import { Timeline } from '../tween/timeline.babel.js';

import { Tweenable } from '../tween/tweenable.babel.js';

import { staggerProperty } from '../helpers/stagger-property.babel.js';

import { staggerFunction } from './stagger-function.babel.js';

import { staggerRand } from './stagger-rand.babel.js';

import { staggerRandFloat } from './stagger-rand-float.babel.js';

import { staggerStep } from './stagger-step.babel.js';

import { staggerMap } from './stagger-map.babel.js';

/* -------------------- */

/* The `Stagger` class */

/* -------------------- */

const Super = Tweenable.__mojsClass;

const Stagger = Object.create(Super);

/**

* `init` - function init the class.

*

* @extends @Tweenable

* @public

*/

Stagger.init = function (o = {}, Module) {

// super call

Super.init.call(this, o);

// create main timeline

this._createTimeline(o.staggerTimeline);

delete this._o.staggerTimeline;

// create modules

this._createModules(Module);

};

/**

* `_createModules` - function to create modules.

*

* @private

* @param {Object} Child module class.

*/

Stagger._createModules = function (Module) {

this._modules = [];

const { items, el = {} } = this._o;

const modulesCount = items || el.length || 1;

for (let i = 0; i < modulesCount; i++) {

const module = new Module({

...this._getStaggerOptions(this._o, i, modulesCount),

totalItemsInStagger: modulesCount,

});

this._modules.push(module);

// get method regarding stagger strategy property and parse stagger function

const addMethod = staggerProperty(this._o.strategy || 'add', i, modulesCount);

this.timeline[addMethod](module);

}

};

/**

* `_getStaggerOptions` - get stagger options for a single module.

*

* @private

* @param {Object} Stagger options.

* @param {Number} Index of a module.

*/

Stagger._getStaggerOptions = function (options, i, modulesCount) {

// pass index to child properties

const o = { index: i };

const keys = Object.keys(options);

for (let j = 0; j < keys.length; j++) {

const key = keys[j];

// `items` - is the special `stagger` keyword, filter out it

if (key !== 'items' && key !== 'strategy') {

o[key] = staggerProperty(options[key], i, modulesCount);

}

}

return o;

};

/**

* `_createTimeline` - function to create a timeline.

*

* @private

* @param {Object} Timeline options.

*/

Stagger._createTimeline = function (options) {

this.timeline = new Timeline(options);

};

/**

* function to wrap a Module with the stagger wrapper.

*/

const stagger = (Module) => { // eslint-disable-line arrow-body-style

return (options) => {

const instance = Object.create(Stagger);

instance.init(options, Module);

return instance;

};

};

stagger.function = staggerFunction;

stagger.rand = staggerRand;

stagger.randFloat = staggerRandFloat;

stagger.step = staggerStep;

stagger.map = staggerMap;

export { stagger };