'use strict';
const fs = require('fs');
const path = require('path');
const url = require('url');
const caw = require('caw');
const decompress = require('decompress');
const filenamify = require('filenamify');
const getStream = require('get-stream');
const got = require('got');
const mkdirp = require('mkdirp');
const pify = require('pify');

const fsP = pify(fs);

const createPromise = (uri, output, stream, opts) => {
	const response = opts.encoding === null ? getStream.buffer(stream) : getStream(stream, opts);

	return response.then(data => {
		if (!output && opts.extract) {
			return decompress(data, opts);
		}

		if (!output) {
			return data;
		}

		if (opts.extract) {
			return decompress(data, path.dirname(output), opts);
		}

		return pify(mkdirp)(path.dirname(output))
			.then(() => fsP.writeFile(output, data))
			.then(() => data);
	});
};

module.exports = (uri, output, opts) => {
	if (typeof output === 'object') {
		opts = output;
		output = null;
	}

	opts = Object.assign({
		encoding: null,
		rejectUnauthorized: process.env.npm_config_strict_ssl !== 'false'
	}, opts);

	let protocol = url.parse(uri).protocol;

	if (protocol) {
		protocol = protocol.slice(0, -1);
	}

	const agent = caw(opts.proxy, {protocol});
	const stream = got.stream(uri, Object.assign(opts, {agent}));
	const dest = output ? path.join(output, filenamify(path.basename(uri))) : null;
	const promise = createPromise(uri, dest, stream, opts);

	stream.then = promise.then.bind(promise);
	stream.catch = promise.catch.bind(promise);

	return stream;
};