/*
  add.c: A demonstration/test program for the GEF (General Exception-
  Handling Facility) library.  Demonstrates the use of exception-handling.

  Copyright (C) 1998-2000 Bruce W. Bigby, bbigby@alum.MIT.edu

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License
  as published by the Free Software Foundation; either version 2
  of the License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <gef/posix.h>

static
void
UnhandledException(void* e) {
    fprintf(stderr, "Unhandled exception = %d\n", (int) e);
}

static
void
gef_configure(int* argc, char*** argv) {
    GEFAttr_t gefattrs;
    sigset_t set;

    GEFInitialize(argc, argv);
    sigemptyset(&set);
    sigaddset(&set, SIGALRM);
    GEFInitializeSignals(set);
    GEFAttr_Init(&gefattrs);
    GEFAttr_SetUnhandledException(&gefattrs, UnhandledException);
    GEFInitializeThread(gefattrs);
}

static
void
PrintAdditionQuestion(int number1, int number2) {
    printf("\t\t\t %2d\n", number1);
    printf("\t\t\t+%2d\n", number2);
    printf("\t\t\t---\n", number2);
    printf("\t\t\t %2s\n", "?");
}

static
void
PrintAdditionAnswer(int number1, int number2) {
    printf("\t\t\t %2d\n", number1);
    printf("\t\t\t+%2d\n", number2);
    printf("\t\t\t---\n", number2);
    printf("\t\t\t %2d\n", number1 + number2);
}

static
void
ExecuteAdditionTest(void) {
    int number1;
    int number2;
    int keypress;
    int count;
    int maxtime = 5;
    system("clear");
    printf("Welcome to Math Practice: Addition!\n");
    printf("You will have %d seconds to answer each question.\n", maxtime);
    printf("When you are ready to begin, press 'Enter'.");
    (void) getchar();
    do {
        system("clear");
        printf("You have %d seconds to answer...\n\n", maxtime);
        number1 = 1 + (random() % 9);
        number2 = 5 + (random() % 5);
        PrintAdditionQuestion(number1, number2);
        putchar('\n');
        count = 5;
        gef_enable_async_support;
        gef_protect_repeat_try(count) {
            printf("\rFor the answer, press 'Enter' (%d sec)...", count--);
            alarm(1);
            (void) getchar();
            alarm(0);
            system("clear");
        } gef_catch(e) {
              switch((int) e) {
              case SIGALRM:
                  if (count == 0) {
                      putchar('\a');
                      system("clear");
                      printf("Time's up!  ");
                      gef_break;
                  }
                  break;
              default: break;
              }
        } gef_end;
        gef_disable_async_support;
        printf("The answer is...\n\n");
        PrintAdditionAnswer(number1, number2);
        putchar('\n');
        printf("\rTo continue, press 'Enter'.  To stop, press 'q'; then press 'Enter':");
        keypress = getchar();
    } while (keypress != 'q');
}


int
main(int argc, char** argv) {
    int number1;
    int number2;
    int keypress;
    int count;
    int maxtime = 5;

    gef_configure(&argc, &argv);

    srandom((unsigned int) time((void*) NULL));
    ExecuteAdditionTest();
    return(0);
}