raterhub_logger.c

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



void welcome_msg();

void session(const int time_base); // starts and logs/records a new session (punch in)

void punch_out(FILE *fp, unsigned int h, unsigned int m, unsigned int s);

void reset(unsigned int* time_unit, const int time_base); // resets time_unit to remainder

void time_stamp(FILE* fp, char* time_code); // Time code is punched in or punched out

void goodbye_msg();




int main(){
    const int time_base = 60;  //time base unit, a constant

    welcome_msg();

    char answer = getchar();

    // New session
    if(answer == 's' || answer == 'S'){
        session(time_base);
    }
    goodbye_msg();

    return 0;
}



/*
 * Function definitions
 * */

void reset(unsigned int* time_unit, const int time_base)
{
    *time_unit = *time_unit % time_base;
}

void welcome_msg()
{
    printf("\nWelcome to the worktime tracking system.\nEnter:\n");
    printf("\tS\\s: To start a new worktime session.\n\n");
    printf("\tE\\e: To exit. (CTRL-D is an equivalent of EOF)\n");
}

void goodbye_msg()
{
    printf("\nThank you for using the worktime tracking system.\n");
    printf("Goodbye!\n");
}

/*
*   TIME_STAMP
*   inputs: FILE *fp to write to, time_code (whether punching in or out)
*/
void time_stamp(FILE* fp, char* time_code)
{
    time_t current_time;
    char* c_time_string;

    // Obtain current time.
    current_time = time(NULL);

    if(current_time == ((time_t)-1))
    {
        (void)fprintf(stderr, "Failure to obtain time.\n");
        exit(EXIT_FAILURE);
    }

    // Convert to local time format.
    c_time_string = ctime(&current_time);

    if(c_time_string == NULL)
    {
        (void) fprintf(stderr, "Failure to convert the current time.\n");
        exit(EXIT_FAILURE);
    }

    // Print to stdout. ctime() has already added a terminating newline character.
    strcat(time_code, c_time_string);
    (void) fprintf(fp, "\nYou %s.", time_code);
}

/*
*   PUNCH_OUT
*   inputs: FILE *fp, unsigned in h, unsigned int m, unsinged int s
*   outputs: void
*/
void punch_out(FILE *fp, unsigned int h, unsigned int m, unsigned int s){
    char time_code[45] = "punched out: ";

    // print to stdout
    printf(
        "You have worked: %d hours, %d minutes, and %d seconds.\n",
        h, m, s
    );

    //print to file
    fprintf(
        fp,
        "You have worked: %d hours, %d minutes, and %d seconds.",
        h, m, s
    );

    time_stamp(fp, time_code);// Ending time for a session
}

/*
*   SESSION
*   inputs: const int time_base
*/
void session(const int time_base)
{
    unsigned int hours = 0, minutes = 0, seconds = 0, session_count = 0;
    double new_minutes;
    FILE *fp = fopen("hours.txt","a");
    char time_code[45] = "punched in: ";

    if(fp){
    (void) fprintf(fp, "\nStarting new session.");
        time_stamp(fp, time_code);
    } else{
        perror("Failed to open the file for writing.\nExiting.\n");
        exit(EXIT_FAILURE);
    }

    printf("Starting new session for time tracking.\n");
    printf("CTRL-D at any time to save state and exit.\n");

    printf("Add minutes: ");
    while(scanf("%lf", &new_minutes) != EOF){
        minutes += (unsigned int)new_minutes;
        seconds += (new_minutes - floor(new_minutes))*100 + 1;//recover lost second

        if( minutes >= time_base )
        {
            hours += minutes / time_base;
            reset(&minutes, time_base);
        }
        if( seconds >= time_base)
        {
            minutes += seconds / time_base;
            reset(&seconds, time_base);
        }   session_count++;
        printf("Add minutes: ");
    }

    // We are done with the session/exited, time to cleanup
    if(session_count < 1){
        // this is an exit
        fclose(fp);
    } else{// valid session so log out
        punch_out(fp, hours, minutes, seconds);
        (void) fprintf(fp, "Ending session.\n");
        fclose(fp);
    }
}