import * as THREE from "three";
import { OrbitControls } from "three/examples/jsm/controls/OrbitControls.js";
import { VoxelGrid } from "../grid/VoxelGrid.js";
import { VoxelManager } from "../grid/VoxelManager.js";
import { UnitManager } from "../managers/UnitManager.js";
import { CaveGenerator } from "../generation/CaveGenerator.js";
import { RuinGenerator } from "../generation/RuinGenerator.js";
// import { TurnSystem } from '../systems/TurnSystem.js';

export class GameLoop {
  constructor() {
    this.isRunning = false;

    // 1. Core Systems
    this.scene = new THREE.Scene();
    this.camera = null;
    this.renderer = null;
    this.controls = null;

    this.grid = null;
    this.voxelManager = null;
    this.unitManager = null;

    // 2. State
    this.runData = null;
  }

  init(container) {
    // Setup Three.js
    this.camera = new THREE.PerspectiveCamera(
      45,
      window.innerWidth / window.innerHeight,
      0.1,
      1000
    );
    this.camera.position.set(20, 20, 20);
    this.camera.lookAt(0, 0, 0);

    this.renderer = new THREE.WebGLRenderer({ antialias: true });
    this.renderer.setSize(window.innerWidth, window.innerHeight);
    this.renderer.setClearColor(0x111111); // Dark background
    container.appendChild(this.renderer.domElement);

    // Setup OrbitControls
    this.controls = new OrbitControls(this.camera, this.renderer.domElement);
    this.controls.enableDamping = true; // Smooth camera movement
    this.controls.dampingFactor = 0.05;
    this.controls.screenSpacePanning = false;
    this.controls.minDistance = 5;
    this.controls.maxDistance = 100;
    this.controls.maxPolarAngle = Math.PI / 2; // Prevent going below ground

    // Lighting
    const ambient = new THREE.AmbientLight(0xffffff, 0.6);
    const dirLight = new THREE.DirectionalLight(0xffffff, 0.8);
    dirLight.position.set(10, 20, 10);
    this.scene.add(ambient);
    this.scene.add(dirLight);

    // Handle Resize
    window.addEventListener("resize", () => {
      this.camera.aspect = window.innerWidth / window.innerHeight;
      this.camera.updateProjectionMatrix();
      this.renderer.setSize(window.innerWidth, window.innerHeight);
    });

    this.animate = this.animate.bind(this);
  }

  /**
   * Starts a Level based on Run Data (New or Loaded).
   */
  async startLevel(runData) {
    console.log("GameLoop: Starting Level...");
    this.runData = runData;
    this.isRunning = true;

    // 1. Initialize Grid (20x10x20 for prototype)
    this.grid = new VoxelGrid(20, 10, 20);

    // 2. Generate World (Using saved seed)
    // TODO: Switch generator based on runData.biome_id
    const generator = new RuinGenerator(this.grid, runData.seed);
    generator.generate();

    // 3. Initialize Visuals
    this.voxelManager = new VoxelManager(this.grid, this.scene);

    // Apply textures generated by the biome logic
    this.voxelManager.updateMaterials(generator.generatedAssets);
    this.voxelManager.update();

    // Center camera using the focus target
    if (this.controls) {
      this.voxelManager.focusCamera(this.controls);
    }

    // 4. Initialize Units
    // Mock Registry for Prototype so UnitManager doesn't crash on createUnit
    const mockRegistry = {
      get: (id) => {
        return {
          type: "EXPLORER",
          name: id, // Fallback name
          stats: { hp: 100, attack: 10, speed: 10 },
        };
      },
    };

    this.unitManager = new UnitManager(mockRegistry);
    this.spawnSquad(runData.squad);

    // Start Loop
    this.animate();
  }

  spawnSquad(squadManifest) {
    if (!squadManifest || !this.unitManager) return;

    // Simple spawn logic: line them up starting at (2, 1, 2)
    // In a full implementation, the Generator would provide 'StartPoints'
    let spawnX = 2;
    let spawnZ = 2;
    const spawnY = 1; // Assuming flat floor at y=1 for Ruins

    squadManifest.forEach((member) => {
      if (!member) return;

      // Create Unit (this uses the registry to look up stats)
      const unit = this.unitManager.createUnit(member.classId, "PLAYER");

      // Override name if provided in manifest
      if (member.name) unit.name = member.name;

      // Find a valid spot (basic collision check)
      let placed = false;
      // Try a few spots if the first is taken
      for (let i = 0; i < 5; i++) {
        const pos = { x: spawnX + i, y: spawnY, z: spawnZ };

        // Ensure we don't spawn inside a wall or off the map
        if (this.grid.isValidBounds(pos) && !this.grid.isSolid(pos)) {
          this.grid.placeUnit(unit, pos);
          console.log(
            `Spawned ${unit.name} (${unit.id}) at ${pos.x},${pos.y},${pos.z}`
          );
          placed = true;
          // Update X for next unit to be next to this one
          spawnX = pos.x + 1;
          break;
        }
      }

      if (!placed) {
        console.warn(`Could not find spawn point for ${unit.name}`);
      }
    });
  }

  animate() {
    if (!this.isRunning) return;
    requestAnimationFrame(this.animate);

    // Update Logic
    // TWEEN.update();

    if (this.controls) {
      this.controls.update();
    }

    // Render
    this.renderer.render(this.scene, this.camera);
  }

  stop() {
    this.isRunning = false;
    // Cleanup Three.js resources if needed
    if (this.controls) this.controls.dispose();
  }
}