using UnityEngine;
using UnityEngine.AI;
using UnityEngine.InputSystem;

public class ClickToMoveInputSystem : MonoBehaviour
{
    [Header("References")]
    public Camera cam;
    public LayerMask movementLayers;   // ground
    public LayerMask selectionLayers;  // enemies, NPCs, interactables

    [Header("Options")]
    [SerializeField]
    private bool useLegacyMouseFallback = false;
    [SerializeField]
    private bool enableDebugLogs = false;

    Camera cachedCam;
    Vector2 pointerScreenPos;
    PlayerInteractionController cachedInteraction;
    NavMeshMovementController cachedMovement;
    PlayerCombatController cachedCombat;

    void Awake()
    {
        CacheCameraReference();
        CachePlayerReferences();
    }

    void CacheCameraReference()
    {
        if (cam != null)
        {
            cachedCam = cam;
        }
        else
        {
            cachedCam = Camera.main;
            if (cachedCam == null)
                Debug.LogError("ClickToMoveInputSystem: No camera found! Assign one in the inspector or ensure Camera.main exists.", gameObject);
        }
    }

    void CachePlayerReferences()
    {
        if (Player.current == null)
        {
            cachedInteraction = null;
            cachedMovement = null;
            cachedCombat = null;
            return;
        }

        cachedInteraction = Player.current.GetComponent<PlayerInteractionController>();
        cachedMovement = Player.current.MovementController;
        cachedCombat = Player.current.GetComponent<PlayerCombatController>();
        if (cachedMovement == null)
        {
            cachedMovement = Player.current.GetComponent<NavMeshMovementController>();
        }
    }

    PlayerInteractionController GetInteraction()
    {
        if (Player.current == null) return null;
        if (cachedInteraction == null || cachedInteraction.gameObject != Player.current.gameObject)
        {
            CachePlayerReferences();
        }
        return cachedInteraction;
    }

    NavMeshMovementController GetMovement()
    {
        if (Player.current == null) return null;
        if (cachedMovement == null || cachedMovement.gameObject != Player.current.gameObject)
        {
            CachePlayerReferences();
        }
        return cachedMovement;
    }

    PlayerCombatController GetCombat()
    {
        if (Player.current == null) return null;
        if (cachedCombat == null || cachedCombat.gameObject != Player.current.gameObject)
        {
            CachePlayerReferences();
        }
        return cachedCombat;
    }

    void Log(string message)
    {
        if (enableDebugLogs)
        {
            Debug.Log(message, gameObject);
        }
    }

    // Hook this to PointerPos action (Value Vector2)
    public void OnPointerPos(InputAction.CallbackContext ctx)
    {
        pointerScreenPos = ctx.ReadValue<Vector2>();
    }

    // Hook this to LeftClick action (Button)
    public void OnLeftClick(InputAction.CallbackContext ctx)
    {
        if (!ctx.performed) return;
        HandleLeftClick();
    }

    private void HandleLeftClick()
    {
        if (cachedCam == null) return;

        Ray ray = cachedCam.ScreenPointToRay(pointerScreenPos);
        
        if (Physics.Raycast(ray, out RaycastHit hit, 500f, selectionLayers))
        {
            // Try NPC first
            var npc = hit.collider.GetComponentInParent<NPC>();
            if (npc != null)
            {
                // Check if NPC has a Selectable component
                var selectable = npc.GetComponent<Selectable>();
                if (selectable != null && SelectionManager.Instance != null)
                {
                    SelectionManager.Instance.Select(selectable);
                }
                Debug.Log($"Selected NPC: {npc.npcName} ({npc.npcType})");
                return;
            }

            // Try building first
            var building = hit.collider.GetComponentInParent<Building>();
            if (building != null)
            {
                if (SelectionManager.Instance != null)
                    SelectionManager.Instance.Select(building);
                Log($"Selected building: {building.buildingName}");
                return;
            }

            // Try to find a Selectable (Character, NPC, etc.)
            var selectable2 = hit.collider.GetComponentInParent<Selectable>();
            if (selectable2 != null)
            {
                if (SelectionManager.Instance != null)
                    SelectionManager.Instance.Select(selectable2);
                
                // Set player target if it's a character
                var character = selectable2.GetComponent<Character>();
                if (character != null && Player.current != null)
                {
                    Player.current.SetTarget(character);
                }
                
                Log($"Selected: {selectable2.displayName}");
                return;
            }

            // Check for interactive objects (gates, bridges, ledges without Selection Manager)
            var interactiveObject = hit.collider.GetComponentInParent<IInteractiveObject>();
            if (interactiveObject != null)
            {
                Log($"Selected interactive object: {interactiveObject.GetDisplayName()}");
                return;
            }

            // Generic interactable (if needed)
            var interactable = hit.collider.GetComponentInParent<Interactable>();
            if (interactable != null)
            {
                interactable.OnSelect();
                Log($"Interacted with: {interactable.name}");
                return;
            }
        }

        // Nothing selected, clear selection and target
        if (SelectionManager.Instance != null)
            SelectionManager.Instance.ClearSelection();
        if (Player.current != null)
            Player.current.SetTarget(null);
    }

    // Hook this to RightClick action (Button)
    public void OnRightClick(InputAction.CallbackContext ctx)
    {
        if (!ctx.performed) return;
        HandleRightClick();
    }

    private void HandleRightClick()
    {
        if (cachedCam == null || Player.current == null) return;

        Ray ray = cachedCam.ScreenPointToRay(pointerScreenPos);
        
        // First check if right-clicking on a building to interact with it
        if (Physics.Raycast(ray, out RaycastHit hit, 500f, selectionLayers))
        {
            // Check for enemy combat target first
            var enemy = hit.collider.GetComponentInParent<Enemy>();
            if (enemy != null)
            {
                var combat = GetCombat();
                if (combat != null)
                {
                    combat.SetTargetEnemy(enemy);
                    Log($"Set combat target: {enemy.enemyName}");
                }
                else
                {
                    // Fallback: move to enemy and look at them
                    var movement = GetMovement();
                    if (movement != null)
                    {
                        movement.MoveToAndLookAt(enemy.transform.position, enemy.transform.position);
                    }
                }
                return;
            }

            // Check for NPC interaction first
            var npc = hit.collider.GetComponentInParent<NPC>();
            if (npc != null)
            {
                var combat = GetCombat();
                if (combat != null) combat.ClearCombatTarget();

                var interaction = GetInteraction();
                if (interaction != null)
                {
                    interaction.SetPendingNPCInteraction(npc);
                    Log($"Set interaction target: {npc.npcName}");
                }
                else
                {
                    // Fallback: move to NPC and look at them
                    var movement = GetMovement();
                    if (movement != null)
                    {
                        movement.MoveToAndLookAt(npc.transform.position, npc.transform.position);
                        Log($"Moving to NPC: {npc.npcName}");
                    }
                }
                return;
            }

            var building = hit.collider.GetComponentInParent<Building>();
            if (building != null)
            {
                var combat = GetCombat();
                if (combat != null) combat.ClearCombatTarget();

                // If building can be entered and has an entry point, move to the door
                if (building.canEnter && building.entryPoint != null)
                {
                    var interaction = GetInteraction();
                    if (interaction != null)
                    {
                        interaction.SetPendingBuildingInteraction(building);
                        Log($"Set interaction target: {building.buildingName}");
                    }
                    else
                    {
                        // Fallback: move to entry point and look at it
                        var movement = GetMovement();
                        if (movement != null)
                        {
                            movement.MoveToAndLookAt(building.entryPoint.position, building.transform.position);
                        }
                    }
                }
                else
                {
                    // Cannot enter building - move as close as possible via NavMesh and look at building
                    var movement = GetMovement();
                    if (movement != null)
                    {
                        // Move toward the hit point and set look target to building center
                        movement.MoveToAndLookAt(hit.point, building.transform.position);
                        Log($"Moving toward building: {building.buildingName}");
                    }
                }
                return;
            }

            // Check for other interactive objects (gates, bridges, ledges, etc.)
            var interactiveObject = hit.collider.GetComponentInParent<IInteractiveObject>();
            if (interactiveObject != null)
            {
                var combat = GetCombat();
                if (combat != null) combat.ClearCombatTarget();

                var interaction = GetInteraction();
                if (interaction != null)
                {
                    Vector3 interactionPoint = interactiveObject.GetInteractionPoint();
                    interaction.SetPendingInteraction(interactiveObject, interactionPoint);
                    Log($"Set interaction target: {interactiveObject.GetDisplayName()}");
                }
                else
                {
                    // Fallback if no PlayerInteractionController - move to interaction point directly and look at it
                    var movement = GetMovement();
                    if (movement != null)
                    {
                        Vector3 interactionPoint = interactiveObject.GetInteractionPoint();
                        movement.MoveToAndLookAt(interactionPoint, interactionPoint);
                        Log($"Moving to interactive object: {interactiveObject.GetDisplayName()}");
                    }
                }
                return;
            }
        }

        // If not an interactive object, check for movement destination
        if (Physics.Raycast(ray, out RaycastHit groundHit, 500f, movementLayers))
        {
            var combat = GetCombat();
            if (combat != null) combat.ClearCombatTarget();

            var movement = GetMovement();
            if (movement != null)
            {
                movement.MoveTo(groundHit.point);
                Log($"Moving to point: {groundHit.point}");
            }
            else
            {
                // fallback: try to find NavMeshAgent on player root
                var agent = Player.current.GetComponent<NavMeshAgent>();
                if (agent != null) agent.SetDestination(groundHit.point);
            }
        }
    }

    // Optional fallback if PointerPos not wired
    void Update()
    {
        if (!useLegacyMouseFallback) return;
        if (cachedCam == null) return;
        if (Mouse.current == null) return;

        pointerScreenPos = Mouse.current.position.ReadValue();

        if (Mouse.current.leftButton.wasPressedThisFrame)
        {
            HandleLeftClick();
        }

        if (Mouse.current.rightButton.wasPressedThisFrame)
        {
            HandleRightClick();
        }
    }
}