/*******************************
 *          Build Task
 *******************************/

const
    gulp         = require('gulp'),

    // node dependencies
    console      = require('better-console'),

    // gulp dependencies
    autoprefixer = require('gulp-autoprefixer'),
    chmod        = require('gulp-chmod'),
    concatCSS    = require('gulp-concat-css'),
    dedupe       = require('gulp-dedupe'),
    flatten      = require('gulp-flatten'),
    gulpif       = require('gulp-if'),
    header       = require('gulp-header'),
    less         = require('gulp-less'),
    minifyCSS    = require('gulp-clean-css'),
    normalize    = require('normalize-path'),
    plumber      = require('gulp-plumber'),
    print        = require('gulp-print').default,
    rename       = require('gulp-rename'),
    replace      = require('gulp-replace'),
    replaceExt   = require('replace-ext'),
    rtlcss       = require('gulp-rtlcss'),

    // config
    config       = require('../config/user'),
    docsConfig   = require('../config/docs'),
    tasks        = require('../config/tasks'),
    install      = require('../config/project/install'),

    // shorthand
    globs        = config.globs,
    assets       = config.paths.assets,

    banner       = tasks.banner,
    filenames    = tasks.filenames,
    comments     = tasks.regExp.comments,
    log          = tasks.log,
    settings     = tasks.settings
;

/**
 * Builds the css
 * @param src
 * @param type
 * @param compress
 * @param config
 * @param opts
 * @return {*}
 */
function build(src, type, compress, config, opts) {
    let fileExtension;
    if (type === 'rtl' && compress) {
        fileExtension = settings.rename.rtlMinCSS;
    } else if (type === 'rtl') {
        fileExtension = settings.rename.rtlCSS;
    } else if (compress) {
        fileExtension = settings.rename.minCSS;
    }

    return gulp.src(src, opts)
        .pipe(plumber(settings.plumber.less))
        .pipe(less(settings.less))
        .pipe(autoprefixer(settings.prefix))
        .pipe(gulpif(type === 'rtl', rtlcss()))
        .pipe(replace(comments.variables.in, comments.variables.out))
        .pipe(replace(comments.license.in, comments.license.out))
        .pipe(replace(comments.large.in, comments.large.out))
        .pipe(replace(comments.small.in, comments.small.out))
        .pipe(replace(comments.tiny.in, comments.tiny.out))
        .pipe(flatten())
        .pipe(replace(
            config.paths.assets.source,
            compress ? config.paths.assets.compressed : config.paths.assets.uncompressed
        ))
        .pipe(gulpif(compress, minifyCSS(settings.minify)))
        .pipe(gulpif(fileExtension, rename(fileExtension)))
        .pipe(gulpif(config.hasPermissions, chmod(config.parsedPermissions)))
        .pipe(gulp.dest(compress ? config.paths.output.compressed : config.paths.output.uncompressed))
        .pipe(print(log.created))
    ;
}

/**
 * Packages the css files in dist
 * @param {string} type - type of the css processing (none, rtl, docs)
 * @param {boolean} compress - should the output be compressed
 */
function pack(type, compress) {
    const output       = type === 'docs' ? docsConfig.paths.output : config.paths.output;
    const ignoredGlobs = type === 'rtl' ? globs.ignoredRTL + '.rtl.css' : globs.ignored + '.css';

    let concatenatedCSS;
    if (type === 'rtl') {
        concatenatedCSS = compress ? filenames.concatenatedMinifiedRTLCSS : filenames.concatenatedRTLCSS;
    } else {
        concatenatedCSS = compress ? filenames.concatenatedMinifiedCSS : filenames.concatenatedCSS;
    }

    let src = output.uncompressed + '/**/' + globs.components + ignoredGlobs;
    if (globs.components.indexOf('table') < 0 && globs.components.indexOf('tab') > 0) {
        src = [src, '!' + output.uncompressed + '/**/table.css'];
    }

    return gulp.src(src)
        .pipe(plumber())
        .pipe(dedupe())
        .pipe(replace(assets.uncompressed, assets.packaged))
        .pipe(concatCSS(concatenatedCSS, settings.concatCSS))
        .pipe(gulpif(config.stripHeaders, replace(comments.header.in, comments.header.out)))
        .pipe(gulpif(config.hasPermissions, chmod(config.parsedPermissions)))
        .pipe(gulpif(compress, minifyCSS(settings.concatMinify)))
        .pipe(header(banner, settings.header))
        .pipe(gulp.dest(output.packaged))
        .pipe(print(log.created))
    ;
}

function buildCSS(src, type, config, opts, callback) {
    if (!install.isSetup()) {
        console.error('Cannot build CSS files. Run "gulp install" to set-up Fomantic');
        callback();

        return;
    }

    if (callback === undefined) {
        callback = opts;
        opts = config;
        config = type;
        type = src;
        src = config.paths.source.definitions + '/**/' + config.globs.components + '.less';
    }

    if (globs.individuals !== undefined && typeof src === 'string') {
        const components = config.globs.components.replace(/[{}]/g, '') + ',' + config.globs.individuals.replace(/[{}]/g, '');

        src = config.paths.source.definitions + '/**/{' + components + '}.less';
    }

    const buildUncompressed       = () => build(src, type, false, config, opts);
    buildUncompressed.displayName = 'Building uncompressed CSS';

    const buildCompressed       = () => build(src, type, true, config, opts);
    buildCompressed.displayName = 'Building compressed CSS';

    const packUncompressed       = () => pack(type, false);
    packUncompressed.displayName = 'Packing uncompressed CSS';

    const packCompressed       = () => pack(type, true);
    packCompressed.displayName = 'Packing compressed CSS';

    gulp.parallel(
        gulp.series(
            buildUncompressed,
            gulp.parallel(packUncompressed, packCompressed)
        ),
        gulp.series(buildCompressed)
    )(callback);
}

function rtlAndNormal(src, callback) {
    if (callback === undefined) {
        callback = src;
        src = config.paths.source.definitions + '/**/' + config.globs.components + '.less';
    }

    const rtl       = (callback) => buildCSS(src, 'rtl', config, {}, callback);
    rtl.displayName = 'CSS Right-To-Left';
    const css       = (callback) => buildCSS(src, 'default', config, {}, callback);
    css.displayName = 'CSS';

    if (config.rtl === true || config.rtl === 'Yes') {
        rtl(callback);
    } else if (config.rtl === 'both') {
        gulp.series(rtl, css)(callback);
    } else {
        css(callback);
    }
}

function docs(src, callback) {
    if (callback === undefined) {
        callback = src;
        src = config.paths.source.definitions + '/**/' + config.globs.components + '.less';
    }

    const func       = (callback) => buildCSS(src, 'docs', config, {}, callback);
    func.displayName = 'CSS Docs';

    func(callback);
}

// Default tasks
module.exports = rtlAndNormal;

// We keep the changed files in an array to call build with all of them at the same time
let
    timeout,
    files = []
;

/**
 * Watch changes in CSS files and call the correct build pipe
 * @param type
 * @param config
 */
module.exports.watch = function (type, config) {
    const method = type === 'docs' ? docs : rtlAndNormal;

    // Watch theme.config file
    gulp.watch([
        normalize(config.paths.source.config),
        normalize(config.paths.source.site + '/**/site.variables'),
        normalize(config.paths.source.themes + '/**/site.variables'),
    ])
        .on('all', function () {
            // Clear timeout and reset files
            if (timeout) {
                clearTimeout(timeout);
            }
            files = [];

            return gulp.series(method)();
        })
    ;

    // Watch any less / overrides / variables files
    gulp.watch([
        normalize(config.paths.source.definitions + '/**/*.less'),
        normalize(config.paths.source.site + '/**/*.{overrides,variables}'),
        normalize(config.paths.source.themes + '/**/*.{overrides,variables}'),
    ])
        .on('all', function (event, path) {
            // We don't handle deleted files yet
            if (event === 'unlink' || event === 'unlinkDir') {
                return;
            }

            // Clear timeout
            if (timeout) {
                clearTimeout(timeout);
            }

            // Determine which LESS file has to be recompiled
            let lessPath;
            if (path.indexOf('site.variables') !== -1) {
                return;
            }
            if (path.indexOf(config.paths.source.themes) !== -1) {
                console.log('Change detected in packaged theme');
                lessPath = replaceExt(path, '.less');
                lessPath = lessPath.replace(tasks.regExp.theme, config.paths.source.definitions);
            } else if (path.indexOf(config.paths.source.site) !== -1) {
                console.log('Change detected in site theme');
                lessPath = replaceExt(path, '.less');
                lessPath = lessPath.replace(config.paths.source.site, config.paths.source.definitions);
            } else {
                console.log('Change detected in definition');
                lessPath = path;
            }

            // Add file to internal changed files array
            if (!files.includes(lessPath)) {
                files.push(lessPath);
            }

            // Update timeout
            timeout = setTimeout(() => {
                // Copy files to build in another array
                const buildFiles = [...files];
                // Call method
                gulp.series((callback) => method(buildFiles, callback))();
                // Reset internal changed files array
                files = [];
            }, 1000);
        })
    ;
};

// Expose build css method
module.exports.buildCSS = buildCSS;