Mastodon_lottery.js

(async () => {
  const lotteryStatusUrl = 'https://bgme.me/@bgme/105206731005287886'; // 抽奖嘟文URL
  const lotteryType = 'reblog'; // 抽奖类型：转发（reblog），收藏（favourite）
  const candidateNumber = 5; // 候选中奖者人数
  main();


  async function main() {
    const domain = document.location.hostname;
    const token = JSON.parse(document.querySelector('#initial-state').text).meta.access_token;
    const API = {
      'verify': `https://${domain}/api/v1/accounts/verify_credentials`,
      'notifications': `https://${domain}/api/v1/notifications`,
      'status': `https://${domain}/api/v1/statuses/`,
    };
    const searchParamMap = new Map([
      ['reblog', 'exclude_types[]=follow&exclude_types[]=follow_request&exclude_types[]=favourite&exclude_types[]=mention&exclude_types[]=poll'],
      ['favourite', 'exclude_types[]=follow&exclude_types[]=follow_request&exclude_types[]=reblog&exclude_types[]=mention&exclude_types[]=poll'],
    ]);
    const searchParam = new URLSearchParams(searchParamMap.get(lotteryType));

    const statusID = lotteryStatusUrl.match(/(\d+)$/)[0];
    let statusTNumber;
    let lotterLog;


    logout(`开始抽奖……\n当前浏览器：${navigator.userAgent}\n开始时间：${(new Date()).toISOString()}`);
    logout(`抽奖嘟文：${lotteryStatusUrl}，抽奖类型：${lotteryType}，候选中奖者人数：${candidateNumber}\n\n`);
    let verify;
    [verify, statusTNumber] = await doVerify(API, lotteryStatusUrl, statusID, lotteryType, statusTNumber);
    if (!verify) {
      throw Error('抽奖嘟文非本人发送');
    }
    const matchAccouts = await getmatchAccouts(API, statusID, statusTNumber, searchParam);
    randomTest(matchAccouts);
    const luckGuys = getLuckGuy(matchAccouts);
    const cadidatesText = getCandidate(luckGuys, candidateNumber);
    const notificationText = `嘿！感谢各位参与本次小抽奖活动。\n${cadidatesText}\n\n希望这条艾特您的信息没有造成骚扰，如您对奖品感兴趣请和我私信联系吧？`;
    await postStatus(notificationText, statusID, 'public');
    logout(`抽奖结束！\n结束时间：${(new Date()).toISOString()}`);
    saveFile(lotterLog, `lotterLog-${Date.now()}.log`, 'text/plain; charset=utf-8');


    async function doVerify(API, lotteryStatusUrl, statusID, lotteryType, statusTNumber) {
      const v = await request(API.verify);
      const s = await request(`${API.status}${statusID}`);
      logout(`抽奖嘟文URL：${lotteryStatusUrl}\n回复数：${s.replies_count}，转发数：${s.reblogs_count}，收藏数：${s.favourites_count}`);

      const numbers = new Map([['reblog', s.reblogs_count], ['favourite', s.favourites_count]]);
      if (numbers.has(lotteryType)) {
        statusTNumber = numbers.get(lotteryType);
      } else {
        throw Error('抽奖类型设置不正确');
      }

      if (v.acct === s.account.acct && (new URL(s.account.url)).hostname === (new URL(lotteryStatusUrl)).hostname) {
        return [true, statusTNumber];
      } else {
        return [false, statusTNumber];
      }
    }

    async function getmatchAccouts(API, statusID, statusTNumber, searchParam) {
      const matchAccouts = [];

      while (matchAccouts.length !== statusTNumber) {
        const nlist = await request(`${API.notifications}?${searchParam.toString()}`);
        if (!nlist.length) {
          logout('nlist.lenth === 0, end loop!!!')
          break;
        }

        const nextID = nlist.slice(-1)[0].id;
        searchParam.set('max_id', nextID);

        nlist.forEach((obj) => {
          if (obj.status && obj.status.id === statusID) {
            matchAccouts.push(obj.account.acct);
          }
        });
      }

      matchAccouts.sort();
      logout(`共有${matchAccouts.length}名符合条件的抽奖参与者\n她们是：`);
      matchAccouts.forEach(logout);

      return matchAccouts;
    }

    function randomTest(matchAccouts) {
      logout('随机函数测试：');
      const testResults = [];
      const n = 20;
      for (let i = 0; i < (n * 20); i++) {
        testResults.push(getRandomIndex(matchAccouts));
      }
      for (let i = 0; i < n; i++) {
        logout(testResults.slice((i * 20), ((i + 1) * 20)).join(', '));
      }
    }

    function getLuckGuy(matchAccouts) {
      const luckGuys = [];
      const n = matchAccouts.length;
      const luckGuysMap = new Map();
      for (let i = 0; i < (n * 100); i++) {
        const luckGuy = matchAccouts[getRandomIndex(matchAccouts)];
        if (luckGuysMap.get(luckGuy)) {
          luckGuysMap.set(luckGuy, luckGuysMap.get(luckGuy) + 1);
        } else {
          luckGuysMap.set(luckGuy, 1);
        }
      }

      luckGuysMap.forEach((v, k, map) => {
        luckGuys.push([k, v]);
      });
      luckGuys.sort((a, b) => (b[1] - a[1]));
      return luckGuys;
    }

    function getCandidate(luckGuys, candidateNumber) {
      if (candidateNumber > luckGuys.length) {
        throw Error('抽奖参与者太少！')
      }  
      
      let output = '本次抽奖备选中奖者：';
      for (let i = 0; i < candidateNumber; i++) {
        output = `${output}\nNo.${i + 1}：@${luckGuys[i][0]}  （幸运指数：${luckGuys[i][1]}）`;
      }
      logout(output);
      return output;
    }

    function getRandomIndex(arr) {
      return Math.floor(arr.length * Math.random());
    }

    async function request(url) {
      logout(`正在请求：${url}`);
      const resp = await fetch(url, {
        headers: {
          Authorization: `Bearer ${token}`,
        },
        method: 'GET',
      });
      const date = new Date(resp.headers.get('date'));
      const request_id = resp.headers.get('x-request-id');
      const runtime = resp.headers.get('x-runtime');
      const ratelimit_remaining = resp.headers.get('x-ratelimit-remaining');
      logout(`请求 ${url} 完成\n请求时间：${date.toISOString()}，API剩余限额：${ratelimit_remaining}，x-runtime：${runtime}，x-request-id：${request_id}`);
      return await resp.json();
    }

    function logout(text) {
      console.log(text);
      if (lotterLog) {
        lotterLog = lotterLog + '\n' + text;
      } else {
        lotterLog = text;
      }
    }

    function saveFile(data, filename, type) {
      const file = new Blob([data], {type: type});
      const a = document.createElement('a');
      const url = URL.createObjectURL(file);
      a.href = url;
      a.download = filename;
      document.body.appendChild(a);
      a.click();
      setTimeout(function() {
        document.body.removeChild(a);
        window.URL.revokeObjectURL(url);
      }, 0);
    }

    async function postStatus(text, in_reply_to_id, visibility='public') {
      const postDate = {
        'in_reply_to_id': in_reply_to_id,
        'media_ids': [],
        'poll': null,
        'sensitive': false,
        'spoiler_text': '',
        'status': text,
        'visibility': visibility,
      };

      logout(`发送嘟文中……\n嘟文内容：\n${text}\n回复嘟文ID：${in_reply_to_id}\n可见范围：${visibility}`);
      const resp = await fetch(API.status, {
        'headers': {
          'Content-Type': 'application/json;charset=utf-8',
          'Authorization': `Bearer ${token}`,
        },
        'body': JSON.stringify(postDate),
        'method': 'POST',
        'mode': 'cors',
      });
      const date = new Date(resp.headers.get('date'));
      const request_id = resp.headers.get('x-request-id');
      const runtime = resp.headers.get('x-runtime');
      const ratelimit_remaining = resp.headers.get('x-ratelimit-remaining');
      logout(`嘟文发送完成，完成请求时间：${date.toISOString()}，API剩余限额：${ratelimit_remaining}，x-runtime：${runtime}，x-request-id：${request_id}`);
      return await resp.json();
    }
  }
})();