import Phaser from "phaser";
import type { Spawner } from "boardgame-phaser";
import { spawnEffect } from "boardgame-phaser";
import type { CombatState, CombatEntity, EnemyEntity } from "boardgame-core/samples/slay-the-spire-like";
import { CombatUnitContainer, type CombatUnitData } from "./CombatUnitContainer";

export class CombatUnitSpawner implements Spawner<CombatUnitData, CombatUnitContainer> {
  constructor(private scene: Phaser.Scene) {}

  *getData(): Iterable<CombatUnitData> {
    const combat = this.getCombatState();
    if (!combat) return;

    yield {
      key: "player",
      entity: combat.player,
      name: "Player",
      isPlayer: true,
    };

    for (let i = 0; i < combat.enemies.length; i++) {
      const enemy = combat.enemies[i];
      yield {
        key: `enemy-${i}`,
        entity: enemy,
        name: enemy.enemy.name,
        isPlayer: false,
      };
    }
  }

  getKey(t: CombatUnitData): string {
    return t.key;
  }

  onSpawn(t: CombatUnitData): CombatUnitContainer | null {
    const { width, height } = this.scene.scale;
    const combat = this.getCombatState();
    if (!combat) return null;

    const totalUnits = 1 + combat.enemies.length;
    const spacing = 220;
    const totalWidth = (totalUnits - 1) * spacing;
    const startX = width / 2 - totalWidth / 2;

    let x = startX;
    if (t.key.startsWith("enemy-")) {
      const index = parseInt(t.key.replace("enemy-", ""), 10);
      x = startX + (index + 1) * spacing;
    }

    const y = height / 2;

    const container = new CombatUnitContainer(this.scene, x, y, t);
    container.playSpawnEffect();
    return container;
  }

  onUpdate(t: CombatUnitData, obj: CombatUnitContainer): void {
    obj.updateFromData(t);
  }

  onDespawn(obj: CombatUnitContainer): void {
    obj.destroy();
  }

  private getCombatState(): CombatState | null {
    const registry = this.scene.registry;
    return (registry.get("combatState") as CombatState | undefined) ?? null;
  }
}

export function createCombatUnitSpawner(scene: Phaser.Scene) {
  return spawnEffect(new CombatUnitSpawner(scene));
}