/*****************************************************************
* AUTHOR : Summer Huang
* Assignment #6 : Hangman
* CLASS : CS 002
* SECTION : MTWR: 7:30a – 12:30p
* Due Date : 1/22/2018
*****************************************************************/
#include <iostream>
#include <string>
#include <cctype>
#include <cstdlib>

using namespace std;

// function declarations
string setupNotSolved(string);
char getGuess(string);
string updateNotSolved(string phrase,string unsolved,char guess);
string prevGuesses;
string phrase;
void clearscreen();

// global variables to maintain the game status
int incorrectGuesses=0;
bool isFinished = false;
bool validGuess = false;

int main()
{
    string unsolved;
    int a;
    char ch;

    // prompt the first player to enter a phrase
    cout << "Enter phrase: ";
    getline(cin, phrase);

    unsolved = setupNotSolved(phrase);
    system("CLS");

    // start the game
    while (!isFinished && incorrectGuesses < 7)
    {
        // display the unsolved phrase
        cout << endl << "Phrase: ";
        cout << unsolved << endl;

        // display correctly guessed characters up until now
        cout << "Guessed so far: " << prevGuesses << endl;

        // prompt the user to enter a guess
        ch = getGuess(prevGuesses);
        unsolved = updateNotSolved(phrase, unsolved, ch);
        cout << "Wrong guesses left: " << 7 - incorrectGuesses << endl;
    }
    system("CLS");
    // display game result
    if (isFinished)
    {
        cout << "Congratulations!! You won!" << endl;
    }
    if (incorrectGuesses >= 7)
    {
        cout << "You lost!" << endl;
    }
    return 0;
}

///@brief Puts dashes in place of alphabetic characters in the phrase.
///@param phrase the phrase to be solved
///@return the phrase with all alphabetic characters converted to dashes

string setupNotSolved(string phrase)
{
     // creating unsolved phrase
     for(int k = 0;k < phrase.length(); k++)
     {
       if (isalpha(phrase.at(k)))
       {
         phrase.at(k) = '-';
       }
     }
     return phrase;
}

///@brief Replaces the dashes with the guessed character.
///@param phrase the phrase to be solved
///@param unsolved the phrase with dashes for all unsolved characters
///@param guess the char containing the current guessed character
///@return the new un solved string with dashes replaced by new guess

string updateNotSolved(string phrase,string unsolved,char guess)

{
     int i;
     int j;
     int len;

     len = 0;

     validGuess=false;
     // pre processing the phrase
     for(i = 0; i < unsolved.length(); i++)
     {
          if(unsolved.at(i)!='-')
          {
              phrase.at(i)='-';
          }
     }
     for(j = 0;j < phrase.length(); j++)
     {
          //if valid guess
          if(guess == phrase.at(j))
          {
              validGuess = true;
              unsolved.at(j) = guess;
              phrase.at(j) = '-';
              prevGuesses.append(string(1,guess));
              break;
          }
     }
    // update incorrect guesses count, if the guess is not a valid one
     if(!validGuess)
     {
         incorrectGuesses++;
     }
     // update the status of the game as finished,
     // if the phrase contains only '_'s
          for(i = 0;i < phrase.length(); i++)
          {
              if(phrase.at(i) == '-')
              {
                   len++;
              }
          }

          if(len == phrase.length())
          {
              isFinished=true;
          }

     return unsolved;
}

///@brief Gets validguess as input.
///
/// A guess is taken as input as a character. It is valid if
/// 1)it is an alphabetic character; and
/// 2)the character has not already been guessed
///
///@param prevGuesses the string containing all characters guessed so far
///@return a valid guess and only a valid guess as a character

char getGuess(string prevGuesses)
{
     char ch;
     prevGuesses = "";

     // prompt user to enter a valid guess
     cout << "Enter a guess: ";
     cin >> ch;
     cout << endl;
     if(isalpha(ch))
     {
          return ch;
     }
     else
     {
       while(!isalpha(ch))
       {
         cout << "Invalid guess! Please re-enter a guess: ";
         cin >> ch;
         cout << endl;
       }
     }

}