import { Player } from '../entities/Player.js';
import { WaveManager } from '../systems/WaveManager.js';
import { XPSystem } from '../systems/XPSystem.js';
import { SkillTree } from '../systems/SkillTree.js';
import { HUD } from '../ui/HUD.js';
import { SkillTreeUI } from '../ui/SkillTreeUI.js';

export class GameScene extends Phaser.Scene {
  constructor() {
    super({ key: 'GameScene' });
  }

  preload() {
    this.load.json('zones', './js/data/zones.json');
    this.load.json('skillTree', './js/data/skillTree.json');
  }

  create() {
    const W = this.scale.width;
    const H = this.scale.height;

    this._drawArena(W, H);

    this.physics.world.setBounds(0, 0, W, H);

    // Core systems — data already loaded by preload()
    this.skillTree = new SkillTree();
    this.skillTree.load(this.cache.json.get('skillTree'));

    this.player = new Player(this, W / 2, H / 2);

    this.xpSystem = new XPSystem(this);

    this.waveManager = new WaveManager(this, this.player);
    this.waveManager.load(this.cache.json.get('zones'));

    this.hud = new HUD(this, this.player, this.xpSystem);

    // Enemy projectile group for collision
    this._enemyProjectiles = [];

    // Event wiring
    this.events.on('enemy-killed', ({ xp }) => this.xpSystem.addXP(xp));
    this.events.on('enemy-projectile-spawned', proj => this._enemyProjectiles.push(proj));
    this.events.on('level-up', level => this._showLevelUp(level));
    this.events.on('game-over', () => this._onGameOver());
    this.events.on('victory', () => this._onVictory());

    this._levelUpPending = false;
    this._frozen = false;

    this.waveManager.start();
  }

  _drawArena(W, H) {
    // Dark background
    this.add.rectangle(W / 2, H / 2, W, H, 0x111118);

    // Grid lines for depth cue
    const g = this.add.graphics();
    g.lineStyle(1, 0x222233, 0.5);
    for (let x = 0; x <= W; x += 80) { g.lineBetween(x, 0, x, H); }
    for (let y = 0; y <= H; y += 80) { g.lineBetween(0, y, W, y); }

    // Arena border
    g.lineStyle(3, 0x334466, 1);
    g.strokeRect(2, 2, W - 4, H - 4);
  }

  update(time, delta) {
    if (!this.player || this._frozen) return;

    this.player.update(delta);
    this.waveManager.update(delta);
    this.hud.update();

    this._checkBulletHits();
    this._checkEnemyProjectileHits();
    this._pruneEnemyProjectiles();
  }

  _checkBulletHits() {
    const bullets = this.player.bullets.getChildren();
    const enemies = this.waveManager.enemies;

    for (const bullet of bullets) {
      if (!bullet.active) continue;
      for (const enemy of enemies) {
        if (!enemy.active) continue;
        const dist = Phaser.Math.Distance.Between(bullet.x, bullet.y, enemy.x, enemy.y);
        if (dist < enemy.radius + 5) {
          enemy.takeDamage(bullet.damage);
          bullet.destroy();
          break;
        }
      }
    }
  }

  _checkEnemyProjectileHits() {
    this._enemyProjectiles = this._enemyProjectiles.filter(p => p?.active);
    this._enemyProjectiles.forEach(proj => {
      if (!proj.active) return;
      const dist = Phaser.Math.Distance.Between(proj.x, proj.y, this.player.x, this.player.y);
      if (dist < 16 + 6) {
        this.player.takeDamage(proj.damage);
        proj.destroy();
      }
    });
  }

  _pruneEnemyProjectiles() {
    this._enemyProjectiles = this._enemyProjectiles.filter(p => p?.active);
  }

  _showLevelUp(level) {
    if (this._levelUpPending) return;
    this._levelUpPending = true;

    // Only show if there are skills available
    const available = this.skillTree.getAvailable();
    if (available.length === 0) {
      this._levelUpPending = false;
      return;
    }

    this._frozen = true;
    this.physics.world.pause();

    new SkillTreeUI(this, this.skillTree, this.player, () => {
      this._levelUpPending = false;
      this._frozen = false;
      this.physics.world.resume();
    });
  }

  _onGameOver() {
    this.scene.launch('GameOverScene');
    this.scene.pause();
  }

  _onVictory() {
    const W = this.scale.width;
    const H = this.scale.height;

    this.add.rectangle(W / 2, H / 2, W, H, 0x000000, 0.7).setDepth(30);
    this.add.text(W / 2, H / 2 - 40, 'VICTORY!', {
      fontSize: '72px', fill: '#ffdd00', fontStyle: 'bold'
    }).setOrigin(0.5).setDepth(31);

    const prompt = this.add.text(W / 2, H / 2 + 60, 'Press R to return to menu', {
      fontSize: '22px', fill: '#ffffff'
    }).setOrigin(0.5).setDepth(31);
    this.tweens.add({ targets: prompt, alpha: 0, duration: 700, yoyo: true, repeat: -1 });

    this.input.keyboard.once('keydown-R', () => {
      this.scene.start('IntroScene');
    });
  }

  shutdown() {
    this.events.removeAllListeners();
    this.player?.destroy();
    this.waveManager?.reset();
    this.hud?.destroy();
    this._enemyProjectiles = [];
  }
}