/**
 * @author       Richard Davey <rich@photonstorm.com>
 * @copyright    2022 Photon Storm Ltd.
 * @license      {@link https://opensource.org/licenses/MIT|MIT License}
 */

var Class = require('../../utils/Class');
var FloatBetween = require('../../math/FloatBetween');
var GetEaseFunction = require('../../tweens/builders/GetEaseFunction');
var GetFastValue = require('../../utils/object/GetFastValue');
var Wrap = require('../../math/Wrap');

/**
 * @classdesc
 * This class is responsible for taking control over a single property
 * in the Particle class and managing its emission and updating functions.
 *
 * Particles properties such as `x`, `y`, `scaleX`, `lifespan` and others all use
 * EmitterOp instances to manage them, as they can be given in a variety of
 * formats: from simple values, to functions, to dynamic callbacks.
 *
 * See the `ParticleEmitter` class for more details on emitter op configuration.
 *
 * @class EmitterOp
 * @memberof Phaser.GameObjects.Particles
 * @constructor
 * @since 3.0.0
 *
 * @param {Phaser.Types.GameObjects.Particles.ParticleEmitterConfig} config - Settings for the Particle Emitter that owns this property.
 * @param {string} key - The name of the property.
 * @param {Phaser.Types.GameObjects.Particles.EmitterOpOnEmitType} defaultValue - The default value of the property.
 * @param {boolean} [emitOnly=false] - Whether the property can only be modified when a Particle is emitted.
 */
var EmitterOp = new Class({

    initialize:

    function EmitterOp (config, key, defaultValue, emitOnly)
    {
        if (emitOnly === undefined) { emitOnly = false; }

        /**
         * The name of this property.
         *
         * @name Phaser.GameObjects.Particles.EmitterOp#propertyKey
         * @type {string}
         * @since 3.0.0
         */
        this.propertyKey = key;

        /**
         * The current value of this property.
         *
         * This can be a simple value, an array, a function or an onEmit
         * configuration object.
         *
         * @name Phaser.GameObjects.Particles.EmitterOp#propertyValue
         * @type {Phaser.Types.GameObjects.Particles.EmitterOpOnEmitType}
         * @since 3.0.0
         */
        this.propertyValue = defaultValue;

        /**
         * The default value of this property.
         *
         * This can be a simple value, an array, a function or an onEmit
         * configuration object.
         *
         * @name Phaser.GameObjects.Particles.EmitterOp#defaultValue
         * @type {Phaser.Types.GameObjects.Particles.EmitterOpOnEmitType}
         * @since 3.0.0
         */
        this.defaultValue = defaultValue;

        /**
         * The number of steps for stepped easing between {@link Phaser.GameObjects.Particles.EmitterOp#start} and
         * {@link Phaser.GameObjects.Particles.EmitterOp#end} values, per emit.
         *
         * @name Phaser.GameObjects.Particles.EmitterOp#steps
         * @type {number}
         * @default 0
         * @since 3.0.0
         */
        this.steps = 0;

        /**
         * The step counter for stepped easing, per emit.
         *
         * @name Phaser.GameObjects.Particles.EmitterOp#counter
         * @type {number}
         * @default 0
         * @since 3.0.0
         */
        this.counter = 0;

        /**
         * The start value for this property to ease between.
         *
         * @name Phaser.GameObjects.Particles.EmitterOp#start
         * @type {number}
         * @default 0
         * @since 3.0.0
         */
        this.start = 0;

        /**
         * The end value for this property to ease between.
         *
         * @name Phaser.GameObjects.Particles.EmitterOp#end
         * @type {number}
         * @default 0
         * @since 3.0.0
         */
        this.end = 0;

        /**
         * The easing function to use for updating this property.
         *
         * @name Phaser.GameObjects.Particles.EmitterOp#ease
         * @type {?function}
         * @since 3.0.0
         */
        this.ease;

        /**
         * Whether this property can only be modified when a Particle is emitted.
         *
         * Set to `true` to allow only {@link Phaser.GameObjects.Particles.EmitterOp#onEmit} callbacks to be set and
         * affect this property.
         *
         * Set to `false` to allow both {@link Phaser.GameObjects.Particles.EmitterOp#onEmit} and
         * {@link Phaser.GameObjects.Particles.EmitterOp#onUpdate} callbacks to be set and affect this property.
         *
         * @name Phaser.GameObjects.Particles.EmitterOp#emitOnly
         * @type {boolean}
         * @since 3.0.0
         */
        this.emitOnly = emitOnly;

        /**
         * The callback to run for Particles when they are emitted from the Particle Emitter.
         *
         * @name Phaser.GameObjects.Particles.EmitterOp#onEmit
         * @type {Phaser.Types.GameObjects.Particles.EmitterOpOnEmitCallback}
         * @since 3.0.0
         */
        this.onEmit = this.defaultEmit;

        /**
         * The callback to run for Particles when they are updated.
         *
         * @name Phaser.GameObjects.Particles.EmitterOp#onUpdate
         * @type {Phaser.Types.GameObjects.Particles.EmitterOpOnUpdateCallback}
         * @since 3.0.0
         */
        this.onUpdate = this.defaultUpdate;

        /**
         * Set to `false` to disable this EmitterOp.
         *
         * @name Phaser.GameObjects.Particles.EmitterOp#active
         * @type {boolean}
         * @since 3.60.0
         */
        this.active = true;

        /**
         * The onEmit method type of this EmitterOp.
         *
         * Set as part of `setMethod` and cached here to avoid
         * re-setting when only the value changes.
         *
         * @name Phaser.GameObjects.Particles.EmitterOp#method
         * @type {number}
         * @since 3.60.0
         */
        this.method = 0;

        this.loadConfig(config);
    },

    /**
     * Load the property from a Particle Emitter configuration object.
     *
     * Optionally accepts a new property key to use, replacing the current one.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#loadConfig
     * @since 3.0.0
     *
     * @param {Phaser.Types.GameObjects.Particles.ParticleEmitterConfig} [config] - Settings for the Particle Emitter that owns this property.
     * @param {string} [newKey] - The new key to use for this property, if any.
     */
    loadConfig: function (config, newKey)
    {
        if (config === undefined)
        {
            config = {};
        }

        if (newKey)
        {
            this.propertyKey = newKey;
        }

        this.propertyValue = GetFastValue(
            config,
            this.propertyKey,
            this.defaultValue
        );

        var method = this.getMethod();

        this.setMethods(method);

        if (this.emitOnly)
        {
            //  Reset it back again
            this.onUpdate = this.defaultUpdate;
        }
    },

    /**
     * Build a JSON representation of this Particle Emitter property.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#toJSON
     * @since 3.0.0
     *
     * @return {object} A JSON representation of this Particle Emitter property.
     */
    toJSON: function ()
    {
        return JSON.stringify(this.propertyValue);
    },

    /**
     * Change the current value of the property and update its callback methods.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#onChange
     * @since 3.0.0
     *
     * @param {Phaser.Types.GameObjects.Particles.EmitterOpOnEmitType} value - The value of the property.
     *
     * @return {this} This Emitter Op object.
     */
    onChange: function (value)
    {
        this.propertyValue = value;

        var method = this.getMethod();

        if (method !== this.method || method === 3)
        {
            this.setMethods(method);
        }

        return this;
    },

    /**
     * Checks the type of `EmitterOp.propertyValue` to determine which
     * method is required in order to return values from this op function.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#getMethod
     * @since 3.60.0
     *
     * @return {number} A number between 0 and 8 which should be passed to `setMethods`.
     */
    getMethod: function ()
    {
        var value = this.propertyValue;

        //  `moveToX` and `moveToY` are null by default
        if (value === null)
        {
            return 0;
        }

        var t = typeof value;

        if (t === 'number')
        {
            return 1;
        }
        else if (Array.isArray(value))
        {
            return 2;
        }
        else if (t === 'function')
        {
            return 3;
        }
        else if (t === 'object')
        {
            if (this.hasBoth(value, 'start', 'end'))
            {
                if (this.has(value, 'steps'))
                {
                    return 4;
                }
                else
                {
                    return 5;
                }
            }
            else if (this.hasBoth(value, 'min', 'max'))
            {
                return 6;
            }
            else if (this.has(value, 'random'))
            {
                return 7;
            }
            else if (this.hasEither(value, 'onEmit', 'onUpdate'))
            {
                return 8;
            }
        }

        return 0;
    },

    /**
     * Update the {@link Phaser.GameObjects.Particles.EmitterOp#onEmit} and
     * {@link Phaser.GameObjects.Particles.EmitterOp#onUpdate} callbacks based on the method returned
     * from `getMethod`. The method is stored in the `EmitterOp.method` property
     * and is a number between 0 and 8 inclusively.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#setMethods
     * @since 3.0.0
     *
     * @param {number} method - The operation method to use. A value between 0 and 8 (inclusively) as returned from `getMethod`.
     *
     * @return {this} This Emitter Op object.
     */
    setMethods: function (method)
    {
        var value = this.propertyValue;

        var onEmit;
        var onUpdate;

        switch (method)
        {
            case 1:
                onEmit = this.staticValueEmit;
                onUpdate = this.staticValueUpdate;
                break;

            case 2:
                onEmit = this.randomStaticValueEmit;
                break;

            case 3:
                if (this.emitOnly)
                {
                    onEmit = value;
                }
                else
                {
                    onUpdate = value;
                }
                break;

            case 4:
                this.start = value.start;
                this.end = value.end;
                this.steps = value.steps;
                this.counter = this.start;
                onEmit = this.steppedEmit;
                break;

            case 5:
                this.start = value.start;
                this.end = value.end;
                var easeType = this.has(value, 'ease') ? value.ease : 'Linear';
                this.ease = GetEaseFunction(easeType, value.easeParams);
                onEmit = this.has(value, 'random') ? this.randomRangedValueEmit : this.easedValueEmit;
                onUpdate = this.easeValueUpdate;
                break;

            case 6:
                this.start = value.min;
                this.end = value.max;
                onEmit = this.randomRangedValueEmit;
                break;

            case 7:
                var rnd = value.random;

                if (Array.isArray(rnd))
                {
                    this.start = rnd[0];
                    this.end = rnd[1];
                }

                onEmit = this.randomRangedValueEmit;
                break;

            case 8:
                onEmit = (this.has(value, 'onEmit')) ? value.onEmit : this.defaultEmit;
                onUpdate = (this.has(value, 'onUpdate')) ? value.onUpdate : this.defaultUpdate;
                break;

            default:
                onEmit = this.defaultEmit;
                onUpdate = this.defaultUpdate;
        }

        this.onEmit = onEmit;
        this.onUpdate = onUpdate;

        this.method = method;
    },

    /**
     * Check whether an object has the given property.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#has
     * @since 3.0.0
     *
     * @param {object} object - The object to check.
     * @param {string} key - The key of the property to look for in the object.
     *
     * @return {boolean} `true` if the property exists in the object, `false` otherwise.
     */
    has: function (object, key)
    {
        return object.hasOwnProperty(key);
    },

    /**
     * Check whether an object has both of the given properties.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#hasBoth
     * @since 3.0.0
     *
     * @param {object} object - The object to check.
     * @param {string} key1 - The key of the first property to check the object for.
     * @param {string} key2 - The key of the second property to check the object for.
     *
     * @return {boolean} `true` if both properties exist in the object, `false` otherwise.
     */
    hasBoth: function (object, key1, key2)
    {
        return object.hasOwnProperty(key1) && object.hasOwnProperty(key2);
    },

    /**
     * Check whether an object has at least one of the given properties.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#hasEither
     * @since 3.0.0
     *
     * @param {object} object - The object to check.
     * @param {string} key1 - The key of the first property to check the object for.
     * @param {string} key2 - The key of the second property to check the object for.
     *
     * @return {boolean} `true` if at least one of the properties exists in the object, `false` if neither exist.
     */
    hasEither: function (object, key1, key2)
    {
        return object.hasOwnProperty(key1) || object.hasOwnProperty(key2);
    },

    /**
     * The returned value sets what the property will be at the START of the particles life, on emit.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#defaultEmit
     * @since 3.0.0
     *
     * @param {Phaser.GameObjects.Particles.Particle} particle - The particle.
     * @param {string} key - The name of the property.
     * @param {number} [value] - The current value of the property.
     *
     * @return {number} The new value of the property.
     */
    defaultEmit: function (particle, key, value)
    {
        return value;
    },

    /**
     * The returned value updates the property for the duration of the particles life.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#defaultUpdate
     * @since 3.0.0
     *
     * @param {Phaser.GameObjects.Particles.Particle} particle - The particle.
     * @param {string} key - The name of the property.
     * @param {number} t - The T value (between 0 and 1)
     * @param {number} value - The current value of the property.
     *
     * @return {number} The new value of the property.
     */
    defaultUpdate: function (particle, key, t, value)
    {
        return value;
    },

    /**
     * An `onEmit` callback that returns the current value of the property.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#staticValueEmit
     * @since 3.0.0
     *
     * @return {number} The current value of the property.
     */
    staticValueEmit: function ()
    {
        return this.propertyValue;
    },

    /**
     * An `onUpdate` callback that returns the current value of the property.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#staticValueUpdate
     * @since 3.0.0
     *
     * @return {number} The current value of the property.
     */
    staticValueUpdate: function ()
    {
        return this.propertyValue;
    },

    /**
     * An `onEmit` callback that returns a random value from the current value array.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#randomStaticValueEmit
     * @since 3.0.0
     *
     * @return {number} The new value of the property.
     */
    randomStaticValueEmit: function ()
    {
        var randomIndex = Math.floor(Math.random() * this.propertyValue.length);

        return this.propertyValue[randomIndex];
    },

    /**
     * An `onEmit` callback that returns a value between the {@link Phaser.GameObjects.Particles.EmitterOp#start} and
     * {@link Phaser.GameObjects.Particles.EmitterOp#end} range.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#randomRangedValueEmit
     * @since 3.0.0
     *
     * @param {Phaser.GameObjects.Particles.Particle} particle - The particle.
     * @param {string} key - The key of the property.
     *
     * @return {number} The new value of the property.
     */
    randomRangedValueEmit: function (particle, key)
    {
        var value = FloatBetween(this.start, this.end);

        if (particle && particle.data[key])
        {
            particle.data[key].min = value;
        }

        return value;
    },

    /**
     * An `onEmit` callback that returns a stepped value between the
     * {@link Phaser.GameObjects.Particles.EmitterOp#start} and {@link Phaser.GameObjects.Particles.EmitterOp#end}
     * range.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#steppedEmit
     * @since 3.0.0
     *
     * @return {number} The new value of the property.
     */
    steppedEmit: function ()
    {
        var current = this.counter;

        var next = this.counter + (this.end - this.start) / this.steps;

        this.counter = Wrap(next, this.start, this.end);

        return current;
    },

    /**
     * An `onEmit` callback for an eased property.
     *
     * It prepares the particle for easing by {@link Phaser.GameObjects.Particles.EmitterOp#easeValueUpdate}.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#easedValueEmit
     * @since 3.0.0
     *
     * @param {Phaser.GameObjects.Particles.Particle} particle - The particle.
     * @param {string} key - The name of the property.
     *
     * @return {number} {@link Phaser.GameObjects.Particles.EmitterOp#start}, as the new value of the property.
     */
    easedValueEmit: function (particle, key)
    {
        if (particle && particle.data[key])
        {
            var data = particle.data[key];

            data.min = this.start;
            data.max = this.end;
        }

        return this.start;
    },

    /**
     * An `onUpdate` callback that returns an eased value between the
     * {@link Phaser.GameObjects.Particles.EmitterOp#start} and {@link Phaser.GameObjects.Particles.EmitterOp#end}
     * range.
     *
     * @method Phaser.GameObjects.Particles.EmitterOp#easeValueUpdate
     * @since 3.0.0
     *
     * @param {Phaser.GameObjects.Particles.Particle} particle - The particle.
     * @param {string} key - The name of the property.
     * @param {number} t - The T value (between 0 and 1)
     *
     * @return {number} The new value of the property.
     */
    easeValueUpdate: function (particle, key, t)
    {
        var data = particle.data[key];

        return (data.max - data.min) * this.ease(t) + data.min;
    }
});

module.exports = EmitterOp;