using System;
using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;

#if UNITY_EDITOR
using UnityEditor;
#endif

namespace AEG.FSR
{
    public class FSRRenderPass : ScriptableRenderPass
    {
        private CommandBuffer cmd;

        private FSR3_URP m_fsrURP;
        private readonly Vector4 flipVector = new Vector4(1, -1, 0, 1);

        public FSRRenderPass(FSR3_URP _fsrURP) {
            renderPassEvent = RenderPassEvent.AfterRendering + 5;
            m_fsrURP = _fsrURP;
        }

        public void OnSetReference(FSR3_URP _fsrURP) {
            m_fsrURP = _fsrURP;
        }

        // The actual execution of the pass. This is where custom rendering occurs.
        public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData) {
            try {
                cmd = CommandBufferPool.Get("FSRRender");

                if(m_fsrURP.generateReactiveMask) {
                    m_fsrURP.m_context.GenerateReactiveMask(m_fsrURP.m_genReactiveDescription, cmd);
                }
                m_fsrURP.m_context.Dispatch(m_fsrURP.m_dispatchDescription, cmd);


#if UNITY_2022_1_OR_NEWER
                Blitter.BlitCameraTexture(cmd, m_fsrURP.m_fsrOutput, renderingData.cameraData.renderer.cameraColorTargetHandle, flipVector, 0, false);
#else
                Blit(cmd, m_fsrURP.m_fsrOutput, renderingData.cameraData.renderer.cameraColorTarget);
#endif
                context.ExecuteCommandBuffer(cmd);
                CommandBufferPool.Release(cmd);
            }
            catch { }
        }
    }

    public class FSRBufferPass : ScriptableRenderPass
    {
        private FSR3_URP m_fsrURP;

#if !UNITY_2022_1_OR_NEWER
        private readonly int depthTexturePropertyID = Shader.PropertyToID("_CameraDepthTexture");
#endif
        private readonly int motionTexturePropertyID = Shader.PropertyToID("_MotionVectorTexture");

        public FSRBufferPass(FSR3_URP _fsrURP) {
            renderPassEvent = RenderPassEvent.AfterRenderingPostProcessing;
            ConfigureInput(ScriptableRenderPassInput.Depth);
            m_fsrURP = _fsrURP;
        }

        //2022 and up
        public void Setup(RenderTargetIdentifier color, RenderTargetIdentifier depth) {
            if(!Application.isPlaying) {
                return;
            }
            if(m_fsrURP == null) {
                return;
            }

            m_fsrURP.m_dispatchDescription.Color = color;
            m_fsrURP.m_dispatchDescription.Depth = depth;
            m_fsrURP.m_dispatchDescription.MotionVectors = Shader.GetGlobalTexture(motionTexturePropertyID);
        }

        public void OnSetReference(FSR3_URP _fsrURP) {
            m_fsrURP = _fsrURP;
        }

        // The actual execution of the pass. This is where custom rendering occurs.
        public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData) {
#if UNITY_2022_1_OR_NEWER
            m_fsrURP.m_dispatchDescription.Color = renderingData.cameraData.renderer.cameraColorTargetHandle;
#else

            m_fsrURP.m_dispatchDescription.Color = renderingData.cameraData.renderer.cameraColorTarget;
            m_fsrURP.m_dispatchDescription.Depth = Shader.GetGlobalTexture(depthTexturePropertyID);
            m_fsrURP.m_dispatchDescription.MotionVectors = Shader.GetGlobalTexture(motionTexturePropertyID);

            try {
                m_fsrURP.m_dispatchDescription.DepthFormat = Shader.GetGlobalTexture(depthTexturePropertyID).graphicsFormat == UnityEngine.Experimental.Rendering.GraphicsFormat.None;
            }
            catch { 
                m_fsrURP.m_dispatchDescription.DepthFormat = true; 
            }
#endif
        }
    }

    public class FSROpaqueOnlyPass : ScriptableRenderPass
    {
        private CommandBuffer cmd;
        private FSR3_URP m_fsrURP;

        public FSROpaqueOnlyPass(FSR3_URP _fsrURP) {
            renderPassEvent = RenderPassEvent.BeforeRenderingTransparents;
            m_fsrURP = _fsrURP;
        }

        public void OnSetReference(FSR3_URP _fsrURP) {
            m_fsrURP = _fsrURP;
        }

        // The actual execution of the pass. This is where custom rendering occurs.
        public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData) {
            cmd = CommandBufferPool.Get("FSROpaqueOnly");

#if UNITY_2022_1_OR_NEWER
            Blit(cmd, renderingData.cameraData.renderer.cameraColorTargetHandle, m_fsrURP.m_opaqueOnlyColorBuffer);
#else
            Blit(cmd, renderingData.cameraData.renderer.cameraColorTarget, m_fsrURP.m_opaqueOnlyColorBuffer);
#endif
            context.ExecuteCommandBuffer(cmd);
            CommandBufferPool.Release(cmd);
        }
    }

    public class FSRTransparentPass : ScriptableRenderPass
    {
        private CommandBuffer cmd;
        private FSR3_URP m_fsrURP;

        public FSRTransparentPass(FSR3_URP _fsrURP) {
            renderPassEvent = RenderPassEvent.AfterRenderingTransparents;
            m_fsrURP = _fsrURP;
        }

        public void OnSetReference(FSR3_URP _fsrURP) {
            m_fsrURP = _fsrURP;
        }

        // The actual execution of the pass. This is where custom rendering occurs.
        public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData) {
            cmd = CommandBufferPool.Get("FSRTransparent");

#if UNITY_2022_1_OR_NEWER
            Blit(cmd, renderingData.cameraData.renderer.cameraColorTargetHandle, m_fsrURP.m_afterOpaqueOnlyColorBuffer);
#else
            Blit(cmd, renderingData.cameraData.renderer.cameraColorTarget, m_fsrURP.m_afterOpaqueOnlyColorBuffer);
#endif
            context.ExecuteCommandBuffer(cmd);
            CommandBufferPool.Release(cmd);
        }
    }
}