// Lab 3 Solution
// Do not distribute beyond class this semester.

/*
Pseudocode solution:

MAX_LEN = 5
history: [string; MAX_LEN]
current_len: int = 0

func get_input()
func add_to_history(input)
func print_history()

func main():
    loop:
        let input = get_input()
        add_to_history(input)
        if input == "print":
            print_history()

func add_to_history(input):
    if current_len < MAX_LEN:
        history[current_len] = input
        current_len += 1
    else:
        remove_oldest_record()
        history[current_len] = input
        current_len += 1

func remove_oldest_record():
    ensure(current_len > 0)
    free(history[0])
    for i from 1 to current_len:
        history[i - 1] = history[i]
    current_len -= 1

func print_history():
    for i from 0 to current_len:
        print(history[i])

*/


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

#define MAX_LEN 5

char *input_history[MAX_LEN];
int history_count = 0;


void add_to_history(char *input);
void remove_oldest_record();
void print_history();
char *get_input();

int main() {
    while (1) {
        char *input = get_input();
        add_to_history(input);
        if (strcmp(input, "print") == 0) {
            print_history();
        }
    }
    // TODO: Free the memory of the input history
    return 0;
}

char *get_input() {
    char *buffer = NULL;
    size_t bufsize = 0;
    printf("Enter input: ");
    size_t len = getline(&buffer, &bufsize, stdin);
    if (len == -1) {
        exit(1);
    }
    // Remove the newline character at the end of the input
    buffer[len - 1] = '\0';
    return buffer;
}

void add_to_history(char *input) {
    if (history_count >= MAX_LEN) {
        remove_oldest_record();
    }
    input_history[history_count] = input;
    history_count++;
}

void remove_oldest_record() {
    if (history_count > 0) {
        // Free the memory of the oldest record
        free(input_history[0]);
        for (int i = 1; i < history_count; i++) {
            input_history[i - 1] = input_history[i];
        }
        history_count--;
    }
}

void print_history() {
    for (int i = 0; i < history_count; i++) {
        printf("%s\n", input_history[i]);
    }
}