#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>
#include <string.h>

char history[1000][512];
int curr_history = 0;

char buff[512];
int curr_pos;

int curr_cmd = 0;

void redraw_buff()
{
    int i;
     printf("\r");
	printf("<myshell:%d> ", curr_cmd);

	for (i=0; i<50; i++) printf(" ");
	printf("\r");
	buff[curr_pos] = '\0';
	printf("<myshell:%d> %s", curr_cmd, buff); fflush(0);
}

int main()
{
	char ch;
	struct termios save_termios;
	// int val;
	int curr_h;

	if (tcgetattr(STDIN_FILENO, &save_termios) < 0) /* get whatever is there */
		perror("getattr");

	/* save_termios.c_lflag &= ~ICANON;*/ /* set non canonical mode */
	save_termios.c_lflag &= ~(ECHO | ICANON); /* set non canonical mode, turn of
												 echo */
	save_termios.c_cc[VMIN] = 0;  /* one byte at a time */
	save_termios.c_cc[VTIME] = 0; /* no timer */

	if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &save_termios) < 0) 
		perror("setattr");

	/*
	   fcntl(STDIN_FILENO, F_GETFL, val);
	   val |= O_NONBLOCK;
	   fcntl(STDIN_FILENO, F_SETFL, val);
	   */

	curr_pos = 0;

	printf("<myshell:%d> ", curr_cmd);fflush(0);
	while (1) {    
		if (read(STDIN_FILENO, &ch, 1) > 0) {
			if (ch == '\n') {
				putchar(ch);
				fflush(0);
				buff[curr_pos ++] = '\0';
				printf("buf = %s\n", buff);
				strcpy(history[curr_history++], buff);
				curr_h = curr_history;
				curr_cmd++;
				printf("<myshell:%d> ", curr_cmd);fflush(0);
				curr_pos = 0;
			} else if (ch == 1) { /* ctrl-A */ 
				if (curr_pos > 0) {
					curr_pos --;
					redraw_buff();
				}
			} else if (ch == 16) { /* ctrl-P */
				if (curr_h > 0) {
					strcpy(buff, history[curr_h-1]);
					curr_h--;
					curr_pos = strlen(buff);
					redraw_buff();
				}
			} else {
				buff[curr_pos ++] = ch;
				putchar(ch);fflush(0);
			}
		}
	}
}