/**
 * Copyright (c) 2026 Dominic Masters
 *
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#include "cube.h"
#include "assert/assert.h"

mesh_t CUBE_MESH_SIMPLE;
meshvertex_t CUBE_MESH_SIMPLE_VERTICES[CUBE_VERTEX_COUNT];

errorret_t cubeInit() {
  vec3 min = { 0.0f, 0.0f, 0.0f };
  vec3 max = { 1.0f, 1.0f, 1.0f };
  cubeBuffer(
    CUBE_MESH_SIMPLE_VERTICES, min, max
    #if MESH_ENABLE_COLOR
      , COLOR_WHITE_4B
    #endif
  );
  errorChain(meshInit(
    &CUBE_MESH_SIMPLE,
    CUBE_PRIMITIVE_TYPE,
    CUBE_VERTEX_COUNT,
    CUBE_MESH_SIMPLE_VERTICES
  ));
  errorOk();
}

// Helper macro: set one vertex position, UV and color.
#if MESH_ENABLE_COLOR
  #define CUBE_VERT(i, px, py, pz, u, v) \
    vertices[i].color  = color; \
    vertices[i].pos[0] = (px); \
    vertices[i].pos[1] = (py); \
    vertices[i].pos[2] = (pz); \
    vertices[i].uv[0]  = (u);  \
    vertices[i].uv[1]  = (v);
#else
  #define CUBE_VERT(i, px, py, pz, u, v) \
    vertices[i].pos[0] = (px); \
    vertices[i].pos[1] = (py); \
    vertices[i].pos[2] = (pz); \
    vertices[i].uv[0]  = (u);  \
    vertices[i].uv[1]  = (v);
#endif

void cubeBuffer(
  meshvertex_t *vertices,
  const vec3 min,
  const vec3 max
  #if MESH_ENABLE_COLOR
    , const color_t color
  #endif
) {
  assertNotNull(vertices, "Vertices cannot be NULL");
  assertNotNull(min, "Min vector cannot be NULL");
  assertNotNull(max, "Max vector cannot be NULL");

  const float_t x0 = min[0], y0 = min[1], z0 = min[2];
  const float_t x1 = max[0], y1 = max[1], z1 = max[2];

  // Front face (+Z normal): CCW when viewed from +Z
  CUBE_VERT( 0, x0, y0, z1,  0.0f, 0.0f);
  CUBE_VERT( 1, x1, y0, z1,  1.0f, 0.0f);
  CUBE_VERT( 2, x1, y1, z1,  1.0f, 1.0f);
  CUBE_VERT( 3, x0, y0, z1,  0.0f, 0.0f);
  CUBE_VERT( 4, x1, y1, z1,  1.0f, 1.0f);
  CUBE_VERT( 5, x0, y1, z1,  0.0f, 1.0f);

  // Back face (-Z normal): CCW when viewed from -Z
  CUBE_VERT( 6, x1, y0, z0,  0.0f, 0.0f);
  CUBE_VERT( 7, x0, y0, z0,  1.0f, 0.0f);
  CUBE_VERT( 8, x0, y1, z0,  1.0f, 1.0f);
  CUBE_VERT( 9, x1, y0, z0,  0.0f, 0.0f);
  CUBE_VERT(10, x0, y1, z0,  1.0f, 1.0f);
  CUBE_VERT(11, x1, y1, z0,  0.0f, 1.0f);

  // Right face (+X normal): CCW when viewed from +X
  CUBE_VERT(12, x1, y0, z1,  0.0f, 0.0f);
  CUBE_VERT(13, x1, y0, z0,  1.0f, 0.0f);
  CUBE_VERT(14, x1, y1, z0,  1.0f, 1.0f);
  CUBE_VERT(15, x1, y0, z1,  0.0f, 0.0f);
  CUBE_VERT(16, x1, y1, z0,  1.0f, 1.0f);
  CUBE_VERT(17, x1, y1, z1,  0.0f, 1.0f);

  // Left face (-X normal): CCW when viewed from -X
  CUBE_VERT(18, x0, y0, z0,  0.0f, 0.0f);
  CUBE_VERT(19, x0, y0, z1,  1.0f, 0.0f);
  CUBE_VERT(20, x0, y1, z1,  1.0f, 1.0f);
  CUBE_VERT(21, x0, y0, z0,  0.0f, 0.0f);
  CUBE_VERT(22, x0, y1, z1,  1.0f, 1.0f);
  CUBE_VERT(23, x0, y1, z0,  0.0f, 1.0f);

  // Top face (+Y normal): CCW when viewed from +Y
  CUBE_VERT(24, x0, y1, z1,  0.0f, 0.0f);
  CUBE_VERT(25, x1, y1, z1,  1.0f, 0.0f);
  CUBE_VERT(26, x1, y1, z0,  1.0f, 1.0f);
  CUBE_VERT(27, x0, y1, z1,  0.0f, 0.0f);
  CUBE_VERT(28, x1, y1, z0,  1.0f, 1.0f);
  CUBE_VERT(29, x0, y1, z0,  0.0f, 1.0f);

  // Bottom face (-Y normal): CCW when viewed from -Y
  CUBE_VERT(30, x0, y0, z0,  0.0f, 0.0f);
  CUBE_VERT(31, x1, y0, z0,  1.0f, 0.0f);
  CUBE_VERT(32, x1, y0, z1,  1.0f, 1.0f);
  CUBE_VERT(33, x0, y0, z0,  0.0f, 0.0f);
  CUBE_VERT(34, x1, y0, z1,  1.0f, 1.0f);
  CUBE_VERT(35, x0, y0, z1,  0.0f, 1.0f);

  #undef CUBE_VERT
}