var app = require('http').createServer(handler)
	, sockets = require('./sockets.js')
	, log = require("./log.js").log
	, path = require('path')
	, url = require('url')
	, fs = require("fs")
	, crypto = require("crypto")
	, serveStatic = require("serve-static")
	, createSVG = require("./createSVG.js")
	, templating = require("./templating.js")
	, config = require("./configuration.js");


var MIN_NODE_VERSION = 10.0;

if (parseFloat(process.versions.node) < MIN_NODE_VERSION) {
	console.warn(
		"!!! You are using node " + process.version +
		", wbo requires at least " + MIN_NODE_VERSION + " !!!");
}

var io = sockets.start(app);

app.listen(config.PORT);
log("server started", { port: config.PORT });

var CSP = "default-src 'self'; style-src 'self' 'unsafe-inline'; connect-src 'self' ws: wss:";

var fileserver = serveStatic(config.WEBROOT, {
	maxAge: 2 * 3600 * 1000,
	setHeaders: function (res) {
		res.setHeader("X-UA-Compatible", "IE=Edge");
		res.setHeader("Content-Security-Policy", CSP);
	}
});

var errorPage = fs.readFileSync(path.join(config.WEBROOT, "error.html"));
function serveError(request, response) {
	return function (err) {
		log("error", { "error": err, "url": request.url });
		response.writeHead(err ? 500 : 404, { "Content-Length": errorPage.length });
		response.end(errorPage);
	}
}

function logRequest(request) {
	log('connection', {
		ip: request.connection.remoteAddress,
		original_ip: request.headers['x-forwarded-for'] || request.headers['forwarded'],
		user_agent: request.headers['user-agent'],
		referer: request.headers['referer'],
		language: request.headers['accept-language'],
		url: request.url,
	});
}

function handler(request, response) {
	try {
		handleRequest(request, response);
	} catch (err) {
		console.trace(err);
		response.writeHead(500, { 'Content-Type': 'text/plain' });
		response.end(err.toString());
	}
}

const boardTemplate = new templating.BoardTemplate(path.join(config.WEBROOT, 'board.html'));
const indexTemplate = new templating.Template(path.join(config.WEBROOT, 'index.html'));

function handleRequest(request, response) {
	var parsedUrl = url.parse(request.url, true);
	var parts = parsedUrl.pathname.split('/');
	if (parts[0] === '') parts.shift();

	if (parts[0] === "boards") {
		// "boards" refers to the root directory
		if (parts.length === 1 && parsedUrl.query.board) {
			// '/boards?board=...' This allows html forms to point to boards
			var headers = { Location: 'boards/' + encodeURIComponent(parsedUrl.query.board) };
			response.writeHead(301, headers);
			response.end();
		} else if (parts.length === 2 && request.url.indexOf('.') === -1) {
			// If there is no dot and no directory, parts[1] is the board name
			boardTemplate.serve(request, response);
		} else { // Else, it's a resource
			request.url = "/" + parts.slice(1).join('/');
			fileserver(request, response, serveError(request, response));
		}
	} else if (parts[0] === "download") {
		var boardName = encodeURIComponent(parts[1]),
			history_file = path.join(config.HISTORY_DIR, "board-" + boardName + ".json");
		if (parts.length > 2 && /^[0-9A-Za-z.\-]+$/.test(parts[2])) {
			history_file += '.' + parts[2] + '.bak';
		}
		log("download", { "file": history_file });
		fs.readFile(history_file, function (err, data) {
			if (err) return serveError(request, response)(err);
			response.writeHead(200, {
				"Content-Type": "application/json",
				"Content-Disposition": 'attachment; filename="' + boardName + '.wbo"',
				"Content-Length": data.length,
			});
			response.end(data);
		});
	} else if (parts[0] === "preview") {
		var boardName = encodeURIComponent(parts[1]),
			history_file = path.join(config.HISTORY_DIR, "board-" + boardName + ".json");
		createSVG.renderBoard(history_file, function (err, svg) {
			if (err) {
				log(err);
				response.writeHead(404, { 'Content-Type': 'application/json' });
				return response.end(JSON.stringify(err));
			}
			response.writeHead(200, {
				"Content-Type": "image/svg+xml",
				"Content-Security-Policy": CSP,
				'Content-Length': Buffer.byteLength(svg),
			});
			response.end(svg);
		});
	} else if (parts[0] === "random") {
		var name = crypto.randomBytes(32).toString('base64').replace(/[^\w]/g, '-');
		response.writeHead(307, { 'Location': '/boards/' + name });
		response.end(name);

	} else if (parts[0] === "") { // Index page
		logRequest(request);
		indexTemplate.serve(request, response);
	} else {
		fileserver(request, response, serveError(request, response));
	}
}


module.exports = app;