#include <iostream.h>
#include <iomanip.h>
#include <fstream.h>
#include <ctype.h>
#include <limits.h>
#include <conio.h>


// returns true if string "str" contains character "ch"
// and false otherwise.  lower and upper case characters are
// considered equivalent (i.e. the string "ABC" contains 'a').
bool letter_present (const char str[], char ch) {

  int i;

  for (i = 0; str[i] != '\0'; i++) {
    if (toupper(str[i]) == toupper(ch)) {
      return true;
    }
  }
  return false;

}


// displays the target string.  matched letters (letters which have
// been guessed) are displayed normally, as are all characters which
// are not letters (i.e. numbers, spaces, punctuation, and so on).
// unmatched letters are displayed as stars.  returns the number of
// unmatched letters in the target string (i.e. the number of stars output).
int display_target (const char target[], const char guesses[]) {

  int i, letters_left = 0;

  cout << "Your target is: ";

  for (i = 0; target[i] != '\0'; i++) {

    if (!isalpha(target[i])) {
      cout << target[i];
    } else if (letter_present (guesses, target[i])) {
      cout << target[i];
    } else{
      cout << '*';
      letters_left++;
    }

  }
  cout << endl;

  return letters_left;

}


// displays a graphical representation of how many mistakes have
// been made and also outputs a message giving the same information.
// returns true if the maximum allowable number of mistakes have been
// made and false otherwise.
bool display_gallows (int mistakes) {

  // ouputting this string draws the basic gallows
  char pattern[] = " =====\n |   |\n |   |\n |    \n |     \n |     \n"
                   " |    \n=========\n";
  // if there has been one mistake, string position 26 should be replaced
  // with an 'O' before the string is output.  in general,  array "locations"
  // contains the positions at which replsacements should occur, and array
  // "drop_ins" contains the replacement characters.
  const int locations[6] = { 26, 33, 32, 34, 40, 42 };
  const char drop_ins[6] = { 'O', '|', '/', '\\', '/', '\\' };
  int i;

  // adjust the standard pattern as required by replacing characters.
  for (i = 0; i < mistakes; i++) {
    pattern[locations[i]] = drop_ins[i];
  }
  // now output the adjusted pattern followed by a text message.
  cout << pattern
       << "\nSo far you have made " << mistakes << " mistakes.\n";

  return (bool) (mistakes == 6);

}


// prompts the player for their next guess and keeps at it until a
// valid guess is entered.  inputs which are nor letters are rejected,
// as are guess which match a previous guess.  returns the valid guess.
char get_valid_guess (const char guesses[] /* previous guesses */) {

  char guess;

  for (;;) {

    cout << "Please enter your choice of letter: ";
    cin >> guess;
    cin.ignore (INT_MAX, '\n');

    if (!isalpha(guess)) {
      cout << "Your guess must be a letter.\n";
    } else if (letter_present(guesses, guess)) {
      cout << "You've already guessed that letter.\n";
    } else {
      // we have an acceptable guess
      return guess;
    }

  }

}


// plays a single game of hangman using the target string supllied.
void play_game (const char target[]) {

  // string "guesses" contains all guess made.  initially this string
  // is empty (the terminator is at guesses[0]).  guesses are added to
  // the string as the game proceeds.
  char guesses[27] = "",  // we can't possible have more than 26 guesses
       guess;
  int guess_count = 0, mistakes = 0;

  for (;;) {

    clrscr ();

    // display the target and see if the player has won
    if (display_target (target, guesses) == 0) {
      cout << "\nCongratulations - you've have worked out the target.\n";
      return;
    }

    cout << endl;

    // display the situation and see if the player has lost
    if (display_gallows (mistakes)) {
      cout << "\nYou're dead.\nThe target was \"" << target << "\".\n";
      return;
    }

    cout << endl;

    // get the player's next guess
    guess = get_valid_guess(guesses);

    // add the guess to the guess string
    guesses[guess_count++] = guess;
    guesses[guess_count] = '\0'; // must keep the string terminated

    // if the guess is wrong, we've got one more mistake
    if (!letter_present (target, guess)) {
      mistakes++;
    }

  }

}


int main () {

  const int max_filename_length = 80,
            max_target_length = 50; // including the terminator
  char target[max_target_length], filename[max_filename_length], reply;
  ifstream fin;

  for (;;) {

    cout << "Please enter name of file containing the targets: ";
    cin >> filename;

    fin.open(filename);

    if (!fin.fail()) {
      break; // file successfully opened
    }

    cout << "Unable to open file <" << filename << ">.\n";

  }

  do {

    // the "ws" manipulator discards "whitespace" characters (blanks,
    // tabs and newlines).  one effect of doing this here is that, if
    // any file line contains leading blanks, they will be ignored.
    // also any completely blank lines will also be ignored.
    fin >> ws; // "ws" is a manipulator (like setw) and not a variable!!

    // read the next target
    fin.getline (target, max_target_length);

    if (fin.fail()) {
      if (fin.eof()) {
        cout << "Sorry - the end of the target file has been reached.\n";
      } else {
        // most unlikely as all possible file contents are valid.
        // might happy if a floppy became corrupted or something similar.
        cout << "An error occurred in reading the target file.\n";
      }
      return 0;
    }

    play_game (target);

    cout << "\nDo you want to play again (Y/N): ";
    cin >> reply;
    // ignore any extra characters that may have been entered
    cin.ignore (INT_MAX, '\n');

  } while (toupper(reply) == 'Y');

  return 0;


}