// movementManager.js
import * as THREE from 'three';

export class MovementManager {
  constructor(vrm, animationMgr, scene) {
    this.vrm = vrm;
    this.animationMgr = animationMgr;
    this.scene = scene;
    
    // Movement state
    this.isMoving = false;
    this.targetPosition = null;
    this.moveSpeed = 1.5; // units per second
    this.rotationSpeed = 5; // radians per second
    this.stopDistance = 0.1; // how close to get before stopping
    
    // Animation states
    this.idleAction = null;
    this.walkAction = null;
    this.runAction = null;
    this.currentAction = null;
    
    // Movement mixer (separate from VRMA mixer)
    this.movementMixer = new THREE.AnimationMixer(vrm.scene);
    
    // Debug helper (optional)
    this.targetMarker = null;
    this.showDebugMarker = false;
  }

  // Load locomotion animations (idle, walk, run)
  async loadLocomotionAnimations(idleUrl, walkUrl, runUrl = null) {
    const loader = new THREE.GLTFLoader();
    
    try {
      // Load idle animation
      if (idleUrl) {
        const idleGltf = await loader.loadAsync(idleUrl);
        const idleClip = idleGltf.animations[0];
        this.idleAction = this.movementMixer.clipAction(idleClip);
        this.idleAction.setLoop(THREE.LoopRepeat);
      }
      
      // Load walk animation
      if (walkUrl) {
        const walkGltf = await loader.loadAsync(walkUrl);
        const walkClip = walkGltf.animations[0];
        this.walkAction = this.movementMixer.clipAction(walkClip);
        this.walkAction.setLoop(THREE.LoopRepeat);
      }
      
      // Load run animation (optional)
      if (runUrl) {
        const runGltf = await loader.loadAsync(runUrl);
        const runClip = runGltf.animations[0];
        this.runAction = this.movementMixer.clipAction(runClip);
        this.runAction.setLoop(THREE.LoopRepeat);
      }
      
      // Start with idle
      if (this.idleAction) {
        this.currentAction = this.idleAction;
        this.idleAction.play();
      }
      
      console.log("✅ Locomotion animations loaded");
    } catch (error) {
      console.error("Failed to load locomotion animations:", error);
    }
  }

  // Transition between animations with crossfade
  crossFadeTo(targetAction, duration = 0.3) {
    if (!targetAction || targetAction === this.currentAction) return;
    
    targetAction.reset();
    targetAction.setEffectiveTimeScale(1);
    targetAction.setEffectiveWeight(1);
    targetAction.play();
    
    if (this.currentAction) {
      this.currentAction.crossFadeTo(targetAction, duration, false);
    }
    
    this.currentAction = targetAction;
  }

  // Move to a specific position
  moveTo(x, y, z, speed = null) {
    this.targetPosition = new THREE.Vector3(x, y, z);
    this.isMoving = true;
    
    if (speed) {
      this.moveSpeed = speed;
    }
    
    // Switch to walk animation
    if (this.walkAction) {
      this.crossFadeTo(this.walkAction, 0.2);
    }
    
    // Show debug marker
    if (this.showDebugMarker) {
      this.createTargetMarker(this.targetPosition);
    }
    
    console.log(`🚶 Moving to position: (${x.toFixed(2)}, ${y.toFixed(2)}, ${z.toFixed(2)})`);
  }

  // Stop movement
  stop() {
    this.isMoving = false;
    this.targetPosition = null;
    
    // Switch back to idle
    if (this.idleAction) {
      this.crossFadeTo(this.idleAction, 0.3);
    }
    
    // Remove debug marker
    if (this.targetMarker) {
      this.scene.remove(this.targetMarker);
      this.targetMarker = null;
    }
  }

  // Update loop (call this in your main animation loop)
  update(deltaTime) {
    // Update movement mixer
    if (this.movementMixer) {
      this.movementMixer.update(deltaTime);
    }
    
    // Handle movement
    if (this.isMoving && this.targetPosition) {
      const currentPos = this.vrm.scene.position;
      const direction = new THREE.Vector3()
        .subVectors(this.targetPosition, currentPos);
      
      const distance = direction.length();
      
      // Check if we've arrived
      if (distance < this.stopDistance) {
        this.stop();
        console.log("✅ Arrived at destination");
        return;
      }
      
      // Normalize direction
      direction.normalize();
      
      // Move towards target
      const moveDistance = this.moveSpeed * deltaTime;
      const actualMove = Math.min(moveDistance, distance);
      
      currentPos.x += direction.x * actualMove;
      currentPos.z += direction.z * actualMove;
      // Keep Y position (don't move vertically unless specified)
      if (this.targetPosition.y !== currentPos.y) {
        currentPos.y = this.targetPosition.y;
      }
      
      // Rotate to face direction of movement
      const targetRotation = Math.atan2(direction.x, direction.z);
      const currentRotation = this.vrm.scene.rotation.y;
      
      // Smooth rotation interpolation
      let rotationDiff = targetRotation - currentRotation;
      
      // Normalize rotation difference to [-PI, PI]
      while (rotationDiff > Math.PI) rotationDiff -= Math.PI * 2;
      while (rotationDiff < -Math.PI) rotationDiff += Math.PI * 2;
      
      const maxRotation = this.rotationSpeed * deltaTime;
      const actualRotation = Math.max(-maxRotation, Math.min(maxRotation, rotationDiff));
      
      this.vrm.scene.rotation.y += actualRotation;
    }
  }

  // Create a visual marker at target position (for debugging)
  createTargetMarker(position) {
    // Remove old marker
    if (this.targetMarker) {
      this.scene.remove(this.targetMarker);
    }
    
    // Create new marker
    const geometry = new THREE.SphereGeometry(0.1, 16, 16);
    const material = new THREE.MeshBasicMaterial({ 
      color: 0xff0000,
      transparent: true,
      opacity: 0.7
    });
    this.targetMarker = new THREE.Mesh(geometry, material);
    this.targetMarker.position.copy(position);
    this.scene.add(this.targetMarker);
  }

  // Enable/disable debug marker
  setDebugMarker(enabled) {
    this.showDebugMarker = enabled;
    if (!enabled && this.targetMarker) {
      this.scene.remove(this.targetMarker);
      this.targetMarker = null;
    }
  }

  // Set movement speed
  setSpeed(speed) {
    this.moveSpeed = speed;
    
    // Optionally switch to run animation for higher speeds
    if (this.runAction && speed > 2.5 && this.isMoving) {
      this.crossFadeTo(this.runAction, 0.2);
    } else if (this.walkAction && speed <= 2.5 && this.isMoving) {
      this.crossFadeTo(this.walkAction, 0.2);
    }
  }

  // Get current position
  getPosition() {
    return this.vrm.scene.position.clone();
  }

  // Check if currently moving
  isCurrentlyMoving() {
    return this.isMoving;
  }
}