import * as fs from 'fs';
import * as log4js from 'log4js';
import * as path from 'path';

import { relativeDate } from './datetime';

const logger = log4js.getLogger('command');
logger.level = (global as any).loglevel;

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

function sub(chat: IChat, args: string[], lock: ILock, lockfile: string): string {
  if (args.length === 0) {
    return '找不到要订阅的链接。';
  }
  const match = parseLink(args[0]);
  if (!match) {
    return `订阅链接格式错误：
示例：
https://twitter.com/Saito_Shuka
https://twitter.com/rikakomoe/lists/lovelive`;
  }
  const link = match.link;
  let flag = false;
  lock.feed.forEach(fl => {
    if (fl === link) flag = true;
  });
  if (!flag) lock.feed.push(link);
  if (!lock.threads[link]) {
    lock.threads[link] = {
      offset: 0,
      subscribers: [],
      updatedAt: '',
    };
  }
  flag = false;
  lock.threads[link].subscribers.forEach(c => {
    if (c.chatID === chat.chatID && c.chatType === chat.chatType) flag = true;
  });
  if (!flag) lock.threads[link].subscribers.push(chat);
  logger.warn(`chat ${JSON.stringify(chat)} has subscribed ${link}`);
  fs.writeFileSync(path.resolve(lockfile), JSON.stringify(lock));
  return `已为此聊天订阅 ${link}`;
}

function unsub(chat: IChat, args: string[], lock: ILock, lockfile: string): string {
  if (args.length === 0) {
    return '找不到要退订的链接。';
  }
  const match = parseLink(args[0]);
  if (!match) {
    return '链接格式有误。';
  }
  const link = match.link;
  if (!lock.threads[link]) {
    return '您没有订阅此链接。\n' + list(chat, args, lock);
  }
  let flag = false;
  lock.threads[link].subscribers.forEach((c, index) => {
    if (c.chatID === chat.chatID && c.chatType === chat.chatType) {
      flag = true;
      lock.threads[link].subscribers.splice(index, 1);
    }
  });
  if (flag) {
    fs.writeFileSync(path.resolve(lockfile), JSON.stringify(lock));
    logger.warn(`chat ${JSON.stringify(chat)} has unsubscribed ${link}`);
    return `已为此聊天退订 ${link}`;
  }
  return '您没有订阅此链接。\n' + list(chat, args, lock);
}

function list(chat: IChat, args: string[], lock: ILock): string {
  const links = [];
  Object.keys(lock.threads).forEach(key => {
    lock.threads[key].subscribers.forEach(c => {
      if (c.chatID === chat.chatID && c.chatType === chat.chatType) links.push(`${key} ${relativeDate(lock.threads[key].updatedAt)}`);
    });
  });
  return '此聊天中订阅的链接：\n' + links.join('\n');
}

export {sub, list, unsub};