/* 
 * Simple ASCII art program.
 * FIXME preliminary version from 10/21 class, with a few additions. 
 */
#include <stdio.h>

void clear(int rows, int cols, char grid[rows][cols]);
void print(int rows, int cols, char grid[rows][cols]);
void set(int rows, int cols, char grid[rows][cols], int r, int c, char ch);
void clear_line();

int main(void) {
	puts("how many rows, cols?");
	int rows, cols;
	if (scanf("%d %d", &rows, &cols) != 2) { 
		puts("input must be integer"); return 1; 
	}
	if ((rows <= 0) || (cols <= 0)) {
		puts("both values must be positive"); return 1; 
	}

	char canvas[rows][cols];
	clear(rows, cols, canvas);

	char cmd;
	int row, col;
	char ch;
	do {
		clear_line();
		puts("enter command");
		puts("\tp to print");
		puts("\tc to clear");
		puts("\ts row col char to set an element");
		puts("\tq to quit");
		cmd = getchar();
		switch(cmd) {
			case 'p':
				print(rows, cols, canvas);
				break;
			case 'c':
				clear(rows, cols, canvas);
				break;
			case 's':
				if (scanf("%d %d %c", &row, &col, &ch) != 3) {
					puts("invalid");
				}
				else {
					set(rows, cols, canvas, row, col, ch);
				}
				break;
			case 'q':
				break;
			default:
				puts("invalid command");
		}
	} while (cmd != 'q');
}

void clear(int rows, int cols, char grid[rows][cols]) {
	for (int r = 0; r < rows; ++r) {
		for (int c = 0; c < cols; ++c) {
			grid[r][c] = ' ';

		}
	}
}
/* ADDED after class -- code to print top, bottom rows of border */
void printborder(int cols) {
	putchar('+');
	for (int c = 0; c < cols; ++c) {
		putchar('-');
	}
	putchar('+');
	putchar('\n');
}
void print(int rows, int cols, char grid[rows][cols]) {
	printborder(cols);
	for (int r = 0; r < rows; ++r) {
		putchar('|');
		for (int c = 0; c < cols; ++c) {
			putchar(grid[r][c]);
		}
		putchar('|');
		putchar('\n');
	}
	printborder(cols);
}
void set(int rows, int cols, char grid[rows][cols], int r, int c, char ch) {
	if (r < 0 || r >= rows || c < 0 || c >= cols) {
		puts("invalid");
	}
	else {
		grid[r][c] = ch;

	}
}

/* discard input until end of line */
void clear_line() {
	while (getchar() != '\n') { }
}