#include <vector>
#include "Mesh.h"
#include "../lib/loaders/tinyobj.h"

Mesh createMesh(const char* obj_file) {
    Scratch temp = scratchStart(0, 0);

    Mesh result = {0};

    tinyobj::ObjReader reader = tinyobj::ObjReader();
    bool success = reader.ParseFromFile(obj_file);
    log("%s\n", reader.Error().c_str());

    const tinyobj::attrib_t attrib = reader.GetAttrib();

    std::vector<tinyobj::index_t> indices_t = reader.GetShapes().at(0).mesh.indices;
    list<uint32> indices = PushFullList(temp.arena, uint32, indices_t.size());

    list<real32> vertices = PushFullList(temp.arena, real32, 3*indices_t.size());
    list<real32> normals = PushFullList(temp.arena, real32, 3*indices_t.size());
    list<real32> texcoords = PushFullList(temp.arena, real32, 2*indices_t.size());

    for (int i = 0; i < indices_t.size(); i++) {
        tinyobj::index_t vertex_data = indices_t[i];
        vertices.data[3*i] = attrib.vertices[3*vertex_data.vertex_index];
        vertices.data[3*i+1] = attrib.vertices[3*vertex_data.vertex_index + 1];
        vertices.data[3*i+2] = attrib.vertices[3*vertex_data.vertex_index + 2];

        normals.data[3*i] = attrib.normals[3*vertex_data.normal_index];
        normals.data[3*i+1] = attrib.normals[3*vertex_data.normal_index + 1];
        normals.data[3*i+2] = attrib.normals[3*vertex_data.normal_index + 2];

        texcoords.data[2*i] = attrib.texcoords[2*vertex_data.texcoord_index];
        texcoords.data[2*i+1] = attrib.texcoords[2*vertex_data.texcoord_index + 1];

        indices.data[i] = i;
    }

    result.num_indices = indices_t.size();
    glGenVertexArrays(1, &result.vao);
    glGenBuffers(1, &result.vbo_xyz);
    glGenBuffers(1, &result.vbo_uv);
    glGenBuffers(1, &result.vbo_norm);
    //glGenBuffers(1, &ebo);

    glBindVertexArray(result.vao);

    glBindBuffer(GL_ARRAY_BUFFER, result.vbo_xyz);
    glBufferData(GL_ARRAY_BUFFER, vertices.length * sizeof(float), vertices.data, GL_STATIC_DRAW);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);

    glBindBuffer(GL_ARRAY_BUFFER, result.vbo_uv);
    glBufferData(GL_ARRAY_BUFFER, texcoords.length * sizeof(float), texcoords.data, GL_STATIC_DRAW);
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(1);

    glBindBuffer(GL_ARRAY_BUFFER, result.vbo_norm);
    glBufferData(GL_ARRAY_BUFFER, normals.length * sizeof(float), normals.data, GL_STATIC_DRAW);
    glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(2);

    //glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
    //glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(unsigned int), indices.data(), GL_STATIC_DRAW);

    scratchEnd(temp);
    return result;
}

Mesh createMesh(const Shape* shape) {
    Mesh result = {0};

    result.num_indices = shape->indices_size;
    glGenVertexArrays(1, &result.vao);
    glGenBuffers(1, &result.vbo_xyz);
    glGenBuffers(1, &result.vbo_uv);
    glGenBuffers(1, &result.ebo);

    glBindVertexArray(result.vao);

    glBindBuffer(GL_ARRAY_BUFFER, result.vbo_xyz);
    glBufferData(GL_ARRAY_BUFFER, shape->xyz_size * sizeof(float), shape->xyz, GL_STATIC_DRAW);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);

    glBindBuffer(GL_ARRAY_BUFFER, result.vbo_uv);
    glBufferData(GL_ARRAY_BUFFER, shape->uv_size * sizeof(float), shape->uv, GL_STATIC_DRAW);
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(1);

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, result.ebo);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, shape->indices_size * sizeof(unsigned int), shape->indices, GL_STATIC_DRAW);

    return result;
}