var https = require("https");
var http = require("http");
var extend = require("./extend");
var HttpsProxyAgent = require("https-proxy-agent");
var userAgent = getUA();

function getUA() {
	var os = require("os");
	var version = require("../package.json").version;

	return os.platform() + "/" + os.release() + " " +
		"node/" + process.versions.node + " " +
		"node-browserstack/" + version;
}

var BaseClient = function(settings) {
	if (!settings.username) {
		throw new Error("Username is required.");
	}
	if (!settings.password) {
		throw new Error("Password is required.");
	}

	extend(this, settings);

	this.authHeader = "Basic " +
		Buffer.from(this.username + ":" + this.password).toString("base64");
};

BaseClient.prototype.request = function(options, data, fn) {
	if (typeof data === "function") {
		fn = data;
		data = null;
	}

	fn = fn || function() {};

	var reqOptions = extend({
		host: this.server.host,
		port: this.server.port,
		method: "GET",
		headers: {
			authorization: this.authHeader,
			"content-type": "application/json",
			"user-agent": userAgent,
			"content-length": typeof data === "string" ? data.length : 0
		},
		agent: (this.proxy) ? new HttpsProxyAgent(this.proxy) : null
	}, options);

	var req = (this.useHttp ? http : https).request(reqOptions, function(res) {
		var response = "";
		res.setEncoding("utf8");
		res.on("data", function(chunk) {
			response += chunk;
		});
		res.on("end", function() {
			if (res.statusCode !== 200) {
				var message;
				if (res.headers["content-type"].indexOf("json") !== -1) {
					response = JSON.parse(response);
					message = response.message;
					if (response.errors) {
						if (Array.isArray(response.errors) && response.errors.length) {
							message += " - " + response.errors.map(function(error) {
								return "`" + error.field + "` " + error.code;
							}).join(", ");
						} else {
							message += " - " + response.errors.toString();
						}
					}
				} else {
					message = response;
				}
				if (!message && res.statusCode === 403) {
					message = "Forbidden";
				}
				fn(new Error(message));
			} else {
				fn(null, JSON.parse(response));
			}
		});
	});

	req.on("error", fn);

	if (data) {
		req.write(data);
	}

	req.end();
};

module.exports = BaseClient;