import {compose, TickingPromise} from '@avocado/core';
import {Vector} from '@avocado/math';

import {StateProperty, Trait} from '../trait';

const decorate = compose(
  StateProperty('isMobile'),
  StateProperty('speed'),
)

export class Mobile extends decorate(Trait) {

  static defaultState() {
    return {
      isMobile: true,
      speed: 0,
    };
  }

  static type() {
    return 'mobile';
  }

  constructor(entity, params, state) {
    super(entity, params, state);
    this.appliedMovement = [0, 0];
  }

  methods() {
    return {

      moveFor: (duration) => {
        const direction = this.entity.direction;
        let resolve;
        const promise = new TickingPromise(_resolve => resolve = _resolve);
        promise.ticker = (elapsed) => {
          duration -= elapsed;
          if (duration <= 0) {
            return resolve();
          }
          this.entity.requestMovement(Vector.fromDirection(direction));
        }
        return promise;
      },

      applyMovement: (vector) => {
        this.appliedMovement = Vector.add(this.appliedMovement, vector);
      },

      forceMovement: (movement) => {
        this.entity.x += movement[0];
        this.entity.y += movement[1];
      },

      requestMovement: (vector) => {
        if (!this.isMobile) {
          return;
        }
        this.entity.applyMovement(Vector.scale(
          Vector.normalize(vector),
          this.speed
        ));
        this.entity.emit('movementRequest', this.appliedMovement);
      },

    }
  }

  tick(elapsed) {
    if (Vector.isZero(this.appliedMovement)) {
      return;
    }
    if (this.entity.is('physical')) {
      this.entity.applyImpulse(this.appliedMovement);
    }
    else {
      const appliedMovement = Vector.scale(
        this.appliedMovement,
        elapsed
      );
      this.entity.forceMovement(appliedMovement);
    }
    this.appliedMovement = [0, 0];
  }

}