/*************************************************************
 *
 *  Copyright (c) 2017 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 CHTMLmo wrapper for the MmlMo object
 *
 * @author dpvc@mathjax.org (Davide Cervone)
 */

import {CHTMLWrapper, CHTMLConstructor, StringMap} from '../Wrapper.js';
import {CommonMo, CommonMoMixin, DirectionVH} from '../../common/Wrappers/mo.js';
import {MmlMo} from '../../../core/MmlTree/MmlNodes/mo.js';
import {BBox} from '../BBox.js';
import {StyleList} from '../../common/CssStyles.js';
import {DIRECTION, NOSTRETCH} from '../FontData.js';

/*****************************************************************/
/**
 * The CHTMLmo wrapper for the MmlMo object
 *
 * @template N  The HTMLElement node class
 * @template T  The Text node class
 * @template D  The Document class
 */
export class CHTMLmo<N, T, D> extends CommonMoMixin<CHTMLConstructor<any, any, any>>(CHTMLWrapper) {

    public static kind = MmlMo.prototype.kind;

    public static styles: StyleList = {
        'mjx-stretchy-h': {
            display: 'inline-table',
            width: '100%'
        },
        'mjx-stretchy-h > *': {
            display: 'table-cell',
            width: 0
        },
        'mjx-stretchy-h > * > mjx-c': {
            display: 'inline-block'
        },
        'mjx-stretchy-h > * > mjx-c::before': {
            padding: '.001em 0',                  // for blink
            width: 'initial'
        },
        'mjx-stretchy-h > mjx-ext': {
            overflow: 'hidden',
            width: '100%'
        },
        'mjx-stretchy-h > mjx-ext > mjx-c::before': {
            transform: 'scalex(500)'
        },
        'mjx-stretchy-h > mjx-ext > mjx-c': {
            width: 0
        },
        'mjx-stretchy-h > mjx-beg > mjx-c': {
            'margin-right': '-.1em'
        },
        'mjx-stretchy-h > mjx-end > mjx-c': {
            'margin-left': '-.1em'
        },

        'mjx-stretchy-v': {
            display: 'inline-block'
        },
        'mjx-stretchy-v > *': {
            display: 'block'
        },
        'mjx-stretchy-v > mjx-beg': {
            height: 0
        },
        'mjx-stretchy-v > mjx-end > mjx-c': {
            display: 'block'
        },
        'mjx-stretchy-v > * > mjx-c': {
            transform: 'scale(1)',                // improves Firefox positioning
            'transform-origin': 'left center',
            overflow: 'hidden'
        },
        'mjx-stretchy-v > mjx-ext': {
            display: 'block',
            height: '100%',
            'box-sizing': 'border-box',
            border: '0px solid transparent',
            overflow: 'hidden'
        },
        'mjx-stretchy-v > mjx-ext > mjx-c::before': {
            width: 'initial'
        },
        'mjx-stretchy-v > mjx-ext > mjx-c': {
            transform: 'scaleY(500) translateY(.1em)',
            overflow: 'visible'
        },
        'mjx-mark': {
            display: 'inline-block',
            height: '0px'
        }

    };

    /**
     * @override
     */
    public toCHTML(parent: N) {
        const attributes = this.node.attributes;
        const symmetric = (attributes.get('symmetric') as boolean) && this.stretch.dir !== DIRECTION.Horizontal;
        const stretchy = this.stretch.dir !== DIRECTION.None;
        if (stretchy && this.size === null) {
            this.getStretchedVariant([]);
        }
        let chtml = this.standardCHTMLnode(parent);
        if (this.noIC) {
            this.adaptor.setAttribute(chtml, 'noIC', 'true');
        }
        if (stretchy && this.size < 0) {
            this.stretchHTML(chtml, symmetric);
        } else {
            if (symmetric || attributes.get('largeop')) {
                const bbox = BBox.empty();
                super.computeBBox(bbox);
                const u = this.em((bbox.d - bbox.h) / 2 + this.font.params.axis_height);
                if (u !== '0') {
                    this.adaptor.setStyle(chtml, 'verticalAlign', u);
                }
            }
            for (const child of this.childNodes) {
                child.toCHTML(chtml);
            }
        }
    }

    /**
     * Create the HTML for a multi-character stretchy delimiter
     *
     * @param {N} chtml  The parent element in which to put the delimiter
     * @param {boolean} symmetric  Whether delimiter should be symmetric about the math axis
     */
    protected stretchHTML(chtml: N, symmetric: boolean) {
        const c = this.getText().charCodeAt(0);
        const delim = this.stretch;
        delim.used = true;
        const stretch = delim.stretch;
        const content: N[] = [];
        //
        //  Set up the beginning, extension, and end pieces
        //
        if (stretch[0]) {
            content.push(this.html('mjx-beg', {}, [this.html('mjx-c')]));
        }
        content.push(this.html('mjx-ext', {}, [this.html('mjx-c')]));
        if (stretch.length === 4) {
            //
            //  Braces have a middle and second extensible piece
            //
            content.push(
                this.html('mjx-mid', {}, [this.html('mjx-c')]),
                this.html('mjx-ext', {}, [this.html('mjx-c')])
            );
        }
        if (stretch[2]) {
            content.push(this.html('mjx-end', {}, [this.html('mjx-c')]));
        }
        //
        //  Set the styles needed
        //
        const styles: StringMap = {};
        const {h, d, w} = this.bbox;
        if (delim.dir === DIRECTION.Vertical) {
            //
            //  Vertical needs an extra (empty) element to get vertical position right
            //  in some browsers (e.g., Safari)
            //
            content.push(this.html('mjx-mark'));
            styles.height = this.em(h + d);
            styles.verticalAlign = this.em(-d);
        } else {
            styles.width = this.em(w);
        }
        //
        //  Make the main element and add it to the parent
        //
        const dir = DirectionVH[delim.dir];
        const properties = {class: this.char(delim.c || c), style: styles};
        const html = this.html('mjx-stretchy-' + dir, properties, content);
        this.adaptor.append(chtml, html);
    }

}