#include <pthread.h>
#include <time.h>
#include "errors.h"

typedef struct alarm_tag {
    struct alarm_tag    *link;
    int                 seconds;
    time_t              time;   /* seconds from EPOCH */
    char                message[128];
    int                 id;
    int                 dsp_id;
} alarm_t;

pthread_mutex_t alarm_mutex = PTHREAD_MUTEX_INITIALIZER;
alarm_t *alarm_list = NULL;

int main (int argc, char *argv[])
{
    int status;
    char line[128];
    alarm_t *alarm, **last, *next;
    pthread_t thread;

    status = pthread_create (
        &thread, NULL, alarm_thread, NULL);
    if (status != 0)
        err_abort (status, "Create alarm thread");
    while (1) {
        printf ("alarm> ");
        if (fgets (line, sizeof (line), stdin) == NULL) exit (0);
        if (strlen (line) <= 1) continue;
        alarm = (alarm_t*)malloc (sizeof (alarm_t));
        if (alarm == NULL)
            errno_abort ("Allocate alarm");

        if (sscanf (line, "Start_Alarm(%d) %d %128[^\n]",
        &alarm->id, &alarm->seconds, alarm->message)) {
            status = pthread_mutex_lock (&alarm_mutex);
            if (status != 0)
                err_abort (status, "Lock mutex");

            printf ("Alarm(%d) Inserted by Main Thread %ld Into Alarm List at\
            %ld: %d %s\n", alarm->id, pthread_self(), time(NULL),
            alarm->seconds, alarm->message);

            alarm->time = time (NULL) + alarm->seconds;

            /*
             * Insert the new alarm into the list of alarms, sorted by
             * order of their id (increasing order).
             */
            last = &alarm_list;
            next = *last;
            while (next != NULL) {
                if (next->id <= alarm->id) {
                    alarm->link = next;
                    *last = alarm;
                    break;
                }
                last = &next->link;
                next = next->link;
            }

            if (next == NULL) {
                *last = alarm;
                alarm->link = NULL;
            }

            status = pthread_mutex_unlock (&alarm_mutex);
            if (status != 0)
                err_abort (status, "Unlock mutex");
        }
        else if (sscanf (line, "Change_Alarm(%d) %d %128[^\n]",
        &alarm->id, &alarm->seconds, alarm->message)) {
            status = pthread_mutex_lock (&alarm_mutex);
            if (status != 0)
                err_abort (status, "Lock mutex");

            // Do Something

            status = pthread_mutex_unlock (&alarm_mutex);
            if (status != 0)
                err_abort (status, "Unlock mutex");
        }
        else {
            fprintf (stderr, "Bad command\n");
            free (alarm);
        }
    }
}