// Defining requirements
var fs = require('fs');
var gulp = require('gulp');
var plumber = require('gulp-plumber');
var sass = require('gulp-sass')(require('sass'));
var sassImportJson = require('gulp-sass-import-json');
var cssnano = require('gulp-cssnano');
var rename = require('gulp-rename');
var concat = require('gulp-concat');
var uglify = require('gulp-uglify');
var replace = require('gulp-replace');
var loadJsonFile = require('load-json-file');
var browserSync = require('browser-sync').create();
var autoprefixer = require('gulp-autoprefixer');
var sourcemaps = require('gulp-sourcemaps');
var del = require('del');



// Defining settings
var _gulpSettings = loadJsonFile.sync( 'gulp-settings.json' );
var _gulpSettingsLocal = {};
var _package = {},
	_assetsVersion = '';



// Try loading local gulpfile settings
try{ _gulpSettingsLocal = loadJsonFile.sync( 'gulp-settings.local.json' ); }
catch ( err ) {}



// Run:
// gulp update-ver
// Update the project version
gulp.task( 'update-ver', gulp.series( function( done ) {
	_package = loadJsonFile.sync( 'package.json' );
	_assetsVersion = '-' + _package.version.replace( /\./gi, '' );

	gulp.src( _package.main )
	// See http://mdn.io/string.replace#Specifying_a_string_as_a_parameter
	.pipe(replace(/Version: (.)*/g, 'Version: ' + _package.version ))
	.pipe(gulp.dest('./'));

	done();
} ) );

// Run:
// gulp update-ver
// Update the project version for full releases, including the version and date in the changelog
gulp.task( 'update-ver-release', gulp.series( 'update-ver', function( done ) {
	var today = new Date();
	_package = loadJsonFile.sync( 'package.json' );
	_assetsVersion = '-' + _package.version.replace( /\./gi, '' );

	// Only update readme.txt for full release versions
	if ( _package.version.indexOf( 'beta' ) < 0 && _package.version.indexOf( 'dev' ) < 0 ) {
		gulp.src( _gulpSettings.changelogFile )
		// See http://mdn.io/string.replace#Specifying_a_string_as_a_parameter
		.pipe(replace(/Stable tag: (.)*/g, 'Stable tag: ' + _package.version ))
		.pipe(replace(/= Unreleased (.)*/g, '= ' + _package.version + ' - ' + today.toISOString().slice(0, 10) + ' =' ))
		.pipe(gulp.dest('./'));
	}

	done();
} ) );



// Run:
// gulp clean-css
// Delete existing generated css files
gulp.task( 'clean-css', function( done ) {
	del.sync( [ './css' ] );
	done();
} );



// Run:
// gulp clean-js
// Delete existing generated js files
gulp.task( 'clean-js', function( done ) {
	del.sync( [ './js' ] );
	done();
} );



// Run:
// gulp build-css
// Builds css from scss for production environment and apply other changes.
gulp.task( 'build-css', gulp.series( 'update-ver', 'clean-css', function( done ) {
	
	// MAIN STYLES
	if ( _gulpSettings.sassSources.main ) {
		gulp.src( _gulpSettings.sassSources.main )
		.pipe(sassImportJson({
			isScss: true
		}))
		.pipe(plumber())
		// No source maps
		.pipe(sassImportJson({
			isScss: true
		}))
		.pipe(sass())
		.pipe(autoprefixer({ cascade: false }))
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./css/')) // save .css
		.pipe(cssnano( { zindex:false, discardComments: {removeAll: true}, discardUnused: {fontFace: false}, reduceIdents: {keyframes: false} } ) )
		.pipe(rename( { suffix: '.min' } ) )
		.pipe(sourcemaps.write('maps'))
		.pipe(gulp.dest('./css/')); // save .min.css
	}

	// ADMIN STYLES
	if ( _gulpSettings.sassSources.admin ) {
		gulp.src( _gulpSettings.sassSources.admin )
		.pipe(sassImportJson({
			isScss: true
		}))
		.pipe(plumber())
		// No source maps
		.pipe(sassImportJson({
			isScss: true
		}))
		.pipe(sass())
		.pipe(autoprefixer({ cascade: false }))
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./css/admin/')) // save .css
		.pipe(cssnano( { zindex:false, discardComments: {removeAll: true}, discardUnused: {fontFace: false}, reduceIdents: {keyframes: false} } ) )
		.pipe(rename( { suffix: '.min' } ) )
		.pipe(sourcemaps.write('maps'))
		.pipe(gulp.dest('./css/admin/')); // save .min.css
	}
	
	// PLUGIN COMPATIBILITY STYLES
	if ( _gulpSettings.sassSources.pluginCompat ) {
		gulp.src( _gulpSettings.sassSources.pluginCompat )
		.pipe(plumber())
		// No source maps
		.pipe(sassImportJson({
			isScss: true
		}))
		.pipe(sass())
		.pipe(autoprefixer({ cascade: false }))
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./css/compat/plugins/')) // save .css
		.pipe(cssnano( { zindex:false, discardComments: {removeAll: true}, discardUnused: {fontFace: false}, reduceIdents: {keyframes: false} } ) )
		.pipe(rename( { suffix: '.min' } ) )
		.pipe(sourcemaps.write('maps'))
		.pipe(gulp.dest('./css/compat/plugins/')); // save .min.css
	}

	// THEME COMPATIBILITY STYLES
	if ( _gulpSettings.sassSources.themeCompat ) {
		gulp.src( _gulpSettings.sassSources.themeCompat )
		.pipe(plumber())
		// No source maps
		.pipe(sassImportJson({
			isScss: true
		}))
		.pipe(sass())
		.pipe(autoprefixer({ cascade: false }))
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./css/compat/themes/')) // save .css
		.pipe(cssnano( { zindex:false, discardComments: {removeAll: true}, discardUnused: {fontFace: false}, reduceIdents: {keyframes: false} } ) )
		.pipe(rename( { suffix: '.min' } ) )
		.pipe(sourcemaps.write('maps'))
		.pipe(gulp.dest('./css/compat/themes/')); // save .min.css
	}

	done();
} ) );



// Run:
// gulp build-css-dev
// Builds css from scss for development environment and apply other changes.
gulp.task( 'build-css-dev', gulp.series( 'update-ver', 'clean-css', function( done ) {
	
	// MAIN STYLES
	if ( _gulpSettings.sassSources.main ) {
		gulp.src( _gulpSettings.sassSources.main )
		.pipe(plumber())
		.pipe(sourcemaps.init())
		.pipe(sassImportJson({
			isScss: true
		}))
		.pipe(sass())
		.pipe(autoprefixer({ cascade: false }))
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./css/')) // save .css
		// No css nano
		.pipe(rename( { suffix: '.min' } ) ) // Files are not minified on dev build but file name needs the .min sufix
		.pipe(sourcemaps.write('maps'))
		.pipe(gulp.dest('./css/')) // save .min.css
		.pipe(browserSync.stream());
	}

	// ADMIN STYLES
	if ( _gulpSettings.sassSources.admin ) {
		gulp.src( _gulpSettings.sassSources.admin )
		.pipe(plumber())
		.pipe(sourcemaps.init())
		.pipe(sassImportJson({
			isScss: true
		}))
		.pipe(sass())
		.pipe(autoprefixer({ cascade: false }))
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./css/admin/')) // save .css
		// No css nano
		.pipe(rename( { suffix: '.min' } ) ) // Files are not minified on dev build but file name needs the .min sufix
		.pipe(sourcemaps.write('maps'))
		.pipe(gulp.dest('./css/admin/')) // save .min.css
		.pipe(browserSync.stream());
	}

	// PLUGIN COMPATIBILITY STYLES
	if ( _gulpSettings.sassSources.pluginCompat ) {
		gulp.src( _gulpSettings.sassSources.pluginCompat )
		.pipe(plumber())
		.pipe(sourcemaps.init())
		.pipe(sassImportJson({
			isScss: true
		}))
		.pipe(sass())
		.pipe(autoprefixer({ cascade: false }))
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./css/compat/plugins/')) // save .css
		// No css nano
		.pipe(rename( { suffix: '.min' } ) ) // Files are not minified on dev build but file name needs the .min sufix
		.pipe(sourcemaps.write('maps'))
		.pipe(gulp.dest('./css/compat/plugins/')) // save .min.css
		.pipe(browserSync.stream());
	}

	// THEME COMPATIBILITY STYLES
	if ( _gulpSettings.sassSources.themeCompat ) {
		gulp.src( _gulpSettings.sassSources.themeCompat )
		.pipe(plumber())
		.pipe(sourcemaps.init())
		.pipe(sassImportJson({
			isScss: true
		}))
		.pipe(sass())
		.pipe(autoprefixer({ cascade: false }))
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./css/compat/themes/')) // save .css
		// No css nano
		.pipe(rename( { suffix: '.min' } ) ) // Files are not minified on dev build but file name needs the .min sufix
		.pipe(sourcemaps.write('maps'))
		.pipe(gulp.dest('./css/compat/themes/')) // save .min.css
		.pipe(browserSync.stream());
	}

	done();
} ) );



// Run:
// gulp build-js.
// Uglifies and concat all JS files into one
gulp.task( 'build-js', gulp.series( 'update-ver', 'clean-js', function( done ) {

	// JS LIBRARIES
	if ( _gulpSettings.jsSources.libraries ) {
		gulp.src( _gulpSettings.jsSources.libraries )
		.pipe(sourcemaps.init())
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./js/lib/')) // save .js
		.pipe(uglify())
		.pipe(rename({suffix: '.min'}))
		.pipe(gulp.dest('./js/lib/')); // save .min.js
	}

	// POLYFILLS
	if ( _gulpSettings.jsSources.polyfills ) {
		gulp.src( _gulpSettings.jsSources.polyfills )
		.pipe(sourcemaps.init())
		.pipe(uglify())
		.pipe(gulp.dest('./js/lib/')); // save .min.js
	}

	// BUNDLES.JS
	if ( _gulpSettings.jsSources.bundles ) {
		gulp.src( _gulpSettings.jsSources.bundles )
		.pipe(sourcemaps.init())
		.pipe(concat('bundles.js'))
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./js/')) // save .js
		.pipe(uglify())
		.pipe(rename({suffix: '.min'}))
		.pipe(sourcemaps.write('maps'))
		.pipe(gulp.dest('./js/')); // save .min.js
	}

	// MAIN SCRIPT
	if ( _gulpSettings.jsSources.main ) {
		gulp.src( _gulpSettings.jsSources.main )
		.pipe(sourcemaps.init())
		.pipe(concat('main.js'))
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./js/')) // save .js
		.pipe(uglify())
		.pipe(rename({suffix: '.min'}))
		.pipe(sourcemaps.write('maps'))
		.pipe(gulp.dest('./js/')); // save .min.js
	}

	// STANDALONE SCRIPTS
	if ( _gulpSettings.jsSources.standalone ) {
		gulp.src( _gulpSettings.jsSources.standalone )
		.pipe(sourcemaps.init())
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./js/')) // save .js
		.pipe(uglify())
		.pipe(rename({suffix: '.min'}))
		.pipe(sourcemaps.write('maps'))
		.pipe(gulp.dest('./js/')); // save .min.js
	}

	// ADMIN SCRIPTS
	if ( _gulpSettings.jsSources.admin ) {
		gulp.src( _gulpSettings.jsSources.admin )
		.pipe(sourcemaps.init())
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./js/admin/')) // save .js
		.pipe(uglify())
		.pipe(rename({suffix: '.min'}))
		.pipe(sourcemaps.write('maps'))
		.pipe(gulp.dest('./js/admin/')); // save .min.js
	}

	// PLUGIN COMPAT SCRIPTS
	if ( _gulpSettings.jsSources.pluginCompat ) {
		gulp.src( _gulpSettings.jsSources.pluginCompat )
		.pipe(sourcemaps.init())
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./js/compat/plugins/')) // save .js
		.pipe(uglify())
		.pipe(rename({suffix: '.min'}))
		.pipe(sourcemaps.write('maps'))
		.pipe(gulp.dest('./js/compat/plugins/')); // save .min.js
	}

	// THEME COMPAT SCRIPTS
	if ( _gulpSettings.jsSources.themeCompat ) {
		gulp.src( _gulpSettings.jsSources.themeCompat )
		.pipe(sourcemaps.init())
		.pipe(rename({suffix: _assetsVersion}))
		.pipe(gulp.dest('./js/compat/themes/')) // save .js
		.pipe(uglify())
		.pipe(rename({suffix: '.min'}))
		.pipe(sourcemaps.write('maps'))
		.pipe(gulp.dest('./js/compat/themes/')); // save .min.js
	}

	done();
} ) );



// Run:
// gulp build
// Build css and js assets
gulp.task( 'build', gulp.series( gulp.parallel( 'build-js', 'build-css' ) ) );



// Run:
// gulp copy-updater
// Copy the theme/plugin updater class into the project
gulp.task( 'copy-updater', gulp.series( function( done ) {
	if ( _gulpSettings.copyUpdater ) {
		del.sync( _gulpSettings.copyUpdater.destination );
		
		gulp.src( _gulpSettings.copyUpdater.source )
		.pipe( gulp.dest( _gulpSettings.copyUpdater.destination ) );
	}

	done();
} ) );



// Run:
// gulp browser-sync
// Starts browser-sync task for starting the server.
gulp.task( 'browser-sync', gulp.series( function( done ) {
	if ( _gulpSettings.browserSyncWatch && _gulpSettingsLocal.browserSyncOptions ) {
		browserSync.init( _gulpSettings.browserSyncWatch, _gulpSettingsLocal.browserSyncOptions );
	}

	done();
} ) );

// Run:
// gulp browser-sync
// Starts browser-sync task for starting the server.
gulp.task( 'browser-sync-reload', function( done ) {
	browserSync.reload();
	done();
} );



// Run:
// gulp watch
// Starts watcher. Watcher runs appropriate tasks on file changes
gulp.task( 'watch', gulp.series( function( done ) {
	_gulpSettings.watch.forEach( function ( item ) {
		var watchPattern = item[ 0 ];
		var runTasks = item[ 1 ];
		gulp.watch( watchPattern, gulp.series( runTasks ) );
	} );

	done();
} ) );



// Run:
// gulp watch-reload
// Starts watcher with browser-sync. Browser-sync reloads page automatically on your browser
gulp.task( 'watch-reload', gulp.series( gulp.parallel( 'build-js', 'build-css-dev' ), gulp.series( 'watch', 'browser-sync' ) ) );



// Run:
// gulp
// Defines gulp default task
gulp.task( 'default', gulp.series( 'watch-reload' ) );