#pragma once

#include <assimp/Importer.hpp>
#include <assimp/scene.h>

#include <engine/Backend/Shader.h>
#include <engine/Backend/Mesh.h>

class Model
{
public:
    // model data
    vector<Texture> textures_loaded;	// stores all the textures loaded so far, optimization to make sure textures aren't loaded more than once.
    vector<Mesh>    meshes;
    string directory;
    bool gammaCorrection;

    // constructor, expects a filepath to a 3D model.
    Model(string const &path, bool gamma = false);

    // draws the model, and thus all its meshes
    void Draw(Shader &shader);

private:
    // loads a model with supported ASSIMP extensions from file and stores the resulting meshes in the meshes vector.
    void loadModel(string const &path);

    // processes a node in a recursive fashion. Processes each individual mesh located at the node and repeats this process on its children nodes (if any).
    void processNode(aiNode *node, const aiScene *scene);

    Mesh processMesh(aiMesh *mesh, const aiScene *scene);

    // checks all material textures of a given type and loads the textures if they're not loaded yet.
    // the required info is returned as a Texture struct.
    vector<Texture> loadMaterialTextures(aiMaterial *mat, aiTextureType type, string typeName, bool fallback = false);
};

unsigned inline int TextureFromFile(const char *path, const string &directory, bool gamma = false);