using UnityEngine;
using UnityEngine.InputSystem;
using Unheimlich.Core;
using Unheimlich.Gameplay.Portals;
using InputManager = Unheimlich.Managers.PlayerInputManager;

namespace Unheimlich.Gameplay.Player
{
    /// <summary>
    /// Handles first-person camera rotation and look mechanics for the player.
    /// Supports both mouse and gamepad input with adaptive sensitivity.
    /// Includes aim assist for dialogue choices and camera shake effects.
    /// </summary>
    public class PlayerLook : Singleton<PlayerLook>
{
    private const float INPUT_DEADZONE = 0.1f;
    private const float MOUSE_DELTA_MULTIPLIER = 0.001f;

    [Header("Components")]
    [SerializeField] private Transform _playerCamera, _playerCameraPivot; 

    [Header("Settings")]
    [SerializeField] private int _frameRate = 120; 
    [SerializeField] private float _mouseSensitivity = 0.2f; 
    [SerializeField] private float _gamepadSensitivity = 100f; 
    [SerializeField] private float _minLookAngle = -60f; 
    [SerializeField] private float _maxLookAngle = 60f; 

    [Header("Aim Assist")]
    [SerializeField] private float _aimAssistStrength = 25f;
    [SerializeField] private float _aimAssistMaxAngle = 10f;

    public bool HasActiveLookInput { get; private set; }
    public bool IsAimLocked { get; private set; } = false;

    [Header("Shake Control")]
    [SerializeField] private float _shakeFrequency = 40f; 
    private float _shakeInterval; 
    private float _shakeTimer = 0f;
    private Vector3 _shakeTarget = Vector3.zero;
    private Vector3 _shakeOriginalPos = Vector3.zero;
    private float _shakeSmoothness = 0f;

    private float _horizontalRotation; 
    private float _verticalRotation;
    private bool _isUsingGamepad = false;

    protected override void OnAwake()
    {
        QualitySettings.vSyncCount = 0; 
        Application.targetFrameRate = _frameRate; 

    }

    private void Start()
    {
        Cursor.lockState = CursorLockMode.Locked; 
        Cursor.visible = false; 
        _shakeInterval = 1f / _shakeFrequency;
    }

    private void Update()
    {
        if(!InputManager.IsLookingEnabled)
            return; 

        HandleLook();   
    }

    /// <summary>
    /// Processes look input from mouse or gamepad and updates camera rotation.
    /// Automatically detects input device and applies appropriate sensitivity.
    /// Clamps vertical rotation to prevent over-rotation.
    /// </summary>
    private void HandleLook()
    {
        Vector2 lookInput = InputManager.Instance.LookInput; 

        HasActiveLookInput = lookInput.magnitude > INPUT_DEADZONE;

        if (Gamepad.current != null && Gamepad.current.rightStick.ReadValue().magnitude > PortalConstants.GAMEPAD_DEADZONE)
            _isUsingGamepad = true;
        else if (Mouse.current != null && Mouse.current.delta.ReadValue().magnitude > PortalConstants.GAMEPAD_DEADZONE)
            _isUsingGamepad = false;

        float sensitivity = _isUsingGamepad ? _gamepadSensitivity : _mouseSensitivity;
        float deltaMultiplier = _isUsingGamepad ? Time.deltaTime : MOUSE_DELTA_MULTIPLIER;

        _horizontalRotation += lookInput.x * sensitivity * deltaMultiplier; 
        transform.rotation = Quaternion.Euler(0, _horizontalRotation, 0f); 
               
        _verticalRotation -= lookInput.y * sensitivity * deltaMultiplier; 
        _verticalRotation = Mathf.Clamp(_verticalRotation, _minLookAngle, _maxLookAngle); 

        _playerCamera.localRotation = Quaternion.Euler(_verticalRotation, 0f, 0f); 
    }

    /// <summary>
    /// Smoothly rotates the player camera toward a target using spherical interpolation.
    /// Assists player aiming by gently pulling the view toward dialogue choices when looking near them.
    /// Automatically unlocks if player provides manual input.
    /// </summary>
    public void ApplyAimAssist(Vector3 targetCenter)
    {
        if (IsAimLocked && HasActiveLookInput)    
            IsAimLocked = false;
        
        Vector3 directionToTarget = (targetCenter - _playerCamera.position).normalized;
        float angleError = Vector3.Angle(_playerCamera.forward, directionToTarget);

        if (IsAimLocked || (angleError > 0.01f && angleError < _aimAssistMaxAngle))
        {
            Quaternion targetRotation = Quaternion.LookRotation(directionToTarget);
            
            Quaternion correctedRotation = Quaternion.Slerp(
                _playerCamera.rotation, 
                targetRotation, 
                _aimAssistStrength * Time.deltaTime
            );
            Quaternion newBodyRotation = Quaternion.Euler(0, correctedRotation.eulerAngles.y, 0);
            
            _horizontalRotation = newBodyRotation.eulerAngles.y; 
            transform.rotation = newBodyRotation; 
            
            float newVerticalAngle = correctedRotation.eulerAngles.x;
            
            if (newVerticalAngle > 180) newVerticalAngle -= 360; 
            
            _verticalRotation = Mathf.Clamp(newVerticalAngle, _minLookAngle, _maxLookAngle);
            _playerCamera.localRotation = Quaternion.Euler(_verticalRotation, 0f, 0f);
        }
    }

    /// <summary>
    /// Creates a random camera shake effect for feedback (e.g., impacts, events).
    /// Uses a timer-based interval to control shake frequency.
    /// Amplitude controls both the intensity and duration of the shake.
    /// Smoothness controls how quickly the camera interpolates to the shake position (0 = instant, higher = smoother).
    /// </summary>
    public void Shake(float amplitude, float smoothness = 0f)
    {
        _shakeSmoothness = smoothness;
        _shakeTimer -= Time.deltaTime;

        if (_shakeTimer <= 0f)
        {
            _shakeTimer = _shakeInterval * amplitude;
            _shakeOriginalPos = _playerCameraPivot.position;

            float x = Random.Range(-1f, 1f) * amplitude;
            float y = Random.Range(-1f, 1f) * amplitude;

            _shakeTarget = _shakeOriginalPos + new Vector3(x, y, 0f);
        }
        
        if (_shakeSmoothness > 0f)
        {
            _playerCameraPivot.position = Vector3.Lerp(_playerCameraPivot.position, _shakeTarget, Time.deltaTime * _shakeSmoothness);
        }
        else
        {
            _playerCameraPivot.position = _shakeTarget;
        }
    }

    public void LockAim(bool locked)
    {
       IsAimLocked = locked; 
    }
}
}