'use strict';
const bufferStream = require('./buffer-stream');

function getStream(inputStream, opts) {
	if (!inputStream) {
		return Promise.reject(new Error('Expected a stream'));
	}

	opts = Object.assign({maxBuffer: Infinity}, opts);

	const maxBuffer = opts.maxBuffer;
	let stream;
	let clean;

	const p = new Promise((resolve, reject) => {
		const error = err => {
			if (err) { // null check
				err.bufferedData = stream.getBufferedValue();
			}

			reject(err);
		};

		stream = bufferStream(opts);
		inputStream.once('error', error);
		inputStream.pipe(stream);

		stream.on('data', () => {
			if (stream.getBufferedLength() > maxBuffer) {
				reject(new Error('maxBuffer exceeded'));
			}
		});
		stream.once('error', error);
		stream.on('end', resolve);

		clean = () => {
			// some streams doesn't implement the `stream.Readable` interface correctly
			if (inputStream.unpipe) {
				inputStream.unpipe(stream);
			}
		};
	});

	p.then(clean, clean);

	return p.then(() => stream.getBufferedValue());
}

module.exports = getStream;
module.exports.buffer = (stream, opts) => getStream(stream, Object.assign({}, opts, {encoding: 'buffer'}));
module.exports.array = (stream, opts) => getStream(stream, Object.assign({}, opts, {array: true}));