using System;
using UnityEngine;
using Cinemachine;
using System.Collections;

public class CameraManager : MonoBehaviour
{
	public InputReader inputReader;
	public Camera mainCamera;
	public CinemachineFreeLook freeLookVCam;
	public CinemachineImpulseSource impulseSource;
	private bool _isRMBPressed;

	[SerializeField][Range(.5f, 3f)] private float _speedMultiplier = 1f; //TODO: make this modifiable in the game settings											
	[SerializeField] private TransformAnchor _cameraTransformAnchor = default;
	[SerializeField] private TransformAnchor _protagonistTransformAnchor = default;

	[Header("Listening on channels")]
	[Tooltip("The CameraManager listens to this event, fired by protagonist GettingHit state, to shake camera")]
	[SerializeField] private VoidEventChannelSO _camShakeEvent = default;

	private bool _cameraMovementLock = false;

	private void OnEnable()
	{
		inputReader.cameraMoveEvent += OnCameraMove;
		inputReader.enableMouseControlCameraEvent += OnEnableMouseControlCamera;
		inputReader.disableMouseControlCameraEvent += OnDisableMouseControlCamera;

		_protagonistTransformAnchor.OnAnchorProvided += SetupProtagonistVirtualCamera;
		_camShakeEvent.OnEventRaised += impulseSource.GenerateImpulse;

		_cameraTransformAnchor.Provide(mainCamera.transform);
	}

	private void OnDisable()
	{
		inputReader.cameraMoveEvent -= OnCameraMove;
		inputReader.enableMouseControlCameraEvent -= OnEnableMouseControlCamera;
		inputReader.disableMouseControlCameraEvent -= OnDisableMouseControlCamera;

		_protagonistTransformAnchor.OnAnchorProvided -= SetupProtagonistVirtualCamera;
		_camShakeEvent.OnEventRaised -= impulseSource.GenerateImpulse;

		_cameraTransformAnchor.Unset();
	}

	private void Start()
	{
		//Setup the camera target if the protagonist is already available
		if(_protagonistTransformAnchor.isSet)
			SetupProtagonistVirtualCamera();
	}

	private void OnEnableMouseControlCamera()
	{
		_isRMBPressed = true;

		Cursor.lockState = CursorLockMode.Locked;
		Cursor.visible = false;

		StartCoroutine(DisableMouseControlForFrame());
	}

	IEnumerator DisableMouseControlForFrame()
	{
		_cameraMovementLock = true;
		yield return new WaitForEndOfFrame();
		_cameraMovementLock = false;
	}

	private void OnDisableMouseControlCamera()
	{
		_isRMBPressed = false;

		Cursor.lockState = CursorLockMode.None;
		Cursor.visible = true;

		// when mouse control is disabled, the input needs to be cleared
		// or the last frame's input will 'stick' until the action is invoked again
		freeLookVCam.m_XAxis.m_InputAxisValue = 0;
		freeLookVCam.m_YAxis.m_InputAxisValue = 0;
	}

	private void OnCameraMove(Vector2 cameraMovement, bool isDeviceMouse)
	{
		if (_cameraMovementLock)
			return;

		if (isDeviceMouse && !_isRMBPressed)
			return;

		//Using a "fixed delta time" if the device is mouse,
		//since for the mouse we don't have to account for frame duration
		float deviceMultiplier = isDeviceMouse ? 0.02f : Time.deltaTime;

		freeLookVCam.m_XAxis.m_InputAxisValue = cameraMovement.x * deviceMultiplier * _speedMultiplier;
		freeLookVCam.m_YAxis.m_InputAxisValue = cameraMovement.y * deviceMultiplier * _speedMultiplier;
	}

	/// <summary>
	/// Provides Cinemachine with its target, taken from the TransformAnchor SO containing a reference to the player's Transform component.
	/// This method is called every time the player is reinstantiated.
	/// </summary>
	public void SetupProtagonistVirtualCamera()
	{
		Transform target = _protagonistTransformAnchor.Value;

		freeLookVCam.Follow = target;
		freeLookVCam.LookAt = target;
		freeLookVCam.OnTargetObjectWarped(target, target.position - freeLookVCam.transform.position - Vector3.forward);
	}
}