using System;
using BabylonExport.Entities;
using UnityEngine;

namespace Unity3D2Babylon
{
    partial class SceneBuilder
    {
        private BabylonAbstractMesh ConvertUnityMeshToInstance(GameObject gameObject)
        {
            BabylonAbstractMesh babylonMesh = new BabylonAbstractMesh();

            Transform transform = gameObject.transform;
            babylonMesh.name = gameObject.name;
            babylonMesh.position = new float[3];
            babylonMesh.position[0] = transform.position.x;
            babylonMesh.position[1] = transform.position.y;
            babylonMesh.position[2] = transform.position.z;

            babylonMesh.rotation = new float[3];
            babylonMesh.rotation[0] = transform.rotation.eulerAngles.x * (float)Math.PI / 180;
            babylonMesh.rotation[1] = transform.rotation.eulerAngles.y * (float)Math.PI / 180;
            babylonMesh.rotation[2] = transform.rotation.eulerAngles.z * (float)Math.PI / 180;

            babylonMesh.scaling = new float[3];
            babylonMesh.scaling[0] = transform.localScale.x;
            babylonMesh.scaling[1] = transform.localScale.y;
            babylonMesh.scaling[2] = transform.localScale.z;
            return babylonMesh;
        }

        private void ConvertTransform(BabylonMesh babylonMesh, Transform transform, GameObject gameObject, BabylonAbstractMesh[] instances = null)
        {
            Action SetTransformFromGameobject = () =>
            {
                babylonMesh.position = transform.localPosition.ToFloat();

                babylonMesh.rotation = new float[3];
                babylonMesh.rotation[0] = transform.localRotation.eulerAngles.x * (float)Math.PI / 180;
                babylonMesh.rotation[1] = transform.localRotation.eulerAngles.y * (float)Math.PI / 180;
                babylonMesh.rotation[2] = transform.localRotation.eulerAngles.z * (float)Math.PI / 180;

                babylonMesh.scaling = transform.localScale.ToFloat();
            };

            Action SetTransformFromFirstInstance = () =>
            {
                BabylonAbstractMesh first = instances[0];

                babylonMesh.position = new float[3];
                babylonMesh.position[0] = first.position[0];
                babylonMesh.position[1] = first.position[1];
                babylonMesh.position[2] = first.position[2];

                babylonMesh.rotation = new float[3];
                babylonMesh.rotation[0] = first.rotation[0];
                babylonMesh.rotation[1] = first.rotation[1];
                babylonMesh.rotation[2] = first.rotation[2];

                babylonMesh.scaling = new float[3];
                babylonMesh.scaling[0] = first.scaling[0];
                babylonMesh.scaling[1] = first.scaling[1];
                babylonMesh.scaling[2] = first.scaling[2];
            };

            //Check if this is a prefab
            if (instances != null)
            {
                /*
                    Unity3D prefabs don't have transforms (position, rotation, scale) because they are just a template and are not drawn on screen          
                    but Babylon.js meshes must have a transform because they are drawn on the screen
                    so what we do is take the first instance
                    copy its transform (position, rotation, scale) into the prefab mesh
                    then remove that first instance
                */

                babylonMesh.instances = new BabylonAbstractMesh[instances.Length - 1];

                //Effectively remove first instance from list of all instances
                for (int i = 0; i < instances.Length - 1; i++)
                {
                    babylonMesh.instances[i] = instances[i + 1];
                }

                //If this is the root object then copy values directly from first instance
                if (GetParentID(transform) == null)
                {
                    SetTransformFromFirstInstance();
                }
                else
                {
                    GameObject parent = gameObject.transform.parent.gameObject;
                    if ((parent.GetComponent<Light>() == null) && (parent.GetComponent<Camera>() == null))
                    {
                        SetTransformFromGameobject();
                    } else
                    {
                        SetTransformFromFirstInstance();
                    }
                }
            }
            else
            {
                SetTransformFromGameobject();
            }
        }

        private void ConvertUnityEmptyObjectToBabylon(GameObject gameObject, BabylonAbstractMesh[] instances = null)
        {
            BabylonMesh babylonMesh = new BabylonMesh { name = gameObject.name, id = GetID(gameObject) };

            var transform = gameObject.transform;

            babylonMesh.parentId = GetParentID(transform);
            ConvertTransform(babylonMesh, transform, gameObject, instances);

            babylonScene.MeshesList.Add(babylonMesh);

            // Animations
            ExportAnimations(transform, babylonMesh);

            if (IsRotationQuaternionAnimated(babylonMesh))
            {
                babylonMesh.rotationQuaternion = transform.localRotation.ToFloat();
            }
        }

        private void ConvertUnityMeshToBabylon(Mesh mesh, Transform transform, GameObject gameObject, float progress, BabylonAbstractMesh[] instances = null)
        {
            BabylonMesh babylonMesh = new BabylonMesh();
            var renderer = gameObject.GetComponent<Renderer>();

            ExporterWindow.ReportProgress(progress, "Exporting mesh: " + gameObject.name);

            babylonMesh.name = gameObject.name;
            babylonMesh.id = GetID(transform.gameObject);
            babylonMesh.receiveShadows = renderer.receiveShadows;

            babylonMesh.parentId = GetParentID(transform);
            ConvertTransform(babylonMesh, transform, gameObject, instances);

            babylonMesh.positions = new float[mesh.vertexCount * 3];

            for (int i = 0; i < mesh.vertices.Length; i++)
            {
                babylonMesh.positions[i * 3] = mesh.vertices[i].x;
                babylonMesh.positions[(i * 3) + 1] = mesh.vertices[i].y;
                babylonMesh.positions[(i * 3) + 2] = mesh.vertices[i].z;

                // Computing world extends
                var worldPosition = transform.TransformPoint(mesh.vertices[i]);

                if (worldPosition.x > babylonScene.MaxVector.X)
                {
                    babylonScene.MaxVector.X = worldPosition.x;
                }
                if (worldPosition.y > babylonScene.MaxVector.Y)
                {
                    babylonScene.MaxVector.Y = worldPosition.y;
                }
                if (worldPosition.z > babylonScene.MaxVector.Z)
                {
                    babylonScene.MaxVector.Z = worldPosition.z;
                }

                if (worldPosition.x < babylonScene.MinVector.X)
                {
                    babylonScene.MinVector.X = worldPosition.x;
                }
                if (worldPosition.y < babylonScene.MinVector.Y)
                {
                    babylonScene.MinVector.Y = worldPosition.y;
                }
                if (worldPosition.z < babylonScene.MinVector.Z)
                {
                    babylonScene.MinVector.Z = worldPosition.z;
                }
            }

            babylonMesh.normals = new float[mesh.vertexCount * 3];

            for (int i = 0; i < mesh.normals.Length; i++)
            {
                babylonMesh.normals[i * 3] = mesh.normals[i].x;
                babylonMesh.normals[(i * 3) + 1] = mesh.normals[i].y;
                babylonMesh.normals[(i * 3) + 2] = mesh.normals[i].z;
            }

            babylonMesh.uvs = new float[mesh.vertexCount * 2];

            for (int i = 0; i < mesh.uv.Length; i++)
            {
                babylonMesh.uvs[i * 2] = mesh.uv[i].x;
                babylonMesh.uvs[(i * 2) + 1] = mesh.uv[i].y;
            }

            if (mesh.uv2 != null)
            {
                babylonMesh.uvs2 = new float[mesh.vertexCount * 2];

                for (int i = 0; i < mesh.uv2.Length; i++)
                {
                    babylonMesh.uvs2[i * 2] = mesh.uv2[i].x;
                    babylonMesh.uvs2[(i * 2) + 1] = mesh.uv2[i].y;
                }
            }

            babylonMesh.indices = new int[mesh.triangles.Length];

            for (int i = 0; i < mesh.triangles.Length; i += 3)
            {
                babylonMesh.indices[i] = mesh.triangles[i + 2];
                babylonMesh.indices[i + 1] = mesh.triangles[i + 1];
                babylonMesh.indices[i + 2] = mesh.triangles[i];
            }

            if (mesh.subMeshCount > 1) // Multimaterials
            {
                BabylonMultiMaterial bMultiMat;
                if (!multiMatDictionary.ContainsKey(renderer.sharedMaterial.name))
                {
                    bMultiMat = new BabylonMultiMaterial
                    {
                        materials = new string[mesh.subMeshCount],
                        id = Guid.NewGuid().ToString(),
                        name = renderer.sharedMaterial.name
                    };

                    for (int i = 0; i < renderer.sharedMaterials.Length; i++)
                    {
                        var bMat = DumpMaterial(renderer.sharedMaterials[i], renderer);
                        bMultiMat.materials[i] = bMat.id;
                    }
                    if (mesh.subMeshCount > 1)
                    {
                        multiMatDictionary.Add(bMultiMat.name, bMultiMat);
                    }
                }
                else
                {
                    bMultiMat = multiMatDictionary[renderer.sharedMaterial.name];
                }

                babylonMesh.materialId = bMultiMat.id;
                babylonMesh.subMeshes = new BabylonSubMesh[mesh.subMeshCount];

                var offset = 0;
                for (int materialIndex = 0; materialIndex < mesh.subMeshCount; materialIndex++)
                {
                    var unityTriangles = mesh.GetTriangles(materialIndex);

                    babylonMesh.subMeshes[materialIndex] = new BabylonSubMesh
                    {
                        verticesStart = 0,
                        verticesCount = mesh.vertexCount,
                        materialIndex = materialIndex,
                        indexStart = offset,
                        indexCount = unityTriangles.Length
                    };

                    offset += unityTriangles.Length;
                }
            }
            else
            {
                babylonMesh.materialId = DumpMaterial(renderer.sharedMaterial, renderer).id;
            }

            babylonScene.MeshesList.Add(babylonMesh);

            // Animations
            ExportAnimations(transform, babylonMesh);

            if (IsRotationQuaternionAnimated(babylonMesh))
            {
                babylonMesh.rotationQuaternion = transform.localRotation.ToFloat();
            }

            // Collisions
            if (exportationOptions.ExportCollisions)
            {
                var collider = gameObject.GetComponent<Collider>();

                if (collider != null)
                {
                    babylonMesh.checkCollisions = true;
                }
            }
        }
    }
}