using UnityEngine;
using Cinemachine;
using System.Collections;
using Unity.BossRoom.CameraUtils;

public class EdgePanningController : MonoBehaviour
{
    [Header("Camera References")]
    public CinemachineFreeLook virtualCamera;
    private CinemachineCameraOffset cameraOffset;
    private Transform cameraTransform;
    
    [Header("Edge Panning Settings")]
    public float edgeThreshold = 10f; // Distance from screen edge to trigger panning
    public float panSpeed = 20f; // World units per second
    public float maxPanDistance = 30f; // Maximum distance from player
    public float returnSpeed = 15f; // Speed when returning to player
    public float returnDelay = 0.5f; // Delay before auto-return starts
    
    [Header("Smoothing")]
    public float smoothTime = 0.1f; // Camera movement smoothing
    
    // Camera state
    private Transform targetCharacter;
    private Vector3 panOffset = Vector3.zero;
    private Vector3 currentVelocity = Vector3.zero;
    private float timeSincePanStopped = 0f;
    private bool isPanning = false;
    private bool isReturning = false;
    private Vector3 lastValidPosition;
    
    // Free camera mode (for debugging)
    private bool isFreeRoamMode = false;
    public float freeRoamSpeed = 20f;
    
    // Camera shake
    private Coroutine shakeCoroutine;
    
    private void Start()
    {
        // Get camera offset component
        cameraOffset = virtualCamera.GetComponent<CinemachineCameraOffset>();
        if (cameraOffset == null)
        {
            cameraOffset = virtualCamera.gameObject.AddComponent<CinemachineCameraOffset>();
        }
        
        // Cache camera transform
        cameraTransform = virtualCamera.transform;
        
        // Initialize offset
        cameraOffset.m_Offset = Vector3.zero;
    }
    
    private void Awake()
    {
        CameraController.OnCameraAttached += SetTargetCharacter;
    }
    
    private void OnDestroy()
    {
        CameraController.OnCameraAttached -= SetTargetCharacter;
    }
    
    private void SetTargetCharacter(Transform characterTransform)
    {
        targetCharacter = characterTransform.parent;
        lastValidPosition = targetCharacter.position;
    }
    
    private void LateUpdate()
    {
        // Toggle free roam mode
        if (Input.GetKeyDown(KeyCode.Backspace))
        {
            ToggleFreeRoamMode();
        }
        
        if (isFreeRoamMode)
        {
            HandleFreeRoam();
            return;
        }
        
        if (targetCharacter == null) return;
        
        HandleDotaStylePanning();
    }
    
    private void HandleDotaStylePanning()
    {
        Vector3 mousePos = Input.mousePosition;
        Vector3 panDirection = Vector3.zero;
        
        // Check screen edges
        bool nearEdge = false;
        
        // Left edge
        if (mousePos.x <= edgeThreshold)
        {
            float strength = 1f - (mousePos.x / edgeThreshold);
            panDirection.x = -strength;
            nearEdge = true;
        }
        // Right edge
        else if (mousePos.x >= Screen.width - edgeThreshold)
        {
            float strength = 1f - ((Screen.width - mousePos.x) / edgeThreshold);
            panDirection.x = strength;
            nearEdge = true;
        }
        
        // Bottom edge
        if (mousePos.y <= edgeThreshold)
        {
            float strength = 1f - (mousePos.y / edgeThreshold);
            panDirection.z = -strength;
            nearEdge = true;
        }
        // Top edge
        else if (mousePos.y >= Screen.height - edgeThreshold)
        {
            float strength = 1f - ((Screen.height - mousePos.y) / edgeThreshold);
            panDirection.z = strength;
            nearEdge = true;
        }
        
        // Handle panning state
        if (nearEdge)
        {
            isPanning = true;
            isReturning = false;
            timeSincePanStopped = 0f;
            
            // Convert pan direction to world space (relative to camera orientation)
            Vector3 forward = cameraTransform.forward;
            forward.y = 0;
            forward.Normalize();
            
            Vector3 right = cameraTransform.right;
            right.y = 0;
            right.Normalize();
            
            Vector3 worldPanDirection = (right * panDirection.x + forward * panDirection.z).normalized * panDirection.magnitude;
            
            // Apply panning
            Vector3 targetOffset = panOffset + worldPanDirection * panSpeed * Time.deltaTime;
            
            // Clamp to max distance
            if (targetOffset.magnitude > maxPanDistance)
            {
                targetOffset = targetOffset.normalized * maxPanDistance;
            }
            
            panOffset = targetOffset;
        }
        else
        {
            // Not near edge - handle return to player
            if (isPanning)
            {
                isPanning = false;
                timeSincePanStopped = 0f;
            }
            
            // Check if we should return to player
            timeSincePanStopped += Time.deltaTime;
            
            if (timeSincePanStopped >= returnDelay && panOffset.magnitude > 0.1f)
            {
                isReturning = true;
                
                // Smoothly return to player
                float returnAmount = returnSpeed * Time.deltaTime;
                if (panOffset.magnitude <= returnAmount)
                {
                    panOffset = Vector3.zero;
                    isReturning = false;
                }
                else
                {
                    panOffset = Vector3.Lerp(panOffset, Vector3.zero, returnAmount / panOffset.magnitude);
                }
            }
        }
        
        // Apply the offset smoothly
        Vector3 targetPosition = targetCharacter.position + panOffset;
        cameraOffset.m_Offset = Vector3.SmoothDamp(cameraOffset.m_Offset, panOffset, ref currentVelocity, smoothTime);
        
        // Double-click to center on hero (Dota feature)
        if (Input.GetMouseButtonDown(0) && Input.GetMouseButtonDown(0)) // Simplified double-click detection
        {
            CenterOnHero();
        }
        
        // Space bar to instantly center (another Dota feature)
        if (Input.GetKeyDown(KeyCode.Space))
        {
            CenterOnHero();
        }
    }
    
    private void CenterOnHero()
    {
        panOffset = Vector3.zero;
        cameraOffset.m_Offset = Vector3.zero;
        currentVelocity = Vector3.zero;
        isPanning = false;
        isReturning = false;
        timeSincePanStopped = returnDelay; // Skip the delay
    }
    
    private void ToggleFreeRoamMode()
    {
        isFreeRoamMode = !isFreeRoamMode;
        
        if (isFreeRoamMode)
        {
            virtualCamera.Follow = null;
            virtualCamera.LookAt = null;
        }
        else
        {
            if (targetCharacter != null)
            {
                virtualCamera.Follow = targetCharacter;
                virtualCamera.LookAt = targetCharacter;
            }
            CenterOnHero();
        }
    }
    
    private void HandleFreeRoam()
    {
        float horizontal = Input.GetAxis("Horizontal");
        float vertical = Input.GetAxis("Vertical");
        float ascent = 0f;
        
        if (Input.GetKey(KeyCode.E)) ascent = 1f;
        else if (Input.GetKey(KeyCode.Q)) ascent = -1f;
        
        Vector3 movement = new Vector3(horizontal, ascent, vertical);
        cameraTransform.position += cameraTransform.rotation * movement * freeRoamSpeed * Time.deltaTime;
    }
    
    public void ShakeCamera(float duration = 0.3f, float magnitude = 0.2f)
    {
        if (shakeCoroutine != null)
        {
            StopCoroutine(shakeCoroutine);
        }
        shakeCoroutine = StartCoroutine(ShakeRoutine(duration, magnitude));
    }
    
    private IEnumerator ShakeRoutine(float duration, float magnitude)
    {
        float elapsed = 0f;
        
        while (elapsed < duration)
        {
            float x = Random.Range(-1f, 1f) * magnitude;
            float y = Random.Range(-1f, 1f) * magnitude;
            float z = Random.Range(-1f, 1f) * magnitude;
            
            // Apply shake on top of existing offset
            Vector3 shakeOffset = new Vector3(x, y, z);
            cameraOffset.m_Offset = panOffset + shakeOffset;
            
            elapsed += Time.deltaTime;
            yield return null;
        }
        
        // Reset to current pan offset
        cameraOffset.m_Offset = panOffset;
    }
    
    // Helper method to check if cursor is over UI
    private bool IsCursorOverUI()
    {
        return UnityEngine.EventSystems.EventSystem.current != null && 
               UnityEngine.EventSystems.EventSystem.current.IsPointerOverGameObject();
    }
    
    // Debug visualization
    private void OnDrawGizmos()
    {
        if (!Application.isPlaying || targetCharacter == null) return;
        
        // Draw max pan distance
        Gizmos.color = Color.yellow;
        Gizmos.DrawWireSphere(targetCharacter.position, maxPanDistance);
        
        // Draw current offset
        if (panOffset.magnitude > 0.1f)
        {
            Gizmos.color = Color.red;
            Gizmos.DrawLine(targetCharacter.position, targetCharacter.position + panOffset);
            Gizmos.DrawWireSphere(targetCharacter.position + panOffset, 1f);
        }
    }
}