// systems/InputSystem.js
import { clearSelection, setActiveUnit } from './ControlMode.js';

export class InputSystem {
  constructor(scene) {
    this.scene = scene;
    this.selectionStart = null;

    // 初始化键盘
    const kb = scene.input.keyboard;
    this.keys = {
      up: [kb.addKey(Phaser.Input.Keyboard.KeyCodes.W), kb.addKey(Phaser.Input.Keyboard.KeyCodes.UP)],
      down: [kb.addKey(Phaser.Input.Keyboard.KeyCodes.S), kb.addKey(Phaser.Input.Keyboard.KeyCodes.DOWN)],
      left: [kb.addKey(Phaser.Input.Keyboard.KeyCodes.A), kb.addKey(Phaser.Input.Keyboard.KeyCodes.LEFT)],
      right: [kb.addKey(Phaser.Input.Keyboard.KeyCodes.D), kb.addKey(Phaser.Input.Keyboard.KeyCodes.RIGHT)]
    };

    // 禁用浏览器右键菜单
    scene.input.mouse.disableContextMenu();

    // 鼠标/触摸事件
    scene.input.on('pointerdown', this.onPointerDown, this);
    scene.input.on('pointermove', this.onPointerMove, this);
    scene.input.on('pointerup', this.onPointerUp, this);
  }

  isKeyDown(keyGroup) {
    return keyGroup.some(key => key.isDown);
  }

  update() {
    // 键盘相对移动（仅当有激活单位）
    const dir = { x: 0, y: 0 };
    if (this.isKeyDown(this.keys.left)) dir.x -= 1;
    if (this.isKeyDown(this.keys.right)) dir.x += 1;
    if (this.isKeyDown(this.keys.up)) dir.y -= 1;
    if (this.isKeyDown(this.keys.down)) dir.y += 1;

    // 无论是否有按键按下，都发送移动事件
    // 当dir.x和dir.y都为0时，单位会停止移动
    this.scene.events.emit('move-relative', dir);
  }

  onPointerDown(pointer) {
    // 检查鼠标是否在小地图或摇杆上，如果是则不处理框选
    if (this.isMouseOnMiniMap(pointer) || this.isMouseOnJoystick(pointer)) {
      return;
    }
    
    if (pointer.leftButtonDown()) {
      const worldX = pointer.worldX;
      const worldY = pointer.worldY;

      // 检查是否点中某个单位
      let clickedUnit = null;
      this.scene.unitGroup.getChildren().forEach(unit => {
        const bounds = unit.getBounds();
        if (worldX >= bounds.x && worldX <= bounds.right &&
            worldY >= bounds.y && worldY <= bounds.bottom) {
          clickedUnit = unit;
        }
      });

      if (clickedUnit) {
        // 切换控制目标
        this.scene.events.emit('select-unit', clickedUnit);
      } else {
        // 开始框选或移动指令
        // 存储世界坐标用于框选
        this.selectionStart = { x: worldX, y: worldY };
        this.scene.events.emit('selection-start', this.selectionStart);
      }
    } else if (pointer.rightButtonDown()) {
      // 右键点击：移动选中的单位
      const worldX = pointer.worldX;
      const worldY = pointer.worldY;
      this.scene.events.emit('move-to-point', worldX, worldY);
    }
  }

  onPointerMove(pointer) {
    // 检查鼠标是否在小地图或摇杆上，如果是则不处理框选
    if (this.isMouseOnMiniMap(pointer) || this.isMouseOnJoystick(pointer)) {
      return;
    }
    
    if (this.selectionStart) {
      // 使用世界坐标计算框选区域
      const currentWorldX = pointer.worldX;
      const currentWorldY = pointer.worldY;
      
      // 计算当前选择框的位置和大小
      const rect = new Phaser.Geom.Rectangle(
        Math.min(this.selectionStart.x, currentWorldX),
        Math.min(this.selectionStart.y, currentWorldY),
        Math.abs(currentWorldX - this.selectionStart.x),
        Math.abs(currentWorldY - this.selectionStart.y)
      );

      // 更新选择框的位置和大小
      this.scene.events.emit('selection-update', rect);
    }
  }

  onPointerUp(pointer) {
    // 检查鼠标是否在小地图或摇杆上，如果是则不处理框选
    if (this.isMouseOnMiniMap(pointer) || this.isMouseOnJoystick(pointer)) {
      this.selectionStart = null;
      return;
    }
    
    if (this.selectionStart) {
      // 使用世界坐标计算最终框选区域
      const currentWorldX = pointer.worldX;
      const currentWorldY = pointer.worldY;
      
      const rect = new Phaser.Geom.Rectangle(
        Math.min(this.selectionStart.x, currentWorldX),
        Math.min(this.selectionStart.y, currentWorldY),
        Math.abs(currentWorldX - this.selectionStart.x),
        Math.abs(currentWorldY - this.selectionStart.y)
      );

      // 如果框太小，视为“点击地面移动”
      if (rect.width < 10 && rect.height < 10) {
        this.scene.events.emit('move-to-point', pointer.worldX, pointer.worldY);
      } else {
        // 否则执行框选
        this.scene.events.emit('selection-end', rect);
      }

      this.selectionStart = null;
    }
  }

  /**
   * 检查鼠标是否在小地图上
   * @param {Phaser.Input.Pointer} pointer
   * @returns {boolean}
   */
  isMouseOnMiniMap(pointer) {
    // 检查场景中是否有小地图
    if (!this.scene.miniMap) {
      return false;
    }
    
    const miniMap = this.scene.miniMap;
    const mouseX = pointer.x;
    const mouseY = pointer.y;
    
    // 计算小地图的边界
    const mapLeft = miniMap.x;
    const mapRight = miniMap.x + miniMap.mapSize;
    const mapTop = miniMap.y;
    const mapBottom = miniMap.y + miniMap.mapSize;
    
    // 检查鼠标是否在小地图边界内
    return mouseX >= mapLeft && mouseX <= mapRight &&
           mouseY >= mapTop && mouseY <= mapBottom;
  }
  
  /**
   * 检查鼠标是否在摇杆上
   * @param {Phaser.Input.Pointer} pointer
   * @returns {boolean}
   */
  isMouseOnJoystick(pointer) {
    // 检查场景中是否有虚拟摇杆
    if (!this.scene.virtualJoystick) {
      return false;
    }
    
    const joystick = this.scene.virtualJoystick;
    const mouseX = pointer.x;
    const mouseY = pointer.y;
    
    // 计算摇杆的边界（包括摇杆和操作区域）
    const joystickRadius = joystick.radius * 2; // 操作区域是摇杆半径的两倍
    const joystickLeft = joystick.centerX - joystickRadius;
    const joystickRight = joystick.centerX + joystickRadius;
    const joystickTop = joystick.centerY - joystickRadius;
    const joystickBottom = joystick.centerY + joystickRadius;
    
    // 检查鼠标是否在摇杆边界内
    return mouseX >= joystickLeft && mouseX <= joystickRight &&
           mouseY >= joystickTop && mouseY <= joystickBottom;
  }
}