using UnityEngine;
using UnityGameFramework.Runtime;
using Object = UnityEngine.Object;

namespace SepCore.CameraModule
{
    /// <summary>
    /// UnityGameFramework 侧的相机模块组件。
    /// 作为 GameEntry.CameraModule 访问入口，统一持有并转发 CameraModule 控制器能力。
    /// </summary>
    [DisallowMultipleComponent]
    public class CameraModuleComponent : GameFrameworkComponent
    {
        [SerializeField] private CinemachineCameraController _cinemachineController;
        [SerializeField] private bool _autoSearchController = true;
        [SerializeField] private bool _logMissingControllerWarnings = true;

        private ICameraController _controller;
        private bool _hasLoggedMissingController;

        public ICameraController Controller
        {
            get
            {
                ResolveController(false);
                return IsControllerValid(_controller) ? _controller : null;
            }
        }

        public bool HasController => Controller != null;

        public Transform Target => Controller?.Target;

        public CameraEffectSettings CurrentSettings => Controller?.CurrentSettings ?? CameraEffectSettings.Default;

        protected override void Awake()
        {
            base.Awake();
            ResolveController(false);
        }

        public void RegisterController(ICameraController controller)
        {
            if (!IsControllerValid(controller))
            {
                Log.Warning("CameraModuleComponent.RegisterController() controller is invalid.");
                return;
            }

            _controller = controller;
            _hasLoggedMissingController = false;
            if (controller is CinemachineCameraController cinemachineController)
            {
                _cinemachineController = cinemachineController;
            }
        }

        public void UnregisterController(ICameraController controller)
        {
            if (controller != null && !ReferenceEquals(_controller, controller))
            {
                return;
            }

            _controller = null;
            _cinemachineController = null;
        }

        public void SetTarget(Transform target)
        {
            if (!EnsureController())
            {
                return;
            }

            _controller.SetTarget(target);
        }

        public void ApplySettings(CameraEffectSettings settings)
        {
            if (!EnsureController())
            {
                return;
            }

            _controller.ApplySettings(settings);
        }

        public void EnableEffect(CameraEffectType effect)
        {
            if (!EnsureController())
            {
                return;
            }

            _controller.EnableEffect(effect);
        }

        public void DisableEffect(CameraEffectType effect)
        {
            if (!EnsureController())
            {
                return;
            }

            _controller.DisableEffect(effect);
        }

        public bool IsEffectEnabled(CameraEffectType effect)
        {
            return EnsureController() && _controller.IsEffectEnabled(effect);
        }

        private bool EnsureController()
        {
            ResolveController(_logMissingControllerWarnings);
            return IsControllerValid(_controller);
        }

        private void ResolveController(bool logWarning)
        {
            if (IsControllerValid(_controller))
            {
                return;
            }

            if (_cinemachineController != null)
            {
                _controller = _cinemachineController;
                _hasLoggedMissingController = false;
                return;
            }

            if (!_autoSearchController)
            {
                LogMissingController(logWarning);
                return;
            }

            _cinemachineController = GetComponentInChildren<CinemachineCameraController>(true);
            if (_cinemachineController == null)
            {
#if UNITY_2023_1_OR_NEWER
                _cinemachineController = FindFirstObjectByType<CinemachineCameraController>(FindObjectsInactive.Include);
#else
                _cinemachineController = FindObjectOfType<CinemachineCameraController>(true);
#endif
            }

            if (_cinemachineController != null)
            {
                _controller = _cinemachineController;
                _hasLoggedMissingController = false;
                return;
            }

            LogMissingController(logWarning);
        }

        private void LogMissingController(bool logWarning)
        {
            if (!logWarning || _hasLoggedMissingController)
            {
                return;
            }

            _hasLoggedMissingController = true;
            Log.Warning(
                "CameraModuleComponent requires a CinemachineCameraController. " +
                "Assign one in Inspector or place one in the loaded scene.");
        }

        private static bool IsControllerValid(ICameraController controller)
        {
            if (controller == null)
            {
                return false;
            }

            if (controller is Object unityObject && unityObject == null)
            {
                return false;
            }

            return true;
        }
    }
}