let Verify = require('./Verify');
let CopyFilesTask = require('./tasks/CopyFilesTask');
let ConcatFilesTask = require('./tasks/ConcatenateFilesTask');
let VersionFilesTask = require('./tasks/VersionFilesTask');
let webpack = require('webpack');
let glob = require('glob');
let _ = require('lodash');
let path = require('path');

class Api {
    /**
     * Register the Webpack entry/output paths.
     *
     * @param {string|Array} entry
     * @param {string} output
     */
    js(entry, output) {
        Verify.js(entry, output);

        entry = [].concat(entry).map(file => new File(file));
        output = new File(output);

        Config.js.push({ entry, output });

        return this;
    }


    /**
     * Register support for the React framework.
     *
     * @param {string|Array} entry
     * @param {string} output
     */
    react(entry, output) {
        Config.react = true;

        Verify.dependency('babel-preset-react', ['babel-preset-react']);

        return this.js(entry, output);
    };

    /**
     * Register support for the Preact framework.
     *
     * @param {string|Array} entry
     * @param {string} output
     */
    preact(entry, output) {
        Config.preact = true;

        Verify.dependency('babel-preset-preact', ['babel-preset-preact']);

        return this.js(entry, output);
    };


    /**
     * Register support for the TypeScript.
     */
    ts(entry, output) {
        Config.typeScript = true;

        Verify.dependency('ts-loader', ['ts-loader', 'typescript']);

        return this.js(entry, output);
    };


    /**
     * Register support for the TypeScript.
     */
    typeScript(entry, output) {
        return this.ts(entry, output);
    }


    /**
     * Register Sass compilation.
     *
     * @param {string} src
     * @param {string} output
     * @param {object} pluginOptions
     */
    sass(src, output, pluginOptions = {}) {
        pluginOptions = Object.assign({
            precision: 8,
            outputStyle: 'expanded'
        }, pluginOptions, { sourceMap: true });

        return this.preprocess('sass', src, output, pluginOptions);
    }


    /**
     * Register standalone-Sass compilation that will not run through Webpack.
     *
     * @param {string} src
     * @param {string} output
     * @param {object} pluginOptions
     */
    standaloneSass(src, output, pluginOptions = {}) {
        Verify.exists(src);

        return this.preprocess('fastSass', src, output, pluginOptions);
    };


    /**
     * Alias for standaloneSass.
     *
     * @param {string} src
     * @param {string} output
     * @param {object} pluginOptions
     */
    fastSass(...args) {
        return this.standaloneSass(...args);
    }


    /**
     * Register Less compilation.
     *
     * @param {string} src
     * @param {string} output
     * @param {object} pluginOptions
     */
    less(src, output, pluginOptions) {
        Verify.dependency('less-loader', ['less-loader', 'less']);

        return this.preprocess('less', src, output, pluginOptions);
    }


    /**
     * Register Stylus compilation.
     *
     * @param {string} src
     * @param {string} output
     * @param {object} pluginOptions
     */
    stylus(src, output, pluginOptions = {}) {
        Verify.dependency('stylus-loader', ['stylus-loader', 'stylus']);

        return this.preprocess('stylus', src, output, pluginOptions);
    };


    /**
     * Register postcss compilation.
     *
     * @param {string} src
     * @param {string} output
     * @param {array}  postCssPlugins
     */
    postCss(src, output, postCssPlugins = []) {
        Verify.preprocessor('postCss', src, output);

        src = new File(src);

        output = this._normalizeOutput(new File(output), src.nameWithoutExtension() + '.css');

        Config.preprocessors['postCss'] = (Config.preprocessors['postCss'] || []).concat({
            src, output, postCssPlugins
        });

        return this;
    };


    /**
     * Register a generic CSS preprocessor.
     *
     * @param {string} type
     * @param {string} src
     * @param {string} output
     * @param {object} pluginOptions
     */
    preprocess(type, src, output, pluginOptions = {}) {
        Verify.preprocessor(type, src, output);

        src = new File(src);

        output = this._normalizeOutput(new File(output), src.nameWithoutExtension() + '.css');

        Config.preprocessors[type] = (Config.preprocessors[type] || []).concat({
            src, output, pluginOptions
        });

        if (type === 'fastSass') {
            Mix.addAsset(output);
        }

        return this;
    }


    /**
     * Combine a collection of files.
     *
     * @param {string|Array} src
     * @param {string}       output
     * @param {Boolean}      babel
     */
    combine(src, output = '', babel = false) {
        output = new File(output);

        Verify.combine(src, output);

        if (typeof src === 'string' && File.find(src).isDirectory()) {
            src = _.pull(
                glob.sync(path.join(src, '**/*'), { nodir: true }),
                output.relativePath()
            );
        }

        let task = new ConcatFilesTask({ src, output, babel });

        Mix.addTask(task);

        return this;
    };


    /**
     * Alias for this.Mix.combine().
     *
     * @param {string|Array} src
     * @param {string}       output
     */
    scripts(src, output) {
        return this.combine(src, output);
    };


    /**
     * Identical to this.Mix.combine(), but includes Babel compilation.
     *
     * @param {string|Array} src
     * @param {string}       output
     */
    babel(src, output) {
        return this.combine(src, output, true);

        return this;
    };


    /**
     * Alias for this.Mix.combine().
     *
     * @param {string|Array} src
     * @param {string}       output
     */
    styles(src, output) {
        return this.combine(src, output);
    };


    /**
     * Minify the provided file.
     *
     * @param {string|Array} src
     */
    minify(src) {
        if (Array.isArray(src)) {
            src.forEach(file => this.minify(file));

            return this;
        }

        let output = src.replace(/\.([a-z]{2,})$/i, '.min.$1');

        return this.combine(src, output);
    };


    /**
     * Copy one or more files to a new location.
     *
     * @param {string} from
     * @param {string} to
     */
    copy(from, to) {
        let task = new CopyFilesTask({
            from, to: new File(to)
        });

        Mix.addTask(task);

        return this;
    };


    /**
     * Copy a directory to a new location. This is identical
     * to mix.copy().
     *
     * @param {string} from
     * @param {string} to
     */
    copyDirectory(from, to) {
        return this.copy(from, to);
    };


    /**
     * Enable Browsersync support for the project.
     *
     * @param {object} config
     */
    browserSync(config = {}) {
        Verify.dependency(
            'browser-sync-webpack-plugin',
            ['browser-sync-webpack-plugin', 'browser-sync'],
            true
        );

        if (typeof config === 'string') {
            config = { proxy: config };
        }

        Config.browserSync = config;

        return this;
    };


    /**
     * Enable automatic file versioning.
     *
     * @param {Array} files
     */
    version(files = []) {
        Config.versioning = true;

        files = flatten([].concat(files).map(filePath => {
            if (File.find(filePath).isDirectory()) {
                filePath += (path.sep + '**/*');
            }

            if (! filePath.includes('*')) return filePath;

            return glob.sync(
                new File(filePath).forceFromPublic().relativePath(),
                { nodir: true }
            );
        }));

        Mix.addTask(
            new VersionFilesTask({ files })
        );

        return this;
    }


    /**
     * Register vendor libs that should be extracted.
     * This helps drastically with long-term caching.
     *
     * @param {Array}  libs
     * @param {string} output
     */
    extract(libs, output) {
        Config.extractions.push({ libs, output });

        return this;
    };


    /**
     * Enable sourcemap support.
     *
     * @param {Boolean} productionToo
     * @param {string}  type
     */
    sourceMaps(productionToo = true, type = 'inline-source-map') {
        if (Mix.inProduction()) {
            type = productionToo ? 'cheap-source-map' : false;
        }

        Config.sourcemaps = type;

        return this;
    };


    /**
     * Override the default path to your project's public directory.
     *
     * @param {string} defaultPath
     */
    setPublicPath(defaultPath) {
        Config.publicPath = path.normalize(defaultPath.replace(/\/$/, ''));

        return this;
    }


    /**
     * Set a prefix for all generated asset paths.
     *
     * @param {string} path
     */
    setResourceRoot(path) {
        Config.resourceRoot = path;

        return this;
    };


    /**
     * Disable all OS notifications.
     */
    disableNotifications() {
        Config.notifications = false;

        return this;
    };

    /**
     * Disable success notifications.
     */
    disableSuccessNotifications() {
        Config.notifications = {
            onSuccess: false,
            onFailure: true
        };

        return this;
    };


    /**
     * Register libraries to automatically "autoload" when
     * the appropriate variable is references in your JS.
     *
     * @param {Object} libs
     */
    autoload(libs) {
        let aliases = {};

        Object.keys(libs).forEach(library => {
            [].concat(libs[library]).forEach(alias => {
                aliases[alias] = library;
            });
        });

        Config.autoload = aliases;

        return this;
    };


    /**
     * Merge custom config with the provided webpack.config file.
     *
     * @param {object} config
     */
    webpackConfig(config) {
        Config.webpackConfig = (typeof config == 'function') ? config(webpack) : config;

        return this;
    }


    /* Set Mix-specific options.
     *
     * @param {object} options
     */
    options(options) {
        if (options.purifyCss) {
            options.purifyCss = require('./PurifyPaths').build(options.purifyCss);

            Verify.dependency(
                'purifycss-webpack',
                ['purifycss-webpack', 'purify-css'],
                true // abortOnComplete
            );
        }

        Config.merge(options);

        return this;
    };


    /**
     * Register a Webpack build event handler.
     *
     * @param {Function} callback
     */
    then(callback) {
        Mix.listen('build', callback);

        return this;
    }


    /**
     * Helper for determining a production environment.
     */
    inProduction() {
        return Mix.inProduction();
    }


    /**
     * Generate a full output path, using a fallback
     * file name, if a directory is provided.
     *
     * @param {Object} output
     * @param {Object} fallbackName
     */
    _normalizeOutput(output, fallbackName) {
        if (output.isDirectory()) {
            output = new File(path.join(output.filePath, fallbackName));
        }

        return output;
    }
}

module.exports = Api;