/*
    Copyright 2008-2026
        Matthias Ehmann,
        Michael Gerhaeuser,
        Carsten Miller,
        Bianca Valentin,
        Alfred Wassermann,
        Peter Wilfahrt

    This file is part of JSXGraph.

    JSXGraph is free software dual licensed under the GNU LGPL or MIT License.

    You can redistribute it and/or modify it under the terms of the

      * GNU Lesser General Public License as published by
        the Free Software Foundation, either version 3 of the License, or
        (at your option) any later version
      OR
      * MIT License: https://github.com/jsxgraph/jsxgraph/blob/master/LICENSE.MIT

    JSXGraph is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License and
    the MIT License along with JSXGraph. If not, see <https://www.gnu.org/licenses/>
    and <https://opensource.org/licenses/MIT/>.
 */

/*global JXG: true, define: true*/
/*jslint nomen: true, plusplus: true*/

/**
 * @fileoverview Example file for a triangle implemented as a extension to JSXGraph.
 */

import JXG from "../jxg.js";
import Type from "../utils/type.js";
import Const from "../base/constants.js";
import Polygon from "../base/polygon.js";

var priv = {
    removeSlopeTriangle: function () {
        Polygon.prototype.remove.call(this);

        this.board.removeObject(this.toppoint);
        this.board.removeObject(this.glider);

        this.board.removeObject(this.baseline);
        this.board.removeObject(this.basepoint);

        this.board.removeObject(this.label);

        if (this._isPrivateTangent) {
            this.board.removeObject(this.tangent);
        }
    },
    Slope: function () {
        return this.tangent.getSlope();
    },
    getAngle: function (unit) {
        return this.tangent.getAngle(unit);
    },
    DeltaX: function () {
        return this.borderHorizontal.Direction()[0];
    },
    DeltaY: function () {
        return this.borderVertical.Direction()[1];
    },
    Direction: function () {
        return this.tangent.Direction();
    }
};

/**
 * @class Slope triangle to visualize the slope of a tangent to a curve, circle or line.
 * @pseudo
 * @name Slopetriangle
 * @augments JXG.Line
 * @constructor
 * @type JXG.Polygon
 * @throws {Error} If the element cannot be constructed with the given parent objects an exception is thrown.
 * Parameter options:
 * @param {JXG.Line} t A tangent based on a glider on some object, e.g. curve, circle, line or turtle.
 * @param {JXG.Line_JXG.Point} li, p A line and a point on that line.
 *  The user has to take care that the point is a member of the line.
 * @example
 * // Create a slopetriangle on a tangent
 * var f = board.create('plot', ['sin(x)']),
 *     g = board.create('glider', [1, 2, f]),
 *     t = board.create('tangent', [g]),
 *
 *     st = board.create('slopetriangle', [t]);
 *
 * </pre><div class="jxgbox" id="JXG951ccb6a-52bc-4dc2-80e9-43db064f0f1b" style="width: 300px; height: 300px;"></div>
 * <script type="text/javascript">
 * (function () {
 *   var board = JXG.JSXGraph.initBoard('JXG951ccb6a-52bc-4dc2-80e9-43db064f0f1b', {boundingbox: [-5, 5, 5, -5], axis: true, showcopyright: false, shownavigation: false}),
 *     f = board.create('plot', ['sin(x)']),
 *     g = board.create('glider', [1, 2, f]),
 *     t = board.create('tangent', [g]),
 *
 *     st = board.create('slopetriangle', [t]);
 * })();
 * </script><pre>
 *
 * @example
 * // Create a on a line and a point on that line
 * var p1 = board.create('point', [-2, 3]),
 *     p2 = board.create('point', [2, -3]),
 *     li = board.create('line', [p1, p2]),
 *     p = board.create('glider', [0, 0, li]),
 *
 *     st = board.create('slopetriangle', [li, p]);
 *
 * </pre><div class="jxgbox" id="JXGb52f451c-22cf-4677-852a-0bb9d764ee95" style="width: 300px; height: 300px;"></div>
 * <script type="text/javascript">
 * (function () {
 *   var board = JXG.JSXGraph.initBoard('JXGb52f451c-22cf-4677-852a-0bb9d764ee95', {boundingbox: [-5, 5, 5, -5], axis: true, showcopyright: false, shownavigation: false}),
 *     p1 = board.create('point', [-2, 3]),
 *     p2 = board.create('point', [2, -3]),
 *     li = board.create('line', [p1, p2]),
 *     p = board.create('glider', [0, 0, li]),
 *
 *     st = board.create('slopetriangle', [li, p]);
 * })();
 * </script><pre>
 */
JXG.createSlopeTriangle = function (board, parents, attributes) {
    var el, tangent, tglide, glider,
        toppoint, baseline, basepoint,
        label, attr,
        isPrivateTangent = false;

    if (parents.length === 1 && parents[0].type === Const.OBJECT_TYPE_TANGENT) {
        tangent = parents[0];
        tglide = tangent.glider;
    } else if (parents.length === 1 && parents[0].type === Const.OBJECT_TYPE_GLIDER) {
        tglide = parents[0];
        attr = Type.copyAttributes(attributes, board.options, "slopetriangle", 'tangent');
        tangent = board.create("tangent", [tglide], attr);
        isPrivateTangent = true;
    } else if (
        parents.length === 2 &&
        parents[0].elementClass === Const.OBJECT_CLASS_LINE &&
        Type.isPoint(parents[1])
    ) {
        tangent = parents[0];
        tglide = parents[1];
    } else {
        throw new Error(
            "JSXGraph: Can't create slope triangle with parent types '" +
            typeof parents[0] +
            "'."
        );
    }

    attr = Type.copyAttributes(attributes, board.options, "slopetriangle", 'basepoint');
    basepoint = board.create(
        "point",
        [
            function () {
                return [tglide.X() + 1, tglide.Y()];
            }
        ],
        attr
    );

    attr = Type.copyAttributes(attributes, board.options, "slopetriangle", 'baseline');
    baseline = board.create("line", [tglide, basepoint], attr);

    attr = Type.copyAttributes(attributes, board.options, "slopetriangle", 'glider');
    glider = board.create("glider", [tglide.X() + 1, tglide.Y(), baseline], attr);

    attr = Type.copyAttributes(attributes, board.options, "slopetriangle", 'toppoint');
    toppoint = board.create(
        "point",
        [
            function () {
                return [
                    glider.X(),
                    glider.Y() + (glider.X() - tglide.X()) * tangent.getSlope()
                ];
            }
        ],
        attr
    );

    attr = Type.copyAttributes(attributes, board.options, 'slopetriangle');
    // attr.borders = Type.copyAttributes(attr.borders, board.options, "slopetriangle", 'borders');
    el = board.create("polygon", [tglide, glider, toppoint], attr);
    el.elType = 'slopetriangle';

    /**
     * Returns the slope of the tangent.
     * @name Slope
     * @memberOf Slopetriangle.prototype
     * @function
     * @returns {Number} slope of the tangent.
     */
    el.Slope = priv.Slope;

    /**
     * Returns the angle between the tangent and the x-axis.
     * @name getAngle
     * @memberOf Slopetriangle.prototype
     * @function
     * @param {String} [unit='radians'] Unit of the returned values. Possible units are
     * <ul>
     * <li> 'radians' (default): angle value in radians
     * <li> 'degrees': angle value in degrees
     * <li> 'semicircle': angle value in radians as a multiple of &pi;, e.g. if the angle is 1.5&pi;, 1.5 will be returned.
     * <li> 'circle': angle value in radians as a multiple of 2&pi;
     * </ul>
     * @returns {Number}
     */
    el.getAngle = priv.getAngle;

    /**
     * Returns &delta;x of the slope triangle, that is the slope of the tangent.
     * This value is less than 0 if the line points to the left.
     * @name DeltaX
     * @memberOf Slopetriangle.prototype
     * @function
     * @returns {Number}
     */
    el.DeltaX = priv.DeltaX;

    /**
     * Returns &delta;y of the slope triangle, that is the slope of the tangent.
     * This value is less than 0 if the line points to the bottom.
     * @name DeltaY
     * @memberOf Slopetriangle.prototype
     * @function
     * @returns {Number}
     */
    el.DeltaY = priv.DeltaY;

    /**
     * Returns the direction of the slope triangle, that is the direction of the tangent.
     * @name Direction
     * @memberOf Slopetriangle.prototype
     * @see Line#Direction
     * @function
     * @returns {Number} slope of the tangent.
     */
    el.Direction = priv.Direction;
    el.tangent = tangent;
    el._isPrivateTangent = isPrivateTangent;

    el.borderHorizontal = el.borders[0];
    el.borderVertical = el.borders[1];
    el.borderParallel = el.borders[2];

    //el.borderHorizontal.setArrow(false, {type: 2, size: 10});
    //el.borderVertical.setArrow(false, {type: 2, size: 10});
    el.borderParallel.setArrow(false, false);

    attr = Type.copyAttributes(attributes, board.options, "slopetriangle", 'label');
    //label = board.create("text", [
    //         function () {
    //             return glider.X() + 0.1;
    //         },
    //         function () {
    //             return (glider.Y() + toppoint.Y()) * 0.5;
    //         },
    //         function () {
    //             return "";
    //         }
    //     ],
    //     attr
    // );

    attr = Type.copyAttributes(attr, board.options, 'label');
    // Add label to vertical polygon edge
    attr.isLabel = true;
    attr.anchor = el.borderVertical;
    attr.priv = el.borderVertical.visProp.priv;
    attr.id = el.borderVertical.id + 'Label';

    label = board.create("text", [0, 0, function () { return ""; }], attr);
    label.elType = 'label';
    label.needsUpdate = true;
    label.dump = false;
    el.borderVertical.label = label;
    el.borderVertical.hasLabel = true;
    el.borderVertical.visProp.withlabel = true;

    el.borderVertical.slopetriangle = el;
    el.borderHorizontal.slopetriangle = el;
    glider.slopetriangle = el;
    basepoint.slopetriangle = el;
    baseline.slopetriangle = el;
    toppoint.slopetriangle = el;
    label.slopetriangle = el;

    label.setText(function () {
        var prefix = '',
            suffix = '',
            digits = label.evalVisProp('digits'),
            val = el.Slope();

        if (label.evalVisProp('showprefix')) {
            prefix = label.evalVisProp('prefix');
        }
        if (label.evalVisProp('showsuffix')) {
            suffix = label.evalVisProp('suffix');
        }

        if (digits === 'none') {
            // do nothing
        } else if (digits === 'auto') {
            if (label.useLocale()) {
                val = label.formatNumberLocale(val);
            } else {
                val = Type.autoDigits(val);
            }
        } else {
            if (label.useLocale()) {
                val = label.formatNumberLocale(val, digits);
            } else {
                val = Type.toFixed(val, digits);
            }
        }

        if (Type.isFunction(el.visProp.formatvalue)) {
            val = el.visProp.formatvalue(el, val);
        }

        return prefix + val + suffix;
    });
    label.fullUpdate();

    el.glider = glider;
    el.basepoint = basepoint;
    el.baseline = baseline;
    el.toppoint = toppoint;
    el.label = label;

    el.subs = {
        glider: glider,
        basePoint: basepoint,
        baseLine: baseline,
        topPoint: toppoint,
        label: label
    };
    el.inherits.push(glider, basepoint, baseline, toppoint, label);

    el.remove = priv.removeSlopeTriangle;

    Type.extendInstanceMethodMap(el, {
        tangent: "tangent",
        glider: "glider",
        basepoint: "basepoint",
        baseline: "baseline",
        toppoint: "toppoint",
        borderHorizontal: "borderHorizontal",
        borderVertical: "borderVertical",
        borderParallel: "borderParallel",
        label: "label",
        Value: "Slope",
        V: "Slope",
        Slope: "Slope",
        Angle: "getAngle",
        getAngle: "getAngle",
        DeltaX: "DeltaX",
        DeltaY: "DeltaY",
        Direction: "Direction"
    });

    return el;
};

JXG.registerElement("slopetriangle", JXG.createSlopeTriangle);

// export default {
//     createSlopeTriangle: JXG.createSlopeTriangle
// };
