/*************************************************************
 *
 *  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 CcommonMtr wrapper mixin for the MmlMtr object
 *                and CommonMlabeledtr wrapper mixin for MmlMlabeledtr
 *
 * @author dpvc@mathjax.org (Davide Cervone)
 */

import {AnyWrapper, WrapperConstructor, Constructor} from '../Wrapper.js';
import {BBox} from '../BBox.js';
import {MmlMtr, MmlMlabeledtr} from '../../../core/MmlTree/MmlNodes/mtr.js';
import {DIRECTION} from '../FontData.js';

/*****************************************************************/
/**
 * The CommonMtr interface
 *
 * @template C  The class for table cells
 */
export interface CommonMtr<C extends AnyWrapper> extends AnyWrapper {

    /**
     * The number of mtd's in the mtr
     */
    readonly numCells: number;

    /**
     * True if this is a labeled row
     */
    readonly labeled: boolean;

    /**
     * The child nodes that are part of the table (no label node)
     */
    readonly tableCells: C[];

    /**
     * @param {nunber} i   The index of the child to get (skipping labels)
     * @return {C}         The ith child node wrapper
     */
    getChild(i: number): C;

    /**
     * @return {BBox[]}  An array of the bounding boxes for the mtd's in the row
     */
    getChildBBoxes(): BBox[];

    /**
     * Handle vertical stretching of cells to match height of
     *  other cells in the row.
     *
     * @param {number[]=} HD   The total height and depth for the row [H, D]
     *
     * If this isn't specified, the maximum height and depth is computed.
     */
    stretchChildren(HD?: number[]): void;

    /**
     * @override;
     */
    childNodes: C[];
}

/**
 * Shorthand for the CommonMtr constructor
 *
 * @template C  The class for table cells
 */
export type MtrConstructor<C extends AnyWrapper> = Constructor<CommonMtr<C>>;

/*****************************************************************/
/**
 * The CommonMtr wrapper for the MmlMtr object
 *
 * @template C  The class for table cells
 * @template T  The Wrapper class constructor type
 */
export function CommonMtrMixin<C extends AnyWrapper,
                               T extends WrapperConstructor>(Base: T): MtrConstructor<C> & T {
    return class extends Base {

        /**
         * @override
         */
        get fixesPWidth() {
            return false;
        }

        /**
         * @return {number}   The number of mtd's in the mtr
         */
        get numCells() {
            return this.childNodes.length;
        }

        /**
         * @return {boolean}   True if this is a labeled row
         */
        get labeled() {
            return false;
        }

        /**
         * @return {C[]}  The child nodes that are part of the table (no label node)
         */
        get tableCells() {
            return this.childNodes as C[];
        }

        /**
         * @param {number} i   The index of the child to get (skipping labels)
         * @return {C}         The ith child node wrapper
         */
        public getChild(i: number) {
            return this.childNodes[i] as C;
        }

        /**
         * @return {BBox[]}  An array of the bounding boxes for the mtd's in the row
         */
        public getChildBBoxes() {
            return this.childNodes.map(cell => cell.getBBox());
        }

        /**
         * Handle vertical stretching of cells to match height of
         *  other cells in the row.
         *
         * @param {number[]} HD   The total height and depth for the row [H, D]
         *
         * If this isn't specified, the maximum height and depth is computed.
         */
        public stretchChildren(HD: number[] = null) {
            let stretchy: AnyWrapper[] = [];
            let children = (this.labeled ? this.childNodes.slice(1) : this.childNodes);
            //
            //  Locate and count the stretchy children
            //
            for (const mtd of children) {
                const child = mtd.childNodes[0];
                if (child.canStretch(DIRECTION.Vertical)) {
                    stretchy.push(child);
                }
            }
            let count = stretchy.length;
            let nodeCount = this.childNodes.length;
            if (count && nodeCount > 1) {
                if (HD === null) {
                    let H = 0, D = 0;
                    //
                    //  If all the children are stretchy, find the largest one,
                    //  otherwise, find the height and depth of the non-stretchy
                    //  children.
                    //
                    let all = (count > 1 && count === nodeCount);
                    for (const mtd of children) {
                        const child = mtd.childNodes[0];
                        const noStretch = (child.stretch.dir === DIRECTION.None);
                        if (all || noStretch) {
                            const {h, d} = child.getBBox(noStretch);
                            if (h > H) {
                                H = h;
                            }
                            if (d > D) {
                                D = d;
                            }
                        }
                    }
                    HD = [H, D];
                }
                //
                //  Stretch the stretchable children
                //
                for (const child of stretchy) {
                    child.coreMO().getStretchedVariant(HD);
                }
            }
        }

    };

}

/*****************************************************************/
/**
 * The CommonMlabeledtr interface
 *
 * @template C  The class for table cells
 */
export interface CommonMlabeledtr<C extends AnyWrapper> extends CommonMtr<C> {
}

/**
 * Shorthand for the CommonMlabeledtr constructor
 *
 * @template C  The class for table cells
 */
export type MlabeledtrConstructor<C extends AnyWrapper> = Constructor<CommonMlabeledtr<C>>;

/*****************************************************************/
/**
 * The CommonMlabeledtr wrapper mixin for the MmlMlabeledtr object
 *
 * @template C  The class for table cells
 * @template T  The Wrapper class constructor type
 */
export function CommonMlabeledtrMixin<C extends AnyWrapper,
                                      T extends MtrConstructor<C>>(Base: T): MlabeledtrConstructor<C> & T {
    return class extends Base {

        /**
         * @override
         */
        get numCells() {
            //
            //  Don't include the label mtd
            //
            return Math.max(0, this.childNodes.length - 1);
        }

        /**
         * @override
         */
        get labeled() {
            return true;
        }

        /**
         * @override
         */
        get tableCells() {
            return this.childNodes.slice(1) as C[];
        }

        /**
         * @override
         */
        public getChild(i: number) {
            return this.childNodes[i + 1] as C;
        }

        /**
         * @override
         */
        public getChildBBoxes() {
            //
            //  Don't include the label mtd
            //
            return this.childNodes.slice(1).map(cell => cell.getBBox());
        }

    };

}