using System;
using UnityEditor;
using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.HighDefinition;

namespace Unity.Toonshader
{
    [Serializable, VolumeComponentMenu("Rendering/Unity Toon Shader")]
    public class UTSRenderer : VolumeComponent
    {
        // flags
        bool m_initialized = false;
        bool m_srpCallbackInitialized = false;

        const int kAdjustmentCurvePrecision = 128;

        const string kCompensationPropName = "_ToonEvAdjustmentCompensation";
        const string kExposureAdjustmentPropName = "_ToonEvAdjustmentCurve";
        const string kExposureArrayPropName = "_ToonEvAdjustmentValueArray";
        const string kExposureMinPropName = "_ToonEvAdjustmentValueMin";
        const string kExposureMaxPropName = "_ToonEvAdjustmentValueMax";
        const string kToonLightFilterPropName = "_ToonLightHiCutFilter";
        const string kIgnoreVolumeExposurePropName = "_ToonIgnoreExposureMultiplier";

        [SerializeField]
        internal float[] m_ExposureArray;
        [SerializeField]
        internal float m_Max, m_Min;

        CustomPassVolume customPassVolume = new();
        UTSOutlinePass outlinePass = new();

#if UNITY_EDITOR
#pragma warning restore CS0414
        bool m_isCompiling = false;
#endif

        public BoolParameter enable = new BoolParameter(false, BoolParameter.DisplayType.EnumPopup);

        [Space]
        [Header("Outline")]
        public BoolParameter enableOutline = new BoolParameter(false);
        public MinFloatParameter outlineMaxWidth = new MinFloatParameter(1.0f, 0.0f);

        [Space]
        [Header("Hair Shadow")]
        public BoolParameter enableHairShadow = new BoolParameter(false);
        public ClampedFloatParameter shadowDistance = new ClampedFloatParameter(5.0f, 0.0f, 20.0f);
        public ClampedFloatParameter shadowDistanceScale = new ClampedFloatParameter(0.5f, 0.0f, 1.0f);
        public ClampedFloatParameter shadowDepthBias = new ClampedFloatParameter(0f, 0.0f, 0.01f);
        public FloatParameter shadowFadeIn = new FloatParameter(45f);
        public FloatParameter shadowFadeOut = new FloatParameter(50f);

        [Space]
        [Header("Exposure")]
        public BoolParameter ignoreVolumeExposure = new BoolParameter(false);
        public BoolParameter lightIntensityLimiter = new BoolParameter(false);
        public MinFloatParameter compensation = new MinFloatParameter(0.0f, 0.0f);
        public BoolParameter toonEVAdjustment = new BoolParameter(false);
        public AnimationCurveParameter adjustmentCurve = new AnimationCurveParameter(DefaultAnimationCurve());

        UTSRenderer()
        {
            displayName = "UTS Renderer";
        }

        protected override void OnEnable()
        {
            base.OnEnable();
            UTSDebugPanel.OnEnable();
            Initialize();
        }

        protected override void OnDisable()
        {
            base.OnDisable();
            UTSDebugPanel.OnDisable();
            Release();
        }

        private void OnValidate()
        {
            if (!enable.value)
            {
                Release();
                return;
            }

            Initialize();

            if (!m_initialized)
            {
                return;
            }

            // Fail safe in case the curve is deleted / has 0 point
            var curve = adjustmentCurve.value;


            if (curve == null || curve.length == 0)
            {
                m_Min = 0f;
                m_Max = 0f;

                for (var i = 0; i < kAdjustmentCurvePrecision; i++)
                    m_ExposureArray[i] = 0.0f;
            }
            else
            {
                m_Min = curve[0].time;
                m_Max = curve[curve.length - 1].time;
                var step = (m_Max - m_Min) / (kAdjustmentCurvePrecision - 1f);

                for (var i = 0; i < kAdjustmentCurvePrecision; i++)
                    m_ExposureArray[i] = curve.Evaluate(m_Min + step * i);
            }


#if UNITY_EDITOR
            // handle script recompile
            if (EditorApplication.isCompiling && !m_isCompiling)
            {
                // on compile begin
                m_isCompiling = true;
                //                Release(); no need
                return; // 
            }
            else if (!EditorApplication.isCompiling && m_isCompiling)
            {
                // on compile end
                m_isCompiling = false;
            }
#endif
            Shader.SetGlobalFloatArray(kExposureArrayPropName, m_ExposureArray);
            Shader.SetGlobalFloat(kExposureMinPropName, m_Min);
            Shader.SetGlobalFloat(kExposureMaxPropName, m_Max);
            Shader.SetGlobalInt(kExposureAdjustmentPropName, toonEVAdjustment.value ? 1 : 0);
            Shader.SetGlobalInt(kToonLightFilterPropName, lightIntensityLimiter.value ? 1 : 0);
            Shader.SetGlobalInt(kIgnoreVolumeExposurePropName, ignoreVolumeExposure.value ? 1 : 0);
            Shader.SetGlobalFloat(kCompensationPropName, compensation.value);
        }

        internal static AnimationCurve DefaultAnimationCurve()
        {
            return AnimationCurve.Linear(-10f, -10f, -1.32f, -1.32f);
        }

        void Initialize()
        {
            if (m_initialized)
            {
                return;
            }
#if UNITY_EDITOR
            // initializing renderer can interfere GI baking. so wait until it is completed.

            if (EditorApplication.isCompiling)
                return;
#endif

            if (m_ExposureArray == null || m_ExposureArray.Length != kAdjustmentCurvePrecision)
            {
                m_ExposureArray = new float[kAdjustmentCurvePrecision];
            }

            m_initialized = true;
        }

        protected override void OnDestroy()
        {
            base.OnDestroy();
            Release();
        }

        void Release()
        {
            if (m_initialized)
            {
                m_ExposureArray = null;
                Shader.SetGlobalFloat(kExposureMinPropName, 0);
                Shader.SetGlobalFloat(kExposureMaxPropName, 0);
                Shader.SetGlobalInt(kExposureAdjustmentPropName, 0);
                Shader.SetGlobalInt(kToonLightFilterPropName, 0);
                Shader.SetGlobalInt(kIgnoreVolumeExposurePropName, 0);
                Shader.SetGlobalFloat(kCompensationPropName, 0);
            }

            m_initialized = false;

        }

        private void Reset()
        {
            OnDisable();
            OnEnable();
            DefaultAnimationCurve();
        }
    }
}