using Echovoid.Runtime.Behavior.Rendering;
using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;

namespace SLSUtilities.Rendering.PostProcessing
{
    [System.Serializable, VolumeComponentMenu("SLS/Postprocessing/Sharpen")]
    public class Sharpen : ScriptablePostProcessorVolume
    {
        // 放在所有后处理之后，对最终画面进行锐化
        public override CustomPostProcessInjectionPoint InjectionPoint => CustomPostProcessInjectionPoint.AfterPostProcess;
        // 排序靠后，确保是最后几步操作之一
        public override int OrderInInjectionPoint => 10;

        [Header("General Settings")]
        [Tooltip("锐化强度。值越大画面越锋利。建议范围 0.5 - 2.0。过大会导致失真。")]
        public ClampedFloatParameter sharpness = new(0f, 0f, 5f);

        [Header("Optimizations (Visual Quality)")]
        [Tooltip("对比度阈值（降噪）。\n只有当像素差异大于此值时才锐化。\n增加此值可避免平坦区域（如天空、皮肤）出现噪点。\n建议值：0.01 - 0.05。")]
        public ClampedFloatParameter threshold = new(0.01f, 0f, 0.2f);

        [Tooltip("最大亮度钳制（防光晕）。\n限制像素亮度的最大变化幅度，防止边缘出现刺眼的白边或黑边。\n减小此值可让锐化更自然。\n建议值：0.1 - 0.3。")]
        public ClampedFloatParameter clamp = new(0.2f, 0f, 1f);

        public override string GetShaderName() => "SLS/Postprocessing/Sharpen";

        public override void Render(CommandBuffer cmd, ref RenderingData renderingData, RTHandle source, RTHandle destination)
        {
            if (material == null) return;

            Vector4 paramsVec = new Vector4(
                sharpness.value,
                threshold.value,
                clamp.value,
                0 // unused
            );
            
            material.SetVector(InternalShaderHelpers.ID._SharpnessParams, paramsVec);

            Blitter.BlitCameraTexture(cmd, source, destination, material, 0);
        }

        // 只有强度大于 0 时才激活
        public override bool IsActive() => sharpness.value > 0f;
    }
}