/**
 * Copyright (c) 2025 Dominic Masters
 * 
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#include "rpgcamera.h"
#include "util/memory.h"
#include "rpg/entity/entity.h"
#include "rpg/overworld/map.h"
#include "assert/assert.h"

rpgcamera_t RPG_CAMERA;

void rpgCameraInit(void) {
  memoryZero(&RPG_CAMERA, sizeof(rpgcamera_t));
}

errorret_t rpgCameraUpdate(void) {
  if(!mapIsLoaded()) errorOk();
  
  chunkpos_t chunkPos;

  switch(RPG_CAMERA.mode) {
    case RPG_CAMERA_MODE_FREE:
      worldPosToChunkPos(&RPG_CAMERA.free, &chunkPos);
      break;

    case RPG_CAMERA_MODE_FOLLOW_ENTITY: {
      entity_t *entity = &ENTITIES[RPG_CAMERA.followEntity.followEntityId];
      if(entity->type == ENTITY_TYPE_NULL) {
        errorOk();
      }

      // Update map position to match camera. By default map wants to know the
      // top left but we want to set the center, so we need to sub half map size
      worldPosToChunkPos(&entity->position, &chunkPos);
      break;
    }

    default:
      assertUnreachable("Invalid RPG camera mode");
  }
  
  errorChain(mapPositionSet((chunkpos_t){
    .x = chunkPos.x - (MAP_CHUNK_WIDTH / 2),
    .y = chunkPos.y - (MAP_CHUNK_HEIGHT / 2),
    .z = chunkPos.z - (MAP_CHUNK_DEPTH / 2)
  }));
  errorOk();
}