using System;
using UnityEngine;
using UnityEngine.Profiling;
using UnityEngine.Rendering;

namespace FidelityFX
{
    internal abstract class FfxPassBase<TDispatch>: IDisposable
        //where TDispatch: struct
    {
        private readonly string _techName;
        
        protected ComputeShader ComputeShader;
        protected int KernelIndex;
        
        protected CustomSampler Sampler;

        protected FfxPassBase(string techName)
        {
            _techName = techName;
        }
        
        public void ScheduleDispatch(CommandBuffer commandBuffer, in TDispatch dispatchParams, int bufferIndex, int dispatchX, int dispatchY, int dispatchZ = 1)
        {
            commandBuffer.BeginSample(Sampler);
            DoScheduleDispatch(commandBuffer, dispatchParams, bufferIndex, dispatchX, dispatchY, dispatchZ);
            commandBuffer.EndSample(Sampler);
        }

        protected abstract void DoScheduleDispatch(CommandBuffer commandBuffer, in TDispatch dispatchParams, int bufferIndex, int dispatchX, int dispatchY, int dispatchZ);

        protected virtual void InitComputeShader(string passName, ComputeShader shader, string kernelName = "CS")
        {
            if (shader == null)
            {
                throw new MissingReferenceException($"Shader for {_techName} pass '{passName}' could not be loaded! Please ensure it is included in the project correctly.");
            }

            ComputeShader = shader;
            KernelIndex = ComputeShader.FindKernel(kernelName);
            Sampler = CustomSampler.Create(passName);
        }

        public virtual void Dispose()
        {
        }
    }

    internal abstract class FfxPassWithFlags<TDispatch, TFlags> : FfxPassBase<TDispatch>
        //where TDispatch: struct
        where TFlags: Enum
    {
        protected readonly TFlags Flags;

        protected FfxPassWithFlags(string techName, TFlags flags) : base(techName)
        {
            Flags = flags;
        }

        protected override void InitComputeShader(string passName, ComputeShader shader, string kernelName = "CS")
        {
            base.InitComputeShader(passName, shader, kernelName);
            SetupShaderKeywords();
        }

        protected abstract void SetupShaderKeywords();
    }
}