const threads = require("../data/threads");
const moment = require('moment');
const utils = require("../utils");

const LOG_LINES_PER_PAGE = 10;

module.exports = ({ bot, knex, config, commands }) => {
  const logsCmd = async (msg, args, thread) => {
    let userId = args.userId || (thread && thread.user_id);
    if (! userId) return;

    let userThreads = await threads.getClosedThreadsByUserId(userId);

    // Descending by date
    userThreads.sort((a, b) => {
      if (a.created_at > b.created_at) return -1;
      if (a.created_at < b.created_at) return 1;
      return 0;
    });

    // Pagination
    const totalUserThreads = userThreads.length;
    const maxPage = Math.ceil(totalUserThreads / LOG_LINES_PER_PAGE);
    const inputPage = args.page;
    const page = Math.max(Math.min(inputPage ? parseInt(inputPage, 10) : 1, maxPage), 1); // Clamp page to 1-<max page>
    const isPaginated = totalUserThreads > LOG_LINES_PER_PAGE;
    const start = (page - 1) * LOG_LINES_PER_PAGE;
    const end = page * LOG_LINES_PER_PAGE;
    userThreads = userThreads.slice((page - 1) * LOG_LINES_PER_PAGE, page * LOG_LINES_PER_PAGE);

    const threadLines = await Promise.all(userThreads.map(async thread => {
      const logUrl = await thread.getLogUrl();
      const formattedDate = moment.utc(thread.created_at).format('MMM Do [at] HH:mm [UTC]');
      return `\`${formattedDate}\`: <${logUrl}>`;
    }));

    let message = isPaginated
      ? `**Log files for <@${userId}>** (page **${page}/${maxPage}**, showing logs **${start + 1}-${end}/${totalUserThreads}**):`
      : `**Log files for <@${userId}>:**`;

    message += `\n${threadLines.join('\n')}`;

    if (isPaginated) {
      message += `\nTo view more, add a page number to the end of the command.`;
    }

    // Send the list of logs in chunks of 15 lines per message
    const lines = message.split('\n');
    const chunks = utils.chunk(lines, 15);

    let root = Promise.resolve();
    chunks.forEach(lines => {
      root = root.then(() => msg.channel.createMessage(lines.join('\n')));
    });
  };

  commands.addInboxServerCommand('logs', '<userId:userId> [page:number]', logsCmd);
  commands.addInboxServerCommand('logs', '[page:number]', logsCmd);

  commands.addInboxServerCommand('loglink', [], async (msg, args, thread) => {
    if (! thread) {
      thread = await threads.findSuspendedThreadByChannelId(msg.channel.id);
      if (! thread) return;
    }

    const logUrl = await thread.getLogUrl();
    thread.postSystemMessage(`Log URL: ${logUrl}`);
  });
};