/*************************************************************
 *
 *  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 SVGmmultiscripts wrapper for the MmlMmultiscripts object
 *
 * @author dpvc@mathjax.org (Davide Cervone)
 */

import {SVGWrapper, Constructor} from '../Wrapper.js';
import {SVGmsubsup} from './msubsup.js';
import {CommonMmultiscripts, CommonMmultiscriptsMixin} from '../../common/Wrappers/mmultiscripts.js';
import {MmlMmultiscripts} from '../../../core/MmlTree/MmlNodes/mmultiscripts.js';
import {BBox} from '../BBox.js';

/*****************************************************************/
/**
 * The SVGmmultiscripts wrapper for the MmlMmultiscripts object
 *
 * @template N  The HTMLElement node class
 * @template T  The Text node class
 * @template D  The Document class
 */
export class SVGmmultiscripts<N, T, D> extends
CommonMmultiscriptsMixin<SVGWrapper<N, T, D>, Constructor<SVGmsubsup<N, T, D>>>(SVGmsubsup) {

    public static kind = MmlMmultiscripts.prototype.kind;

    /**
     * @override
     */
    public toSVG(parent: N) {
        const svg = this.standardSVGnode(parent);
        const data = this.getScriptData();
        //
        //  Combine the bounding boxes of the pre- and post-scripts,
        //  and get the resulting baseline offsets
        //
        const sub = this.combinePrePost(data.sub, data.psub);
        const sup = this.combinePrePost(data.sup, data.psup);
        const [u, v, q] = this.getUVQ(data.base, sub, sup);
        //
        //  Place the pre-scripts, then the base, then the post-scripts
        //
        let x = 0;  // scriptspace
        if (data.numPrescripts) {
            x = this.addScripts(.05, u, v, true, this.firstPrescript, data.numPrescripts);
        }
        const base = this.baseChild;
        base.toSVG(svg);
        base.place(x, 0);
        x += base.getBBox().w;
        if (data.numScripts) {
            this.addScripts(x, u, v, false, 1, data.numScripts);
        }
    }

    /**
     * Create a table with the super and subscripts properly separated and aligned.
     *
     * @param {number} x       The x offset of the scripts
     * @param {number} u       The baseline offset for the superscripts
     * @param {number} v       The baseline offset for the subscripts
     * @param {boolean} isPre  True for prescripts, false for scripts
     * @param {number} i       The starting index for the scripts
     * @param {number} n       The number of sub/super-scripts
     * @return {number}        The right-hand offset of the scripts
     */
    protected addScripts(x: number, u: number, v: number, isPre: boolean, i: number, n: number) {
        const adaptor = this.adaptor;
        const supRow = adaptor.append(this.element, this.svg('g'));
        const subRow = adaptor.append(this.element, this.svg('g'));
        this.place(x, u, supRow);
        this.place(x, v, subRow);
        let m = i + 2 * n, child;
        let dx = 0;
        while (i < m) {
            const [sub, sup] = [this.childNodes[i++], this.childNodes[i++]];
            const [subbox, supbox] = [sub.getBBox(), sup.getBBox()];
            const [subr, supr] = [subbox.rscale, supbox.rscale];
            const w = Math.max(subbox.w * subr, supbox.w * supr);
            sub.toSVG(subRow);
            sup.toSVG(supRow);
            sub.place(dx + (isPre ? w - subbox.w * subr: 0), 0);
            sup.place(dx + (isPre ? w - supbox.w * supr: 0), 0);
            dx += w;
        }
        return x + dx;
    }

}