"use strict";

const net = require("net");
const Promise = require("bluebird");
const chalk = require("chalk");

const CRLF = "\r\n";

module.exports = function createMockServer({ steps, test, handle = ()=>{} }) {
	let counter = 0;

	const server = net.createServer((socket) => {
		let buffer = "";

		socket.write("* OK asdf\r\n");

		socket.on("data", (data) => {
			buffer += data.toString("utf8");
			
			if (buffer.includes(CRLF)) {
				let lines = buffer.split(CRLF);
				buffer = lines.pop();

				Promise.map(lines, (line) => {
					return Promise.try(() => {
						console.log(chalk.gray(line));
						
						return handle(line);
					}).then((result) => {
						if (result == null) {
							let step = steps[counter];
							counter += 1;
			
							if (step.expected != null) {
								test.same(line, step.expected);
							}
							
							return (typeof step.response === "function")
								? step.response()
								: step.response;
						} else {
							return result;
						}
					}).then((response) => {
						socket.write(response);
					});
				}, { concurrency: 1 });
			}
		});
	});

	return new Promise((resolve, reject) => {
		server.listen(0, "127.0.0.1", () => {
			// FIXME: Error condition?
			resolve({
				server: server,
				port: server.address().port,
				finalize: function () {
					if (counter < steps.length) {
						test.ok(false, `Mock server expected ${steps.length} steps but only saw ${counter}`);
					}
				}
			});
		});
	});
};