//
// testCharStack.cpp
// CSC 311
// John Rogers
//
// This program tests the CharStack class written for Assignment 3.
//

#include "charstack.h"
#include <iostream>
#include <cctype>
#include <string>

using namespace std;

//
// isPalindrome checks whether the string parameter s contains
// a palindrome, that is, a string that reads the same left-to-right
// and right-to-left, ignoring spaces, case, and punctuation.
//
bool isPalindrome(const string& s)
{
	string s2;
	CharStack cs;

	// The alphabetic characters in the argument string s are changed
	// to lower case and copied to s2.

	string::size_type index;
	for (index = 0; index < s.length(); index++) {
		if (isalpha(s[index])) {
			s2 += tolower(s[index]);
		}
	}

	// The characters of s2 are pushed onto the stack in 
	// left-to-right order.
	for (index = 0; index < s2.length(); index++) {
		cs.push(s2[index]);
	}
	
	// The characters on the stack are in reverse order of
	// the characters of s2.  They are compared and, if a 
	// mismatch is found, false is returned.
	for (index = 0; index < s2.length(); index++) {
		if (cs.top() != s2[index])
			return false;
		cs.pop();
	}
	
	return true;
}

//
// newline removes the newline character '\n' from the
// input stream so that it won't interfere with later
// input stream extractions.
//
void newline()
{
	char c;
	do {
		cin.get(c);
	} while (c != '\n');
}

//
// askYesNoQuestion asks the question in its parameter and waits
// until the user has typed a 'y' or an 'n', returning true
// if a 'y' was typed.
//
bool askYesNoQuestion(string question)
{
	char answer;
	do {
		cout << question;
		cin >> answer;
		answer = tolower(answer);
	} while (answer != 'n' && answer != 'y');
	newline();
	return answer == 'y';
}

int main()
{
	string s;

	// Test whether the basic stack functions of charStack work by calling 
	// the palindrome tester.
	
	do {
		cout << "Enter a string to test whether it's a palindrome: ";
		getline(cin, s);

		if (isPalindrome(s)) {
			cout << "It is a palindrome!" << endl;
		}
		else {
			cout << "It is NOT a palindrome!" << endl;
		}
	} while (askYesNoQuestion("Do you wish to test another string? "));
	
	// Test whether growing the stack automatically works correctly.
	
	CharStack cs;
	for (int index = 1; index <= 1000; index++) {
		cs.push(' ');
	}
	
	return 0;
}