/* Copyright (C) 2019  C. McEnroe <june@causal.agency>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef LAYOUT_H
#define LAYOUT_H

#include <SDL_rect.h>
#include <assert.h>

#include "stack.h"

#ifndef LAYOUT_CAP
#define LAYOUT_CAP 64
#endif

typedef unsigned uint;

struct Item {
	SDL_Rect rect;
	Card card;
};

struct List {
	uint len;
	struct Item items[LAYOUT_CAP];
};

static inline void listClear(struct List *list) {
	list->len = 0;
}

static inline void
listPush(struct List *list, const struct SDL_Rect *rect, Card card) {
	assert(list->len < LAYOUT_CAP);
	struct Item item = { *rect, card };
	list->items[list->len++] = item;
}

static inline struct Item *listFind(struct List *list, const SDL_Point *point) {
	for (uint i = list->len - 1; i < list->len; --i) {
		if (SDL_PointInRect(point, &list->items[i].rect)) {
			return &list->items[i];
		}
	}
	return NULL;
}

struct Layout {
	struct List main;
	struct List drag;
	struct Item dragItem;
};

static inline void layoutClear(struct Layout *layout) {
	listClear(&layout->main);
	listClear(&layout->drag);
}

struct Style {
	uint increment;
	int deltaXBack;
	int deltaYBack;
	int deltaXFront;
	int deltaYFront;
};

enum {
	SquareIncrement = 24 / 3,
	SquareDeltaX = 2,
	SquareDeltaY = 1,
};
static const struct Style Flat = { 1, 0, 0, 0, 0 };
static const struct Style Square = {
	SquareIncrement, SquareDeltaX, SquareDeltaY, SquareDeltaX, SquareDeltaY,
};

static inline void
layoutStack(
	struct Layout *layout, SDL_Rect *rect,
	const struct Stack *stack, const struct Style *style
) {
	struct List *list = &layout->main;
	for (uint i = 0; i < stack->len; ++i) {
		Card card = stack->cards[i];
		if (card == layout->dragItem.card) {
			list = &layout->drag;
			*rect = layout->dragItem.rect;
		}
		listPush(list, rect, card);
		if ((i + 1) % style->increment == 0) {
			rect->x += (card > 0 ? style->deltaXFront : style->deltaXBack);
			rect->y += (card > 0 ? style->deltaYFront : style->deltaYBack);
		}
	}
}

#endif