import { expect } from "@esm-bundle/chai";
import sinon from "sinon";
import * as THREE from "three";
import { GameLoop } from "../../src/core/GameLoop.js";

describe("Core: GameLoop (Integration)", function () {
  // Increase timeout for WebGL/Shader compilation overhead
  this.timeout(30000);

  let gameLoop;
  let container;

  beforeEach(() => {
    // Create a mounting point
    container = document.createElement("div");
    document.body.appendChild(container);

    gameLoop = new GameLoop();
  });

  afterEach(() => {
    gameLoop.stop();
    if (container.parentNode) {
      container.parentNode.removeChild(container);
    }

    // Cleanup Three.js resources if possible to avoid context loss limits
    if (gameLoop.renderer) {
      gameLoop.renderer.dispose();
      gameLoop.renderer.forceContextLoss();
    }
  });

  it("CoA 1: init() should setup Three.js scene, camera, and renderer", () => {
    gameLoop.init(container);

    expect(gameLoop.scene).to.be.instanceOf(THREE.Scene);
    expect(gameLoop.camera).to.be.instanceOf(THREE.PerspectiveCamera);
    expect(gameLoop.renderer).to.be.instanceOf(THREE.WebGLRenderer);

    // Verify renderer is attached to DOM
    expect(container.querySelector("canvas")).to.exist;
  });

  it("CoA 2: startLevel() should initialize grid, visuals, and generate world", async () => {
    gameLoop.init(container);

    const runData = {
      seed: 12345,
      depth: 1,
      squad: [],
    };

    await gameLoop.startLevel(runData);

    // Grid should be populated
    expect(gameLoop.grid).to.exist;
    // Check center of map (likely not empty for RuinGen) or at least check valid bounds
    expect(gameLoop.grid.size.x).to.equal(20);

    // VoxelManager should be initialized
    expect(gameLoop.voxelManager).to.exist;
    // Should have visual meshes
    expect(gameLoop.scene.children.length).to.be.greaterThan(0);
  });

  it("CoA 3: Deployment Phase should separate zones and allow manual placement", async () => {
    gameLoop.init(container);

    const runData = {
      seed: 12345, // Deterministic seed
      depth: 1,
      squad: [{ id: "u1", classId: "CLASS_VANGUARD" }],
    };

    // startLevel should now prepare the map but NOT spawn units immediately
    await gameLoop.startLevel(runData);

    // 1. Verify Spawn Zones Generated
    // The generator/loop should identify valid tiles for player start and enemy start
    expect(gameLoop.playerSpawnZone).to.be.an("array").that.is.not.empty;
    expect(gameLoop.enemySpawnZone).to.be.an("array").that.is.not.empty;

    // 2. Verify Zone Separation
    // Create copies to ensure we don't test against mutated arrays later
    const pZone = [...gameLoop.playerSpawnZone];
    const eZone = [...gameLoop.enemySpawnZone];

    const overlap = pZone.some((pTile) =>
      eZone.some((eTile) => eTile.x === pTile.x && eTile.z === pTile.z)
    );
    expect(overlap).to.be.false;

    // 3. Test Manual Deployment (User Selection)
    const unitDef = runData.squad[0];
    const validTile = pZone[0]; // Pick first valid tile from player zone

    // Expect a method to manually place a unit from the roster onto a specific tile
    const unit = gameLoop.deployUnit(unitDef, validTile);

    expect(unit).to.exist;
    expect(unit.position.x).to.equal(validTile.x);
    expect(unit.position.z).to.equal(validTile.z);

    // Verify visual mesh created
    const mesh = gameLoop.unitMeshes.get(unit.id);
    expect(mesh).to.exist;
    expect(mesh.position.x).to.equal(validTile.x);

    // 4. Test Enemy Spawning (Finalize Deployment)
    // This triggers the actual start of combat/AI
    gameLoop.finalizeDeployment();

    const enemies = gameLoop.unitManager.getUnitsByTeam("ENEMY");
    expect(enemies.length).to.be.greaterThan(0);

    // Verify enemies are in their zone
    // Note: finalizeDeployment removes used spots from gameLoop.enemySpawnZone,
    // so we check against our copy `eZone`.
    const enemyPos = enemies[0].position;
    const isInZone = eZone.some(
      (t) => t.x === enemyPos.x && t.z === enemyPos.z
    );

    expect(
      isInZone,
      `Enemy spawned at ${enemyPos.x},${enemyPos.z} which is not in enemy zone`
    ).to.be.true;
  });

  it("CoA 4: stop() should halt animation loop", (done) => {
    gameLoop.init(container);
    gameLoop.isRunning = true;

    // Spy on animate
    const spy = sinon.spy(gameLoop, "animate");

    gameLoop.stop();

    // Wait a short duration to ensure loop doesn't fire
    // Using setTimeout instead of requestAnimationFrame for reliability in headless env
    setTimeout(() => {
      expect(gameLoop.isRunning).to.be.false;
      done();
    }, 50);
  });
});