var gulp = require("gulp");
var gutil = require("gulp-util");
var clean = require("gulp-clean");
var newer = require("gulp-newer");
var combine = require("stream-combiner");
var fs = require("fs");
var Promise = require("bluebird");
var request = require("request-promise");
var unzip = require("unzipper");
var webpack = require("webpack");

var icons = require("./gulpfile-icons");
var webpackConfig = require("./webpack.config.js");

let webpackCompiler = webpack(webpackConfig);

const staticFrontendFile = `${__dirname}/build/frontend.js`;
const staticClientFile = `${__dirname}/build/client.js`;

gulp.task("default", [ "webpack", "symlinks" ]);

gulp.task("clean", function() {
	return combine(
		gulp.src("build"),
		clean()
	);
});

gulp.task("download-icons", function() {
	return new Promise((resolve, reject) => {
		fs.exists("build/Open-SVG-Map-Icons", (exists) => {
			resolve(exists);
		});
	}).then((exists) => {
		if(exists)
			return;

		let extract = unzip.Extract({
			path: "build/"
		});

		let download = request.get("https://github.com/twain47/Open-SVG-Map-Icons/archive/master.zip");
		download.pipe(extract);
		download.catch((err) => {
			extract.emit("error", err);
		});

		return extract.promise().then(() => {
			return Promise.promisify(fs.rename)("build/Open-SVG-Map-Icons-master", "build/Open-SVG-Map-Icons");
		});
	});
});

gulp.task("icons", ["download-icons"], function() {
	return combine(
		gulp.src("build/Open-SVG-Map-Icons/svg/**/*.svg"),
		newer("build/icons.js"),
		icons("icons.js", "angular.module(\"facilmap\").constant(\"fmIcons\", %s);"),
		gulp.dest("build")
	);
});

gulp.task("webpack", [ "icons" ], function() {
	return Promise.promisify(webpackCompiler.run.bind(webpackCompiler))().then(function(stats) {
		gutil.log("[webpack]", stats.toString());

		if(stats.compilation.errors && stats.compilation.errors.length > 0)
			throw new gutil.PluginError("webpack", "There were compilation errors.");

		return new Promise((resolve, reject) => {
			fs.exists(staticFrontendFile, resolve);
		}).then((exists) => {
			if(exists)
				return Promise.promisify(fs.unlink)(staticFrontendFile);
		}).then(() => {
			// Create symlink with fixed file name so that people can include https://facilmap.org/frontend.js
			return Promise.promisify(fs.symlink)(`frontend-index-${stats.hash}.js`, `${__dirname}/build/frontend.js`);
	    });
	});
});

gulp.task("symlinks", [ "webpack" /* To create the build directory */ ], function() {
	// Create symlink to facilmap-client so that people can include https://facilmap.org/client.js
	return new Promise((resolve, reject) => {
		fs.exists(staticClientFile, resolve);
	}).then((exists) => {
		if(!exists)
			return Promise.promisify(fs.symlink)(require.resolve("facilmap-client/build/client"), staticClientFile);
	});
});

gulp.task("watch", [ "icons" ], function() {
	webpackCompiler.watch({
	}, function(err, stats) {
        gutil.log("[webpack]", err ? err : stats.toString());
    });
});