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

#pragma once
#include "tile.h"
#include "display/display.h"

#define CHUNK_WIDTH 8
#define CHUNK_HEIGHT 8
#define CHUNK_TILE_COUNT (CHUNK_WIDTH * CHUNK_HEIGHT)
#define CHUNK_ENTITY_COUNT_MAX 8

#define CHUNK_MAP_WIDTH (((DISPLAY_WIDTH / TILE_WIDTH_HEIGHT)/CHUNK_WIDTH)+2)
#define CHUNK_MAP_HEIGHT (((DISPLAY_HEIGHT / TILE_WIDTH_HEIGHT)/CHUNK_HEIGHT)+2)
#define CHUNK_MAP_COUNT (CHUNK_MAP_WIDTH * CHUNK_MAP_HEIGHT)

typedef struct {
  uint16_t x, y;
  tile_t tilesBase[CHUNK_TILE_COUNT];
  tile_t tilesBaseOverlay[CHUNK_TILE_COUNT];
  uint32_t entityIDs[CHUNK_ENTITY_COUNT_MAX];
  uint8_t entityCount;
} chunk_t;

typedef struct {
  chunk_t chunks[CHUNK_MAP_COUNT];
  chunk_t *chunkOrder[CHUNK_MAP_COUNT];

  uint16_t topLeftX;
  uint16_t topLeftY;
} chunkmap_t;

extern chunkmap_t CHUNK_MAP;

/**
 * Initializes the chunk map.
 */
void chunkMapInit();

/**
 * Shifts the chunk map by the specified x and y offsets.
 * 
 * @param x The x offset to shift the chunk map.
 * @param y The y offset to shift the chunk map.
 */
void chunkMapShift(const int16_t x, const int16_t y);

/**
 * Sets the position of the chunk map to the specified coordinates.
 * 
 * @param x The x coordinate of the top-left chunk.
 * @param y The y coordinate of the top-left chunk.
 */
void chunkMapSetPosition(const uint16_t x, const uint16_t y);

/**
 * Gets the chunk at the specified chunk coordinates.
 * 
 * @param chunkX The x coordinate of the chunk.
 * @param chunkY The y coordinate of the chunk.
 * @return A pointer to the chunk at the specified chunk coordinates, or NULL if
 *         no chunk exists at those coordinates.
 */
chunk_t * chunkGetChunkAt(const uint16_t chunkX, const uint16_t chunkY);

/**
 * Loads a chunk at the specified coordinates.
 * 
 * @param chunk The chunk to load.
 * @param x The x coordinate of the chunk.
 * @param y The y coordinate of the chunk.
 */
void chunkLoad(chunk_t *chunk, const uint16_t x, const uint16_t y);

/**
 * Unloads a chunk (that is currently loaded).
 * 
 * @param chunk The chunk to unload.
 */
void chunkUnload(chunk_t *chunk);