'use strict';

// Include Gulp & tools we'll use
var gulp = require('gulp');
var $ = require('gulp-load-plugins')();
var del = require('del');
var runSequence = require('run-sequence');
var browserSync = require('browser-sync');
var reload = browserSync.reload;
var merge = require('merge-stream');
var path = require('path');
var fs = require('fs');
var glob = require('glob-all');
var historyApiFallback = require('connect-history-api-fallback');
var packageJson = require('./package.json');
var crypto = require('crypto');
var ensureFiles = require('./tasks/ensure-files.js');
var inlinesource = require('gulp-inline-source');

// var ghPages = require('gulp-gh-pages');

var AUTOPREFIXER_BROWSERS = [
    'ie >= 10',
    'ie_mob >= 10',
    'ff >= 30',
    'chrome >= 34',
    'safari >= 7',
    'opera >= 23',
    'ios >= 7',
    'android >= 4.4',
    'bb >= 10'
];

var DIST = 'dist';

var dist = function(subpath) {
    return !subpath ? DIST : path.join(DIST, subpath);
};

var styleTask = function(stylesPath, srcs) {
    return gulp.src(srcs.map(function(src) {
            return path.join('app', stylesPath, src);
        }))
        .pipe($.changed(stylesPath, {
            extension: '.css'
        }))
        .pipe($.autoprefixer(AUTOPREFIXER_BROWSERS))
        .pipe(gulp.dest('.tmp/' + stylesPath))
        .pipe($.minifyCss())
        .pipe(gulp.dest(dist(stylesPath)))
        .pipe($.size({
            title: stylesPath
        }));
};

var imageOptimizeTask = function(src, dest) {
    return gulp.src(src)
        .pipe($.imagemin({
            progressive: true,
            interlaced: true
        }))
        .pipe(gulp.dest(dest))
        .pipe($.size({
            title: 'images'
        }));
};

var optimizeHtmlTask = function(src, dest) {
    var assets = $.useref.assets({
        searchPath: ['.tmp', 'app']
    });

    return gulp.src(src)
        .pipe(assets)
        // Concatenate and minify JavaScript
        .pipe($.if('*.js', $.uglify({
            preserveComments: 'some'
        })))
        // Concatenate and minify styles
        // In case you are still using useref build blocks
        .pipe($.if('*.css', $.minifyCss()))
        .pipe(assets.restore())
        .pipe($.useref())
        // Minify any HTML
        .pipe($.if('*.html', $.minifyHtml({
            quotes: true,
            empty: true,
            spare: true
        })))
        .pipe($.if('*.html', inlinesource()))
        // Output files
        .pipe(gulp.dest(dest))
        .pipe($.size({
            title: 'html'
        }));
};

// Compile and automatically prefix stylesheets
gulp.task('styles', function() {
    return styleTask('styles', ['**/*.css']);
});

gulp.task('elements', function() {
    return styleTask('elements', ['**/*.css']);
});

// Ensure that we are not missing required files for the project
// "dot" files are specifically tricky due to them being hidden on
// some systems.
gulp.task('ensureFiles', function(cb) {
    var requiredFiles = ['.jscsrc', '.jshintrc', '.bowerrc'];

    ensureFiles(requiredFiles.map(function(p) {
        return path.join(__dirname, p);
    }), cb);
});

// Lint JavaScript
gulp.task('lint', ['ensureFiles'], function() {
    return gulp.src([
            'app/scripts/**/*.js',
            'app/elements/**/*.js',
            'app/elements/**/*.html',
            'gulpfile.js'
        ])
        .pipe(reload({
            stream: true,
            once: true
        }))

    // JSCS has not yet a extract option
    .pipe($.if('*.html', $.htmlExtract()))
        .pipe($.jshint())
        .pipe($.jscs())
        .pipe($.jscsStylish.combineWithHintResults())
        .pipe($.jshint.reporter('jshint-stylish'))
        .pipe($.if(!browserSync.active, $.jshint.reporter('fail')));
});

// Optimize images
gulp.task('images', function() {
    return imageOptimizeTask('app/images/**/*', dist('images'));
});

// Copy all files at the root level (app)
gulp.task('copy', function() {
    var app = gulp.src([
        'app/*',
        '!app/test',
        '!app/elements',
        '!app/bower_components',
        '!app/cache-config.json'
    ], {
        dot: true
    }).pipe(gulp.dest(dist()));

    // Copy over only the bower_components we need
    // These are things which cannot be vulcanized
    var bower = gulp.src([
        'app/bower_components/{webcomponentsjs,platinum-sw,sw-toolbox,promise-polyfill}/**/*'
    ]).pipe(gulp.dest(dist('bower_components')));

    return merge(app, bower)
        .pipe($.size({
            title: 'copy'
        }));
});

// Copy web fonts to dist
gulp.task('fonts', function() {
    return gulp.src(['app/fonts/**'])
        .pipe(gulp.dest(dist('fonts')))
        .pipe($.size({
            title: 'fonts'
        }));
});

// Scan your HTML for assets & optimize them
gulp.task('html', function() {
    return optimizeHtmlTask(
        ['app/**/*.html', '!app/{elements,test,bower_components}/**/*.html'],
        dist());
});

// Vulcanize granular configuration
gulp.task('vulcanize', function() {
    return gulp.src('app/elements/elements.html')
        .pipe($.vulcanize({
            stripComments: true,
            inlineCss: true,
            inlineScripts: true
        }))
        .pipe(gulp.dest(dist('elements')))
        .pipe($.size({
            title: 'vulcanize'
        }));
});

// Generate config data for the <sw-precache-cache> element.
// This include a list of files that should be precached, as well as a (hopefully unique) cache
// id that ensure that multiple PSK projects don't share the same Cache Storage.
// This task does not run by default, but if you are interested in using service worker caching
// in your project, please enable it within the 'default' task.
// See https://github.com/PolymerElements/polymer-starter-kit#enable-service-worker-support
// for more context.
gulp.task('cache-config', function(callback) {
    var dir = dist();
    var config = {
        cacheId: packageJson.name || path.basename(__dirname),
        disabled: false
    };

    glob([
        'index.html',
        './',
        'bower_components/webcomponentsjs/webcomponents-lite.min.js',
        '{elements,scripts,styles}/**/*.*'
    ], {
        cwd: dir
    }, function(error, files) {
        if (error) {
            callback(error);
        } else {
            config.precache = files;

            var md5 = crypto.createHash('md5');
            md5.update(JSON.stringify(config.precache));
            config.precacheFingerprint = md5.digest('hex');

            var configPath = path.join(dir, 'cache-config.json');
            fs.writeFile(configPath, JSON.stringify(config), callback);
        }
    });
});

// Clean output directory
gulp.task('clean', function() {
    return del(['.tmp', dist()]);
});

// Watch files for changes & reload
gulp.task('serve', ['styles', 'elements', 'images'], function() {
    browserSync({
        port: 5000,
        notify: false,
        logPrefix: 'PSK',
        ghostMode: false,
        snippetOptions: {
            rule: {
                match: '<span id="browser-sync-binding"></span>',
                fn: function(snippet) {
                    return snippet;
                }
            }
        },
        // Run as an https by uncommenting 'https: true'
        // Note: this uses an unsigned certificate which on first access
        //       will present a certificate warning in the browser.
        // https: true,
        server: {
            baseDir: ['.tmp', 'app'],
            middleware: [historyApiFallback()]
        }
    });

    gulp.watch(['app/**/*.html'], reload);
    gulp.watch(['app/styles/**/*.css'], ['styles', reload]);
    gulp.watch(['app/elements/**/*.css'], ['elements', reload]);
    gulp.watch(['app/{scripts,elements}/**/{*.js,*.html}'], ['lint']);
    gulp.watch(['app/images/**/*'], reload);
});

// Build and serve the output from the dist build
gulp.task('serve:dist', ['default'], function() {
    browserSync({
        port: 5001,
        notify: false,
        logPrefix: 'PSK',
        snippetOptions: {
            rule: {
                match: '<span id="browser-sync-binding"></span>',
                fn: function(snippet) {
                    return snippet;
                }
            }
        },
        // Run as an https by uncommenting 'https: true'
        // Note: this uses an unsigned certificate which on first access
        //       will present a certificate warning in the browser.
        // https: true,
        server: dist(),
        middleware: [historyApiFallback()]
    });
});

// Build production files, the default task
gulp.task('default', ['clean'], function(cb) {
    // Uncomment 'cache-config' if you are going to use service workers.
    runSequence(
        ['copy', 'styles'],
        'elements', ['images', 'fonts', 'html'], //'lint',
        'vulcanize', 'cache-config',
        cb);
});

// Build then deploy to GitHub pages gh-pages branch
gulp.task('build-deploy-gh-pages', function(cb) {
    runSequence(
        'default',
        'deploy-gh-pages',
        cb);
});

// Deploy to GitHub pages gh-pages branch
gulp.task('deploy-gh-pages', function() {
    return gulp.src(dist('**/*'))
        // Check if running task from Travis CI, if so run using GH_TOKEN
        // otherwise run using ghPages defaults.
        .pipe($.if(process.env.TRAVIS === 'true', $.ghPages({
            remoteUrl: 'https://$GH_TOKEN@github.com/polymerelements/polymer-starter-kit.git',
            silent: true,
            branch: 'gh-pages'
        }), $.ghPages()));
});

// Load tasks for web-component-tester
// Adds tasks for `gulp test:local` and `gulp test:remote`
require('web-component-tester').gulp.init(gulp);

// Load custom tasks from the `tasks` directory
try {
    require('require-dir')('tasks');
} catch (err) {}