#include "mesh.hpp"

void Mesh::Draw(Shader &shader) {
  unsigned int diffuseNr = 1;
  unsigned int specularNr = 1;
  unsigned int normalNr = 1;
  unsigned int heightNr = 1;

  for(unsigned int i = 0; i < textures.size(); i++) {
    glActiveTexture(GL_TEXTURE0 + i);
    std::string number;
    std::string name = textures[i].type;

    if(name == "texture_diffuse") {
      number = std::to_string(diffuseNr++);
    } else if(name == "texture_specular") {
      number = std::to_string(specularNr++);
    } else if(name == "texture_normal") {
      number = std::to_string(normalNr++);
    } else if(name == "texture_height") {
      number = std::to_string(heightNr++);
    }

    // TODO: Get this uniform ID once and cache it?
    glUniform1i(glGetUniformLocation(shader.ID, (name + number).c_str()), i);
    glBindTexture(GL_TEXTURE_2D, textures[i].id);
  }

  glBindVertexArray(VAO);
  glDrawElements(GL_TRIANGLES, static_cast<unsigned int>(indices.size()), GL_UNSIGNED_INT, 0);
  glBindVertexArray(0);

  glActiveTexture(GL_TEXTURE0);
}


void Mesh::setupMesh() {
  glGenVertexArrays(1, &VAO);
  glGenBuffers(1, &VBO);
  glGenBuffers(1, &EBO);

  glBindVertexArray(VAO);
  glBindBuffer(GL_ARRAY_BUFFER, VBO);
  glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(Vertex), vertices.data(), GL_STATIC_DRAW);

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

  glEnableVertexAttribArray(0);
  glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, Position));

  glEnableVertexAttribArray(1);
  glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, Normal));

  glEnableVertexAttribArray(2);
  glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, TexCoords));
}