#include "primitives.h"

static int honey_mesh_lua_plane(lua_State* L)
{
    float width, height;
    honey_lua_parse_arguments(L, 1, 2,
                              HONEY_NUMBER, &width,
                              HONEY_NUMBER, &height);

    honey_mesh* mesh = lua_newuserdata(L, sizeof(honey_mesh));
    lua_rawgeti(L, LUA_REGISTRYINDEX, honey_mesh_mt_ref);
    lua_setmetatable(L, -2);
    if (honey_mesh_new_textured_plane(mesh, width, height) != HONEY_OK) {
        lua_pushstring(L, "error encountered while building plane");
        lua_error(L);
    }
    return 1;
}

static int honey_mesh_lua_cube(lua_State* L)
{
    float width, height, depth;
    honey_lua_parse_arguments(L, 1, 3,
                              HONEY_NUMBER, &width,
                              HONEY_NUMBER, &height,
                              HONEY_NUMBER, &depth);

    honey_mesh* mesh = lua_newuserdata(L, sizeof(honey_mesh));
    lua_rawgeti(L, LUA_REGISTRYINDEX, honey_mesh_mt_ref);
    lua_setmetatable(L, -2);
    if (honey_mesh_new_textured_cube(mesh, width, height, depth) != HONEY_OK) {
        lua_pushstring(L, "error encountered while building plane");
        lua_error(L);
    }
    return 1;
}

void honey_setup_primitives(lua_State* L)
{
    honey_lua_create_table
	(L, 2,
	 HONEY_FUNCTION, "plane", honey_mesh_lua_plane,
	 HONEY_FUNCTION, "cube",  honey_mesh_lua_cube);
    lua_setfield(L, -2, "primitives");
}

/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */

honey_result honey_mesh_new_textured_plane(honey_mesh* mesh,
                                           float width,
                                           float height) {
  float x0 = 0;
  float y0 = 0;
  float x1 = width;
  float y1 = height;

  float vertices[] = {
    /* position        normal        uv */
    x0, y0, 0,         0, 0, 1,      0, 0,
    x1, y0, 0,         0, 0, 1,      1, 0,
    x0, y1, 0,         0, 0, 1,      0, 1,
    x1, y1, 0,         0, 0, 1,      1, 1 };

  unsigned int indices[] = {
    0, 1, 2,
    3, 2, 1 };

  unsigned int attrib_sizes[] = { 3, 3, 2 };

  honey_result result = honey_mesh_new(mesh,
                                       vertices, 4,
                                       3, attrib_sizes,
                                       indices, 6);
  return result;
}

/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */

honey_result honey_mesh_new_cube(honey_mesh* mesh,
                                 float width,
                                 float height,
                                 float depth) {
  float x0 = 0;
  float y0 = 0;
  float z0 = 0;

  float x1 = width;
  float y1 = height;
  float z1 = depth;

  float vertices[] = {
    /* position        normal     tex coord */
    /* back face */
    x0, y0, z0,       0, 0, -1,
    x1, y0, z0,       0, 0, -1,
    x0, y1, z0,       0, 0, -1,
    x1, y1, z0,       0, 0, -1,

    /* front face */
    x0, y0, z1,       0, 0, 1, 
    x1, y0, z1,       0, 0, 1, 
    x0, y1, z1,       0, 0, 1, 
    x1, y1, z1,       0, 0, 1, 

    /* left face */
    x0, y0, z0,       -1, 0, 0,
    x0, y1, z0,       -1, 0, 0,
    x0, y0, z1,       -1, 0, 0,
    x0, y1, z1,       -1, 0, 0,

    /* right face */
    x1, y0, z0,        1, 0, 0,
    x1, y1, z0,        1, 0, 0,
    x1, y0, z1,        1, 0, 0,
    x1, y1, z1,        1, 0, 0,

    /* bottom face */
    x0, y0, z0,       0, -1, 0,
    x1, y0, z0,       0, -1, 0,
    x0, y0, z1,       0, -1, 0,
    x1, y0, z1,       0, -1, 0,
    
    /* top face */
    x0, y1, z0,       0,  1, 0,
    x1, y1, z0,       0,  1, 0,
    x0, y1, z1,       0,  1, 0,
    x1, y1, z1,       0,  1, 0 };

  unsigned int indices[] = {
    0, 1, 2,
    1, 2, 3,
    4, 5, 6,
    5, 6, 7,
    8, 9, 10,
    9, 10, 11,
    12, 13, 14,
    13, 14, 15,
    16, 17, 18,
    17, 18, 19,
    20, 21, 22,
    21, 22, 23 };

  unsigned int attrib_sizes[] = { 3, 3 };

  honey_result result = honey_mesh_new(mesh,
                                       vertices, 24,
                                       2, attrib_sizes,
                                       indices, 36);

  return result;
}

/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */

honey_result honey_mesh_new_textured_cube(honey_mesh* mesh,
                                          float width,
                                          float height,
                                          float depth) {
  float x0 = 0;
  float y0 = 0;
  float z0 = 0;

  float x1 = width;
  float y1 = height;
  float z1 = depth;

  float vertices[] = {
    /* position        normal     tex coord */
    /* back face */
    x0, y0, z0,       0, 0, -1,     0, 0,
    x1, y0, z0,       0, 0, -1,     1, 0,
    x0, y1, z0,       0, 0, -1,     0, 1,
    x1, y1, z0,       0, 0, -1,     1, 1,

    /* front face */
    x0, y0, z1,       0, 0, 1,      0, 0,
    x1, y0, z1,       0, 0, 1,      1, 0,
    x0, y1, z1,       0, 0, 1,      0, 1,
    x1, y1, z1,       0, 0, 1,      1, 1,

    /* left face */
    x0, y0, z0,       -1, 0, 0,     0, 0,
    x0, y1, z0,       -1, 0, 0,     1, 0,
    x0, y0, z1,       -1, 0, 0,     0, 1,
    x0, y1, z1,       -1, 0, 0,     1, 1,

    /* right face */
    x1, y0, z0,        1, 0, 0,     0, 0,
    x1, y1, z0,        1, 0, 0,     1, 0,
    x1, y0, z1,        1, 0, 0,     0, 1,
    x1, y1, z1,        1, 0, 0,     1, 1,

    /* bottom face */
    x0, y0, z0,       0, -1, 0,     0, 0,
    x1, y0, z0,       0, -1, 0,     1, 0,
    x0, y0, z1,       0, -1, 0,     0, 1,
    x1, y0, z1,       0, -1, 0,     1, 1,
    
    /* top face */
    x0, y1, z0,       0,  1, 0,     0, 0,
    x1, y1, z0,       0,  1, 0,     1, 0,
    x0, y1, z1,       0,  1, 0,     0, 1,
    x1, y1, z1,       0,  1, 0,     1, 1 };

  unsigned int indices[] = {
    0, 1, 2,
    1, 2, 3,
    4, 5, 6,
    5, 6, 7,
    8, 9, 10,
    9, 10, 11,
    12, 13, 14,
    13, 14, 15,
    16, 17, 18,
    17, 18, 19,
    20, 21, 22,
    21, 22, 23 };

  unsigned int attrib_sizes[] = { 3, 3, 2 };

  honey_result result;
  result = honey_mesh_new(mesh, vertices, 24,
                          3, attrib_sizes,
                          indices, 36);
  return result;
}