/* SPDX-License-Identifier: MIT */
/*
 * konrpg.h
 *
 * Copyright (c) 2026 KonAki
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#ifndef KONRPG_H
#define KONRPG_H

#include "kontile.h"

#ifdef __cplusplus
extern "C" {
#endif

/*** directions ***/

/* the order of the rows in an RPG Maker character sheet */
typedef enum kon_dir {
	KON_DIR_DOWN,
	KON_DIR_LEFT,
	KON_DIR_RIGHT,
	KON_DIR_UP
} kon_dir_t;

/* one tile in that direction, y grows downwards */
void kon_dirDelta(kon_dir_t dir, int *dx, int *dy);
kon_dir_t kon_dirOpposite(kon_dir_t dir);

/*** actors ***/

/* something that walks a tile at a time. column, row is the tile it is on, or heading for while it moves.
   the game picks the direction every frame, kon_actorWalk starts a step when it is standing still and kon_actorUpdate moves it along */
typedef struct kon_actor {
	int column, row;
	int fromColumn, fromRow;
	kon_dir_t facing;
	int moving;
	float progress; /* 0 to 1 along the current step */
	float speed; /* tiles a second */

	/* private */
	float carry;
} kon_actor_t;

/* return non-zero if something other than the tilemap stands in the way of a step onto column, row */
typedef int (*kon_blockFn)(int column, int row, void *user);

void kon_actorInit(kon_actor_t *actor, int column, int row, kon_dir_t facing);

/* turns to face dir, then starts a step if the tile ahead is inside the map, not solid (see kon_tilemapBoxHits for solid) and not
   blocked by the callback, which may be NULL. does nothing but turn while a step is going. returns 1 if a step started */
int kon_actorWalk(kon_actor_t *actor, const kon_tilemap_t *map, const uint8_t *solid, int solidCount, kon_dir_t dir, kon_blockFn blocked, void *user);

/* returns 1 on the frame the actor arrives on a tile. time left over at the end of a step is kept for the next one,
   so holding a direction walks at exactly speed at any frame rate */
int kon_actorUpdate(kon_actor_t *actor, float dt);

/* where the actor's top left is in map pixels, in between tiles while it moves */
void kon_actorPixel(const kon_actor_t *actor, const kon_tilemap_t *map, float *x, float *y);

/* the tile the actor is looking at, the one it is on while it moves */
void kon_actorFront(const kon_actor_t *actor, int *column, int *row);

/*** events ***/

typedef enum kon_trigger {
	KON_TRIGGER_TALK, /* the actor faces it and presses the action key */
	KON_TRIGGER_TOUCH, /* the actor walks into it */
	KON_TRIGGER_STEP /* the actor arrives on it */
} kon_trigger_t;

/* a thing on the map the game reacts to. id means whatever the game wants, a switch into its own script, a door, a chest.
   blocks makes it solid like a person or a rock. to move one just change its column and row */
typedef struct kon_tileEvent {
	int column, row;
	kon_trigger_t trigger;
	int id;
	int blocks;
} kon_tileEvent_t;

/* index of the first event on the tile with that trigger, or -1. trigger -1 matches any */
int kon_eventAt(const kon_tileEvent_t *events, int count, int column, int row, int trigger);

/* 1 if a blocking event is on the tile, for kon_actorWalk. user is a kon_eventList_t */
typedef struct kon_eventList { const kon_tileEvent_t *events; int count; } kon_eventList_t;
int kon_eventBlocks(int column, int row, void *user);


#ifdef __cplusplus
}
#endif
#endif