import anim from "animejs";

import { BaseOptions } from "./component";

export interface ToastOptions extends BaseOptions {
  /**
   * The content of the Toast.
   * @default ""
   */
  text: string;
  /**
   * Length in ms the Toast stays before dismissal.
   * @default 4000
   */
  displayLength: number;
  /**
   * Transition in duration in milliseconds.
   * @default 300
   */
  inDuration: number;
  /**
   * Transition out duration in milliseconds.
   * @default 375
   */
  outDuration: number;
  /**
   * Classes to be added to the toast element.
   * @default ""
   */
  classes: string;
  /**
   * Callback function called when toast is dismissed.
   * @default null
   */
  completeCallback: () => void;
  /**
   * The percentage of the toast's width it takes fora drag
   * to dismiss a Toast.
   * @default 0.8
   */
  activationPercent: number;
}

let _defaults: ToastOptions = {
  text: '',
  displayLength: 4000,
  inDuration: 300,
  outDuration: 375,
  classes: '',
  completeCallback: null,
  activationPercent: 0.8
};

export class Toast {
  /** The toast element. */
  el: HTMLDivElement;
  /**
   * The remaining amount of time in ms that the toast
   * will stay before dismissal.
   */
  timeRemaining: number;
  /**
   * Describes the current pan state of the Toast.
   */
  panning: boolean;
  options: ToastOptions;
  message: string;
  counterInterval: NodeJS.Timeout;
  wasSwiped: boolean;
  startingXPos: number;
  xPos: number;
  time: number;
  deltaX: number;
  velocityX: number;

  static _toasts: Toast[];
  static _container: any;
  static _draggedToast: Toast;

  constructor(options: Partial<ToastOptions>) {
    this.options = {
      ...Toast.defaults,
      ...options
    };
    this.message = this.options.text;
    this.panning = false;
    this.timeRemaining = this.options.displayLength;
    if (Toast._toasts.length === 0) {
      Toast._createContainer();
    }
    // Create new toast
    Toast._toasts.push(this);
    let toastElement = this._createToast();
    (toastElement as any).M_Toast = this;
    this.el = toastElement;
    this._animateIn();
    this._setTimer();
  }

  static get defaults(): ToastOptions {
    return _defaults;
  }

  static getInstance(el: HTMLElement): Toast {
    return (el as any).M_Toast;
  }

  static _createContainer() {
    const container = document.createElement('div');
    container.setAttribute('id', 'toast-container');
    // Add event handler
    container.addEventListener('touchstart', Toast._onDragStart);
    container.addEventListener('touchmove', Toast._onDragMove);
    container.addEventListener('touchend', Toast._onDragEnd);
    container.addEventListener('mousedown', Toast._onDragStart);
    document.addEventListener('mousemove', Toast._onDragMove);
    document.addEventListener('mouseup', Toast._onDragEnd);
    document.body.appendChild(container);
    Toast._container = container;
  }

  static _removeContainer() {
    document.removeEventListener('mousemove', Toast._onDragMove);
    document.removeEventListener('mouseup', Toast._onDragEnd);
    Toast._container.remove();
    Toast._container = null;
  }

  static _onDragStart(e: TouchEvent | MouseEvent) {
    if (e.target && (<HTMLElement>e.target).closest('.toast')) {
      const toastElem = (<HTMLElement>e.target).closest('.toast');
      const toast: Toast = (toastElem as any).M_Toast;
      toast.panning = true;
      Toast._draggedToast = toast;
      toast.el.classList.add('panning');
      toast.el.style.transition = '';
      toast.startingXPos = Toast._xPos(e);
      toast.time = Date.now();
      toast.xPos = Toast._xPos(e);
    }
  }

  static _onDragMove(e: TouchEvent | MouseEvent) {
    if (!!Toast._draggedToast) {
      e.preventDefault();
      const toast = Toast._draggedToast;
      toast.deltaX = Math.abs(toast.xPos - Toast._xPos(e));
      toast.xPos = Toast._xPos(e);
      toast.velocityX = toast.deltaX / (Date.now() - toast.time);
      toast.time = Date.now();

      const totalDeltaX = toast.xPos - toast.startingXPos;
      const activationDistance = toast.el.offsetWidth * toast.options.activationPercent;
      toast.el.style.transform = `translateX(${totalDeltaX}px)`;
      toast.el.style.opacity = (1 - Math.abs(totalDeltaX / activationDistance)).toString();
    }
  }

  static _onDragEnd() {
    if (!!Toast._draggedToast) {
      let toast = Toast._draggedToast;
      toast.panning = false;
      toast.el.classList.remove('panning');

      let totalDeltaX = toast.xPos - toast.startingXPos;
      let activationDistance = toast.el.offsetWidth * toast.options.activationPercent;
      let shouldBeDismissed = Math.abs(totalDeltaX) > activationDistance || toast.velocityX > 1;

      // Remove toast
      if (shouldBeDismissed) {
        toast.wasSwiped = true;
        toast.dismiss();
        // Animate toast back to original position
      }
      else {
        toast.el.style.transition = 'transform .2s, opacity .2s';
        toast.el.style.transform = '';
        toast.el.style.opacity = '';
      }
      Toast._draggedToast = null;
    }
  }

  static _xPos(e: TouchEvent | MouseEvent) {
    if (e.type.startsWith("touch") && (e as TouchEvent).targetTouches.length >= 1) {
      return (e as TouchEvent).targetTouches[0].clientX;
    }
    // mouse event
    return (e as MouseEvent).clientX;
  }

  /**
   * dismiss all toasts.
   */
  static dismissAll() {
    for (let toastIndex in Toast._toasts) {
      Toast._toasts[toastIndex].dismiss();
    }
  }

  _createToast() {
    const toast = document.createElement('div');
    toast.classList.add('toast');
    toast.setAttribute('role', 'alert');
    toast.setAttribute('aria-live', 'assertive');
    toast.setAttribute('aria-atomic', 'true');

    // Add custom classes onto toast
    if (this.options.classes.length > 0) {
      toast.classList.add(...this.options.classes.split(' '));
    }

    // Set text content
    toast.innerText = this.message;

    // Append toast
    Toast._container.appendChild(toast);
    return toast;
  }

  _animateIn() {
    // Animate toast in
    anim({
      targets: this.el,
      top: 0,
      opacity: 1,
      duration: this.options.inDuration,
      easing: 'easeOutCubic'
    });
  }

  /**
   * Create setInterval which automatically removes toast when timeRemaining >= 0
   * has been reached.
   */
  _setTimer() {
    if (this.timeRemaining !== Infinity) {
      this.counterInterval = setInterval(() => {
        // If toast is not being dragged, decrease its time remaining
        if (!this.panning) {
          this.timeRemaining -= 20;
        }
        // Animate toast out
        if (this.timeRemaining <= 0) {
          this.dismiss();
        }
      }, 20);
    }
  }

  /**
   * Dismiss toast with animation.
   */
  dismiss() {
    window.clearInterval(this.counterInterval);
    let activationDistance = this.el.offsetWidth * this.options.activationPercent;

    if (this.wasSwiped) {
      this.el.style.transition = 'transform .05s, opacity .05s';
      this.el.style.transform = `translateX(${activationDistance}px)`;
      this.el.style.opacity = '0';
    }

    anim({
      targets: this.el,
      opacity: 0,
      marginTop: -40,
      duration: this.options.outDuration,
      easing: 'easeOutExpo',
      complete: () => {
        // Call the optional callback
        if (typeof this.options.completeCallback === 'function') {
          this.options.completeCallback();
        }
        // Remove toast from DOM
        this.el.remove();
        Toast._toasts.splice(Toast._toasts.indexOf(this), 1);
        if (Toast._toasts.length === 0) {
          Toast._removeContainer();
        }
      }
    });
  }

  static {
    Toast._toasts = [];
    Toast._container = null;
    Toast._draggedToast = null;
  }
}