// Tyler Taormina
// CST 116
// Module 11c
//

#include <iostream>
#include <cstring>
#include <string>

#define MAX 50

using namespace std;

void isPalindrome();
void isAlpha();
void countChar();
void DisplayMenu(int&);
void ProcessMenuChoice(int);

int main() {
    int user_choice;

    cout << "=================================================================" << endl;
    cout << "PROGRAM RUNNING.." << endl;
    cout << "=================================================================" << endl;
    cout << endl;
    
    DisplayMenu(user_choice);
    ProcessMenuChoice(user_choice);

    return 0;

}


void DisplayMenu(int& user_choice)
{
    cout << "Choose what you would like to check for in a word" << endl;
    cout << "that you will enter..." << endl;
    cout << "=================================================================" << endl;
    //displays the menu of functions for the user to choose from

    cout << "1) Check for palindrome.\n";
    cout << "2) Check for all alpha.\n";
    cout << "3) Count the number of times a letter is in a word.\n";
    cout << "4) Exit Program.\n\n";
    cout << "Enter: ";
    cin >> user_choice;
    if (user_choice > 4 || user_choice< 1) {
        cout << "Invalid Entry. Please enter a number from the options list provided.\n\n\n\n" << endl;
        DisplayMenu(user_choice);
    }
} 



void ProcessMenuChoice (int menu_choice) {
    // Uses the user menu choice input to determine which function to call.
    // Also controls the ending or restarting of program.
    int program_rerun = 0;
    switch(menu_choice){
        case 1: 
            isPalindrome();
            break;
        
        case 2: 
            isAlpha();
            break;

        case 3:
            countChar();
            break;

        case 4:
            cout << "Are you sure you want to exit? Enter any number other than 1 to end program." << endl;
            break;

        default:
            break;
    }
    cout << "Press 1 and enter to rerun program. Enter any other number to close program: ";
    cin >> program_rerun;

    if (program_rerun == 1)
        main();
    else {
    cout << "================================================================" << endl;
    cout <<  "Program Closing..." << endl;
    cout << "================================================================\n\n\n" << endl;
    }
}



void isPalindrome () 
{
    char string1[MAX];
    int i, length;
    int flag = 0;
    
    cout << "Enter a string: "; cin >> string1;
    
    length = strlen(string1);
    
    for(i=0;i < length ;i++){
        if(string1[i] != string1[length-i-1]){
            flag = 1;
            break;
   }
}
    
    if (flag) {
        cout << string1 << " is not a palindrome" << endl; 
    }    
    else {
        cout << string1 << " is a palindrome" << endl; 
    }
}


void isAlpha () 
{
    char str[MAX];
    int i;

    cout << "Enter a string to test: ";
    cin >> str;

    for (int i = 0; str[i] != '\0'; i++)
    {
        if (!isalnum(str[i]))
        {
            cout << str[i] << " is not alphanumeric" << endl;
        }
    }
}


void countChar ()
{
    std::string string1;
    char ch;
    cout << "Please enter a word: "; cin >> string1;
    cout << "Please enter a character to count: "; cin >> ch;
 
    int count = 0;
    for (int i = 0; (i = string1.find(ch, i)) != std::string::npos; i++) {
        count++;
    }
 
    std::cout << "Character " << ch << " occurs " << count << " times" << endl << endl;

}