'use strict';

const util = require('util');
const stream = require('stream');
const config = require('config');
const tunnel = require('tunnel');
const bhttp = require('bhttp');
const taskQueue = require('promise-task-queue');

const pipeline = util.promisify(stream.pipeline);
const logger = require('../logger')(__filename);

const defaultHeaders = {
	'user-agent': 'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:15.0) Gecko/20100101 Firefox/15.0.1',
};

const defaultOptions = {
	responseTimeout: 30000,
};

const proxyAgent = tunnel.httpsOverHttp({
	proxy: {
		host: config.proxy.host,
		port: config.proxy.port,
	},
});

function useProxy(url) {
	if (!config.proxy.enable) {
		return false;
	}

	const { hostname } = new URL(url);
	return config.proxy.hostnames.includes(hostname);
}

const queue = taskQueue();
const defaultQueueMethod = '20p';

async function handler({
	url,
	method = 'GET',
	body,
	headers = {},
	options = {},
}) {
	if (body) {
		logger.silly(`${method.toUpperCase()} ${url} with ${JSON.stringify(body)} ${options.queueMethod || defaultQueueMethod}`);
	} else {
		logger.silly(`${method.toUpperCase()} ${url} ${options.queueMethod || defaultQueueMethod}`);
	}

	const reqOptions = {
		headers: {
			...(options?.defaultHeaders !== false && defaultHeaders),
			...headers,
		},
		...defaultOptions,
		...options,
		...(options?.timeout && { responseTimeout: options?.timeout }),
	};

	if (useProxy(url)) {
		reqOptions.agent = proxyAgent;
	}

	const res = ['POST', 'PUT', 'PATCH'].includes(method.toUpperCase())
		? await (options.useSession || bhttp)[method.toLowerCase()](url, body, reqOptions)
		: await (options.useSession || bhttp)[method.toLowerCase()](url, reqOptions);

	if (options?.stream && options?.destination) {
		await pipeline(res, ...(options?.transforms || []), options?.destination);
	}

	const html = Buffer.isBuffer(res.body) ? res.body.toString() : null;
	const json = Buffer.isBuffer(res.body) ? null : res.body;

	return {
		...res,
		originalRes: res,
		html,
		json,
		pipe: res.pipe,
		ok: res.statusCode >= 200 && res.statusCode <= 299,
		code: res.statusCode,
		status: res.statusCode,
	};
}

queue.on('concurrencyReached:http', () => {
	logger.silly('Queueing requests');
});

queue.define('20p', handler, {
	concurrency: 20,
});

queue.define('1s', handler, {
	interval: 1,
});

queue.define('5s', handler, {
	interval: 5,
});

async function get(url, headers, options) {
	return queue.push(options?.queueMethod || defaultQueueMethod, {
		method: 'GET',
		url,
		headers,
		options,
	});
}

async function head(url, headers, options) {
	return queue.push(options?.queueMethod || defaultQueueMethod, {
		method: 'HEAD',
		url,
		headers,
		options,
	});
}

async function post(url, body, headers, options) {
	return queue.push(options?.queueMethod || defaultQueueMethod, {
		method: 'POST',
		url,
		body,
		headers,
		options,
	});
}

function session(headers, options) {
	return bhttp.session({
		headers,
		options,
	});
}

module.exports = {
	get,
	post,
	head,
	session,
};