using System;
using Oculus.Avatar;
using UnityEngine;
using System.Runtime.InteropServices;

public class OvrAvatarAssetMesh : OvrAvatarAsset
{
    public Mesh mesh;
    private ovrAvatarSkinnedMeshPose skinnedBindPose;
    public string[] jointNames;

    public OvrAvatarAssetMesh(UInt64 _assetId, IntPtr asset, ovrAvatarAssetType meshType)
    {
        assetID = _assetId;
        mesh = new Mesh();
        mesh.name = "Procedural Geometry for asset " + _assetId;

        switch (meshType)
        {
            case ovrAvatarAssetType.Mesh:
                {
                    ovrAvatarMeshAssetData meshAssetData = CAPI.ovrAvatarAsset_GetMeshData(asset);

                    AvatarLogger.Log(
                        "OvrAvatarAssetMesh: "
                        + _assetId
                        + " "
                        + meshType.ToString()
                        + " VertexCount:"
                        + meshAssetData.vertexCount);


                    long vertexCount = (long)meshAssetData.vertexCount;
                    Vector3[] vertices = new Vector3[vertexCount];
                    Vector3[] normals = new Vector3[vertexCount];
                    Vector4[] tangents = new Vector4[vertexCount];
                    Vector2[] uv = new Vector2[vertexCount];
                    Color[] colors = new Color[vertexCount];
                    BoneWeight[] boneWeights = new BoneWeight[vertexCount];

                    long vertexSize = (long)Marshal.SizeOf(typeof(ovrAvatarMeshVertex));
                    long vertexBufferStart = meshAssetData.vertexBuffer.ToInt64();

                    for (long i = 0; i < vertexCount; i++)
                    {
                        long offset = vertexSize * i;

                        ovrAvatarMeshVertex vertex = (ovrAvatarMeshVertex)Marshal.PtrToStructure(new IntPtr(vertexBufferStart + offset), typeof(ovrAvatarMeshVertex));
                        vertices[i] = new Vector3(vertex.x, vertex.y, -vertex.z);
                        normals[i] = new Vector3(vertex.nx, vertex.ny, -vertex.nz);
                        tangents[i] = new Vector4(vertex.tx, vertex.ty, -vertex.tz, vertex.tw);
                        uv[i] = new Vector2(vertex.u, vertex.v);
                        colors[i] = new Color(0, 0, 0, 1);

                        boneWeights[i].boneIndex0 = vertex.blendIndices[0];
                        boneWeights[i].boneIndex1 = vertex.blendIndices[1];
                        boneWeights[i].boneIndex2 = vertex.blendIndices[2];
                        boneWeights[i].boneIndex3 = vertex.blendIndices[3];
                        boneWeights[i].weight0 = vertex.blendWeights[0];
                        boneWeights[i].weight1 = vertex.blendWeights[1];
                        boneWeights[i].weight2 = vertex.blendWeights[2];
                        boneWeights[i].weight3 = vertex.blendWeights[3];
                    }

                    mesh.vertices = vertices;
                    mesh.normals = normals;
                    mesh.uv = uv;
                    mesh.tangents = tangents;
                    mesh.boneWeights = boneWeights;
                    mesh.colors = colors;

                    skinnedBindPose = meshAssetData.skinnedBindPose;

                    ulong indexCount = meshAssetData.indexCount;
                    Int16[] indices = new Int16[indexCount];
                    IntPtr indexBufferPtr = meshAssetData.indexBuffer;
                    Marshal.Copy(indexBufferPtr, indices, 0, (int)indexCount);
                    Int32[] triangles = new Int32[indexCount];
                    for (ulong i = 0; i < indexCount; i += 3)
                    {
                        triangles[i + 2] = (Int32)indices[i];
                        triangles[i + 1] = (Int32)indices[i + 1];
                        triangles[i] = (Int32)indices[i + 2];
                    }
                    mesh.triangles = triangles;

                    UInt32 jointCount = skinnedBindPose.jointCount;
                    jointNames = new string[jointCount];
                    for (UInt32 i = 0; i < jointCount; i++)
                    {
                        jointNames[i] = Marshal.PtrToStringAnsi(skinnedBindPose.jointNames[i]);
                    }
                }
                break;

            case ovrAvatarAssetType.CombinedMesh:
                {
                    ovrAvatarMeshAssetDataV2 meshAssetData = CAPI.ovrAvatarAsset_GetCombinedMeshData(asset);

                    AvatarLogger.Log(
                        "OvrAvatarAssetMesh: "
                        + _assetId
                        + " "
                        + meshType.ToString()
                        + " VertexCount:"
                        + meshAssetData.vertexCount);

                    long vertexCount = (long)meshAssetData.vertexCount;
                    Vector3[] vertices = new Vector3[vertexCount];
                    Vector3[] normals = new Vector3[vertexCount];
                    Vector4[] tangents = new Vector4[vertexCount];
                    Vector2[] uv = new Vector2[vertexCount];
                    Color[] colors = new Color[vertexCount];
                    BoneWeight[] boneWeights = new BoneWeight[vertexCount];

                    long vertexSize = (long)Marshal.SizeOf(typeof(ovrAvatarMeshVertexV2));
                    long vertexBufferStart = meshAssetData.vertexBuffer.ToInt64();

                    for (long i = 0; i < vertexCount; i++)
                    {
                        long offset = vertexSize * i;

                        ovrAvatarMeshVertexV2 vertex = (ovrAvatarMeshVertexV2)Marshal.PtrToStructure(new IntPtr(vertexBufferStart + offset), typeof(ovrAvatarMeshVertexV2));
                        vertices[i] = new Vector3(vertex.x, vertex.y, -vertex.z);
                        normals[i] = new Vector3(vertex.nx, vertex.ny, -vertex.nz);
                        tangents[i] = new Vector4(vertex.tx, vertex.ty, -vertex.tz, vertex.tw);
                        uv[i] = new Vector2(vertex.u, vertex.v);
                        colors[i] = new Color(vertex.r, vertex.g, vertex.b, vertex.a);

                        boneWeights[i].boneIndex0 = vertex.blendIndices[0];
                        boneWeights[i].boneIndex1 = vertex.blendIndices[1];
                        boneWeights[i].boneIndex2 = vertex.blendIndices[2];
                        boneWeights[i].boneIndex3 = vertex.blendIndices[3];
                        boneWeights[i].weight0 = vertex.blendWeights[0];
                        boneWeights[i].weight1 = vertex.blendWeights[1];
                        boneWeights[i].weight2 = vertex.blendWeights[2];
                        boneWeights[i].weight3 = vertex.blendWeights[3];
                    }

                    mesh.vertices = vertices;
                    mesh.normals = normals;
                    mesh.uv = uv;
                    mesh.tangents = tangents;
                    mesh.boneWeights = boneWeights;
                    mesh.colors = colors;

                    skinnedBindPose = meshAssetData.skinnedBindPose;

                    ulong indexCount = meshAssetData.indexCount;
                    Int16[] indices = new Int16[indexCount];
                    IntPtr indexBufferPtr = meshAssetData.indexBuffer;
                    Marshal.Copy(indexBufferPtr, indices, 0, (int)indexCount);
                    Int32[] triangles = new Int32[indexCount];
                    for (ulong i = 0; i < indexCount; i += 3)
                    {
                        triangles[i + 2] = (Int32)indices[i];
                        triangles[i + 1] = (Int32)indices[i + 1];
                        triangles[i] = (Int32)indices[i + 2];
                    }
                    mesh.triangles = triangles;

                    UInt32 jointCount = skinnedBindPose.jointCount;
                    jointNames = new string[jointCount];
                    for (UInt32 i = 0; i < jointCount; i++)
                    {
                        jointNames[i] = Marshal.PtrToStringAnsi(skinnedBindPose.jointNames[i]);
                    }
                }
                break;

            default:
                throw new Exception("Bad Mesh Asset Type");
        }
    }

    public SkinnedMeshRenderer CreateSkinnedMeshRendererOnObject(GameObject target)
    {
        SkinnedMeshRenderer skinnedMeshRenderer = target.AddComponent<SkinnedMeshRenderer>();
        skinnedMeshRenderer.sharedMesh = mesh;
        mesh.name = "AvatarMesh_" + assetID;
        UInt32 jointCount = skinnedBindPose.jointCount;
        GameObject[] bones = new GameObject[jointCount];
        Transform[] boneTransforms = new Transform[jointCount];
        Matrix4x4[] bindPoses = new Matrix4x4[jointCount];
        for (UInt32 i = 0; i < jointCount; i++)
        {
            bones[i] = new GameObject();
            boneTransforms[i] = bones[i].transform;
            bones[i].name = jointNames[i];
            int parentIndex = skinnedBindPose.jointParents[i];
            if (parentIndex == -1)
            {
                bones[i].transform.parent = skinnedMeshRenderer.transform;
                skinnedMeshRenderer.rootBone = bones[i].transform;
            }
            else
            {
                bones[i].transform.parent = bones[parentIndex].transform;
            }

            // Set the position relative to the parent
            Vector3 position = skinnedBindPose.jointTransform[i].position;
            position.z = -position.z;
            bones[i].transform.localPosition = position;

            Quaternion orientation = skinnedBindPose.jointTransform[i].orientation;
            orientation.x = -orientation.x;
            orientation.y = -orientation.y;
            bones[i].transform.localRotation = orientation;

            bones[i].transform.localScale = skinnedBindPose.jointTransform[i].scale;

            bindPoses[i] = bones[i].transform.worldToLocalMatrix * skinnedMeshRenderer.transform.localToWorldMatrix;
        }
        skinnedMeshRenderer.bones = boneTransforms;
        mesh.bindposes = bindPoses;
        return skinnedMeshRenderer;
    }
}