/**
 * Pokemon Showdown log viewer
 *
 * by Zarel
 * @license MIT
 */

import {FS} from "../../lib/fs";
import {Utils} from '../../lib/utils';
import * as child_process from 'child_process';
import * as util from 'util';
import * as path from 'path';
import * as Dashycode from '../../lib/dashycode';
import {QueryProcessManager} from "../../lib/process-manager";
import {Repl} from '../../lib/repl';
import {Config} from '../config-loader';
import {Dex} from '../../sim/dex';
import {Chat} from '../chat';

const DAY = 24 * 60 * 60 * 1000;
const MAX_RESULTS = 3000;
const MAX_MEMORY = 67108864; // 64MB
const MAX_PROCESSES = 1;
const MAX_TOPUSERS = 100;
const execFile = util.promisify(child_process.execFile);

interface ChatlogSearch {
	raw?: boolean;
	search: string;
	room: RoomID;
	date: string;
	limit?: number | null;
	args?: string[];
}

export class LogReaderRoom {
	roomid: RoomID;
	constructor(roomid: RoomID) {
		this.roomid = roomid;
	}

	async listMonths() {
		try {
			const listing = await FS(`logs/chat/${this.roomid}`).readdir();
			return listing.filter(file => /^[0-9][0-9][0-9][0-9]-[0-9][0-9]$/.test(file));
		} catch (err) {
			return [];
		}
	}

	async listDays(month: string) {
		try {
			const listing = await FS(`logs/chat/${this.roomid}/${month}`).readdir();
			return listing.filter(file => file.endsWith(".txt")).map(file => file.slice(0, -4));
		} catch (err) {
			return [];
		}
	}

	async getLog(day: string) {
		const month = LogReader.getMonth(day);
		const log = FS(`logs/chat/${this.roomid}/${month}/${day}.txt`);
		if (!await log.exists()) return null;
		return log.createReadStream();
	}
}

export const LogReader = new class {
	async get(roomid: RoomID) {
		if (!await FS(`logs/chat/${roomid}`).exists()) return null;
		return new LogReaderRoom(roomid);
	}

	async list() {
		const listing = await FS(`logs/chat`).readdir();
		return listing.filter(file => /^[a-z0-9-]+$/.test(file)) as RoomID[];
	}

	async listCategorized(user: User, opts?: string) {
		const list = await this.list();
		const isUpperStaff = user.can('rangeban');
		const isStaff = user.can('lock');

		const official = [];
		const normal = [];
		const hidden = [];
		const secret = [];
		const deleted = [];
		const personal: RoomID[] = [];
		const deletedPersonal: RoomID[] = [];
		let atLeastOne = false;

		for (const roomid of list) {
			const room = Rooms.get(roomid);
			const forceShow = room && (
				// you are authed in the room
				(room.auth.has(user.id) && user.can('mute', null, room)) ||
				// you are staff and currently in the room
				(isStaff && user.inRooms.has(room.roomid))
			);
			if (!isUpperStaff && !forceShow) {
				if (!isStaff) continue;
				if (!room) continue;
				if (!room.checkModjoin(user)) continue;
				if (room.settings.isPrivate === true) continue;
			}

			atLeastOne = true;
			if (roomid.includes('-')) {
				const matchesOpts = opts && roomid.startsWith(`${opts}-`);
				if (matchesOpts || opts === 'all' || forceShow) {
					(room ? personal : deletedPersonal).push(roomid);
				}
			} else if (!room) {
				if (opts === 'all' || opts === 'deleted') deleted.push(roomid);
			} else if (room.settings.isOfficial) {
				official.push(roomid);
			} else if (!room.settings.isPrivate) {
				normal.push(roomid);
			} else if (room.settings.isPrivate === 'hidden') {
				hidden.push(roomid);
			} else {
				secret.push(roomid);
			}
		}

		if (!atLeastOne) return null;
		return {official, normal, hidden, secret, deleted, personal, deletedPersonal};
	}

	async read(roomid: RoomID, day: string, limit: number) {
		const roomLog = await LogReader.get(roomid);
		const stream = await roomLog!.getLog(day);
		let buf = '';
		let i = LogViewer.results || 0;
		if (!stream) {
			buf += `<p class="message-error">Room "${roomid}" doesn't have logs for ${day}</p>`;
		} else {
			for await (const line of stream.byLine()) {
				const rendered = LogViewer.renderLine(line);
				if (rendered) {
					buf += `${line}\n`;
					i++;
					if (i > limit) break;
				}
			}
		}
		return buf;
	}

	getMonth(day?: string) {
		if (!day) day = Chat.toTimestamp(new Date()).split(' ')[0];
		return day.slice(0, 7);
	}
	nextDay(day: string) {
		const nextDay = new Date(new Date(day).getTime() + DAY);
		return nextDay.toISOString().slice(0, 10);
	}
	prevDay(day: string) {
		const prevDay = new Date(new Date(day).getTime() - DAY);
		return prevDay.toISOString().slice(0, 10);
	}
	nextMonth(month: string) {
		const nextMonth = new Date(new Date(`${month}-15`).getTime() + 30 * DAY);
		return nextMonth.toISOString().slice(0, 7);
	}
	prevMonth(month: string) {
		const prevMonth = new Date(new Date(`${month}-15`).getTime() - 30 * DAY);
		return prevMonth.toISOString().slice(0, 7);
	}

	today() {
		return Chat.toTimestamp(new Date()).slice(0, 10);
	}
};

export const LogViewer = new class {
	results: number;
	constructor() {
		this.results = 0;
	}
	async day(roomid: RoomID, day: string, opts?: string) {
		const month = LogReader.getMonth(day);
		let buf = `<div class="pad"><p>` +
			`<a roomid="view-chatlog">◂ All logs</a> / ` +
			`<a roomid="view-chatlog-${roomid}">${roomid}</a> /  ` +
			`<a roomid="view-chatlog-${roomid}--${month}">${month}</a> / ` +
			`<strong>${day}</strong></p><small>${opts ? `Options in use: ${opts}` : ''}</small> <hr />`;

		const roomLog = await LogReader.get(roomid);
		if (!roomLog) {
			buf += `<p class="message-error">Room "${roomid}" doesn't exist</p></div>`;
			return this.linkify(buf);
		}

		const prevDay = LogReader.prevDay(day);
		buf += `<p><a roomid="view-chatlog-${roomid}--${prevDay}" class="blocklink" style="text-align:center">▲<br />${prevDay}</a></p>` +
			`<div class="message-log" style="overflow-wrap: break-word">`;

		const stream = await roomLog.getLog(day);
		if (!stream) {
			buf += `<p class="message-error">Room "${roomid}" doesn't have logs for ${day}</p>`;
		} else {
			for await (const line of stream.byLine()) {
				buf += this.renderLine(line, opts);
			}
		}
		buf += `</div>`;
		if (day !== LogReader.today()) {
			const nextDay = LogReader.nextDay(day);
			buf += `<p><a roomid="view-chatlog-${roomid}--${nextDay}" class="blocklink" style="text-align:center">${nextDay}<br />▼</a></p>`;
		}

		buf += `</div>`;
		return this.linkify(buf);
	}

	renderDayResults(results: {[day: string]: SearchMatch[]}, roomid: RoomID) {
		const renderResult = (match: SearchMatch) => {
			this.results++;
			return (
				this.renderLine(match[0]) +
				this.renderLine(match[1]) +
				`<div class="chat chatmessage highlighted">${this.renderLine(match[2])}</div>` +
				this.renderLine(match[3]) +
				this.renderLine(match[4])
			);
		};

		let buf = ``;
		for (const day in results) {
			const dayResults = results[day];
			const plural = dayResults.length !== 1 ? "es" : "";
			buf += `<details><summary>${dayResults.length} match${plural} on `;
			buf += `<a href="view-chatlog-${roomid}--${day}">${day}</a></summary><br /><hr />`;
			buf += `<p>${dayResults.filter(Boolean).map(result => renderResult(result)).join(`<hr />`)}</p>`;
			buf += `</details><hr />`;
		}
		return buf;
	}

	async searchMonth(roomid: RoomID, month: string, search: string, limit: number, year = false) {
		const {results, total} = await LogSearcher.fsSearchMonth({room: roomid, date: month, search, limit});
		if (!total) {
			return LogViewer.error(`No matches found for ${search} on ${roomid}.`);
		}

		let buf = (
			`<br /><div class="pad"><strong>Searching for "${search}" in ${roomid} (${month}):</strong><hr />`
		);
		buf += this.renderDayResults(results, roomid);
		if (total > limit) {
			// cap is met & is not being used in a year read
			buf += `<br /><strong>Max results reached, capped at ${limit}</strong>`;
			buf += `<br /><div style="text-align:center">`;
			if (total < MAX_RESULTS) {
				buf += `<button class="button" name="send" value="/sl ${search},room:${roomid},date:${month},limit:${limit + 100}">View 100 more<br />&#x25bc;</button>`;
				buf += `<button class="button" name="send" value="/sl ${search},room:${roomid},date:${month},limit:3000">View all<br />&#x25bc;</button></div>`;
			}
		}
		buf += `</div>`;
		this.results = 0;
		return buf;
	}

	async searchYear(roomid: RoomID, year: string | null, search: string, limit: number) {
		const {results, total} = await LogSearcher.fsSearchYear(roomid, year, search, limit);
		if (!total) {
			return LogViewer.error(`No matches found for ${search} on ${roomid}.`);
		}
		let buf = '';
		if (year) {
			buf += `<div class="pad"><strong><br />Searching year: ${year}: </strong><hr />`;
		}	else {
			buf += `<div class="pad"><strong><br />Searching all logs: </strong><hr />`;
		}
		buf += this.renderDayResults(results, roomid);
		if (total > limit) {
			// cap is met
			buf += `<br /><strong>Max results reached, capped at ${total > limit ? limit : MAX_RESULTS}</strong>`;
			buf += `<br /><div style="text-align:center">`;
			if (total < MAX_RESULTS) {
				buf += `<button class="button" name="send" value="/sl ${search}|${roomid}|${year}|${limit + 100}">View 100 more<br />&#x25bc;</button>`;
				buf += `<button class="button" name="send" value="/sl ${search}|${roomid}|${year}|all">View all<br />&#x25bc;</button></div>`;
			}
		}
		this.results = 0;
		return buf;
	}

	renderLine(fullLine: string, opts?: string) {
		if (!fullLine) return ``;
		if (opts === 'txt') return `<div class="chat">${fullLine}</div>`;
		let timestamp = fullLine.slice(0, opts ? 8 : 5);
		let line;
		if (/^[0-9:]+$/.test(timestamp)) {
			line = fullLine.charAt(9) === '|' ? fullLine.slice(10) : '|' + fullLine.slice(9);
		} else {
			timestamp = '';
			line = '!NT|';
		}
		if (opts !== 'all' && (
			line.startsWith(`userstats|`) ||
			line.startsWith('J|') || line.startsWith('L|') || line.startsWith('N|')
		)) return ``;

		const cmd = line.slice(0, line.indexOf('|'));
		if (opts?.includes('onlychat')) {
			if (cmd !== 'c') return '';
			if (opts.includes('txt')) return `<div class="chat">${fullLine}</div>`;
		}
		switch (cmd) {
		case 'c': {
			const [, name, message] = Utils.splitFirst(line, '|', 2);
			if (name.length <= 1) {
				return `<div class="chat"><small>[${timestamp}] </small><q>${Chat.formatText(message)}</q></div>`;
			}
			if (message.startsWith(`/log `)) {
				return `<div class="chat"><small>[${timestamp}] </small><q>${Chat.formatText(message.slice(5))}</q></div>`;
			}
			if (message.startsWith(`/raw `)) {
				return `<div class="notice">${message.slice(5)}</div>`;
			}
			if (message.startsWith(`/uhtml `) || message.startsWith(`/uhtmlchange `)) {
				if (message.startsWith(`/uhtmlchange `)) return ``;
				if (opts !== 'all') return `<div class="notice">[uhtml box hidden]</div>`;
				return `<div class="notice">${message.slice(message.indexOf(',') + 1)}</div>`;
			}
			const group = !name.startsWith(' ') ? `<small>${name.charAt(0)}</small>` : ``;
			return `<div class="chat"><small>[${timestamp}] </small><strong>${group}${Utils.escapeHTML(name.slice(1))}:</strong> <q>${Chat.formatText(message)}</q></div>`;
		}
		case 'html': case 'raw': {
			const [, html] = Utils.splitFirst(line, '|', 1);
			return `<div class="notice">${html}</div>`;
		}
		case 'uhtml': case 'uhtmlchange': {
			if (cmd !== 'uhtml') return ``;
			const [, , html] = Utils.splitFirst(line, '|', 2);
			return `<div class="notice">${html}</div>`;
		}
		case '!NT':
			return `<div class="chat">${Utils.escapeHTML(fullLine)}</div>`;
		case '':
			return `<div class="chat"><small>[${timestamp}] </small>${Utils.escapeHTML(line.slice(1))}</div>`;
		default:
			return `<div class="chat"><small>[${timestamp}] </small><code>${'|' + Utils.escapeHTML(line)}</code></div>`;
		}
	}

	async month(roomid: RoomID, month: string) {
		let buf = `<div class="pad"><p>` +
			`<a roomid="view-chatlog">◂ All logs</a> / ` +
			`<a roomid="view-chatlog-${roomid}">${roomid}</a> / ` +
			`<strong>${month}</strong></p><hr />`;

		const roomLog = await LogReader.get(roomid);
		if (!roomLog) {
			buf += `<p class="message-error">Room "${roomid}" doesn't exist</p></div>`;
			return this.linkify(buf);
		}

		const prevMonth = LogReader.prevMonth(month);
		buf += `<p><a roomid="view-chatlog-${roomid}--${prevMonth}" class="blocklink" style="text-align:center">▲<br />${prevMonth}</a></p><div>`;

		const days = await roomLog.listDays(month);
		if (!days.length) {
			buf += `<p class="message-error">Room "${roomid}" doesn't have logs in ${month}</p></div>`;
			return this.linkify(buf);
		} else {
			for (const day of days) {
				buf += `<p>- <a roomid="view-chatlog-${roomid}--${day}">${day}</a> <small>`;
				for (const opt of ['txt', 'onlychat', 'all', 'txt-onlychat']) {
					buf += ` (<a roomid="view-chatlog-${roomid}--${day}--${opt}">${opt}</a>) `;
				}
				buf += `</small></p>`;
			}
		}

		if (!LogReader.today().startsWith(month)) {
			const nextMonth = LogReader.nextMonth(month);
			buf += `<p><a roomid="view-chatlog-${roomid}--${nextMonth}" class="blocklink" style="text-align:center">${nextMonth}<br />▼</a></p>`;
		}

		buf += `</div>`;
		return this.linkify(buf);
	}
	async room(roomid: RoomID) {
		let buf = `<div class="pad"><p>` +
			`<a roomid="view-chatlog">◂ All logs</a> / ` +
			`<strong>${roomid}</strong></p><hr />`;

		const roomLog = await LogReader.get(roomid);
		if (!roomLog) {
			buf += `<p class="message-error">Room "${roomid}" doesn't exist</p></div>`;
			return this.linkify(buf);
		}

		const months = await roomLog.listMonths();
		if (!months.length) {
			buf += `<p class="message-error">Room "${roomid}" doesn't have logs</p></div>`;
			return this.linkify(buf);
		}

		for (const month of months) {
			buf += `<p>- <a roomid="view-chatlog-${roomid}--${month}">${month}</a></p>`;
		}
		buf += `</div>`;
		return this.linkify(buf);
	}
	async list(user: User, opts?: string) {
		let buf = `<div class="pad"><p>` +
			`<strong>All logs</strong></p><hr />`;

		const categories: {[k: string]: string} = {
			'official': "Official",
			'normal': "Public",
			'hidden': "Hidden",
			'secret': "Secret",
			'deleted': "Deleted",
			'personal': "Personal",
			'deletedPersonal': "Deleted Personal",
		};
		const list = await LogReader.listCategorized(user, opts) as {[k: string]: RoomID[]};

		if (!list) {
			buf += `<p class="message-error">You must be a staff member of a room to view its logs</p></div>`;
			return buf;
		}

		const showPersonalLink = opts !== 'all' && user.can('rangeban');
		for (const k in categories) {
			if (!list[k].length && !(['personal', 'deleted'].includes(k) && showPersonalLink)) {
				continue;
			}
			buf += `<p>${categories[k]}</p>`;
			if (k === 'personal' && showPersonalLink) {
				if (opts !== 'help') buf += `<p>- <a roomid="view-chatlog--help">(show all help)</a></p>`;
				if (opts !== 'groupchat') buf += `<p>- <a roomid="view-chatlog--groupchat">(show all groupchat)</a></p>`;
			}
			if (k === 'deleted' && showPersonalLink) {
				if (opts !== 'deleted') buf += `<p>- <a roomid="view-chatlog--deleted">(show deleted)</a></p>`;
			}
			for (const roomid of list[k]) {
				buf += `<p>- <a roomid="view-chatlog-${roomid}">${roomid}</a></p>`;
			}
		}
		buf += `</div>`;
		return this.linkify(buf);
	}
	error(message: string) {
		return `<div class="pad"><p class="message-error">${message}</p></div>`;
	}
	linkify(buf: string) {
		return buf.replace(/<a roomid="/g, `<a target="replace" href="/`);
	}
};

/** Match with two lines of context in either direction */
type SearchMatch = readonly [string, string, string, string, string];

export const LogSearcher = new class {
	async runSearch(
		context: PageContext, search: string, roomid: RoomID, date: string | null, limit: number | null
	) {
		context.title = `[Search] [${roomid}] ${search}`;
		if (!['ripgrep', 'fs'].includes(Config.chatlogreader)) {
			throw new Error(`Config.chatlogreader must be 'fs' or 'ripgrep'.`);
		}
		context.send(
			`<div class="pad"><h2>Running a chatlog search for "${search}" on room ${roomid}` +
			(date ? date !== 'all' ? `, on the date "${date}"` : ', on all dates' : '') +
			`.</h2></div>`
		);
		const response = await PM.query({search, roomid, date, limit, queryType: 'search'});
		return context.send(response);
	}
	constructSearchRegex(str: string) {
		// modified regex replace
		str = str.replace(/[\\^$.*?()[\]{}|]/g, '\\$&');
		const searches = str.split('+');
		if (searches.length <= 1) {
			if (str.length <= 3) return `\b${str}`;
			return str;
		}

		return `^` + searches.map(term => `(?=.*${term})`).join('');
	}
	constructUserRegex(user: string) {
		const id = toID(user);
		return `.${[...id].join('[^a-zA-Z0-9]*')}[^a-zA-Z0-9]*`;
	}

	fsSearch(roomid: RoomID, search: string, date: string, limit: number | null) {
		const isAll = (date === 'all');
		const isYear = (date.length === 4);
		const isMonth = (date.length === 7);
		if (!limit || limit > MAX_RESULTS) limit = MAX_RESULTS;
		if (isAll) {
			return LogViewer.searchYear(roomid, null, search, limit);
		} else if (isYear) {
			date = date.substr(0, 4);
			return LogViewer.searchYear(roomid, date, search, limit);
		} else if (isMonth) {
			date = date.substr(0, 7);
			return LogViewer.searchMonth(roomid, date, search, limit);
		} else {
			return LogViewer.error("Invalid date.");
		}
	}

	async fsSearchDay(roomid: RoomID, day: string, search: string, limit?: number | null) {
		if (!limit || limit > MAX_RESULTS) limit = MAX_RESULTS;
		const text = await LogReader.read(roomid, day, limit);
		if (!text) return [];
		const lines = text.split('\n');
		const matches: SearchMatch[] = [];

		const searchTerms = search.split('+');
		const searchTermRegexes = searchTerms.map(term => new RegExp(term, 'i'));
		function matchLine(line: string) {
			return searchTermRegexes.every(term => term.test(line));
		}

		for (const [i, line] of lines.entries()) {
			if (matchLine(line)) {
				matches.push([
					lines[i - 2],
					lines[i - 1],
					line,
					lines[i + 1],
					lines[i + 2],
				]);
				if (matches.length > limit) break;
			}
		}
		return matches;
	}

	async fsSearchMonth(opts: ChatlogSearch) {
		let {limit, room: roomid, date: month, search} = opts;
		if (!limit || limit > MAX_RESULTS) limit = MAX_RESULTS;
		const log = await LogReader.get(roomid);
		if (!log) return {results: {}, total: 0};
		const days = await log.listDays(month);
		const results: {[k: string]: SearchMatch[]} = {};
		let total = 0;

		for (const day of days) {
			const dayResults = await this.fsSearchDay(roomid, day, search, limit ? limit - total : null);
			if (!dayResults.length) continue;
			total += dayResults.length;
			results[day] = dayResults;
			if (total > limit) break;
		}
		return {results, total};
	}

	/** pass a null `year` to search all-time */
	async fsSearchYear(roomid: RoomID, year: string | null, search: string, limit?: number | null) {
		if (!limit || limit > MAX_RESULTS) limit = MAX_RESULTS;
		const log = await LogReader.get(roomid);
		if (!log) return {results: {}, total: 0};
		let months = await log.listMonths();
		months = months.reverse();
		const results: {[k: string]: SearchMatch[]} = {};
		let total = 0;

		for (const month of months) {
			if (year && !month.includes(year)) continue;
			const monthSearch = await this.fsSearchMonth({room: roomid, date: month, search, limit});
			const {results: monthResults, total: monthTotal} = monthSearch;
			if (!monthTotal) continue;
			total += monthTotal;
			Object.assign(results, monthResults);
			if (total > limit) break;
		}
		return {results, total};
	}
	async ripgrepSearchMonth(opts: ChatlogSearch) {
		let {raw, search, room: roomid, date: month, args} = opts;
		let results: string[];
		let count = 0;
		if (!raw) {
			search = this.constructSearchRegex(search);
		}
		const resultSep = args?.includes('-m') ? '--' : '\n';
		try {
			const options = [
				'-e', search,
				`logs/chat/${roomid}/${month}`,
				'-i',
			];
			if (args) {
				options.push(...args);
			}
			const {stdout} = await execFile('rg', options, {
				maxBuffer: MAX_MEMORY,
				cwd: path.normalize(`${__dirname}/../../`),
			});
			results = stdout.split(resultSep);
		} catch (e) {
			if (e.code !== 1 && !e.message.includes('stdout maxBuffer') && !e.message.includes('No such file or directory')) {
				throw e; // 2 means an error in ripgrep
			}
			if (e.stdout) {
				results = e.stdout.split(resultSep);
			} else {
				results = [];
			}
		}
		count += results.length;
		return {results, count};
	}
	async ripgrepSearch(
		roomid: RoomID,
		search: string,
		limit?: number | null,
		date?: string | null
	) {
		if (date) {
			// if it's more than 7 chars, assume it's a month
			if (date.length > 7) date = date.substr(0, 7);
			// if it's less, assume they were trying a year
			else if (date.length < 7) date = date.substr(0, 4);
		}
		const months = (date && toID(date) !== 'all' ? [date] : await new LogReaderRoom(roomid).listMonths()).reverse();
		let count = 0;
		let results: string[] = [];
		if (!limit || limit > MAX_RESULTS) limit = MAX_RESULTS;
		if (!date) date = 'all';
		while (count < MAX_RESULTS) {
			const month = months.shift();
			if (!month) break;
			const output = await this.ripgrepSearchMonth({
				room: roomid, search, date: month,
				limit, args: [`-m`, `${limit}`, '-C', '3', '-P'],
			});
			results = results.concat(output.results);
			count += output.count;
		}
		if (count > MAX_RESULTS) {
			const diff = count - MAX_RESULTS;
			results = results.slice(0, -diff);
		}
		return this.renderSearchResults(results, roomid, search, limit, date);
	}

	renderSearchResults(results: string[], roomid: RoomID, search: string, limit: number, month?: string | null) {
		results = results.filter(Boolean);
		if (results.length < 1) return LogViewer.error('No results found.');
		let exactMatches = 0;
		let curDate = '';
		if (limit > MAX_RESULTS) limit = MAX_RESULTS;
		const searchRegex = new RegExp(this.constructSearchRegex(search), "i");
		const sorted = results.sort((aLine, bLine) => {
			const [aName] = aLine.split('.txt');
			const [bName] = bLine.split('.txt');
			const aDate = new Date(aName.split('/').pop()!);
			const bDate = new Date(bName.split('/').pop()!);
			return bDate.getTime() - aDate.getTime();
		}).map(chunk => chunk.split('\n').map(line => {
			if (exactMatches > limit || !toID(line)) return null; // return early so we don't keep sorting
			const sep = line.includes('.txt-') ? '.txt-' : '.txt:';
			const [name, text] = line.split(sep);
			line = LogViewer.renderLine(text, 'all');
			if (!line || name.includes('today')) return null;
				 // gets rid of some edge cases / duplicates
			let date = name.replace(`logs/chat/${roomid}${toID(month) === 'all' ? '' : `/${month}`}`, '').slice(9);
			if (searchRegex.test(line)) {
				if (++exactMatches > limit) return null;
				line = `<div class="chat chatmessage highlighted">${line}</div>`;
			}
			if (curDate !== date) {
				curDate = date;
				date = `</div></details><details open><summary>[<a href="view-chatlog-${roomid}--${date}">${date}</a>]</summary>`;
			} else {
				date = '';
			}
			return `${date} ${line}`;
		}).filter(Boolean).join(' ')).filter(Boolean);
		let buf = `<div class ="pad"><strong>Results on ${roomid} for ${search}:</strong>`;
		buf += limit ? ` ${exactMatches} (capped at ${limit})` : '';
		buf += `<hr /></div><blockquote>`;
		buf += sorted.join('<hr />');
		if (limit) {
			buf += `</details></blockquote><div class="pad"><hr /><strong>Capped at ${limit}.</strong><br />`;
			buf += `<button class="button" name="send" value="/sl ${search},room:${roomid},limit:${limit + 200}">View 200 more<br />&#x25bc;</button>`;
			buf += `<button class="button" name="send" value="/sl ${search},room:${roomid},limit:3000">View all<br />&#x25bc;</button></div>`;
		}
		return buf;
	}
	async runLinecountSearch(context: PageContext, roomid: RoomID, month: string, user?: ID) {
		context.send(
			`<div class="pad"><h2>Searching linecounts on room ${roomid}${user ? ` for the user ${user}` : ''}.</h2></div>`
		);
		const results = await PM.query({roomid, date: month, search: user, queryType: 'linecount'});
		context.send(results);
	}
	async ripgrepSearchLinecounts(room: RoomID, month: string, user?: ID) {
		// don't need to check if logs exist since ripgrepSearchMonth does that
		// eslint-disable-next-line no-useless-escape
		const regexString = user ? `\\|c\\|${this.constructUserRegex(user)}\\|` : `\\|c\\|`;
		const args = [user ? '--count' : ''];
		const response = await this.ripgrepSearchMonth({
			search: regexString, raw: true, date: month, room, args,
		});
		const rawResults = response.results;
		if (!rawResults.length) return LogViewer.error(`No results found.`);
		const results: {[k: string]: {[userid: string]: number}} = {};
		for (const fullLine of rawResults) {
			const [data, line] = fullLine.split('.txt:');
			const date = data.split('/').pop()!;
			if (!results[date]) results[date] = {};
			if (!toID(date)) continue;
			if (user) {
				if (!results[date][user]) results[date][user] = 0;
				const parsed = parseInt(line);
				results[date][user] += isNaN(parsed) ? 0 : parsed;
			} else {
				const parts = line?.split('|').map(toID);
				if (!parts || parts[1] !== 'c') continue;
				const id = parts[2];
				if (!id) continue;
				if (!results[date][id]) results[date][id] = 0;
				results[date][id]++;
			}
		}
		return this.renderLinecountResults(results, room, month, user);
	}
	async fsSearchLinecounts(roomid: RoomID, month: string, user?: ID) {
		const directory = FS(`logs/chat/${roomid}/${month}`);
		if (!directory.existsSync()) {
			throw new Chat.ErrorMessage(`Logs for month '${month}' do not exist on room ${roomid}.`);
		}
		const files = await directory.readdir();
		const results: {[date: string]: {[userid: string]: number}} = {};
		for (const file of files) {
			const day = file.slice(0, -4);
			const stream = FS(`logs/chat/${roomid}/${month}/${file}`).createReadStream();
			for await (const line of stream.byLine()) {
				const parts = line.split('|').map(toID);
				const id = parts[2];
				if (!id) continue;
				if (parts[1] === 'c') {
					if (user && id !== user) continue;
					if (!results[day]) results[day] = {};
					if (!results[day][id]) results[day][id] = 0;
					results[day][id]++;
				}
			}
		}
		return this.renderLinecountResults(results, roomid, month, user);
	}
	renderLinecountResults(
		results: {[date: string]: {[userid: string]: number}},
		roomid: RoomID, month: string, user?: ID
	) {
		let buf = Utils.html`<div class="pad"><h2>Linecounts on `;
		buf += `${roomid}${user ? ` for the user ${user}` : ` (top ${MAX_TOPUSERS})`}</h2>`;
		buf += `<strong>Month: ${month}:</strong><br />`;
		const nextMonth = LogReader.nextMonth(month);
		const prevMonth = LogReader.prevMonth(month);
		if (FS(`logs/chat/${roomid}/${prevMonth}`).existsSync()) {
			buf += `<small><a roomid="view-roomstats-${roomid}--${prevMonth}${user ? `--${user}` : ''}">Previous month</a></small>`;
		}
		if (FS(`logs/chat/${roomid}/${nextMonth}`).existsSync()) {
			buf += ` <small><a roomid="view-roomstats-${roomid}--${nextMonth}${user ? `--${user}` : ''}">Next month</a></small>`;
		}
		buf += `<hr /><ol>`;
		if (user) {
			const sortedDays = Object.keys(results).sort((a, b) => (
				new Date(b).getTime() - new Date(a).getTime()
			));
			for (const day of sortedDays) {
				const dayResults = results[day][user];
				if (isNaN(dayResults)) continue;
				buf += `<li>[<a roomid="view-chatlog-${roomid}--${day}">${day}</a>]: `;
				buf += `${Chat.count(dayResults, 'lines')}</li>`;
			}
		} else {
			// squish the results together
			const totalResults: {[k: string]: number} = {};
			for (const date in results) {
				for (const userid in results[date]) {
					if (!totalResults[userid]) totalResults[userid] = 0;
					totalResults[userid] += results[date][userid];
				}
			}
			const resultKeys = Object.keys(totalResults);
			const sortedResults = resultKeys.sort((a, b) => (
				totalResults[b] - totalResults[a]
			)).slice(0, MAX_TOPUSERS);
			for (const userid of sortedResults) {
				buf += `<li><span class="username"><username>${userid}</username></span>: `;
				buf += `${Chat.count(totalResults[userid], 'lines')}</li>`;
			}
		}
		buf += `</div>`;
		return LogViewer.linkify(buf);
	}
};


export const PM = new QueryProcessManager<AnyObject, string | undefined>(module, async data => {
	try {
		const {date, search, roomid, limit, queryType} = data;
		switch (queryType) {
		case 'linecount':
			switch (Config.chatlogreader) {
			case 'fs':
				return await LogSearcher.fsSearchLinecounts(roomid, date, search);
			case 'ripgrep':
				return await LogSearcher.ripgrepSearchLinecounts(roomid, date, search);
			default: break;
			}
			break;
		case 'search':
			switch (Config.chatlogreader) {
			case 'fs':
				return await LogSearcher.fsSearch(roomid, search, date, limit);
			case 'ripgrep':
				return await LogSearcher.ripgrepSearch(roomid, search, limit, date);
			} // eslint-disable-next-line no-fallthrough
		default:
			return LogViewer.error(`Config.chatlogreader is not configured.`);
		}
	} catch (e) {
		if (e.name?.endsWith('ErrorMessage')) {
			return LogViewer.error(e.message);
		}
		Monitor.crashlog(e, 'A chatlog search query', data);
		return LogViewer.error(`Sorry! Your chatlog search crashed. We've been notified and will fix this.`);
	}
});

if (!PM.isParentProcess) {
	// This is a child process!
	global.Config = Config;
	global.Monitor = {
		crashlog(error: Error, source = 'A chatlog search process', details: AnyObject | null = null) {
			const repr = JSON.stringify([error.name, error.message, source, details]);
			process.send!(`THROW\n@!!@${repr}\n${error.stack}`);
		},
	};
	global.Chat = Chat;
	process.on('uncaughtException', err => {
		if (Config.crashguard) {
			Monitor.crashlog(err, 'A chatlog search child process');
		}
	});
	global.Dex = Dex;
	global.toID = Dex.toID;
	// eslint-disable-next-line no-eval
	Repl.start('chatlog', cmd => eval(cmd));
} else {
	PM.spawn(MAX_PROCESSES);
}

const accessLog = FS(`logs/chatlog-access.txt`).createAppendStream();

export const pages: PageTable = {
	async chatlog(args, user, connection) {
		if (!user.named) return Rooms.RETRY_AFTER_LOGIN;
		if (!user.trusted) {
			return this.errorReply("Access denied.");
		}
		let [roomid, date, opts] = Utils.splitFirst(args.join('-'), '--', 2) as
			[RoomID, string | undefined, string | undefined];
		if (date) date = date.trim();
		if (!roomid || roomid.startsWith('-')) {
			this.title = '[Logs]';
			return LogViewer.list(user, roomid?.slice(1));
		}

		// permission check
		const room = Rooms.get(roomid);
		if (roomid.startsWith('spl') && roomid !== 'splatoon' && !user.can('rangeban')) {
			return this.errorReply("SPL team discussions are super secret.");
		}
		if (roomid.startsWith('wcop') && !user.can('rangeban')) {
			return this.errorReply("WCOP team discussions are super secret.");
		}
		if (room) {
			if (!user.can('lock')) {
				if (!room.persist) return this.errorReply(`Access denied.`);
				this.checkCan('mute', null, room);
			}
		} else {
			this.checkCan('lock');
		}

		void accessLog.writeLine(`${user.id}: <${roomid}> ${date}`);
		this.title = '[Logs] ' + roomid;
		/** null = no limit */
		let limit: number | null = null;
		let search;
		if (opts?.startsWith('search-')) {
			let [input, limitString] = opts.split('--limit-');
			input = input.slice(7);
			search = Dashycode.decode(input);
			if (search.length < 3) return this.errorReply(`That's too short of a search query.`);
			if (limitString) {
				limit = parseInt(limitString) || null;
			} else {
				limit = 500;
			}
			opts = '';
		}
		const isAll = (toID(date) === 'all' || toID(date) === 'alltime');

		const parsedDate = new Date(date as string);
		const validDateStrings = ['all', 'alltime', 'today'];
		// this is apparently the best way to tell if a date is invalid
		if (date && isNaN(parsedDate.getTime()) && !validDateStrings.includes(toID(date))) {
			return this.errorReply(`Invalid date.`);
		}

		if (date && search) {
			return LogSearcher.runSearch(this, search, roomid, isAll ? null : date, limit);
		} else if (date) {
			if (date === 'today') {
				return LogViewer.day(roomid, LogReader.today(), opts);
			} else if (date.split('-').length === 3) {
				return LogViewer.day(roomid, parsedDate.toISOString().slice(0, 10), opts);
			} else {
				return LogViewer.month(roomid, parsedDate.toISOString().slice(0, 7));
			}
		} else {
			return LogViewer.room(roomid);
		}
	},
	roomstats(args, user) {
		const room = this.extractRoom();
		if (room) {
			this.checkCan('mute', null, room);
		} else {
			if (!user.can('bypassall')) {
				return this.errorReply(`You cannot view logs for rooms that no longer exist.`);
			}
		}
		const [, date, target] = Utils.splitFirst(args.join('-'), '--', 3).map(item => item.trim());
		if (isNaN(new Date(date).getTime())) {
			return this.errorReply(`Invalid date.`);
		}
		this.title = `[Log Stats] ${date}`;
		return LogSearcher.runLinecountSearch(this, room ? room.roomid : args[2] as RoomID, date, toID(target));
	},
};

export const commands: ChatCommands = {
	chatlog(target, room, user) {
		const [tarRoom, ...opts] = target.split(',');
		const targetRoom = tarRoom ? Rooms.search(tarRoom) : room;
		const roomid = targetRoom ? targetRoom.roomid : target;
		this.parse(`/join view-chatlog-${roomid}--today${opts ? `--${opts.join('--')}` : ''}`);
	},

	chatloghelp() {
		const strings = [
			`/chatlog [optional room], [opts] - View chatlogs from the given room. `,
			`If none is specified, shows logs from the room you're in. Requires: % @ * # &`,
			`Supported options:`,
			`<code>txt</code> - Do not render logs.`,
			`<code>txt-onlychat</code> - Show only chat lines, untransformed.`,
			`<code>onlychat</code> - Show only chat lines.`,
			`<code>all</code> - Show all lines, including userstats and join/leave messages.`,
		];
		this.runBroadcast();
		return this.sendReplyBox(strings.join('<br />'));
	},

	sl: 'searchlogs',
	logsearch: 'searchlogs',
	searchlog: 'searchlogs',
	searchlogs(target, room) {
		target = target.trim();
		const args = target.split(',').map(item => item.trim());
		if (!target) return this.parse('/help searchlogs');
		let date = 'all';
		const searches: string[] = [];
		let limit = '500';
		for (const arg of args) {
			if (arg.startsWith('room:')) {
				const id = arg.slice(5);
				room = Rooms.search(id as RoomID) as Room | null;
				if (!room) {
					return this.errorReply(`Room "${id}" not found.`);
				}
			} else if (arg.startsWith('limit:')) {
				limit = arg.slice(6);
			} else if (arg.startsWith('date:')) {
				date = arg.slice(5);
			} else {
				searches.push(arg);
			}
		}
		if (!room) {
			return this.parse(`/help searchlogs`);
		}
		return this.parse(
			`/join view-chatlog-${room.roomid}--${date}--search-${Dashycode.encode(searches.join('+'))}--limit-${limit}`
		);
	},
	searchlogshelp() {
		const buffer = `<details class="readmore"><summary><code>/searchlogs [arguments]</code>: ` +
			`searches logs in the current room using the <code>[arguments]</code>.</summary>` +
			`A room can be specified using the argument <code>room: [roomid]</code>. Defaults to the room it is used in.<br />` +
			`A limit can be specified using the argument <code>limit: [number less than or equal to 3000]</code>. Defaults to 500.<br />` +
			`A date can be specified in ISO (YYYY-MM-DD) format using the argument <code>date: [month]</code> (for example, <code>date: 2020-05</code>). Defaults to searching all logs.<br />` +
			`All other arguments will be considered part of the search ` +
			`(if more than one argument is specified, it searches for lines containing all terms).<br />` +
			"Requires: % @ # &</div>";
		return this.sendReplyBox(buffer);
	},
	topusers: 'linecount',
	roomstats: 'linecount',
	linecount(target, room, user) {
		let [roomid, month, userid] = target.split(',').map(item => item.trim());
		const tarRoom = roomid ? toID(roomid) : room?.roomid;
		if (!tarRoom) return this.errorReply(`You must specify a room.`);
		if (!month) month = LogReader.getMonth();
		return this.parse(`/join view-roomstats-${tarRoom}--${month}--${toID(userid)}`);
	},
	linecounthelp: [
		`/topusers OR /linecount [room], [month], [userid] - View room stats in the given [room].`,
		`If a user is provided, searches only for that user, else the top 100 users are shown.`,
		`Requires: % @ # &`,
	],
};