/*************************************************************
 *
 *  Copyright (c) 2018 The MathJax Consortium
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

/**
 * @fileoverview  Implements the CommonMglyph wrapper mixin for the MmlMglyph object
 *
 * @author dpvc@mathjax.org (Davide Cervone)
 */

import {AnyWrapper, WrapperConstructor, Constructor} from '../Wrapper.js';
import {BBox} from '../BBox.js';
import {MmlMglyph} from '../../../core/MmlTree/MmlNodes/mglyph.js';
import {Property} from '../../../core/Tree/Node.js';
import {StyleList, StyleData} from '../../common/CssStyles.js';

/*****************************************************************/
/**
 * The CommonMglyph interface
 */
export interface CommonMglyph extends AnyWrapper {
    /**
     * The image's width, height, and voffset values converted to em's
     */
    width: number;
    height: number;
    voffset: number;

    /**
     * Obtain the width, height, and voffset.
     */
    getParameters(): void;
}

/**
 * Shorthand for the CommonMglyph constructor
 */
export type MglyphConstructor = Constructor<CommonMglyph>;

/*****************************************************************/
/**
 * The CommonMglyph wrapper mixin for the MmlMglyph object
 *
 * @template T  The Wrapper class constructor type
 */
export function CommonMglyphMixin<T extends WrapperConstructor>(Base: T): MglyphConstructor & T {
    return class extends Base {

        /**
         * The image's width, height, and voffset values converted to em's
         */
        public width: number;
        public height: number;
        public voffset: number;

        /**
         * @override
         * @constructor
         */
        constructor(...args: any[]) {
            super(...args);
            this.getParameters();
        }

        /**
         * Obtain the width, height, and voffset.
         * Note:  Currently, the width and height must be specified explicitly, or they default to 1em
         *   Since loading the image may be asynchronous, it would require a restart.
         *   A future extension could implement this either by subclassing this object, or
         *   perhaps as a post-filter on the MathML input jax that adds the needed dimensions
         */
        public getParameters() {
            const {width, height, voffset} = this.node.attributes.getList('width', 'height', 'voffset');
            this.width = (width === 'auto' ? 1 : this.length2em(width));
            this.height = (height === 'auto' ? 1 : this.length2em(height));
            this.voffset = this.length2em(voffset || '0');
        }

        /**
         * @override
         */
        public computeBBox(bbox: BBox, recompute: boolean = false) {
            bbox.w = this.width;
            bbox.h = this.height - this.voffset;
            bbox.d = this.voffset;
        }

    };

}