define([
    'layout.dt/js/metadata/AssetMetadata'
], function(
        AssetMetadata
        ) {

    'use strict';

    /**
     * Collection of the assets (files) that make up a theme. There are several
     * {@link layout.dt/js/api/ThemeAssets.Type types} depending on an asset's
     * functionality.
     *
     * @AbcsExtension stable
     * @version 17.1.5
     *
     * @exports layout.dt/js/api/ThemeAssets
     * @constructor
     *
     * @see {@link layout.dt/js/spi/ThemeProvider Example of a complete
     *       ThemeProvider} including a list of assets
     * @see {@link layout.dt/js/spi/ThemeProvider#getAssets ThemeProvider.getAssets}
     *       theme provider SPI method to return a theme's assets
     */
    var ThemeAssets = function() {
        AbcsLib.checkParameterCount(arguments, 0);
        AbcsLib.checkThis(this);

        var self = this;
        self._assets = [];
    };

    /**
     * Adds an asset to the collection.
     *
     * @AbcsExtension stable
     * @version 17.1.5
     *
     * @param {layout.dt/js/api/ThemeAssets.Type} assetType The type of the asset
     * @param {String} assetPath The path and filename of the asset, relative to
     *         the asset path declared by the ThemeProvider.
     *
     * @returns {layout.dt/js/api/ThemeAssets} a reference to this object to
     *           allow method chaining
     *
     * @see {@link layout.dt/js/spi/ThemeProvider Example of a complete
     *       ThemeProvider} which uses this method
     */
    ThemeAssets.prototype.addAsset = function(assetType, assetPath) {
        AbcsLib.checkParameterCount(arguments, 2);
        AbcsLib.checkDataType(assetType, AbcsLib.Type.STRING); // ThemeAssets.Type is actually String
        AbcsLib.checkDataType(assetPath, AbcsLib.Type.STRING);

        this._assets.push(new AssetMetadata(assetType, assetPath));
        return this;
    };

    /**
     * Gets all theme assets of given type, or all of them if no type defined.
     *
     * @param {layout.dt/js/api/ThemeAssets.Type} [type] type of assets to get,
     *         undefined to return all
     * @returns {AssetMetadata[]} list of assets
     */
    ThemeAssets.prototype.getAssets = function(type) {
        // get all assets
        if (type === undefined) {
            return this._assets;
        }

        var result = [];
        this._assets.forEach(function(asset) {
            if (asset.getType() === type) {
                result.push(asset);
            }
        });
        return result;
    };

    /**
     * Defines valid asset types.
     *
     * @AbcsExtension stable
     * @version 17.1.5
     * @static
     * @constant
     * @enum {String}
     */
    ThemeAssets.Type = {

        /**
         * Styling file.
         *
         * <p>Theme CSS files can include styling for elements within the theme
         * HTML and also elements generated by ABCS, including Oracle JET
         * components.</p>
         *
         * @AbcsExtension stable
         * @version 17.1.5
         * @constant
         * @type {String}
         */
        STYLE: AssetMetadata.Type.STYLE,

        /**
         * Javascript template file.
         *
         * <p>A theme can have custom Javascript code in files other than its
         * {@link layout.dt/js/spi/ThemeProvider ThemeProvider SPI}
         * implementation.</p>
         *
         * @AbcsExtension stable
         * @version 17.1.5
         * @constant
         * @type {String}
         */
        SCRIPT: AssetMetadata.Type.SCRIPT,

        /**
         * HTML template file.
         *
         * <p>A theme should have one HTML file designated as its template,
         * whose contents should be returned by {@link layout.dt/js/spi/ThemeProvider#getTemplate
         * ThemeProvider.getTemplate()}. Further HTML files can be loaded into
         * the theme as templates</p>
         *
         * @AbcsExtension stable
         * @version 17.1.5
         * @constant
         * @type {String}
         */
        TEMPLATE: AssetMetadata.Type.TEMPLATE,

        /**
         * Image file.
         *
         * <p>A theme can include images which can be used within its layout and
         * as theme preview in the theme palette.</p>
         *
         * @AbcsExtension stable
         * @version 17.1.5
         * @constant
         * @type {String}
         */
        IMAGE: AssetMetadata.Type.IMAGE,

        /**
         * Generic type for files which do not belong to any of the previous
         * categories. Not currently used.
         *
         * @constant
         * @type {String}
         */
        OTHER: AssetMetadata.Type.OTHER
    };

    return ThemeAssets;

});