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

#pragma once
#include "display/display.h"
#include "display/color.h"
#include "display/mesh/meshplatform.h"

#ifndef meshInitPlatform
  #error "meshInitPlatform must be defined"
#endif
#ifndef meshDrawPlatform
  #error "meshDrawPlatform must be defined"
#endif
#ifndef meshGetVertexCountPlatform
  #error "meshGetVertexCountPlatform must be defined"
#endif
#ifndef meshDisposePlatform
  #error "meshDisposePlatform must be defined"
#endif

typedef meshprimitivetypeplatform_t meshprimitivetype_t;
typedef meshplatform_t mesh_t;

/**
 * Initializes a mesh.
 * 
 * @param mesh The mesh to initialize.
 * @param primitiveType The OpenGL primitive type (e.g., GL_TRIANGLES).
 * @param vertexCount The number of vertices in the mesh.
 * @param vertices The vertex data for the mesh.
 * @return An error indicating success or failure.
 */
errorret_t meshInit(
  mesh_t *mesh,
  const meshprimitivetype_t primitiveType,
  const int32_t vertexCount,
  const meshvertex_t *vertices
);

/**
 * Instructs the mesh to flush the vertices to the GPU. This is surprisingly 
 * only really necessary on modern devices, as we tend to let older devices
 * read the vertices from the main memory directly.
 * 
 * @param mesh Mesh to flush the vertices for.
 * @param vertexOffset Start vertex to flush.
 * @param vertexCount Count of vertices to flush, set to -1 for all.
 * @return Error state.
 */
errorret_t meshFlush(
  mesh_t *mesh,
  const int32_t vertexOffset,
  const int32_t vertexCount
);

/**
 * Draws a mesh.
 * 
 * @param mesh The mesh to draw.
 * @param vertexOffset The offset in the vertex array to start drawing from.
 * @param vertexCount The number of vertices to draw. If -1, draws all vertices.
 * @return An error indicating success or failure.
 */
errorret_t meshDraw(
  const mesh_t *mesh,
  const int32_t vertexOffset,
  const int32_t vertexCount
);

/**
 * Gets the axis-aligned bounding box of a mesh.
 * 
 * @param mesh The mesh to get the bounds of.
 * @param outMin Output parameter for the minimum corner of the bounding box.
 * @param outMax Output parameter for the maximum corner of the bounding box.
 */
void meshGetBounds(
  const mesh_t *mesh,
  vec3 outMin,
  vec3 outMax
);

/**
 * Gets the vertex count of a mesh.
 * 
 * @param mesh The mesh to get the vertex count from.
 * @return The vertex count of the mesh.
 */
int32_t meshGetVertexCount(const mesh_t *mesh);

/**
 * Disposes a mesh.
 * 
 * @param mesh The mesh to dispose.
 * @return An error indicating success or failure.
 */
errorret_t meshDispose(mesh_t *mesh);