gerard2p/koaton

import * as path from 'upath';

/** @ignore */
const bundletemplates = {
    '.css': (file) => {
        return `<link rel='stylesheet' href='${file}'>`;
    },
    '.js': (file) => {
        return `<script src='${file}'></script>`;
    }
};

/**
 * Represents a Bundle Item used by the template engines to render .css or .js files.
 * @class BundleItem
 * @param {String} target Identifier that will be use as name of the bundle.
 * @param {String|String[]} source File(s) that will be bundled.
 */
export default class BundleItem {
    /**
     * @param {String} target - Identifier that will be use as name of the bundle.
     * @param {String|String[]} source - File(s) that will be bundled.
     */
    constructor (target, source) {
        Object.defineProperty(this, 'kind', {
            enumerable: false,
            value: target.replace(path.trimExt(target), '')
        });
        Object.defineProperty(this, 'file', {
            enumerable: true,
            value: target
        });
        Object.defineProperty(this, 'content', {
            writable: true,
            enumerable: false,
            value: source instanceof Array ? source : (source ? [source] : [])
        });
    }
    /**
     * Adds a new filepath to the bundle.
     * @param {String} item - File location of the file to add.
     * @return {BundleItem} - Returns the BundleItem instace for chaining.
     */
    add (item) {
        if (this.content.indexOf(item) === -1) {
            this.content.push(item);
        }
        return this;
    }
    /**
 * Removes all files added to the bundle.
 * @return {BundleItem} - Returns the BundleItem instace for chaining.
 */
    clear () {
        while (this.content.length > 0) {
            this.content.pop();
        }
        return this;
    }
    /**
     * Compares two BundleItem and returns true is equal.
     * @param {BundleItem} target - BundleItem to campare to.
     * @return {Boolean} - true if they are equal false otherwise.
     */
    equals (target) {
        return this.file === target.file;
    }
    /**
     * Makes sure that calling JSON.stringify return an array with the source files.
     * @return {String[]} - Return the value of the source files.
     */
    toJSON () {
        return this.content;
    }
    /**
     * Return the target file name
     * @return {String}
     */
    valueOf () {
        return this.file;
    }
    /**
     * Returns the representation of the bundle in <link rel='stylesheet' href='...'> or <script src='...'></script> format.
     * @return {String}
     */
    toString () {
        let res = '';
        for (const idx in this.content) {
            res += bundletemplates[this.kind](this.content[idx]);
        }
        return res;
    }
    /**
     * Return an iterator that can be use with for ... of
     * @alias BundleItem#iterator
     * @return {Symbol.iterator}
    */
    [Symbol.iterator] () {
        let index = -1;
        return {
            next: () => ({
                value: this.content[++index],
                done: !(index < this.content.length)
            })
        };
    }
}