#include <gint/defs/types.h>
#include <stdbool.h>

#include "collide.h"
#include "conf.h"
#include "level.h"
#include "tiles.h"

Tile_flags collide_point(Vec point, const Level *level) {
	Vec cursor; /* the final position to test */
	vec_cpy(&cursor, point);
	vec_div(&cursor, TILE_SIZE); /* get the expected tile ID */
	if (point.x < 0 || point.y < 0 ||
		cursor.x >= level->width || cursor.y >= level->height) {
		return P_AIR; /* the point is out of bounds */
	}
	else {
		const Tile tile_id = level->layers[level->solid_layer][cursor.x + cursor.y * level->width];
		return tile_get_flags(tile_id);
	}
}

Tile_flags player_collide_or(Player *player, Vec position, const Level *level) {
	Vec pos;
	vec_cpy(&pos, position);
	Tile_flags flags = 0;
	flags |= collide_point(pos, level);
	pos.x += player->hbox.x;
	flags |= collide_point(pos, level);
	pos.y += player->hbox.y;
	flags |= collide_point(pos, level);
	pos.x -= player->hbox.x;
	flags |= collide_point(pos, level);
	return flags;
}

Tile_flags player_collide_and(Player *player, Vec position, const Level *level) {
	/* DRY, get the collision flags and do &= on flags if there is
	 * any. */
	void process_flags(Player *player, const Level *level, Vec pos, Tile_flags *flags) {
		Tile tile_flags = collide_point(pos, level);
		if (tile_flags) {
			*flags &= tile_flags;
		}
	}
	Vec pos;
	vec_cpy(&pos, position);
	Tile_flags flags = -1; /* since unsigned, max value */
	process_flags(player, level, pos, &flags);
	pos.x += player->hbox.x;
	process_flags(player, level, pos, &flags);
	pos.y += player->hbox.y;
	process_flags(player, level, pos, &flags);
	pos.x -= player->hbox.x;
	process_flags(player, level, pos, &flags);
	return flags;
}