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

public class EdgePanningController : MonoBehaviour
{
    [Header("Camera References")]
    [Tooltip("Assign your Cinemachine FreeLook here.")]
    public CinemachineFreeLook virtualCamera;

    // This is the hero (or unit) we want to eventually recenter on.
    private Transform targetCharacter;

    // We create (or assign) a separate GameObject that the FreeLook will Follow/LookAt.
    private Transform cameraTarget;

    [Header("Edge Panning Settings")]
    [Tooltip("Distance in pixels from screen edge to start panning.")]
    public float edgeThreshold = 10f;
    [Tooltip("Pan speed in world units per second.")]
    public float panSpeed = 20f;
    [Tooltip("Maximum distance (in world units) the camera can pan away from the hero.")]
    public float maxPanDistance = 30f;

    [Header("Centering / Return Settings")]
    [Tooltip("Delay (seconds) after panning stops before auto-centering on hero begins.")]
    public float returnDelay = 0.5f;
    [Tooltip("Speed at which cameraTarget moves back to hero when auto-returning.")]
    public float returnSpeed = 15f;

    // Smoothing for the automatic “return to hero” motion
    [Header("Smoothing")]
    [Tooltip("Time for SmoothDamp when auto-centering back to hero.")]
    public float smoothTime = 0.1f;

    // State-tracking
    private bool isPanning = false;
    private bool isReturning = false;
    private float timeSincePanStopped = 0f;
    private Vector3 currentVelocity = Vector3.zero;

    // Free camera (debug) mode
    private bool isFreeRoamMode = false;
    [Tooltip("Speed for free-roam mode.")]
    public float freeRoamSpeed = 20f;

    private void Awake()
    {
        CameraController.OnCameraAttached += SetTargetCharacter;
    }

    private void OnDestroy()
    {
        CameraController.OnCameraAttached -= SetTargetCharacter;
    }

    private void Start()
    {
        if (virtualCamera == null)
        {
            Debug.LogError("EdgePanningController: You must assign a CinemachineFreeLook to virtualCamera.");
            enabled = false;
            return;
        }

        // Initially, we’ll leave cameraTarget null until we know who the hero is.
    }

    /// <summary>
    /// Called (by BossRoom’s CameraController) when the hero/character is attached.
    /// </summary>
    private void SetTargetCharacter(Transform characterTransform)
    {
        // characterTransform is actually the child transform of the player prefab.
        // We'll treat its parent as the "hero root".
        targetCharacter = characterTransform.parent;

        // Create a new, empty GameObject to serve as the camera’s focus point.
        if (cameraTarget == null)
        {
            GameObject go = new GameObject("CameraTarget");
            cameraTarget = go.transform;
        }

        // Place the cameraTarget initially on the hero’s position.
        cameraTarget.position = targetCharacter.position;

        // Tell the FreeLook to Follow/LookAt this cameraTarget
        virtualCamera.Follow = cameraTarget;
        virtualCamera.LookAt = cameraTarget;
    }

    private void LateUpdate()
    {
        // Toggle free-roam for debugging
        if (Input.GetKeyDown(KeyCode.Backspace))
        {
            ToggleFreeRoamMode();
        }

        if (isFreeRoamMode)
        {
            HandleFreeRoam();
            return;
        }

        if (targetCharacter == null || cameraTarget == null)
            return;

        HandleDotaStylePanning();
    }

    private void HandleDotaStylePanning()
    {
        Vector3 mousePos = Input.mousePosition;
        Vector3 panDirection = Vector3.zero;
        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;
        }

        if (nearEdge)
        {
            // We are actively panning
            isPanning = true;
            isReturning = false;
            timeSincePanStopped = 0f;

            // Compute a world-space direction on the XZ plane relative to camera’s facing
            Vector3 forward = virtualCamera.transform.forward;
            forward.y = 0;
            forward.Normalize();

            Vector3 right = virtualCamera.transform.right;
            right.y = 0;
            right.Normalize();

            Vector3 worldPanDir = (right * panDirection.x + forward * panDirection.z).normalized;

            // Move cameraTarget along that direction (scaled by panSpeed and deltaTime)
            Vector3 newPos = cameraTarget.position + worldPanDir * panSpeed * Time.deltaTime;

            // Clamp so cameraTarget never goes further than maxPanDistance from the hero
            Vector3 offsetFromHero = newPos - targetCharacter.position;
            if (offsetFromHero.magnitude > maxPanDistance)
            {
                offsetFromHero = offsetFromHero.normalized * maxPanDistance;
                newPos = targetCharacter.position + offsetFromHero;
            }

            cameraTarget.position = newPos;
        }
        else
        {
            // No edge-pan input. Start the return-to-hero timer if we were panning.
            if (isPanning)
            {
                isPanning = false;
                timeSincePanStopped = 0f;
            }

            timeSincePanStopped += Time.deltaTime;

            // After returnDelay, smoothly move cameraTarget back toward hero
            if (timeSincePanStopped >= returnDelay && !isReturning)
            {
                isReturning = true;
            }

            if (isReturning)
            {
                // Smoothly interpolate cameraTarget back to the hero’s position
                Vector3 targetPos = targetCharacter.position;
                cameraTarget.position = Vector3.SmoothDamp(
                    cameraTarget.position,
                    targetPos,
                    ref currentVelocity,
                    smoothTime,
                    returnSpeed
                );

                // If close enough, stop returning
                if (Vector3.Distance(cameraTarget.position, targetPos) < 0.1f)
                {
                    cameraTarget.position = targetPos;
                    isReturning = false;
                    currentVelocity = Vector3.zero;
                }
            }
        }

        // Double-click to instantly center on hero
        if (Input.GetMouseButtonDown(0) && Input.GetMouseButtonDown(0))
        {
            CenterOnHero();
        }

        // Space bar to instantly center on hero
        if (Input.GetKeyDown(KeyCode.Space))
        {
            CenterOnHero();
        }
    }

    private void CenterOnHero()
    {
        if (targetCharacter == null || cameraTarget == null)
            return;

        cameraTarget.position = targetCharacter.position;
        isPanning = false;
        isReturning = false;
        timeSincePanStopped = returnDelay; // So it won’t start returning immediately
        currentVelocity = Vector3.zero;
    }

    private void ToggleFreeRoamMode()
    {
        isFreeRoamMode = !isFreeRoamMode;

        if (isFreeRoamMode)
        {
            // Detach camera from any Follow target
            virtualCamera.Follow = null;
            virtualCamera.LookAt = null;
        }
        else
        {
            // Reattach to our cameraTarget
            if (cameraTarget != null)
            {
                virtualCamera.Follow = cameraTarget;
                virtualCamera.LookAt = cameraTarget;
            }
            CenterOnHero();
        }
    }

    private void HandleFreeRoam()
    {
        float h = Input.GetAxis("Horizontal");
        float v = Input.GetAxis("Vertical");
        float upDown = 0f;
        if (Input.GetKey(KeyCode.E)) upDown = 1f;
        else if (Input.GetKey(KeyCode.Q)) upDown = -1f;

        Vector3 move = new Vector3(h, upDown, v);
        virtualCamera.transform.position += virtualCamera.transform.rotation * move * freeRoamSpeed * Time.deltaTime;
    }

    // Optional: If you have camera shake functionality, you'd need to re-implement it differently,
    // because we no longer use CinemachineCameraOffset for panning. Left out here for brevity.
}