import applyStyle, { applyStyleOnLoad } from './applyStyle';
import computeStyle from './computeStyle';
import arrow from './arrow';
import flip from './flip';
import keepTogether from './keepTogether';
import offset from './offset';
import preventOverflow from './preventOverflow';
import shift from './shift';
import hide from './hide';
import inner from './inner';

/**
 * Modifier function, each modifier can have a function of this type assigned
 * to its `fn` property.<br />
 * These functions will be called on each update, this means that you must
 * make sure they are performant enough to avoid performance bottlenecks.
 *
 * @function ModifierFn
 * @argument {dataObject} data - The data object generated by `update` method
 * @argument {Object} options - Modifiers configuration and options
 * @returns {dataObject} The data object, properly modified
 */

/**
 * Modifiers are plugins used to alter the behavior of your poppers.<br />
 * Popper.js uses a set of 9 modifiers to provide all the basic functionalities
 * needed by the library.
 *
 * Usually you don't want to override the `order`, `fn` and `onLoad` props.
 * All the other properties are configurations that could be tweaked.
 * @namespace modifiers
 */
export default {
  /**
   * Modifier used to shift the popper on the start or end of its reference
   * element.<br />
   * It will read the variation of the `placement` property.<br />
   * It can be one either `-end` or `-start`.
   * @memberof modifiers
   * @inner
   */
  shift: {
    /** @prop {number} order=100 - Index used to define the order of execution */
    order: 100,
    /** @prop {Boolean} enabled=true - Whether the modifier is enabled or not */
    enabled: true,
    /** @prop {ModifierFn} */
    fn: shift,
  },

  /**
   * The `offset` modifier can shift your popper on both its axis.
   *
   * It accepts the following units:
   * - `px` or unit-less, interpreted as pixels
   * - `%` or `%r`, percentage relative to the length of the reference element
   * - `%p`, percentage relative to the length of the popper element
   * - `vw`, CSS viewport width unit
   * - `vh`, CSS viewport height unit
   *
   * For length is intended the main axis relative to the placement of the popper.<br />
   * This means that if the placement is `top` or `bottom`, the length will be the
   * `width`. In case of `left` or `right`, it will be the `height`.
   *
   * You can provide a single value (as `Number` or `String`), or a pair of values
   * as `String` divided by a comma or one (or more) white spaces.<br />
   * The latter is a deprecated method because it leads to confusion and will be
   * removed in v2.<br />
   * Additionally, it accepts additions and subtractions between different units.
   * Note that multiplications and divisions aren't supported.
   *
   * Valid examples are:
   * ```
   * 10
   * '10%'
   * '10, 10'
   * '10%, 10'
   * '10 + 10%'
   * '10 - 5vh + 3%'
   * '-10px + 5vh, 5px - 6%'
   * ```
   * > **NB**: If you desire to apply offsets to your poppers in a way that may make them overlap
   * > with their reference element, unfortunately, you will have to disable the `flip` modifier.
   * > You can read more on this at this [issue](https://github.com/FezVrasta/popper.js/issues/373).
   *
   * @memberof modifiers
   * @inner
   */
  offset: {
    /** @prop {number} order=200 - Index used to define the order of execution */
    order: 200,
    /** @prop {Boolean} enabled=true - Whether the modifier is enabled or not */
    enabled: true,
    /** @prop {ModifierFn} */
    fn: offset,
    /** @prop {Number|String} offset=0
     * The offset value as described in the modifier description
     */
    offset: 0,
  },

  /**
   * Modifier used to prevent the popper from being positioned outside the boundary.
   *
   * A scenario exists where the reference itself is not within the boundaries.<br />
   * We can say it has "escaped the boundaries" — or just "escaped".<br />
   * In this case we need to decide whether the popper should either:
   *
   * - detach from the reference and remain "trapped" in the boundaries, or
   * - if it should ignore the boundary and "escape with its reference"
   *
   * When `escapeWithReference` is set to`true` and reference is completely
   * outside its boundaries, the popper will overflow (or completely leave)
   * the boundaries in order to remain attached to the edge of the reference.
   *
   * @memberof modifiers
   * @inner
   */
  preventOverflow: {
    /** @prop {number} order=300 - Index used to define the order of execution */
    order: 300,
    /** @prop {Boolean} enabled=true - Whether the modifier is enabled or not */
    enabled: true,
    /** @prop {ModifierFn} */
    fn: preventOverflow,
    /**
     * @prop {Array} [priority=['left','right','top','bottom']]
     * Popper will try to prevent overflow following these priorities by default,
     * then, it could overflow on the left and on top of the `boundariesElement`
     */
    priority: ['left', 'right', 'top', 'bottom'],
    /**
     * @prop {number} padding=5
     * Amount of pixel used to define a minimum distance between the boundaries
     * and the popper. This makes sure the popper always has a little padding
     * between the edges of its container
     */
    padding: 5,
    /**
     * @prop {String|HTMLElement} boundariesElement='scrollParent'
     * Boundaries used by the modifier. Can be `scrollParent`, `window`,
     * `viewport` or any DOM element.
     */
    boundariesElement: 'scrollParent',
  },

  /**
   * Modifier used to make sure the reference and its popper stay near each other
   * without leaving any gap between the two. Especially useful when the arrow is
   * enabled and you want to ensure that it points to its reference element.
   * It cares only about the first axis. You can still have poppers with margin
   * between the popper and its reference element.
   * @memberof modifiers
   * @inner
   */
  keepTogether: {
    /** @prop {number} order=400 - Index used to define the order of execution */
    order: 400,
    /** @prop {Boolean} enabled=true - Whether the modifier is enabled or not */
    enabled: true,
    /** @prop {ModifierFn} */
    fn: keepTogether,
  },

  /**
   * This modifier is used to move the `arrowElement` of the popper to make
   * sure it is positioned between the reference element and its popper element.
   * It will read the outer size of the `arrowElement` node to detect how many
   * pixels of conjunction are needed.
   *
   * It has no effect if no `arrowElement` is provided.
   * @memberof modifiers
   * @inner
   */
  arrow: {
    /** @prop {number} order=500 - Index used to define the order of execution */
    order: 500,
    /** @prop {Boolean} enabled=true - Whether the modifier is enabled or not */
    enabled: true,
    /** @prop {ModifierFn} */
    fn: arrow,
    /** @prop {String|HTMLElement} element='[x-arrow]' - Selector or node used as arrow */
    element: '[x-arrow]',
  },

  /**
   * Modifier used to flip the popper's placement when it starts to overlap its
   * reference element.
   *
   * Requires the `preventOverflow` modifier before it in order to work.
   *
   * **NOTE:** this modifier will interrupt the current update cycle and will
   * restart it if it detects the need to flip the placement.
   * @memberof modifiers
   * @inner
   */
  flip: {
    /** @prop {number} order=600 - Index used to define the order of execution */
    order: 600,
    /** @prop {Boolean} enabled=true - Whether the modifier is enabled or not */
    enabled: true,
    /** @prop {ModifierFn} */
    fn: flip,
    /**
     * @prop {String|Array} behavior='flip'
     * The behavior used to change the popper's placement. It can be one of
     * `flip`, `clockwise`, `counterclockwise` or an array with a list of valid
     * placements (with optional variations)
     */
    behavior: 'flip',
    /**
     * @prop {number} padding=5
     * The popper will flip if it hits the edges of the `boundariesElement`
     */
    padding: 5,
    /**
     * @prop {String|HTMLElement} boundariesElement='viewport'
     * The element which will define the boundaries of the popper position.
     * The popper will never be placed outside of the defined boundaries
     * (except if `keepTogether` is enabled)
     */
    boundariesElement: 'viewport',
    /**
     * @prop {Boolean} flipVariations=false
     * The popper will switch placement variation between `-start` and `-end` when
     * the reference element overlaps its boundaries.
     *
     * The original placement should have a set variation.
     */
    flipVariations: false,
    /**
     * @prop {Boolean} flipVariationsByContent=false
     * The popper will switch placement variation between `-start` and `-end` when
     * the popper element overlaps its reference boundaries.
     *
     * The original placement should have a set variation.
     */
    flipVariationsByContent: false,
  },

  /**
   * Modifier used to make the popper flow toward the inner of the reference element.
   * By default, when this modifier is disabled, the popper will be placed outside
   * the reference element.
   * @memberof modifiers
   * @inner
   */
  inner: {
    /** @prop {number} order=700 - Index used to define the order of execution */
    order: 700,
    /** @prop {Boolean} enabled=false - Whether the modifier is enabled or not */
    enabled: false,
    /** @prop {ModifierFn} */
    fn: inner,
  },

  /**
   * Modifier used to hide the popper when its reference element is outside of the
   * popper boundaries. It will set a `x-out-of-boundaries` attribute which can
   * be used to hide with a CSS selector the popper when its reference is
   * out of boundaries.
   *
   * Requires the `preventOverflow` modifier before it in order to work.
   * @memberof modifiers
   * @inner
   */
  hide: {
    /** @prop {number} order=800 - Index used to define the order of execution */
    order: 800,
    /** @prop {Boolean} enabled=true - Whether the modifier is enabled or not */
    enabled: true,
    /** @prop {ModifierFn} */
    fn: hide,
  },

  /**
   * Computes the style that will be applied to the popper element to gets
   * properly positioned.
   *
   * Note that this modifier will not touch the DOM, it just prepares the styles
   * so that `applyStyle` modifier can apply it. This separation is useful
   * in case you need to replace `applyStyle` with a custom implementation.
   *
   * This modifier has `850` as `order` value to maintain backward compatibility
   * with previous versions of Popper.js. Expect the modifiers ordering method
   * to change in future major versions of the library.
   *
   * @memberof modifiers
   * @inner
   */
  computeStyle: {
    /** @prop {number} order=850 - Index used to define the order of execution */
    order: 850,
    /** @prop {Boolean} enabled=true - Whether the modifier is enabled or not */
    enabled: true,
    /** @prop {ModifierFn} */
    fn: computeStyle,
    /**
     * @prop {Boolean} gpuAcceleration=true
     * If true, it uses the CSS 3D transformation to position the popper.
     * Otherwise, it will use the `top` and `left` properties
     */
    gpuAcceleration: true,
    /**
     * @prop {string} [x='bottom']
     * Where to anchor the X axis (`bottom` or `top`). AKA X offset origin.
     * Change this if your popper should grow in a direction different from `bottom`
     */
    x: 'bottom',
    /**
     * @prop {string} [x='left']
     * Where to anchor the Y axis (`left` or `right`). AKA Y offset origin.
     * Change this if your popper should grow in a direction different from `right`
     */
    y: 'right',
  },

  /**
   * Applies the computed styles to the popper element.
   *
   * All the DOM manipulations are limited to this modifier. This is useful in case
   * you want to integrate Popper.js inside a framework or view library and you
   * want to delegate all the DOM manipulations to it.
   *
   * Note that if you disable this modifier, you must make sure the popper element
   * has its position set to `absolute` before Popper.js can do its work!
   *
   * Just disable this modifier and define your own to achieve the desired effect.
   *
   * @memberof modifiers
   * @inner
   */
  applyStyle: {
    /** @prop {number} order=900 - Index used to define the order of execution */
    order: 900,
    /** @prop {Boolean} enabled=true - Whether the modifier is enabled or not */
    enabled: true,
    /** @prop {ModifierFn} */
    fn: applyStyle,
    /** @prop {Function} */
    onLoad: applyStyleOnLoad,
    /**
     * @deprecated since version 1.10.0, the property moved to `computeStyle` modifier
     * @prop {Boolean} gpuAcceleration=true
     * If true, it uses the CSS 3D transformation to position the popper.
     * Otherwise, it will use the `top` and `left` properties
     */
    gpuAcceleration: undefined,
  },
};

/**
 * The `dataObject` is an object containing all the information used by Popper.js.
 * This object is passed to modifiers and to the `onCreate` and `onUpdate` callbacks.
 * @name dataObject
 * @property {Object} data.instance The Popper.js instance
 * @property {String} data.placement Placement applied to popper
 * @property {String} data.originalPlacement Placement originally defined on init
 * @property {Boolean} data.flipped True if popper has been flipped by flip modifier
 * @property {Boolean} data.hide True if the reference element is out of boundaries, useful to know when to hide the popper
 * @property {HTMLElement} data.arrowElement Node used as arrow by arrow modifier
 * @property {Object} data.styles Any CSS property defined here will be applied to the popper. It expects the JavaScript nomenclature (eg. `marginBottom`)
 * @property {Object} data.arrowStyles Any CSS property defined here will be applied to the popper arrow. It expects the JavaScript nomenclature (eg. `marginBottom`)
 * @property {Object} data.boundaries Offsets of the popper boundaries
 * @property {Object} data.offsets The measurements of popper, reference and arrow elements
 * @property {Object} data.offsets.popper `top`, `left`, `width`, `height` values
 * @property {Object} data.offsets.reference `top`, `left`, `width`, `height` values
 * @property {Object} data.offsets.arrow] `top` and `left` offsets, only one of them will be different from 0
 */