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

import {StateProperty, Trait} from '../trait';
import {
  TraitUpdateDirectionalDirectionPacket,
} from '../packets/trait-update-directional-direction.packet';

const decorate = compose(
  StateProperty('direction', {
    track: true,
  }),
);

export class Directional extends decorate(Trait) {

  static defaultParams() {
    return {
      directionCount: 1,
      trackMovement: true,
    };
  }

  static defaultState() {
    return {
      direction: 0,
    };
  }

  static type() {
    return 'directional';
  }

  constructor(entity, params, state) {
    super(entity, params, state);
    this.directionCount = this.params.directionCount;
  }

  acceptPacket(packet) {
    if (packet instanceof TraitUpdateDirectionalDirectionPacket) {
      this.entity.direction = packet.data;
    }
  }

  packets(informed) {
    const {direction} = this.stateDifferences();
    if (direction) {
      return new TraitUpdateDirectionalDirectionPacket(direction.value);
    }
  }

  listeners() {
    const listeners = {
      directionChanged: () => {
        this._directionChanged = true;
      },
    };
    if (this.params.trackMovement) {
      listeners.movementRequest = (vector) => {
        if (Vector.isZero(vector)) {
          return;
        }
        this.entity.direction = Vector.toDirection(vector, this.directionCount);
      };
    }
    return listeners;
  }

}