/**
 * Resource Spawner — creates ECS entities for harvestable world objects
 *
 * Scans the generated tile grid for mineral veins and geysers,
 * creates an entity at each with a randomly assigned element.
 */

import { addEntity, addComponent } from 'bitecs';
import type { World } from '../ecs/world';
import { Position, Resource, SpriteRef } from '../ecs/components';
import type { TileGrid, BiomeData } from './types';
import {
  pickResourceElement,
  MINERAL_ELEMENTS,
  GEYSER_ELEMENTS,
  type ResourceInfo,
} from '../player/interaction';

/** Resource spawn configuration per tile type */
interface ResourceTileConfig {
  tileId: number;
  elements: readonly string[];
  minQuantity: number;
  maxQuantity: number;
  interactRange: number;
  spriteColor: number;
  spriteRadius: number;
}

/**
 * Spawn resource entities for all resource tiles in the grid.
 * @returns Map of entity ID → ResourceInfo for string data
 */
export function spawnResources(
  world: World,
  grid: TileGrid,
  biome: BiomeData,
  seed: number,
): Map<number, ResourceInfo> {
  const resourceData = new Map<number, ResourceInfo>();

  // Find tile IDs for resource types (generic: resource + interactive tiles)
  const mineralTile = biome.tiles.find(t => t.resource);
  const geyserTile = biome.tiles.find(t => t.interactive);

  const configs: ResourceTileConfig[] = [];

  if (mineralTile) {
    configs.push({
      tileId: mineralTile.id,
      elements: MINERAL_ELEMENTS,
      minQuantity: 3,
      maxQuantity: 5,
      interactRange: 40,
      spriteColor: 0xffd700, // gold
      spriteRadius: 4,
    });
  }

  if (geyserTile) {
    configs.push({
      tileId: geyserTile.id,
      elements: GEYSER_ELEMENTS,
      minQuantity: 2,
      maxQuantity: 4,
      interactRange: 48,
      spriteColor: 0xff6600, // orange
      spriteRadius: 5,
    });
  }

  const tileSize = biome.tileSize;

  for (let y = 0; y < grid.length; y++) {
    for (let x = 0; x < grid[y].length; x++) {
      const tileId = grid[y][x];
      const config = configs.find(c => c.tileId === tileId);
      if (!config) continue;

      // Pick element deterministically
      const itemId = pickResourceElement(x, y, seed, config.elements);

      // Quantity from deterministic hash
      const qHash = ((x * 48611) ^ (y * 29423) ^ (seed * 61379)) >>> 0;
      const range = config.maxQuantity - config.minQuantity + 1;
      const quantity = config.minQuantity + (qHash % range);

      // Create entity at tile center
      const eid = addEntity(world);
      addComponent(world, eid, Position);
      addComponent(world, eid, Resource);
      addComponent(world, eid, SpriteRef);

      Position.x[eid] = x * tileSize + tileSize / 2;
      Position.y[eid] = y * tileSize + tileSize / 2;
      Resource.quantity[eid] = quantity;
      Resource.interactRange[eid] = config.interactRange;
      SpriteRef.color[eid] = config.spriteColor;
      SpriteRef.radius[eid] = config.spriteRadius;

      resourceData.set(eid, { itemId, tileX: x, tileY: y });
    }
  }

  return resourceData;
}