import { WORLD_WIDTH, WORLD_HEIGHT, type Position } from '@dflike/shared';

export interface PointOfInterest {
  type: 'food' | 'rest';
  position: Position;
}

export class GameMap {
  readonly width: number;
  readonly height: number;
  private obstacles: Set<string> = new Set();
  private pois: PointOfInterest[] = [];
  terrain: number[] = [];           // flat array of Terrain values
  decorations: number[] = [];       // flat array of canopy tile indices (-1 = none)
  trunkDecorations: number[] = [];  // flat array of trunk tile indices (-1 = none)

  constructor(width = WORLD_WIDTH, height = WORLD_HEIGHT) {
    this.width = width;
    this.height = height;
  }

  private key(x: number, y: number): string {
    return `${x},${y}`;
  }

  setObstacle(x: number, y: number): void {
    this.obstacles.add(this.key(x, y));
  }

  loadObstacles(obstacleSet: Set<string>): void {
    for (const key of obstacleSet) {
      this.obstacles.add(key);
    }
  }

  isWalkable(x: number, y: number): boolean {
    if (x < 0 || y < 0 || x >= this.width || y >= this.height) return false;
    return !this.obstacles.has(this.key(x, y));
  }

  addPointOfInterest(poi: PointOfInterest): void {
    this.pois.push(poi);
  }

  getPointsOfInterest(type?: 'food' | 'rest'): PointOfInterest[] {
    if (type) return this.pois.filter(p => p.type === type);
    return this.pois;
  }

  getObstacles(): Position[] {
    return [...this.obstacles].map(k => {
      const [x, y] = k.split(',').map(Number);
      return { x, y };
    });
  }

  findNearestWalkable(centerX: number, centerY: number, radius: number): Position | null {
    if (this.isWalkable(centerX, centerY)) {
      return { x: centerX, y: centerY };
    }
    for (let dist = 1; dist <= radius; dist++) {
      for (let dx = -dist; dx <= dist; dx++) {
        const dyRange = dist - Math.abs(dx);
        for (const dy of [-dyRange, dyRange]) {
          const x = centerX + dx;
          const y = centerY + dy;
          if (this.isWalkable(x, y)) {
            return { x, y };
          }
        }
      }
    }
    return null;
  }

  getRandomWalkable(): Position {
    let x: number, y: number;
    do {
      x = Math.floor(Math.random() * this.width);
      y = Math.floor(Math.random() * this.height);
    } while (!this.isWalkable(x, y));
    return { x, y };
  }
}