/* eslint-disable @typescript-eslint/no-unsafe-return */
/* eslint-disable @typescript-eslint/member-delimiter-style */
/* eslint-disable prefer-arrow/prefer-arrow-functions */
import * as fs from 'fs';
import * as path from 'path';

import { relativeDate } from './datetime';
import { getLogger } from './loggers';
import { sendTimeline, sendTweet, ScreenNameNormalizer as normalizer } from './twitter';
import { BigNumOps } from './utils';

const logger = getLogger('command');

function parseCmd(message: string): {
  cmd: string;
  args: string[];
} {
  message = message.trim();
  message = message.replace('\\\\', '\\0x5c');
  message = message.replace('\\\"', '\\0x22');
  message = message.replace('\\\'', '\\0x27');
  const strs = message.match(/'[\s\S]*?'|(?:\S+=)?"[\s\S]*?"|\S+/mg);
  const cmd = strs?.length ? strs[0].length ? strs[0].substring(0, 1) === '/' ? strs[0].substring(1) : '' : '' : '';
  const args = (strs ?? []).slice(1).map(arg => {
    arg = arg.replace(/^(\S+=)?["']+(?!.*=)|["']+$/g, '$1');
    arg = arg.replace('\\0x27', '\\\'');
    arg = arg.replace('\\0x22', '\\\"');
    arg = arg.replace('\\0x5c', '\\\\');
    return arg;
  });
  return {
    cmd,
    args,
  };
}

function parseLink(link: string): string[] {
  let match =
    /twitter.com\/([^\/?#]+)\/lists\/([^\/?#]+)/.exec(link) ||
    /^([^\/?#]+)\/([^\/?#]+)$/.exec(link);
  if (match) return [match[1], `/lists/${match[2]}`];
  match =
    /twitter.com\/([^\/?#]+)\/status\/(\d+)/.exec(link);
  if (match) return [match[1], `/status/${match[2]}`];
  match =
    /twitter.com\/([^\/?#]+)/.exec(link) ||
    /^([^\/?#]+)$/.exec(link);
  if (match) return [match[1]];
  return;
}

function linkBuilder(userName: string, more = ''): string {
  if (!userName) return;
  return `https://twitter.com/${userName}${more}`;
}

function linkFinder(checkedMatch: string[], chat: IChat, lock: ILock): [string, number] {
  const normalizedLink =
    linkBuilder(normalizer.normalize(checkedMatch[0]), checkedMatch[1]?.toLowerCase());
  const link = Object.keys(lock.threads).find(realLink =>
    normalizedLink === realLink.replace(/\/@/, '/').toLowerCase()
  );
  if (!link) return [null, -1];
  const index = lock.threads[link].subscribers.findIndex(({chatID, chatType}) =>
    chat.chatID === chatID && chat.chatType === chatType
  );
  return [link, index];
}

function sub(chat: IChat, args: string[], reply: (msg: string) => any,
  lock: ILock, lockfile: string
): void {
  if (chat.chatType === ChatType.Temp) {
    return reply('请先添加机器人为好友。');
  }
  if (args.length === 0) {
    return reply('找不到要订阅的链接。');
  }
  const match = parseLink(args[0]);
  if (!match) {
    return reply(`订阅链接格式错误：
示例：
https://twitter.com/Saito_Shuka
https://twitter.com/rikakomoe/lists/lovelive
https://twitter.com/TomoyoKurosawa/status/1294613494860361729`);
  }
  let offset = '0';
  if (match[1]) {
    const matchStatus = /\/status\/(\d+)/.exec(match[1]);
    if (matchStatus) {
      offset = BigNumOps.plus(matchStatus[1], '-1');
      delete match[1];
    }
  }
  const subscribeTo = (link: string, config: {addNew?: boolean, msg?: string} = {}) => {
    const {addNew = false, msg = `已为此聊天订阅 ${link}`} = config;
    if (addNew) {
      lock.feed.push(link);
      lock.threads[link] = {
        offset,
        subscribers: [],
        updatedAt: '',
      };
    }
    lock.threads[link].subscribers.push(chat);
    logger.warn(`chat ${JSON.stringify(chat)} has subscribed ${link}`);
    fs.writeFileSync(path.resolve(lockfile), JSON.stringify(lock));
    reply(msg);
  };
  const [realLink, index] = linkFinder(match, chat, lock);
  if (index > -1) return reply('此聊天已订阅此链接。');
  if (realLink) return subscribeTo(realLink);
  const [rawUserName, more] = match;
  if (rawUserName.toLowerCase() === 'i' && /lists\/(\d+)/.exec(more)) {
    return subscribeTo(linkBuilder('i', more), {addNew: true});
  }
  normalizer.normalizeLive(rawUserName).then(userName => {
    if (!userName) return reply(`找不到用户 ${rawUserName.replace(/^@?(.*)$/, '@$1')}。`);
    const link = linkBuilder(userName, more);
    const msg = (offset === '0') ?
      undefined :
      `已为此聊天订阅 ${link} 并回溯到此动态 ID（含）之后的第一条动态。
（参见：https://blog.twitter.com/engineering/en_us/a/2010/announcing-snowflake.html）`;
    subscribeTo(link, {addNew: true, msg});
  });
}

function unsub(chat: IChat, args: string[], reply: (msg: string) => any,
  lock: ILock, lockfile: string
): void {
  if (chat.chatType === ChatType.Temp) {
    return reply('请先添加机器人为好友。');
  }
  if (args.length === 0) {
    return reply('找不到要退订的链接。');
  }
  const match = parseLink(args[0]);
  if (!match) {
    return reply('链接格式有误。');
  }
  const [link, index] = linkFinder(match, chat, lock);
  if (index === -1) return list(chat, args, msg => reply('您没有订阅此链接。\n' + msg), lock);
  else {
    lock.threads[link].subscribers.splice(index, 1);
    fs.writeFileSync(path.resolve(lockfile), JSON.stringify(lock));
    logger.warn(`chat ${JSON.stringify(chat)} has unsubscribed ${link}`);
    return reply(`已为此聊天退订 ${link}`);
  }
}

function list(chat: IChat, _: string[], reply: (msg: string) => any, lock: ILock): void {
  if (chat.chatType === ChatType.Temp) {
    return reply('请先添加机器人为好友。');
  }
  const links = [];
  Object.keys(lock.threads).forEach(key => {
    if (lock.threads[key].subscribers.find(({chatID, chatType}) => 
      chat.chatID === chatID && chat.chatType === chatType
    )) links.push(`${key} ${relativeDate(lock.threads[key].updatedAt)}`);
  });
  return reply('此聊天中订阅的链接：\n' + links.join('\n'));
}

function view(chat: IChat, args: string[], reply: (msg: string) => any): void {
  if (args.length === 0) {
    return reply('找不到要查看的链接。');
  }
  const match = /^(?:.*twitter.com\/[^\/?#]+\/status\/)?(\d+)/.exec(args[0]);
  if (!match) {
    return reply('链接格式有误。');
  }
  try {
    sendTweet(match[1], chat);
  } catch (e) {
    reply('推特机器人尚未加载完毕，请稍后重试。');
  }
}

function query(chat: IChat, args: string[], reply: (msg: string) => any): void {
  if (args.length === 0) {
    return reply('找不到要查询的用户。');
  }
  const match = 
    /twitter.com\/([^\/?#]+)/.exec(args[0]) ||
    /^([^\/?#]+)$/.exec(args[0]);
  if (!match) {
    return reply('链接格式有误。');
  }
  const conf: {
    username: string,
    count?: string,
    since?: string,
    until?: string,
    noreps: string,
    norts: string,
  } = {username: match[1], noreps: 'on', norts: 'off'};
  const confZH: Record<Exclude<keyof typeof conf, 'username'>, string> = {
    count: '数量上限',
    since: '起始点',
    until: '结束点',
    noreps: '忽略回复推文（on/off）',
    norts: '忽略原生转推（on/off）',
  };
  for (const arg of args.slice(1)) {
    const optMatch = /^(count|since|until|noreps|norts)=(.*)/.exec(arg);
    if (!optMatch) return reply(`未定义的查询参数：${arg}。`);
    const optKey = optMatch[1] as keyof typeof confZH;
    if (optMatch.length === 1) return reply(`查询${confZH[optKey]}参数格式有误。`);
    conf[optKey] = optMatch[2];
    if (optMatch[2] === '') return reply(`查询${confZH[optKey]}参数值不可为空。`);
  }
  if (conf.count !== undefined && !Number(conf.count) || Math.abs(Number(conf.count)) > 50) {
    return reply('查询数量上限参数为零、非数值或超出取值范围。');
  }
  try {
    sendTimeline(conf, chat);
  } catch (e) {
    logger.error(`error querying timeline, error: ${e}`);
    reply('推特机器人尚未加载完毕，请稍后重试。');
  }
}

export { parseCmd, sub, list, unsub, view, query };