#include <deerith/client/graphics/mesh.h>
#include <glad/gl.h>

deerith::mesh_2d_t::mesh_2d_t(
    const glm::vec2 *vertices,
    std::size_t vertex_count,
    const unsigned int *indices,
    std::size_t index_count)
    : index_count(index_count)
{
    glGenVertexArrays(1, &vao);
    glGenBuffers(1, &vbo);
    glGenBuffers(1, &ebo);

    glBindVertexArray(vao);

    glBindBuffer(GL_ARRAY_BUFFER, vbo);
    glBufferData(
        GL_ARRAY_BUFFER,
        vertex_count * sizeof(glm::vec2),
        vertices,
        GL_STATIC_DRAW);

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
    glBufferData(
        GL_ELEMENT_ARRAY_BUFFER,
        index_count * sizeof(unsigned int),
        indices,
        GL_STATIC_DRAW);

    // Position: vec2
    glVertexAttribPointer(
        0,
        2,
        GL_FLOAT,
        GL_FALSE,
        2 * sizeof(float),
        nullptr);

    glEnableVertexAttribArray(0);

    glBindVertexArray(0);
}

deerith::mesh_2d_t::~mesh_2d_t()
{
    glDeleteVertexArrays(1, &vao);
    glDeleteBuffers(1, &vbo);
    glDeleteBuffers(1, &ebo);
}

void deerith::mesh_2d_t::bind() const
{
    glBindVertexArray(vao);
}

void deerith::mesh_2d_t::draw() const
{
    glBindVertexArray(vao);

    glDrawElements(
        GL_TRIANGLES,
        static_cast<GLsizei>(index_count),
        GL_UNSIGNED_INT,
        nullptr);
}

deerith::mesh_3d_t::mesh_3d_t(
    const glm::vec3 *vertices,
    std::size_t _vertex_count,
    const unsigned int *indices,
    std::size_t _index_count)
    : index_count(_index_count), vertex_count(_vertex_count)
{
    glGenVertexArrays(1, &vao);
    glGenBuffers(1, &vbo);
    glGenBuffers(1, &ebo);

    glBindVertexArray(vao);

    glBindBuffer(GL_ARRAY_BUFFER, vbo);
    glBufferData(
        GL_ARRAY_BUFFER,
        vertex_count * sizeof(glm::vec3),
        vertices,
        GL_STATIC_DRAW);

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
    glBufferData(
        GL_ELEMENT_ARRAY_BUFFER,
        index_count * sizeof(unsigned int),
        indices,
        GL_STATIC_DRAW);

    // Position: vec2
    glVertexAttribPointer(
        0,
        3,
        GL_FLOAT,
        GL_FALSE,
        3 * sizeof(float),
        nullptr);

    glEnableVertexAttribArray(0);

    glBindVertexArray(0);
}

deerith::mesh_3d_t::~mesh_3d_t()
{
    glDeleteVertexArrays(1, &vao);
    glDeleteBuffers(1, &vbo);
    glDeleteBuffers(1, &ebo);
}

void deerith::mesh_3d_t::bind() const
{
    glBindVertexArray(vao);
}

void deerith::mesh_3d_t::draw() const
{
    glBindVertexArray(vao);
    glDrawElements(
        GL_TRIANGLES,
        static_cast<GLsizei>(index_count),
        GL_UNSIGNED_INT,
        nullptr);
}

void deerith::mesh_3d_t::draw_lines() const
{
    glBindVertexArray(vao);
    glDrawArrays(GL_LINES, 0, vertex_count);
}