// SPDX-License-Identifier: GPL-3.0-only
/*
 * Copyright (c) 2024, Richard Acayan. All rights reserved.
 */

#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "graphics.h"
#include "layout.h"
#include "parser.h"
#include "ufkbd.h"

static struct ufkbd_layout_row *search_row(struct ufkbd_layout *layout, int y)
{
	struct ufkbd_layout_row *row;
	size_t row1 = 0, row2;
	size_t idx;

	if (layout->rows == NULL)
		return NULL;

	row2 = layout->n_rows - 1;

	do {
		idx = (row1 + row2) / 2;
		row = &layout->rows[idx];

		if (row->y1 <= y)
			row1 = idx;

		if (row->y2 >= y)
			row2 = idx;
	} while (row2 - row1 > 1);

	if (layout->rows[row1].y1 <= y && layout->rows[row1].y2 >= y)
		return &layout->rows[row1];
	else if (layout->rows[row2].y1 <= y && layout->rows[row2].y2 >= y)
		return &layout->rows[row2];

	return NULL;
}

static struct ufkbd_layout_column *search_col(struct ufkbd_layout_row *row, int x)
{
	struct ufkbd_layout_column *col;
	size_t col1 = 0, col2;
	size_t idx;

	col2 = row->n_cols - 1;

	do {
		idx = (col1 + col2) / 2;
		col = &row->cols[idx];

		if (col->x1 <= x)
			col1 = idx;

		if (col->x2 >= x)
			col2 = idx;
	} while (col2 - col1 > 1);

	if (row->cols[col1].x1 <= x && row->cols[col1].x2 >= x)
		return &row->cols[col1];
	else if (row->cols[col2].x1 <= x && row->cols[col2].x2 >= x)
		return &row->cols[col2];

	return NULL;
}

struct ufkbd_key *ufkbd_layout_search(struct ufkbd_layout *layout, int x, int y,
				      int *x1, int *y1, int *x2, int *y2)
{
	struct ufkbd_layout_row *row;
	struct ufkbd_layout_column *col;

	if (layout == NULL)
		return NULL;

	row = search_row(layout, y);
	if (row == NULL)
		return NULL;

	col = search_col(row, x);
	if (col == NULL)
		return NULL;

	if (x1 != NULL)
		*x1 = col->x1;

	if (y1 != NULL)
		*y1 = row->y1;

	if (x2 != NULL)
		*x2 = col->x2;

	if (y2 != NULL)
		*y2 = row->y2;

	return col->key;
}

void ufkbd_layout_foreach(struct ufkbd_layout *layout,
			  void (*func)(struct ufkbd_key *key,
				       int x1, int y1, int x2, int y2,
				       void *data),
			  void *data)
{
	struct ufkbd_layout_row *row;
	struct ufkbd_layout_column *col;
	size_t y, x;

	for (y = 0; y < layout->n_rows; y++) {
		row = &layout->rows[y];

		for (x = 0; x < row->n_cols; x++) {
			col = &row->cols[x];
			func(col->key,
			     col->x1, row->y1, col->x2, row->y2,
			     data);
		}
	}
}

void ufkbd_layout_resize(struct ufkbd_layout *layout, int width, int height)
{
	struct ufkbd_layout_row *row;
	struct ufkbd_layout_column *col;
	size_t y, x;

	for (y = 0; y < layout->n_rows; y++) {
		row = &layout->rows[y];

		row->y1 = row->y1_unscaled * height / layout->n_rows;
		row->y2 = row->y2_unscaled * height / layout->n_rows - 1;

		if (row->y2 < row->y1)
			row->y2 = row->y1;

		for (x = 0; x < row->n_cols; x++) {
			col = &row->cols[x];
			col->x1 = col->x1_unscaled * width / layout->max_cols;
			col->x2 = col->x2_unscaled * width / layout->max_cols - 1;

			if (col->x2 < col->x1)
				col->x2 = col->x1;
		}
	}
}

struct ufkbd_layout *ufkbd_layout_init(void)
{
	struct ufkbd_layout *layout;

	layout = malloc(sizeof(*layout));
	if (layout == NULL)
		return NULL;

	layout->max_cols = 0;
	layout->n_rows = 0;
	layout->rows = NULL;

	return layout;
}

void ufkbd_layout_uninit(struct ufkbd_layout *layout)
{
	struct ufkbd_layout_row *row;
	size_t x, y;

	for (y = 0; y < layout->n_rows; y++) {
		row = &layout->rows[y];

		for (x = 0; x < row->n_cols; x++)
			free(row->cols[x].key);

		free(row->cols);
	}

	free(layout->rows);
	free(layout);
}