'use strict';

const config = require('config');
const bhttp = require('bhttp');

const style = require('../utils/style');

const promptRegex = new RegExp(`^${config.usernamePrefix}?${config.user.username}[:,\\s]`, 'ui');
const history = new Map();

const settings = config.chat;

function setHistory(value, context) {
	if (!value) {
		context.sendMessage(`Chat history is set to ${style.bold(settings.history)}`, context.room.id, { label: false });
		return;
	}

	const newHistory = Number(value);

	if (!Number.isNaN(newHistory)) {
		settings.history = newHistory;

		context.logger.info(`Chat history set to ${newHistory} by ${context.user.username}`);
		context.sendMessage(`Chat history set to ${style.bold(newHistory)} by ${context.user.prefixedUsername}`, context.room.id, { label: false });

		return;
	}

	context.logger.info(`Chat history must be a valid number, ${context.user.prefixedUsername}`);
}

function setModel(model, context) {
	if (!model) {
		context.sendMessage(`Chat model is set to ${style.bold(settings.model)}`, context.room.id, { label: false });
		return;
	}

	if (config.chat.validModels.includes(model)) {
		settings.model = model;

		context.logger.info(`Chat model set to '${model}' by ${context.user.username}`);
		context.sendMessage(`Chat model set to '${style.bold(model)}' by ${context.user.prefixedUsername}`, context.room.id, { label: false });

		return;
	}

	context.logger.info(`Model '${model}' is not supported right now, ${context.user.prefixedUsername}`);
}

function setRule(rule, context) {
	if (!rule) {
		context.sendMessage(`Chat is ${style.bold(settings.rule)}`, context.room.id, { label: false });
		return;
	}

	if (rule === 'reset') {
		settings.rule = config.chat.rule;

		context.logger.info(`Chat reset by ${context.user.username} to be ${config.chat.rule}`);
		context.sendMessage(`Chat reset by ${context.user.prefixedUsername} to be ${style.bold(config.chat.rule)}`, context.room.id, { label: false });

		return;
	}

	if (rule.length > 3) {
		settings.rule = `${rule.replace(/\.+$/, '')}`;

		context.logger.info(`Chat set by ${context.user.username} to be ${rule}`);
		context.sendMessage(`Chat set by ${context.user.prefixedUsername} to be ${style.bold(rule)}`, context.room.id, { label: false });

		return;
	}

	context.sendMessage(`Chat rule must be at least 3 characters long, ${context.user.prefixedUsername}`, context.room.id, { label: false });
}

async function onCommand(args, context) {
	if (context.subcommand === 'history' && config.operators.includes(context.user.username)) {
		setHistory(args[0], context);
		return;
	}

	if (context.subcommand === 'model' && config.operators.includes(context.user.username)) {
		setModel(args[0], context);
		return;
	}

	if (['rule', 'is', 'reset'].includes(context.subcommand) && (config.chat.rulePublic || config.operators.includes(context.user.username))) {
		setRule(context.subcommand === 'reset' ? 'reset' : args.join(' '), context);
		return;
	}

	const prompt = args.join(' ');

	try {
		const message = {
			role: 'user',
			content: `Answer as if you're ${settings.rule}. ${prompt}`,
		};

		const userHistory = (history.get(context.user.username) || []).concat(message);

		context.logger.info(`${context.user.username} asked OpenAI '${config.chat.model}' (${userHistory.length}): ${message.content}`);

		const res = await bhttp.post('https://api.openai.com/v1/chat/completions', JSON.stringify({
			model: settings.model,
			messages: userHistory,
		}), {
			headers: {
				Authorization: `Bearer ${config.chat.apiKey}`,
				'Content-Type': 'application/json',
			},
		});

		const reply = res.body.choices?.[0].message;

		context.logger.info(`OpenAI ${config.chat.model} replied to ${context.user.username} (${res.body.usage.total_tokens} tokens): ${reply.content}`);
		context.sendMessage(`${context.user.prefixedUsername}: ${reply.content}`, context.room.id, { label: false });

		if (config.chat.history > 0) {
			history.set(context.user.username, userHistory.concat(reply).slice(-settings.history));
		}
	} catch (error) {
		context.logger.error(error.response ? `${error.response.status}: ${JSON.stringify(error.response.data)}` : error.message);
		context.sendMessage('Sorry, I can\'t think right now', context.room.id, { label: false });
	}
}

function onMessage(message, context) {
	if (promptRegex.test(message.body)) {
		onCommand([message.body.replace(promptRegex, '').trim()], context);
	}
}

module.exports = {
	onCommand,
	onMessage,
};