var gulp = require("gulp"),
    gulpMinifyCSS = require("gulp-minify-css"),
    gulpRename = require("gulp-rename"),
    gulpWatch = require("gulp-watch"),
    gulpLess = require("gulp-less"),
    cliColor = require("cli-color"),
    utils = require("./utils"),
    us = require("underscore"),

    Q = require("q"),

    colorFilePath = cliColor.yellowBright.bold,
    colorFileEvent = cliColor.blueBright,
    colorStatusSucess = cliColor.greenBright,
    colorStatusFail = cliColor.redBright,

    translateEvent = {
        "add": "added",
        "start": "started",
        "change": "changed",
        "unlink": "unlinked",
    };

function minifyLESS(gulpWatcher) {
    var deferred = Q.defer();

    gulp.src(gulpWatcher.capture)
        .pipe(gulpLess())
        .on("error", function(err) {
            process.stdout.write(colorStatusFail("Failed") + "\n");
            deferred.reject();
            return false;
        })
        .pipe(gulpMinifyCSS())
        .pipe(gulpRename(gulpWatcher.rename))
        .pipe(gulp.dest("www/publics"))
        .on("end", function () {
            process.stdout.write(colorStatusSucess("OK LESS") + "\n");
            deferred.resolve();
        });

    return deferred.promise;
}

function minifyCSS(gulpWatcher) {
    var deferred = Q.defer();

    gulp.src(gulpWatcher.capture)
        .pipe(gulpMinifyCSS())
        .pipe(gulpRename(gulpWatcher.rename))
        .pipe(gulp.dest("www/publics"))
        .on("end", function () {
            process.stdout.write(colorStatusSucess("OK CSS ") + "\n");
            deferred.resolve();
        });

    return deferred.promise;
}

function minifyJS(gulpWatcher) {
    var deferred = Q.defer();

    gulp.src(gulpWatcher.capture)
        .pipe(gulpRename(gulpWatcher.rename))
        .pipe(gulp.dest("www/publics"))
        .on("end", function () {
            process.stdout.write(colorStatusSucess("OK JS") + "\n");
            deferred.resolve();
        });

    return deferred.promise;
}

function startWatcher(gulpWatcher) {
    var promise = Q();

    // Notify.
    promise.then(function () {
        utils.writeTimeline("First build of " + colorFilePath(gulpWatcher.rename) + " was " + colorFileEvent("started") + ": ");
    });

    // Build a LESS style.
    if (gulpWatcher.type === "less") {
        promise.then(minifyLESS(gulpWatcher));
    }

    // Build a CSS style.
    if (gulpWatcher.type === "css") {
        promise.then(minifyCSS(gulpWatcher));
    }

    // Build a JS.
    if (gulpWatcher.type === "js") {
        promise.then(minifyJS(gulpWatcher));
    }

    return promise;
}

gulp.task("watch", function () {
    var gulpWatchers = [
            // Application.
            { "watch": "sources/app.style/**/*.less",
              "capture": "sources/app.style/app.less",
              "rename": "app.css",
              "type": "less" },
            { "watch": "sources/app.script/**/*.js",
              "capture": "sources/app.script/app.js",
              "rename": "app.js",
              "type": "js" },
            // Vendor.
            { "watch": "sources/vendor.style/**/*.css",
              "capture": "sources/vendor.style/*.css",
              "rename": "vendor.css",
              "type": "css" },
            { "watch": "sources/vendor.script/**/*.js",
              "capture": "sources/vendor.script/*.js",
              "rename": "vendor.js",
              "type": "js" },
        ];

    // Promise.
    var promise = Q();

    // Start all watchers.
    process.stdout.write("\n");
    us.each(gulpWatchers, function (gulpWatcher) {
        promise.then(function () {
            return startWatcher(gulpWatcher);
        });
    });

    // Returns the promise.
    return promise;
});