const axios = require('axios');

const BAIDU_OCR_API = {
  token: 'https://aip.baidubce.com/oauth/2.0/token',
  generalBasic: 'https://aip.baidubce.com/rest/2.0/ocr/v1/general_basic',
  accurateBasic: 'https://aip.baidubce.com/rest/2.0/ocr/v1/accurate_basic'
};

let accessTokenCache = {
  token: null,
  expireAt: 0
};

async function getAccessToken() {
  const now = Date.now();
  if (accessTokenCache.token && accessTokenCache.expireAt > now + 60000) {
    return accessTokenCache.token;
  }

  const apiKey = process.env.BAIDU_OCR_API_KEY;
  const secretKey = process.env.BAIDU_OCR_SECRET_KEY;

  if (!apiKey || !secretKey) {
    throw new Error('百度OCR配置缺失：请检查 BAIDU_OCR_API_KEY 和 BAIDU_OCR_SECRET_KEY');
  }

  const response = await axios.post(BAIDU_OCR_API.token, null, {
    params: {
      grant_type: 'client_credentials',
      client_id: apiKey,
      client_secret: secretKey
    },
    headers: {
      'Content-Type': 'application/json',
      'Accept': 'application/json'
    }
  });

  const { access_token, expires_in } = response.data;

  if (!access_token) {
    throw new Error(`获取百度OCR Token失败: ${JSON.stringify(response.data)}`);
  }

  accessTokenCache = {
    token: access_token,
    expireAt: now + (expires_in * 1000)
  };

  return access_token;
}

async function recognizeText(imageBase64, options = {}) {
  const accessToken = await getAccessToken();

  const url = `${BAIDU_OCR_API.generalBasic}?access_token=${accessToken}`;

  const params = new URLSearchParams();
  params.append('image', imageBase64);

  if (options.language_type) {
    params.append('language_type', options.language_type);
  }

  const response = await axios.post(url, params.toString(), {
    headers: {
      'Content-Type': 'application/x-www-form-urlencoded'
    }
  });

  return response.data;
}

async function recognizeTextAccurate(imageBase64, options = {}) {
  const accessToken = await getAccessToken();

  const url = `${BAIDU_OCR_API.accurateBasic}?access_token=${accessToken}`;

  const params = new URLSearchParams();
  params.append('image', imageBase64);

  if (options.language_type) {
    params.append('language_type', options.language_type);
  }

  const response = await axios.post(url, params.toString(), {
    headers: {
      'Content-Type': 'application/x-www-form-urlencoded'
    }
  });

  return response.data;
}

function getDefaultPrice(type, times) {
  const prices = {
    year: '120',
    halfYear: '60',
    quarter: '30',
    month: '10'
  };

  if (type === 'times') {
    const timesCount = parseInt(times) || 1;
    return String(timesCount * 10);
  }

  return prices[type] || '10';
}

function extractMembershipInfo(ocrResult) {
  if (!ocrResult || !ocrResult.words_result || ocrResult.words_result.length === 0) {
    return [];
  }

  const text = ocrResult.words_result.map(w => w.words).join('\n');
  const lines = ocrResult.words_result.map(w => w.words);

  const platformKeywords = {
    '淘宝': ['淘宝', 'taobao', '88vip', '88VIP'],
    '京东': ['京东', 'jd', 'JD', 'plus', 'PLUS'],
    '拼多多': ['拼多多', 'pdd', 'PDD'],
    '美团': ['美团', 'meituan'],
    '饿了么': ['饿了么', 'eleme', 'ele.me'],
    '抖音': ['抖音', 'douyin', 'tiktok'],
    '快手': ['快手', 'kuaishou'],
    '网易云音乐': ['网易云', 'netease', '163'],
    'QQ音乐': ['QQ音乐', 'qq音乐'],
    '优酷': ['优酷', 'youku'],
    '爱奇艺': ['爱奇艺', 'iqiyi'],
    '腾讯视频': ['腾讯视频', 'v.qq'],
    '哔哩哔哩': ['哔哩哔哩', 'bilibili', 'B站'],
    '喜马拉雅': ['喜马拉雅', 'ximalaya'],
    '知乎': ['知乎', 'zhihu'],
    '百度网盘': ['百度网盘', '百度云']
  };

  let platform = null;
  for (const [pName, keywords] of Object.entries(platformKeywords)) {
    for (const keyword of keywords) {
      if (text.toLowerCase().includes(keyword.toLowerCase())) {
        platform = pName;
        break;
      }
    }
    if (platform) break;
  }

  const typePatterns = [
    { patterns: [/年卡/, /年度会员/, /\d+年/], type: 'year' },
    { patterns: [/半年卡/, /半年会员/, /6个月/], type: 'halfYear' },
    { patterns: [/季卡/, /季度会员/, /3个月/], type: 'quarter' },
    { patterns: [/月卡/, /月度会员/, /1个月/], type: 'month' },
    { patterns: [/次卡/, /按次数/], type: 'times' }
  ];

  let detectedType = 'month';
  for (const { patterns, type } of typePatterns) {
    for (const pattern of patterns) {
      if (pattern.test(text)) {
        detectedType = type;
        break;
      }
    }
    if (detectedType !== 'month') break;
  }

  const datePatterns = [
    /(\d{4})[年/-](\d{1,2})[月/-](\d{1,2})/,
    /(\d{4})(\d{2})(\d{2})/,
    /(\d{2})[年/-](\d{1,2})[月/-](\d{1,2})/,
    /有效期[至到:：]\s*(\d{4})[年/-](\d{1,2})[月/-](\d{1,2})/,
    /到期[时间日]:?\s*(\d{4})[年/-](\d{1,2})[月/-](\d{1,2})/,
    /(\d{4})\.(\d{1,2})\.(\d{1,2})/
  ];

  let expireDate = '9999-12-31';
  for (const pattern of datePatterns) {
    const match = text.match(pattern);
    if (match) {
      let year = match[1];
      const month = match[2].padStart(2, '0');
      const day = match[3].padStart(2, '0');

      if (year.length === 2) {
        year = '20' + year;
      }

      expireDate = `${year}-${month}-${day}`;
      break;
    }
  }

  const benefitKeywords = [
    '优酷', '网易云', 'QQ音乐', '酷狗', '酷我',
    '爱奇艺', '腾讯视频', '芒果TV', '哔哩哔哩',
    '饿了么', '美团', '高德打车', '滴滴',
    '夸克', '百度网盘', '迅雷',
    '喜马拉雅', '知乎', '微博',
    '淘票票', '飞猪', '希尔顿', '万豪',
    '视频会员', '超级吃货卡', '天猫超市', '天猫国际',
    '阿里健康', '专属客服', '省钱卡', '网盘会员',
    '打车会员', '金卡', '皮肤装扮', '每日领券',
    '出行礼遇', '专享立减', '游戏特权'
  ];

  const benefits = [];
  for (const line of lines) {
    for (const keyword of benefitKeywords) {
      if (line.includes(keyword)) {
        const existing = benefits.find(b => b.name === keyword);
        if (!existing) {
          benefits.push({
            name: keyword,
            type: detectedType,
            times: detectedType === 'times' ? null : null,
            price: getDefaultPrice(detectedType, null),
            expireDate: expireDate
          });
        }
      }
    }
  }

  if (benefits.length === 0 && platform) {
    benefits.push({
      name: platform,
      type: detectedType,
      times: null,
      price: getDefaultPrice(detectedType, null),
      expireDate: expireDate
    });
  }

  return benefits;
}

module.exports = {
  getAccessToken,
  recognizeText,
  recognizeTextAccurate,
  extractMembershipInfo
};