#ifndef _MYSTNB_ENGINE_H
#define _MYSTNB_ENGINE_H

#include <stdint.h>
#include <stdbool.h>
#include <gint/display.h>
#include "animation.h"

/* Maximum number of players */
#define PLAYER_COUNT 1

/* Maximum number of dynamic tiles on the map */
#define MAP_DYNAMIC_TILES 32

/* Time per engine tick (ms) */
#define ENGINE_TICK 25

/* Directions */
#define DIR_DOWN   0
#define DIR_RIGHT  1
#define DIR_UP     2
#define DIR_LEFT   3

/* struct player: A player on the map, triggering actions as they move */
struct player
{
	/* Position in map */
	int x, y;
	/* Direction currently facing */
	int dir;
	/* Whether player is currently idle (ie. can move) */
	int idle;
	/* Current animation function and data */
	struct anim_data anim;
};

/* struct map: A map with moving doors, collectibles, and fog */
struct map
{
	/* Width and height */
	int w, h;
	/* Whether fog is enabled */
	int fog;
	/* Door cycle string */
	char door_cycle[128];
	/* Mapping of door types to cycle string index */
	uint8_t door_cycle_index[16];
	/* Background image */
	bopti_image_t *img;
	/* Array of tiles in row-major order */
	uint8_t *tiles;
};

/* enum map_tile: Single cell in the map */
enum map_tile
{
	TILE_AIR   = 0,
	TILE_WALL  = 1,
	TILE_START = 2,
	TILE_END   = 3,

	/* 8 keys in interval 16..23 */
	TILE_KEY   = 16,
	/* 8 vertical doors in interval 24..31 */
	TILE_VDOOR = 24,
	/* 8 horizontal doors in interval 32..39 */
	TILE_HDOOR = 32,
};

/* struct dynamic_tile: Dynamic tile information */
struct dynamic_tile
{
	/* Position */
	int x, y;
	/* Current state */
	int state;
	int state2;
	/* Whether animation is idle */
	int idle;
	/* Current animation */
	struct anim_data anim;
};

/* struct game: A running game with a map and some players */
struct game
{
	/* Current map */
	struct map const *map;
	/* Players */
	struct player *players[PLAYER_COUNT + 1];
	/* Current game time (ms) */
	int time;
	/* Dynamic tiles */
	struct dynamic_tile dynamic_tiles[MAP_DYNAMIC_TILES];
	/* Number of dynamic tiles */
	int dynamic_tile_count;
};

/* Load map with no players */
void engine_load(struct game *game, struct map const *map);

/* Spawn all the players on the map */
void engine_spawn(struct game *game);

/* Check whether all players are idle */
bool engine_all_players_idle(struct game *game);

/* Check whether all dynamic tiles are idle */
bool engine_all_dynamic_tiles_idle(struct game *game);

/* Check whether a player stands on the exit */
bool engine_wins(struct game *game, struct player *player);

/* Update animations */
void engine_tick(struct game *game, int dt);

/* Draw the current game frame from scratch; does not dupdate() */
void engine_draw(struct game const *game);

/* Try to move a player along a direction. Returns 1 if the move is successful,
   0 otherwise (collisions or out-of-bounds moves) */
int engine_move(struct game *game, struct player *player, int direction);

/* Process automatic actions at the end of a turn */
void engine_finish_turn(struct game *game);

#endif /* _MYSTNB_ENGINE_H */