const TURN_RATE_DEG = 4;       // degrees per frame at 60fps
const BULLET_SPEED = 700;
const BULLET_DAMAGE = 20;
const BULLET_SIZE = 5;
const PLAYER_RADIUS = 16;
// Sprite faces DOWN at rotation=0; Phaser's 0° is RIGHT, so offset by -90°
const SPRITE_ROTATION_OFFSET = -Math.PI / 2;
// Gun tip distance from sprite center (in pixels)
const GUN_TIP_DIST = 24;

export class Player {
  constructor(scene, x, y) {
    this.scene = scene;
    this.facing = 0; // radians

    // Mutable stat block — modified by skill tree
    this.stats = {
      speed: 200,
      damage: BULLET_DAMAGE,
      fireRate: 1,        // multiplier applied to cooldown
      damageReduction: 0, // 0–1 additive
      maxHp: 100,
    };

    this.hp = this.stats.maxHp;
    this.lives = 3;
    this.invincible = false;
    this._fireCooldown = 0;
    this._baseFireInterval = 250; // ms between shots
    this._isMoving = false;
    this._isShooting = false;

    this._createAnims();
    this._buildSprite(x, y);
    this._setupKeys();
    this.bullets = scene.add.group();
  }

  _createAnims() {
    const anims = this.scene.anims;
    if (anims.exists('player-idle')) return; // already created

    anims.create({ key: 'player-idle',     frames: [{ key: 'player', frame: 0 }],                                        frameRate: 1,  repeat: -1 });
    anims.create({ key: 'player-walk',     frames: anims.generateFrameNumbers('player', { frames: [1, 2] }),              frameRate: 8,  repeat: -1 });
    anims.create({ key: 'player-idle-gun', frames: [{ key: 'player', frame: 3 }],                                        frameRate: 1,  repeat: -1 });
    anims.create({ key: 'player-walk-gun', frames: anims.generateFrameNumbers('player', { frames: [4, 5] }),              frameRate: 8,  repeat: -1 });
  }

  _buildSprite(x, y) {
    this.sprite = this.scene.add.sprite(x, y, 'player').setDepth(6);
    this.scene.physics.add.existing(this.sprite);
    this.sprite.body.setCollideWorldBounds(true);
    // Circle hitbox centered in the 48×48 sprite: radius 16, offset 8 from top-left
    this.sprite.body.setCircle(PLAYER_RADIUS, 8, 8);
    this.sprite.play('player-idle');
  }

  _setupKeys() {
    this.keys = this.scene.input.keyboard.addKeys({
      up: Phaser.Input.Keyboard.KeyCodes.W,
      down: Phaser.Input.Keyboard.KeyCodes.S,
      left: Phaser.Input.Keyboard.KeyCodes.A,
      right: Phaser.Input.Keyboard.KeyCodes.D,
    });
  }

  get x() { return this.sprite.x; }
  get y() { return this.sprite.y; }
  get active() { return this.sprite?.active ?? false; }

  update(delta) {
    this._move();
    this._rotateFacing(delta);
    this._handleFire(delta);
    this._updateAnimation();
    this._updateBullets();
  }

  _move() {
    let dx = 0, dy = 0;
    if (this.keys.left.isDown)  dx -= 1;
    if (this.keys.right.isDown) dx += 1;
    if (this.keys.up.isDown)    dy -= 1;
    if (this.keys.down.isDown)  dy += 1;

    this._isMoving = dx !== 0 || dy !== 0;
    if (dx !== 0 && dy !== 0) { dx *= 0.707; dy *= 0.707; }
    this.sprite.body.setVelocity(dx * this.stats.speed, dy * this.stats.speed);
  }

  _rotateFacing(delta) {
    const ptr = this.scene.input.activePointer;
    const targetAngle = Phaser.Math.Angle.Between(this.x, this.y, ptr.worldX, ptr.worldY);
    const maxTurn = Phaser.Math.DegToRad(TURN_RATE_DEG) * (delta / (1000 / 60));
    this.facing = Phaser.Math.Angle.RotateTo(this.facing, targetAngle, maxTurn);
    // Sprite art faces DOWN; offset by -90° so it faces RIGHT at facing=0
    this.sprite.setRotation(this.facing + SPRITE_ROTATION_OFFSET);
  }

  _handleFire(delta) {
    this._fireCooldown -= delta;
    const ptr = this.scene.input.activePointer;
    this._isShooting = ptr.isDown;
    if (ptr.isDown && this._fireCooldown <= 0) {
      this._fireCooldown = this._baseFireInterval / this.stats.fireRate;
      this._spawnBullet();
    }
  }

  _updateAnimation() {
    let key;
    if (this._isMoving && this._isShooting)       key = 'player-walk-gun';
    else if (this._isMoving)                       key = 'player-walk';
    else if (this._isShooting)                     key = 'player-idle-gun';
    else                                           key = 'player-idle';

    if (this.sprite.anims.currentAnim?.key !== key) {
      this.sprite.play(key);
    }
  }

  _spawnBullet() {
    const bx = this.x + Math.cos(this.facing) * GUN_TIP_DIST;
    const by = this.y + Math.sin(this.facing) * GUN_TIP_DIST;
    const bullet = this.scene.add.circle(bx, by, BULLET_SIZE, 0xffff00);
    this.scene.physics.add.existing(bullet);
    bullet.body.setVelocity(
      Math.cos(this.facing) * BULLET_SPEED,
      Math.sin(this.facing) * BULLET_SPEED
    );
    bullet.damage = this.stats.damage;
    this.bullets.add(bullet);
  }

  _updateBullets() {
    const W = this.scene.scale.width;
    const H = this.scene.scale.height;
    this.bullets.getChildren().forEach(b => {
      if (b.x < -20 || b.x > W + 20 || b.y < -20 || b.y > H + 20) {
        b.destroy();
      }
    });
  }

  takeDamage(amount) {
    if (this.invincible) return;
    const reduced = amount * (1 - Math.min(this.stats.damageReduction, 0.9));
    this.hp -= reduced;

    if (this.hp <= 0) {
      this.hp = 0;
      this._loseLife();
    }
  }

  _loseLife() {
    this.lives--;
    if (this.lives <= 0) {
      this.scene.events.emit('game-over');
      return;
    }
    this.hp = this.stats.maxHp;
    this._startInvincibility();
  }

  _startInvincibility() {
    this.invincible = true;
    this.scene.tweens.add({
      targets: this.sprite,
      alpha: 0,
      duration: 150,
      yoyo: true,
      repeat: 4,
      onComplete: () => {
        this.sprite.setAlpha(1);
        this.invincible = false;
      }
    });
  }

  respawn(x, y) {
    this.sprite.setPosition(x, y);
    this.hp = this.stats.maxHp;
    this._startInvincibility();
  }

  destroy() {
    this.sprite.destroy();
    this.bullets.clear(true, true);
  }
}