/******************************************************************************\
* Project:  Rectangle Display                                                  *
* Authors:  Ronald Swedlow                                                     *
* Version:  2019.09.27                                                         *
* License:  GNU General Public License (GPL) v3                                *
*                                                                              *
* 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 3 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 GPL for more details.         *
\******************************************************************************/

#ifdef __cplusplus
// Automatically inferred from .CPP file extension, unless gcc -x c is used.

// We are not allowed to submit code with C functions in this course.
// This is so we can compile using C++-specific features to pass the class.

#include <iostream>
using std::cin;
using std::cout;

#else
/*
 * This is what I run at home to code things the right way in C. :)
 * No C library calls ever will be used in Computer Science I assignments.
 */

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

#endif

/*
 * These are code cleanliness functions built on top of cin and cout.
 * When gcc -x c or #undef __cplusplus is used, they use C functions.
 */
extern long int userin(const char* promptmsg); /* cout, then cin */
extern void userout(const char* displaymsg); /* just cout */

int
main(void)
{
    long int cols, rows;
    register long int col, row;

    cols = userin("Rectangle how many units wide?  ");
    while (cols <= 0 || cols > 75) {
        cols = userin("Please specify in the domain (0, 75]:  ");
    }
    rows = userin("Rectangle how many units tall?  ");
    while (rows <= 0 || rows > 75) {
        rows = userin("Please specify in the domain (0, 75]:  ");
    }

    for (row = 0; row < rows; row++) {
        for (col = 0; col < cols; col++) {
            userout("X");
        }
        userout("\n");
    }
    return 0;
}
/*
 * Note that when I print "please try again with (0 < x <= 75), I am merely
 * giving the user an algebraic rule expression.  (0 < x <= 75) does not
 * bear any purposeful C expression, just an algebraic expression the user
 * can understand.
 *
 * In C++, (0 < x <= 75) has the identical evaluation:
 * (0 < x) ? ((int)true <= 75) : ((int)false <= 75)
 * Perfectly valid but highly unlikely to be of practical use.
 */

void
userout(const char* displaymsg)
{
#ifdef __cplusplus
    cout << displaymsg;
#else
    fputs(displaymsg, stdout);
#endif
}

long int
userin(const char* promptmsg)
{
#ifndef __cplusplus
    static char txt_buf[512];
#endif
    register long int high_precision_integer;
    int outofbounds;

    userout(promptmsg);
#ifdef __cplusplus
    cin >> high_precision_integer;
    outofbounds = cin.fail() ? 1 : 0;
#else
    fgets(&txt_buf[0], sizeof(txt_buf), stdin);
    high_precision_integer = strtol(txt_buf, NULL, 10);
    outofbounds = (errno != 0) ? 1 : 0;
#endif

    if (outofbounds) {
        userout("WARNING:  Input outside LONG_MAX and LONG_MIN.\n");
    } /* We are not really worrying about this yet. */
    return (high_precision_integer);
}