using System;
using System.Collections.Generic;
using Autodesk.Max;
using BabylonExport.Entities;

namespace Max2Babylon
{
    partial class BabylonExporter
    {
        readonly List<IIGameMaterial> referencedMaterials = new List<IIGameMaterial>();

        private void ExportMaterial(IIGameMaterial materialNode, BabylonScene babylonScene)
        {
            var name = materialNode.MaterialName;
            var id = materialNode.MaxMaterial.GetGuid().ToString();

            RaiseMessage(name, 1);

            if (materialNode.SubMaterialCount > 0)
            {
                var babylonMultimaterial = new BabylonMultiMaterial { name = name, id = id };

                var guids = new List<string>();

                for (var index = 0; index < materialNode.SubMaterialCount; index++)
                {
                    var subMat = materialNode.GetSubMaterial(index);

                    if (subMat != null)
                    {
                        guids.Add(subMat.MaxMaterial.GetGuid().ToString());

                        if (!referencedMaterials.Contains(subMat))
                        {
                            referencedMaterials.Add(subMat);
                            ExportMaterial(subMat, babylonScene);
                        }
                    }
                    else
                    {
                        guids.Add(Guid.Empty.ToString());
                    }
                }

                babylonMultimaterial.materials = guids.ToArray();

                babylonScene.MultiMaterialsList.Add(babylonMultimaterial);
                return;
            }

            var babylonMaterial = new BabylonMaterial
            {
                name = name,
                id = id,
                ambient = materialNode.MaxMaterial.GetAmbient(0, false).ToArray(),
                diffuse = materialNode.MaxMaterial.GetDiffuse(0, false).ToArray(),
                specular = materialNode.MaxMaterial.GetSpecular(0, false).Scale(materialNode.MaxMaterial.GetShinStr(0, false)),
                specularPower = materialNode.MaxMaterial.GetShininess(0, false) * 256,
                emissive =
                    materialNode.MaxMaterial.GetSelfIllumColorOn(0, false)
                        ? materialNode.MaxMaterial.GetSelfIllumColor(0, false).ToArray()
                        : materialNode.MaxMaterial.GetDiffuse(0, false).Scale(materialNode.MaxMaterial.GetSelfIllum(0, false)),
                alpha = 1.0f - materialNode.MaxMaterial.GetXParency(0, false)
            };


            var stdMat = materialNode.MaxMaterial.GetParamBlock(0).Owner as IStdMat2;

            if (stdMat != null)
            {
                babylonMaterial.backFaceCulling = !stdMat.TwoSided;
                babylonMaterial.wireframe = stdMat.Wire;

                // Textures
                BabylonFresnelParameters fresnelParameters;

                babylonMaterial.ambientTexture = ExportTexture(stdMat, 0, out fresnelParameters, babylonScene);                // Ambient
                babylonMaterial.diffuseTexture = ExportTexture(stdMat, 1, out fresnelParameters, babylonScene);                // Diffuse
                if (fresnelParameters != null)
                {
                    babylonMaterial.diffuseFresnelParameters = fresnelParameters;
                }

                babylonMaterial.specularTexture = ExportTexture(stdMat, 2, out fresnelParameters, babylonScene);               // Specular
                babylonMaterial.emissiveTexture = ExportTexture(stdMat, 5, out fresnelParameters, babylonScene);               // Emissive
                if (fresnelParameters != null)
                {
                    babylonMaterial.emissiveFresnelParameters = fresnelParameters;
                    if (babylonMaterial.emissive[0] == 0 &&
                        babylonMaterial.emissive[1] == 0 &&
                        babylonMaterial.emissive[2] == 0 &&
                        babylonMaterial.emissiveTexture == null)
                    {
                        babylonMaterial.emissive = new float[] { 1, 1, 1 };
                    }
                }

                babylonMaterial.opacityTexture = ExportTexture(stdMat, 6, out fresnelParameters, babylonScene, false, true);   // Opacity
                if (fresnelParameters != null)
                {
                    babylonMaterial.opacityFresnelParameters = fresnelParameters;
                    if (babylonMaterial.alpha == 1 &&
                         babylonMaterial.opacityTexture == null)
                    {
                        babylonMaterial.alpha = 0;
                    }
                }

                babylonMaterial.bumpTexture = ExportTexture(stdMat, 8, out fresnelParameters, babylonScene);                   // Bump
                babylonMaterial.reflectionTexture = ExportTexture(stdMat, 9, out fresnelParameters, babylonScene, true);       // Reflection
                if (fresnelParameters != null)
                {
                    if (babylonMaterial.reflectionTexture == null)
                    {
                        RaiseWarning("Fallout cannot be used with reflection channel without a texture", 2);
                    }
                    else
                    {
                        babylonMaterial.reflectionFresnelParameters = fresnelParameters;
                    }
                }

                // Constraints
                if (babylonMaterial.diffuseTexture != null)
                {
                    babylonMaterial.diffuse = new[] { 1.0f, 1.0f, 1.0f };
                }

                if (babylonMaterial.emissiveTexture != null)
                {
                    babylonMaterial.emissive = new float[] { 0, 0, 0 };
                }

                if (babylonMaterial.opacityTexture != null && babylonMaterial.diffuseTexture != null &&
                    babylonMaterial.diffuseTexture.name == babylonMaterial.opacityTexture.name &&
                    babylonMaterial.diffuseTexture.hasAlpha && !babylonMaterial.opacityTexture.getAlphaFromRGB)
                {
                    // This is a alpha testing purpose
                    babylonMaterial.opacityTexture = null;
                    babylonMaterial.diffuseTexture.hasAlpha = true;
                    RaiseWarning("Opacity texture was removed because alpha from diffuse texture can be use instead", 2);
                    RaiseWarning("If you do not want this behavior, just set Alpha Source = None on your diffuse texture", 2);
                }
            }

            babylonScene.MaterialsList.Add(babylonMaterial);
        }
    }
}
