/*************************************************************
 *
 *  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 CommonMaction wrapper mixin for the MmlMaction object
 *
 * @author dpvc@mathjax.org (Davide Cervone)
 */

import {AnyWrapper, WrapperConstructor, Constructor, AnyWrapperClass} from '../Wrapper.js';
import {MmlMaction} from '../../../core/MmlTree/MmlNodes/maction.js';
import {BBox} from '../BBox.js';
import {Property} from '../../../core/Tree/Node.js';
import {split} from '../../../util/string.js';

/*****************************************************************/
/**
 * The types needed to define the actiontypes
 *
 * @template W  The maction wrapper type
 */
export type ActionData = {[name: string]: any};
export type ActionHandler<W extends AnyWrapper> = (node: W, data?: ActionData) => void;
export type ActionPair<W extends AnyWrapper> = [ActionHandler<W>, ActionData];
export type ActionMap<W extends AnyWrapper> = Map<string, ActionPair<W>>;
export type ActionDef<W extends AnyWrapper> = [string, [ActionHandler<W>, ActionData]];

export type EventHandler = (event: Event) => void;

/**
 * Data used for tooltip actions
 */
export const TooltipData = {
    dx: '.2em',          // x-offset of tooltip from right side of maction bbox
    dy: '.1em',          // y-offset of tooltip from bottom of maction bbox

    postDelay: 600,      // milliseconds before tooltip posts
    clearDelay: 100,     // milliseconds before tooltip is removed

    hoverTimer: new Map<any, number>(),    // timers for posting tooltips
    clearTimer: new Map<any, number>(),    // timers for removing tooltips

    /*
     * clear the timers if any are active
     */
    stopTimers: (node: any, data: ActionData) => {
        if (data.clearTimer.has(node)) {
            clearTimeout(data.clearTimer.get(node));
            data.clearTimer.delete(node);
        }
        if (data.hoverTimer.has(node)) {
            clearTimeout(data.hoverTimer.get(node));
            data.hoverTimer.delete(node);
        }
    }

};

/*****************************************************************/
/**
 * The CommonMaction interface
 *
 * @template W  The maction wrapper type
 */
export interface CommonMaction<W extends AnyWrapper> extends AnyWrapper {
    /**
     * The handler for the specified actiontype
     */
    action: ActionHandler<W>;
    data: ActionData;

    /**
     * Tooltip offsets
     */
    dx: number;
    dy: number;

    /**
     * The selected child wrapper
     */
    readonly selected: W;

}

/**
 * The CommonMaction class interface
 *
 * @template W  The maction wrapper type
 */
export interface CommonMactionClass<W extends AnyWrapper> extends AnyWrapperClass {
    /**
     * The valid action types and their handlers
     */
    actions: ActionMap<W>;
}

/**
 * Shorthand for the CommonMaction constructor
 *
 * @template W  The maction wrapper type
 */
export type MactionConstructor<W extends AnyWrapper> = Constructor<CommonMaction<W>>;

/*****************************************************************/
/**
 * The CommonMaction wrapper mixin for the MmlMaction object
 *
 * @template W  The maction wrapper type
 * @template T  The Wrapper class constructor type
 */
export function CommonMactionMixin<W extends AnyWrapper,
                                   T extends WrapperConstructor>(Base: T): MactionConstructor<W> & T {
    return class extends Base {

        /**
         * The handler and data for the specified actiontype
         */
        public action: ActionHandler<W>;
        public data: ActionData;

        public dx: number;
        public dy: number;

        /**
         * @return {W}  The selected child wrapper
         */
        public get selected(): W {
            const selection = this.node.attributes.get('selection') as number;
            const i = Math.max(1, Math.min(this.childNodes.length, selection)) - 1;
            return this.childNodes[i] || this.wrap((this.node as MmlMaction).selected);
        }

        /*************************************************************/

        /**
         * @override
         */
        constructor(...args: any[]) {
            super(...args);
            const actions = (this.constructor as CommonMactionClass<W>).actions;
            const action = this.node.attributes.get('actiontype') as string;
            const [handler, data] = actions.get(action) || [((node, data) => {}) as ActionHandler<W>, {}];
            this.action = handler;
            this.data = data;
            this.getParameters();
        }

        /**
         * Look up attribute parameters
         */
        public getParameters() {
            const offsets = this.node.attributes.get('data-offsets') as string;
            let [dx, dy] = split(offsets || '');
            this.dx = this.length2em(dx || TooltipData.dx);
            this.dy = this.length2em(dy || TooltipData.dy);
        }

        /**
         * @override
         */
        public computeBBox(bbox: BBox, recompute: boolean = false) {
            bbox.updateFrom(this.selected.getBBox());
            this.selected.setChildPWidths(recompute);
        }

    };

}