import { get } from 'https';
import { refererCheck } from '../common/referer-check.js';

// 验证请求合法性
function isValidRequest(req) {
    const isLatitudeValid = /^-?\d+(\.\d+)?$/.test(req.query.latitude);
    const isLongitudeValid = /^-?\d+(\.\d+)?$/.test(req.query.longitude);
    const isLanguageValid = /^[a-z]{2}$/.test(req.query.language);

    if (!isLatitudeValid || !isLongitudeValid || !isLanguageValid) {
        return false;
    } else {
        return true;
    }
}

// 定义白天模式和黑暗模式样式字符串
const styles = {
    Dark: [
        "feature:all|element:geometry.fill|color:0x242f3e",
        "feature:all|element:labels.text.stroke|color:0x242f3e",
        "feature:all|element:labels.text.fill|color:0x746855",
        "feature:administrative.locality|element:labels.text.fill|color:0xd59563",
        "feature:poi|element:labels.text.fill|color:0xd59563",
        "feature:poi.park|element:geometry|color:0x263c3f",
        "feature:poi.park|element:labels.text.fill|color:0x6b9a76",
        "feature:road|element:geometry|color:0x38414e",
        "feature:road|element:geometry.stroke|color:0x212a37",
        "feature:road|element:labels.text.fill|color:0x9ca5b3",
        "feature:road.highway|element:geometry|color:0x746855",
        "feature:road.highway|element:geometry.stroke|color:0x1f2835",
        "feature:road.highway|element:labels.text.fill|color:0xf3d19c",
        "feature:transit|element:geometry|color:0x2f3948",
        "feature:transit.station|element:labels.text.fill|color:0xd59563",
        "feature:water|element:geometry|color:0x17263c",
        "feature:water|element:labels.text.fill|color:0x515c6d",
        "feature:all|element:labels.text.stroke|color:0x17263c"
    ]
};

export default (req, res) => {
    // 限制只能从指定域名访问
    const referer = req.headers.referer;
    if (!refererCheck(referer)) {
        return res.status(403).json({ error: referer ? 'Access denied' : 'What are you doing?' });
    }

    // 检查请求是否合法
    if (!isValidRequest(req)) {
        return res.status(400).json({ error: 'Invalid request' });
    }

    // 使用 req.query 获取参数
    const { latitude, longitude, language, CanvasMode } = req.query;

    if (!latitude || !longitude || !language) {
        return res.status(400).json({ error: 'Missing latitude, longitude, or language' });
    }

    const mapSize = '500x400';
    const fmt = 'jpg';
    const scale = 2;
    const zoom = 3;

    const apiKeys = (process.env.GOOGLE_MAP_API_KEY || '').split(',');
    const apiKey = apiKeys[Math.floor(Math.random() * apiKeys.length)];

    let styleParam = '';
    if (CanvasMode === 'Dark') {
        styleParam = styles.Dark.join('&style=');
    }

    const url = `https://maps.googleapis.com/maps/api/staticmap?center=${latitude},${longitude}&markers=color:blue%7C${latitude},${longitude}&scale=${scale}&zoom=${zoom}&maptype=roadmap&language=${language}&format=${fmt}&size=${mapSize}&style=${styleParam}&key=${apiKey}`;

    get(url, apiRes => {
        apiRes.pipe(res);
    }).on('error', (e) => {
        res.status(500).json({ error: e.message });
    });
};