using System.Collections.Generic;
using System.Linq;
using UnityEngine;

namespace UnityEditor.VFX.Block
{
    class PositionConeDeprecated : PositionBase
    {
        [VFXSetting, Tooltip("Controls whether particles are spawned on the base of the cone, or throughout the entire volume.")]
        public HeightMode heightMode;

        public override string name { get { return string.Format(base.name, "Cone (deprecated)"); } }

        public class InputProperties
        {
            [Tooltip("Sets the cone used for positioning the particles.")]
            public ArcCone ArcCone = ArcCone.defaultValue;
        }

        public class CustomProperties
        {
            [Range(0, 1), Tooltip("Sets the position along the height to emit particles from when ‘Custom Emission’ is used.")]
            public float HeightSequencer = 0.0f;
            [Range(0, 1), Tooltip("Sets the position on the arc to emit particles from when ‘Custom Emission’ is used.")]
            public float ArcSequencer = 0.0f;
        }

        protected override bool needDirectionWrite => true;

        public override void Sanitize(int version)
        {
            var newPositionConeV2 = ScriptableObject.CreateInstance<PositionConeDeprecatedV2>();
            SanitizeHelper.MigrateBlockTShapeFromShape(newPositionConeV2, this);

            var newPositionCone = ScriptableObject.CreateInstance<PositionShape>();
            SanitizeHelper.MigrateBlockPositionToComposed(GetGraph(), GetParent().position, newPositionCone, newPositionConeV2, PositionShapeBase.Type.Cone);

            ReplaceModel(newPositionCone, this);
        }

        public override string source
        {
            get
            {
                string outSource = "";

                if (spawnMode == SpawnMode.Random)
                    outSource += @"float theta = ArcCone_arc * RAND;";
                else
                    outSource += @"float theta = ArcCone_arc * ArcSequencer;";

                outSource += @"
float rNorm = sqrt(volumeFactor + (1 - volumeFactor) * RAND);

float2 sincosTheta;
sincos(theta, sincosTheta.x, sincosTheta.y);
float2 pos = (sincosTheta * rNorm);
";

                if (heightMode == HeightMode.Base)
                {
                    outSource += @"
float hNorm = 0.0f;
";
                }
                else if (spawnMode == SpawnMode.Random)
                {
                    float distributionExponent = positionMode == PositionMode.Surface ? 2.0f : 3.0f;
                    outSource += $@"
float hNorm = 0.0f;
if (abs(ArcCone_radius0 - ArcCone_radius1) > VFX_EPSILON)
{{
    // Uniform distribution on cone
    float heightFactor = ArcCone_radius0 / max(VFX_EPSILON,ArcCone_radius1);
    float heightFactorPow = pow(heightFactor, {distributionExponent});
    hNorm = pow(heightFactorPow + (1.0f - heightFactorPow) * RAND, rcp({distributionExponent}));
    hNorm = (hNorm - heightFactor) / (1.0f - heightFactor); // remap on [0,1]
}}
else
    hNorm = RAND; // Uniform distribution on cylinder
";
                }
                else
                {
                    outSource += @"
float hNorm = HeightSequencer;
";
                }

                outSource += VFXBlockUtility.GetComposeString(compositionDirection, "direction.xzy", "normalize(float3(pos * sincosSlope.x, sincosSlope.y))", "blendDirection") + "\n";
                outSource += VFXBlockUtility.GetComposeString(compositionPosition, "position.xzy", "lerp(float3(pos * ArcCone_radius0, 0.0f), float3(pos * ArcCone_radius1, ArcCone_height), hNorm) + ArcCone_center.xzy", "blendPosition");

                return outSource;
            }
        }
    }
}