using BrewMonster;
using Unity.Cinemachine;
using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;

namespace BrewMonster.Scripts
{
    public class InGameGraphicOption : MonoSingleton<InGameGraphicOption>
    {
        [SerializeField] private UniversalRenderPipelineAsset _renderPipelineAsset;
        [SerializeField] private CinemachineCamera _cinemachineVirtualCamera;

        private static bool _warnedMissingUpdAsset;
        private static bool _warnedMissingCinemachineCam;

        private void TryEnsureRenderPipelineAsset()
        {
            if (_renderPipelineAsset != null)
            {
                return;
            }

            // MonoSingleton creates an empty host when absent from the scene — serialized refs stay null (e.g. animation test scenes).
            // Fall back to the project Quality / Graphics active URP asset. / 未放场景中时序列化字段为空，回退到当前 URP 资源
            _renderPipelineAsset =
                GraphicsSettings.defaultRenderPipeline as UniversalRenderPipelineAsset;

            if (_renderPipelineAsset == null && !_warnedMissingUpdAsset)
            {
                _warnedMissingUpdAsset = true;
                BMLogger.LogWarning(
                    "[InGameGraphicOption] UniversalRenderPipelineAsset missing (Inspector + Graphics Settings). SetRenderScale/SetMSAA are no-ops until URP is set.");
            }
        }

        private CinemachineCamera TryResolveCinemachineCamera()
        {
            if (_cinemachineVirtualCamera != null)
            {
                return _cinemachineVirtualCamera;
            }

            _cinemachineVirtualCamera = FindFirstObjectByType<CinemachineCamera>();
            return _cinemachineVirtualCamera;
        }

        #region public functions

        /// <summary>How far the objects are rendered in the scene.</summary>
        /// <param name="distance"></param>
        public void SetRenderDistance(float distance)
        {
            var cam = TryResolveCinemachineCamera();
            if (cam == null)
            {
                if (!_warnedMissingCinemachineCam)
                {
                    _warnedMissingCinemachineCam = true;
                    BMLogger.LogWarning(
                        "[InGameGraphicOption] No CinemachineCamera — SetRenderDistance skipped (assign _cinemachineVirtualCamera or add a vcam in scene).");
                }

                return;
            }

            distance = Mathf.Clamp(distance, 50f, 500f);
            cam.Lens.FarClipPlane = distance;
        }

        /// <summary>
        /// The scale of the render pipeline. <br/>
        /// The value should be between 0.6 and 1.5.
        /// </summary>
        public void SetRenderScale(float scale)
        {
            TryEnsureRenderPipelineAsset();
            if (_renderPipelineAsset == null)
            {
                return;
            }

            scale = Mathf.Clamp(scale, 0.6f, 1.5f);
            _renderPipelineAsset.renderScale = scale;
        }


        public void SetMSAA(int msaaLevel)
        {
            TryEnsureRenderPipelineAsset();
            if (_renderPipelineAsset == null)
            {
                return;
            }

            // Valid: 0,2,4
            if (msaaLevel != 0 && msaaLevel != 2 && msaaLevel != 4)
            {
                return;
            }

            _renderPipelineAsset.msaaSampleCount = msaaLevel;
        }


        //TODO: figure out a solution for this.
        public void SetActiveShadow(bool active)
        {
            
        }
        #endregion
    }
}