import _ from 'lodash';
import Tile, { Feature, Direction } from './Tile';

export interface Attachment {
  attachTo: Tile;
  side: Direction;
  tile: Tile;
  rotation: number; // Clockwise rotation of a tile
}

export default class TileOnBoard extends Tile {
  neighbors: [Tile, Tile, Tile, Tile];
  orientation: number; // amount of 90-degree counter-clockwise rotations from original orientation
  position: {
    x: number;
    y: number;
  }

  constructor(center: Feature, sides: [Feature, Feature, Feature, Feature], shield = false, orientation = 0) {
    super(center, sides, shield);
    this.orientation = orientation;
  }

  getSide(direction: Direction) {
    return super.getSide(direction + this.orientation);
  }

  rotate(rotation = 1) {
    // We want to rotate clockwise, but orientation stores counter-clockwise rotations,
    // therefore use the difference, not sum.
    this.orientation = this.orientation - rotation;
  }

  getAttachments(tile: Tile): Attachment[] {
    return _.flatten([0, 1, 2, 3].map(side => {
      const item = this.getSide(side);
      return [0, 1, 2, 3]
        .filter(rotation => tile.getSide(side - rotation + 2) === item)
        .map(rotation => ({
          tile,
          rotation,
          side,
          attachTo: this as Tile
        }))
    }));
  }

  attach(tile: Tile, side: Direction) {
    if (this.neighbors[side]) throw new Error('There is something already attached to this side!');
    this.neighbors[side] = tile;
  }
}