province['level'] !== 1) {
            throw new \Exception('未能匹配省市区，请手动选择所在地区');
        }

        return [
            'province' => $province['name'],
            'city' => $city['name'],
            'district' => $district['name'],
        ];
    }

    protected static function findDistrict(array $component)
    {
        $countyId = self::adminCode(isset($component['county_code']) ? $component['county_code'] : '');
        if ($countyId) {
            $district = Area::where('id', $countyId)->where('level', 3)->find();
            if ($district) {
                return $district;
            }
        }

        $county = trim(isset($component['county']) ? $component['county'] : '');
        if ($county === '') {
            return null;
        }

        $cityId = self::adminCode(isset($component['city_code']) ? $component['city_code'] : '');
        $query = Area::where('name', $county)->where('level', 3);
        if ($cityId) {
            $query->where('pid', $cityId);
        }
        return $query->find();
    }

    protected static function detailAddress(array $result, array $component)
    {
        $segments = [];
        $adminNames = [];
        foreach (['province', 'city', 'county'] as $field) {
            $name = trim(isset($component[$field]) ? (string)$component[$field] : '');
            if ($name !== '') {
                $adminNames[] = $name;
            }
        }
        foreach (['town', 'road', 'address', 'poi'] as $field) {
            $segment = trim(isset($component[$field]) ? (string)$component[$field] : '');
            $segment = self::stripAdmin($segment, $adminNames);
            if ($segment === '' || self::isRelative($segment)) {
                continue;
            }
            $replaced = false;
            foreach ($segments as $index => $exist) {
                if (mb_strpos($segment, $exist) !== false) {
                    $segments[$index] = $segment;
                    $replaced = true;
                    break;
                }
                if (mb_strpos($exist, $segment) !== false) {
                    $replaced = true;
                    break;
                }
            }
            if (!$replaced) {
                $segments[] = $segment;
            }
        }
        if ($segments) {
            return implode('', $segments);
        }

        $detail = isset($result['formatted_address']) ? $result['formatted_address'] : '';
        foreach (['province', 'city', 'county'] as $field) {
            $part = trim(isset($component[$field]) ? (string)$component[$field] : '');
            if ($part !== '') {
                $detail = preg_replace('/' . preg_quote($part, '/') . '/u', '', $detail, 1);
            }
        }
        return trim($detail);
    }

    protected static function stripAdmin($segment, array $adminNames)
    {
        foreach ($adminNames as $name) {
            if ($name !== '' && mb_strpos($segment, $name) !== false) {
                $segment = str_replace($name, '', $segment);
            }
            $short = preg_replace('/(省|市|自治区|特别行政区)$/u', '', $name);
            if ($short === '' || $short === $name || mb_strlen($short) < 2) {
                continue;
            }
            if ($segment === $short) {
                return '';
            }
            $suffixLength = mb_strlen($short);
            if (mb_strlen($segment) > $suffixLength && mb_substr($segment, -$suffixLength) === $short) {
                $segment = mb_substr($segment, 0, mb_strlen($segment) - $suffixLength);
            }
        }
        return trim($segment);
    }

    protected static function isRelative($text)
    {
        return (bool)preg_match('/[东西南北].{0,4}约?\d+米/u', $text);
    }

    protected static function adminCode($code)
    {
        $digits = preg_replace('/\D/', '', (string)$code);
        if (strlen($digits) < 6) {
            return 0;
        }
        return (int)substr($digits, -6);
    }

    protected static function gcj02ToWgs84($longitude, $latitude)
    {
        if (self::outOfChina($longitude, $latitude)) {
            return [$longitude, $latitude];
        }

        $offset = self::offset($longitude, $latitude);
        return [$longitude * 2 - $offset[0], $latitude * 2 - $offset[1]];
    }

    protected static function offset($longitude, $latitude)
    {
        $a = 6378245.0;
        $ee = 0.00669342162296594323;
        $dlng = self::transformLng($longitude - 105.0, $latitude - 35.0);
        $dlat = self::transformLat($longitude - 105.0, $latitude - 35.0);
        $radLat = $latitude / 180.0 * M_PI;
        $magic = sin($radLat);
        $magic = 1 - $ee * $magic * $magic;
        $sqrtMagic = sqrt($magic);
        $dlat = ($dlat * 180.0) / (($a * (1 - $ee)) / ($magic * $sqrtMagic) * M_PI);
        $dlng = ($dlng * 180.0) / ($a / $sqrtMagic * cos($radLat) * M_PI);
        return [$longitude + $dlng, $latitude + $dlat];
    }

    protected static function outOfChina($longitude, $latitude)
    {
        return $longitude < 72.004 || $longitude > 137.8347 || $latitude < 0.8293 || $latitude > 55.8271;
    }

    protected static function transformLat($lng, $lat)
    {
        $ret = -100.0 + 2.0 * $lng + 3.0 * $lat + 0.2 * $lat * $lat + 0.1 * $lng * $lat + 0.2 * sqrt(abs($lng));
        $ret += (20.0 * sin(6.0 * $lng * M_PI) + 20.0 * sin(2.0 * $lng * M_PI)) * 2.0 / 3.0;
        $ret += (20.0 * sin($lat * M_PI) + 40.0 * sin($lat / 3.0 * M_PI)) * 2.0 / 3.0;
        $ret += (160.0 * sin($lat / 12.0 * M_PI) + 320 * sin($lat * M_PI / 30.0)) * 2.0 / 3.0;
        return $ret;
    }

    protected static function transformLng($lng, $lat)
    {
        $ret = 300.0 + $lng + 2.0 * $lat + 0.1 * $lng * $lng + 0.1 * $lng * $lat + 0.1 * sqrt(abs($lng));
        $ret += (20.0 * sin(6.0 * $lng * M_PI) + 20.0 * sin(2.0 * $lng * M_PI)) * 2.0 / 3.0;
        $ret += (20.0 * sin($lng * M_PI) + 40.0 * sin($lng / 3.0 * M_PI)) * 2.0 / 3.0;
        $ret += (150.0 * sin($lng / 12.0 * M_PI) + 300.0 * sin($lng / 30.0 * M_PI)) * 2.0 / 3.0;
        return $ret;
    }
}