/// <binding ProjectOpened='watch' />
const path = require('path');
const fs = require('fs');
const { src, dest, watch, parallel, series } = require('gulp');
const sass = require('gulp-sass');
const autoprefixer = require('gulp-autoprefixer');
const sourcemaps = require('gulp-sourcemaps');
const cleanCSS = require('gulp-clean-css');
const rename = require('gulp-rename');
const uglify = require('gulp-uglify');
const babel = require('gulp-babel');
const plumber = require('gulp-plumber');
const notify = require('gulp-notify');
const gulpIf = require('gulp-if');

global.isProduction = false;

// -------------------------------------------------------------------------------
// Utilities

function normalize(p) {
    return p.replace(/\\/g, '/');
}

function root(...paths) {
    const result = [].concat(paths).map(p => {
        return p.startsWith('!') ?
            normalize(`!${path.join(__dirname, p.slice(1))}`) :
            normalize(path.join(__dirname, p))
    })

    return result.length === 1 ? result[0] : result
}

// -------------------------------------------------------------------------------
// Build SASS

function buildSass(...paths) {
    return src(root(...paths), {
        base: root('wwwroot')
    })
        .pipe(plumber({
            errorHandler: function (err) {
                notify.onError({
                    title: "Gulp error in " + err.plugin,
                    message: err.toString()
                })(err)
            }
        }))

        .pipe(sourcemaps.init())
        .pipe(sass({
            outputStyle: 'nested'
        }).on('error', sass.logError))
        .pipe(sourcemaps.write())

        .pipe(sourcemaps.init({ loadMaps: true }))
        .pipe(autoprefixer({
            browsers: [
                '>= 1%',
                'last 2 versions',
                'not dead',
                'Chrome >= 45',
                'Firefox >= 38',
                'Edge >= 12',
                'Explorer >= 10',
                'iOS >= 9',
                'Safari >= 9',
                'Android >= 4.4',
                'Opera >= 30'
            ]
        }))
        .pipe(sourcemaps.write())

        .pipe(dest(root('wwwroot')))

        .pipe(gulpIf(global.isProduction, cleanCSS()))
        .pipe(gulpIf(global.isProduction, rename({
            extname: '.min.css'
        })))
        .pipe(gulpIf(global.isProduction, dest(root('wwwroot'))))
}

// -------------------------------------------------------------------------------
// Tasks

const buildJsTask = function () {
    return src(root(
        'wwwroot/**/*.js',
        '!wwwroot/**/*.es5.js',
        '!wwwroot/**/*.min.js',
        '!wwwroot/vendor/**/*.js'
    ), {
        base: root('wwwroot')
    })
        .pipe(plumber({
            errorHandler: function (err) {
                notify.onError({
                    title: "Gulp error in " + err.plugin,
                    message: err.toString()
                })(err)
            }
        }))

        .pipe(sourcemaps.init())
        .pipe(babel({
            presets: [
                ['@babel/preset-env', {
                    targets: {
                        browsers: [
                            '>= 1%',
                            'last 2 versions',
                            'not dead',
                            'Chrome >= 45',
                            'Firefox >= 38',
                            'Edge >= 12',
                            'Explorer >= 10',
                            'iOS >= 9',
                            'Safari >= 9',
                            'Android >= 4.4',
                            'Opera >= 30'
                        ]
                    }
                }]
            ]
        }))
        .pipe(rename({
            extname: '.es5.js'
        }))
        .pipe(sourcemaps.write())

        .pipe(dest(root('wwwroot')))

        .pipe(gulpIf(global.isProduction, uglify()))
        .pipe(gulpIf(global.isProduction, rename({
            extname: '.min.js'
        })))
        .pipe(gulpIf(global.isProduction, dest(root('wwwroot'))))
}

const buildSassTask = function () {
    return buildSass(
        'wwwroot/**/*.scss',
        '!wwwroot/**/_*.scss',
        '!wwwroot/vendor/**/*.scss'
    )
}

const buildVendorSassTask = function () {
    return buildSass(
        'wwwroot/vendor/css/**/*.scss',
        '!wwwroot/vendor/css/**/_*.scss'
    )
}

const buildVendorLibsTask = function () {
    return buildSass(
        'wwwroot/vendor/libs/**/*.scss',
        '!wwwroot/vendor/libs/**/_*.scss'
    )
}

// -------------------------------------------------------------------------------
// Watch

const watchTask = function () {
    watch(root(
        'wwwroot/**/*.scss',
        '!wwwroot/vendor/**/*.scss',
        'wwwroot/vendor/css/_custom-variables/*.scss',
        'wwwroot/vendor/css/_appwork/_variables*.scss'
    ), buildSassTask)
    watch(root('wwwroot/vendor/css/**/*.scss'), buildVendorSassTask)
    watch(root(
        'wwwroot/vendor/libs/**/*.scss',
        'wwwroot/vendor/css/_custom-variables/*.scss',
        'wwwroot/vendor/css/_appwork/_variables*.scss'
    ), buildVendorLibsTask)
    watch(root(
        'wwwroot/**/*.js',
        '!wwwroot/**/*.es5.js',
        '!wwwroot/**/*.min.js',
        '!wwwroot/vendor/**/*.js'
    ), buildJsTask)
}

// -------------------------------------------------------------------------------
// Custom vendors
//
// You can copy custom assets from the node_modules directory to wwwroot directory
// by adding a vendor file path into the "CUSTOM_VENDORS" object:
//
// const CUSTOM_VENDORS = {
//   ...
//   'Path to source file': 'Path to dest file'
// }
//

const CUSTOM_VENDORS = {
    'node_modules/jquery-validation-unobtrusive/dist/jquery.validate.unobtrusive.min.js': 'wwwroot/vendor/libs/validate/validate.unobtrusive.js',
    'node_modules/jquery/dist/jquery.min.js': 'wwwroot/vendor/libs/jquery/jquery.min.js'
}

buildVendorCopyTask = parallel(
    Object.keys(CUSTOM_VENDORS).reduce(function (tasks, vendorSrc) {
        if (!fs.existsSync(root(vendorSrc))) {
            console.warn(`Vendor source not found: "${root(vendorSrc)}"`)
            return
        } else {
            console.warn(`Vendor: "${root(vendorSrc)}"`);
        }
        const vendorDest = path.dirname(CUSTOM_VENDORS[vendorSrc])
        const vendorName = path.basename(CUSTOM_VENDORS[vendorSrc])
        const functionName = `buildVendorCopy${vendorName.replace(/^./g, m => m.toUpperCase()).replace(/\.(.)/g, (m, $1) => $1.toUpperCase())}Task`
        const taskFunction = function () {
            return src(root(vendorSrc))
                .pipe(rename(vendorName))
                .pipe(dest(root(vendorDest)))
        }

        Object.defineProperty(taskFunction, 'name', {
            value: functionName
        })

        return tasks.concat(taskFunction)
    }, [])
)

// -------------------------------------------------------------------------------
// Build

const buildTask = parallel(
    buildSassTask,
    buildJsTask,
    buildVendorSassTask,
    buildVendorLibsTask,
    buildVendorCopyTask
)

const productionBuildTask = series(
    function setProductionMode(cb) {
        global.isProduction = true
        console.warn('>>> Running Gulp in production mode.')
        cb()
    },
    buildTask
)

// -------------------------------------------------------------------------------
// Exports

module.exports = {
    default: buildTask,
    'build:all': buildTask,
    'build:all:prod': productionBuildTask,
    'build:js': buildJsTask,
    'build:sass': buildSassTask,
    'build:vendor:sass': buildVendorSassTask,
    'build:vendor:libs': buildVendorLibsTask,
    'build:vendor:copy': buildVendorCopyTask,
    watch: watchTask
}