history.c

#include "history.h"
#include "commands.h"
#include <string.h>
#include <stdio.h>

struct cmd_tagged_union _hist[HIST_SIZE];
int _cmd_counter = 0;


int _arr_index(int cmd_num) {
	return cmd_num % HIST_SIZE;
} 

int _cmd_in_memory(int cmd_num) {

	if(cmd_num > _cmd_counter) 
		return 0;

	if(cmd_num < 1)
		return 0;

	if(_cmd_counter - cmd_num >= HIST_SIZE)
		return 0;

	return 1;	
}
 

void hist_add(struct cmd_tagged_union cmd) {
	_cmd_counter++;	

	int cmd_ind = _arr_index(_cmd_counter); 

	_hist[cmd_ind] = cmd;
}


struct cmd_tagged_union *hist_fetch(int cmd_num) {
	
	if(_cmd_in_memory(cmd_num) == 0) 
		return 0; 

	return &_hist[_arr_index(cmd_num)];
}

void hist_print() {

	printf("%s\n", "Command history:");

	for(int i = _cmd_counter - (HIST_SIZE - 2); i <= _cmd_counter; i++) {

		if(_cmd_in_memory(i) == 0) {
			continue;
		}

		struct cmd_tagged_union *cmd = hist_fetch(i);
		printf("%d %s", i, (*cmd).stdin_string);
	}
}