// Copyright (c) 2024 Nico de Poel
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

using UnityEngine;

namespace FidelityFX.FrameInterpolation
{
    /// <summary>
    /// Scriptable object containing all shader resources required by FidelityFX Frame Interpolation.
    /// These can be stored in an asset file and referenced from a scene or prefab, avoiding the need to load the shaders from a Resources folder.
    /// </summary>
    [CreateAssetMenu(fileName = "Frame Interpolation Assets", menuName = "FidelityFX/Frame Interpolation Assets", order = 1112)]
    public class FrameInterpolationAssets : ScriptableObject
    {
        public FrameInterpolationShaders shaders;
        
#if UNITY_EDITOR
        private void Reset()
        {
            shaders = new FrameInterpolationShaders
            {
                reconstructAndDilate = FindComputeShader("ffx_frameinterpolation_reconstruct_and_dilate_pass"),
                setup = FindComputeShader("ffx_frameinterpolation_setup_pass"),
                reconstructPreviousDepth = FindComputeShader("ffx_frameinterpolation_reconstruct_previous_depth_pass"),
                gameMotionVectorField = FindComputeShader("ffx_frameinterpolation_game_motion_vector_field_pass"),
                opticalFlowVectorField = FindComputeShader("ffx_frameinterpolation_optical_flow_vector_field_pass"),
                disocclusionMask = FindComputeShader("ffx_frameinterpolation_disocclusion_mask_pass"),
                interpolation = FindComputeShader("ffx_frameinterpolation_pass"),
                inpaintingPyramid = FindComputeShader("ffx_frameinterpolation_compute_inpainting_pyramid_pass"),
                inpainting = FindComputeShader("ffx_frameinterpolation_inpainting_pass"),
                gameVectorFieldInpaintingPyramid = FindComputeShader("ffx_frameinterpolation_compute_game_vector_field_inpainting_pyramid_pass"),
                debugView = FindComputeShader("ffx_frameinterpolation_debug_view_pass"),
            };
        }

        private static ComputeShader FindComputeShader(string name)
        {
            string[] assetGuids = UnityEditor.AssetDatabase.FindAssets($"t:ComputeShader {name}");
            if (assetGuids == null || assetGuids.Length == 0)
                return null;

            string assetPath = UnityEditor.AssetDatabase.GUIDToAssetPath(assetGuids[0]);
            return UnityEditor.AssetDatabase.LoadAssetAtPath<ComputeShader>(assetPath);
        }
#endif
    }
    
    /// <summary>
    /// All the compute shaders used by Frame Interpolation.
    /// </summary>
    [System.Serializable]
    public class FrameInterpolationShaders
    {
        /// <summary>
        /// The compute shader used by the reconstruct and dilate pass.
        /// </summary>
        public ComputeShader reconstructAndDilate;

        /// <summary>
        /// The compute shader used by the setup pass.
        /// </summary>
        public ComputeShader setup;

        /// <summary>
        /// The compute shader used by the reconstruct previous depth pass.
        /// </summary>
        public ComputeShader reconstructPreviousDepth;

        /// <summary>
        /// The compute shader used by the game motion vector field pass.
        /// </summary>
        public ComputeShader gameMotionVectorField;

        /// <summary>
        /// The compute shader used by the optical flow vector field pass.
        /// </summary>
        public ComputeShader opticalFlowVectorField;

        /// <summary>
        /// The compute shader used by the disocclusion mask pass.
        /// </summary>
        public ComputeShader disocclusionMask;

        /// <summary>
        /// The compute shader used by the interpolation pass.
        /// </summary>
        public ComputeShader interpolation;

        /// <summary>
        /// The compute shader used by the inpainting pyramid pass.
        /// </summary>
        public ComputeShader inpaintingPyramid;
        
        /// <summary>
        /// The compute shader used by the inpainting pass.
        /// </summary>
        public ComputeShader inpainting;
        
        /// <summary>
        /// The compute shader used by the game vector field inpainting pyramid pass.
        /// </summary>
        public ComputeShader gameVectorFieldInpaintingPyramid;
        
        /// <summary>
        /// The compute shader used by the debug view pass.
        /// </summary>
        public ComputeShader debugView;
        
        /// <summary>
        /// Returns a copy of this class and its contents.
        /// </summary>
        public FrameInterpolationShaders Clone()
        {
            return (FrameInterpolationShaders)MemberwiseClone();
        }

        /// <summary>
        /// Returns a copy of this class with clones of all its shaders.
        /// This can be useful if you're running multiple Frame Interpolation instances with different shader configurations.
        /// Be sure to clean up these clones through Dispose once you're done with them.
        /// </summary>
        public FrameInterpolationShaders DeepCopy()
        {
            return new FrameInterpolationShaders
            {
                reconstructAndDilate = Object.Instantiate(reconstructAndDilate),
                setup = Object.Instantiate(setup),
                reconstructPreviousDepth = Object.Instantiate(reconstructPreviousDepth),
                gameMotionVectorField = Object.Instantiate(gameMotionVectorField),
                opticalFlowVectorField = Object.Instantiate(opticalFlowVectorField),
                disocclusionMask = Object.Instantiate(disocclusionMask),
                interpolation = Object.Instantiate(interpolation),
                inpaintingPyramid = Object.Instantiate(inpaintingPyramid),
                inpainting = Object.Instantiate(inpainting),
                gameVectorFieldInpaintingPyramid = Object.Instantiate(gameVectorFieldInpaintingPyramid),
                debugView = Object.Instantiate(debugView),
            };
        }

        /// <summary>
        /// Destroy all the shaders within this instance.
        /// Use this only on clones created through DeepCopy.
        /// </summary>
        public void Dispose()
        {
            Object.Destroy(debugView);
            Object.Destroy(gameVectorFieldInpaintingPyramid);
            Object.Destroy(inpainting);
            Object.Destroy(inpaintingPyramid);
            Object.Destroy(interpolation);
            Object.Destroy(disocclusionMask);
            Object.Destroy(opticalFlowVectorField);
            Object.Destroy(gameMotionVectorField);
            Object.Destroy(reconstructPreviousDepth);
            Object.Destroy(setup);
            Object.Destroy(reconstructAndDilate);
        }
    }
}