import { SpatialGrid, randomRange } from "./utils.js";
import { ENTITY_TYPES, createGenome, reproduce } from "./genetics.js";
import { Entity } from "./entities.js";

export class EntityManager {
  constructor(worldWidth, worldHeight) {
    this.entities = [];
    this.spatialGrid = new SpatialGrid(worldWidth, worldHeight, 60);
    this.worldWidth = worldWidth;
    this.worldHeight = worldHeight;
  }

  add(entity) {
    this.entities.push(entity);
  }

  update(dt, world, particles, stats) {
    this.spatialGrid.clear();
    for (const e of this.entities) {
      if (e.alive) this.spatialGrid.insert(e, e.x, e.y);
    }

    const newborns = [];
    for (const e of this.entities) {
      e.update(dt, world, this.entities, this.spatialGrid, particles);

      const child = e.tryReproduce(this.spatialGrid, particles);
      if (child) {
        newborns.push(child);
        stats.onBirth();
      }
    }

    for (const child of newborns) {
      this.entities.push(child);
    }

    for (let i = this.entities.length - 1; i >= 0; i--) {
      if (!this.entities[i].alive) {
        stats.onDeath();
        this.entities.splice(i, 1);
      }
    }
  }

  render(ctx) {
    this.entities.sort((a, b) => a.y - b.y);
    for (const e of this.entities) {
      e.render(ctx);
    }
  }

  getAlive() {
    return this.entities.filter((e) => e.alive);
  }

  spawnRandom(count, world) {
    const types = Object.keys(ENTITY_TYPES);
    for (let i = 0; i < count; i++) {
      const type = types[Math.floor(Math.random() * types.length)];
      const genome = createGenome(type);
      const x = randomRange(20, world.width - 20);
      const y = randomRange(20, world.height - 20);
      this.entities.push(new Entity(x, y, genome, 0));
    }
  }

  spawnFromPopulation(population, count, world) {
    if (population.length < 2) return;
    const candidates = population.map((e) => ({
      genome: e.genome,
      fitness: e.fitness,
    }));
    for (let i = 0; i < count; i++) {
      const childGenome = reproduce(candidates);
      const x = randomRange(20, world.width - 20);
      const y = randomRange(20, world.height - 20);
      const gen = Math.max(...population.map((e) => e.generation)) + 1;
      this.entities.push(new Entity(x, y, childGenome, gen));
    }
  }
}