#include "resource/model_loader.h"
#include "utils/logger.h"
#include "resource/texture.h"

// Note: This is a simplified implementation without Assimp
// For full implementation, include Assimp and implement properly

namespace are {

bool ModelLoader::load(const std::string& path,
                      std::vector<std::shared_ptr<Mesh>>& meshes,
                      std::vector<std::shared_ptr<Material>>& materials,
                      bool flip_uvs) {
    Logger::error("ModelLoader requires Assimp library (not implemented in this version)");
    Logger::info("To implement: include <assimp/Importer.hpp>, <assimp/scene.h>, <assimp/postprocess.h>");
    
    // Placeholder implementation
    // TODO: Implement with Assimp
    /*
    Assimp::Importer importer;
    const aiScene* scene = importer.ReadFile(path, 
        aiProcess_Triangulate | 
        aiProcess_GenNormals |
        aiProcess_CalcTangentSpace |
        (flip_uvs ? aiProcess_FlipUVs : 0));
    
    if (!scene || scene->mFlags & AI_SCENE_FLAGS_INCOMPLETE || !scene->mRootNode) {
        Logger::error("Failed to load model: " + std::string(importer.GetErrorString()));
        return false;
    }
    
    std::string directory = path.substr(0, path.find_last_of('/'));
    process_node_(scene->mRootNode, scene, meshes, materials, directory);
    
    Logger::info("Model loaded: " + path);
    return true;
    */
    
    return false;
}

bool ModelLoader::load_and_upload(const std::string& path,
                                 std::vector<std::shared_ptr<Mesh>>& meshes,
                                 std::vector<std::shared_ptr<Material>>& materials,
                                 bool flip_uvs) {
    if (!load(path, meshes, materials, flip_uvs)) {
        return false;
    }
    
    // Upload all meshes to GPU
    for (auto& mesh : meshes) {
        if (!mesh->upload_to_gpu()) {
            Logger::error("Failed to upload mesh to GPU");
            return false;
        }
    }
    
    return true;
}

void ModelLoader::process_node_(void* node, void* scene,
                               std::vector<std::shared_ptr<Mesh>>& meshes,
                               std::vector<std::shared_ptr<Material>>& materials,
                               const std::string& directory) {
    // TODO: Implement with Assimp
    /*
    aiNode* ai_node = static_cast<aiNode*>(node);
    const aiScene* ai_scene = static_cast<const aiScene*>(scene);
    
    // Process all meshes in this node
    for (uint i = 0; i < ai_node->mNumMeshes; ++i) {
        aiMesh* ai_mesh = ai_scene->mMeshes[ai_node->mMeshes[i]];
        meshes.push_back(process_mesh_(ai_mesh, ai_scene, materials, directory));
    }
    
    // Process children recursively
    for (uint i = 0; i < ai_node->mNumChildren; ++i) {
        process_node_(ai_node->mChildren[i], ai_scene, meshes, materials, directory);
    }
    */
}

std::shared_ptr<Mesh> ModelLoader::process_mesh_(void* mesh, void* scene,
                                                std::vector<std::shared_ptr<Material>>& materials,
                                                const std::string& directory) {
    // TODO: Implement with Assimp
    /*
    aiMesh* ai_mesh = static_cast<aiMesh*>(mesh);
    const aiScene* ai_scene = static_cast<const aiScene*>(scene);
    
    std::vector<Vertex> vertices;
    std::vector<uint> indices;
    
    // Process vertices
    for (uint i = 0; i < ai_mesh->mNumVertices; ++i) {
        Vertex vertex;
        
        vertex.position_ = Vec3(ai_mesh->mVertices[i].x,
                               ai_mesh->mVertices[i].y,
                               ai_mesh->mVertices[i].z);
        
        if (ai_mesh->HasNormals()) {
            vertex.normal_ = Vec3(ai_mesh->mNormals[i].x,
                                 ai_mesh->mNormals[i].y,
                                 ai_mesh->mNormals[i].z);
        }
        
        if (ai_mesh->mTextureCoords[0]) {
            vertex.texcoord_ = Vec2(ai_mesh->mTextureCoords[0][i].x,
                                   ai_mesh->mTextureCoords[0][i].y);
        }
        
        if (ai_mesh->HasTangentsAndBitangents()) {
            vertex.tangent_ = Vec3(ai_mesh->mTangents[i].x,
                                  ai_mesh->mTangents[i].y,
                                  ai_mesh->mTangents[i].z);
        }
        
        vertices.push_back(vertex);
    }
    
    // Process indices
    for (uint i = 0; i < ai_mesh->mNumFaces; ++i) {
        aiFace face = ai_mesh->mFaces[i];
        for (uint j = 0; j < face.mNumIndices; ++j) {
            indices.push_back(face.mIndices[j]);
        }
    }
    
    // Process material
    uint material_id = materials.size();
    if (ai_mesh->mMaterialIndex >= 0) {
        aiMaterial* ai_material = ai_scene->mMaterials[ai_mesh->mMaterialIndex];
        
        auto material = std::make_shared<Material>();
        
        // Load diffuse color
        aiColor3D color;
        if (ai_material->Get(AI_MATKEY_COLOR_DIFFUSE, color) == AI_SUCCESS) {
            material->set_albedo(Vec3(color.r, color.g, color.b));
        }
        
        // Load textures
        load_material_textures_(ai_material, aiTextureType_DIFFUSE, material, directory);
        load_material_textures_(ai_material, aiTextureType_NORMALS, material, directory);
        
        materials.push_back(material);
    }
    
    auto mesh_obj = std::make_shared<Mesh>();
    mesh_obj->set_vertices(vertices);
    mesh_obj->set_indices(indices);
    mesh_obj->set_material(material_id);
    
    return mesh_obj;
    */
    
    return nullptr;
}

void ModelLoader::load_material_textures_(void* material, int type,
                                         std::shared_ptr<Material>& mat,
                                         const std::string& directory) {
    // TODO: Implement with Assimp
    /*
    aiMaterial* ai_material = static_cast<aiMaterial*>(material);
    aiTextureType ai_type = static_cast<aiTextureType>(type);
    
    for (uint i = 0; i < ai_material->GetTextureCount(ai_type); ++i) {
        aiString str;
        ai_material->GetTexture(ai_type, i, &str);
        
        std::string filename = directory + "/" + std::string(str.C_Str());
        
        auto texture = std::make_shared<Texture>();
        if (texture->load_from_file(filename)) {
            if (ai_type == aiTextureType_DIFFUSE) {
                mat->set_albedo_texture(texture);
            } else if (ai_type == aiTextureType_NORMALS) {
                mat->set_normal_texture(texture);
            }
        }
    }
    */
}

} // namespace are