#include <string>
#include <fstream>
#include <vector>
#include <iostream>
#include <algorithm>
#include <ctime>
#include <random>
#include <set>

using namespace std;

// Global variable.
string rand_word;

// This function picks a random word from a text file, then returns it.
string pick_word(const string picked_word)
{
    vector<string> words;
    ifstream in("dictionary.txt");

    // Checks to see if the file was successfully read.
    if (!in){
        cout << "file not found." << endl;
        return 0;
    }
    while (in) {
        string word;
        in >> word;
        words.push_back(word);
    }

    //srand(time(0));
    string r = words[rand() % words.size()];

    return r;
}

    // This function calls pick_word then starts
    // a hangman game with it.
    int hang_man(string word)
{
    int misses = 0;
    int max_misses = 10;
    int exposed = 0;
    string display = word;
    int word_size = word.size();

    cout << "There are " << word_size << " letters." << endl;

    for (int i = 0; i < word_size; ++i)
        display[i] = '-';


    set<char> guessed;
    char guess;

    while (display != word)
    {

        // Determines wether or not the user has used all his/her guesses.
        if (misses >= max_misses)
        {
            cout << endl;
            cout << " Uh oh! You're out of guesses!n";
            cout << " The word was " << word << "!" << endl;
            cout << endl;

            return 0;
        }

        // Gives the user details on their current game.
        cout << "Already guessed: ";
        copy(guessed.begin(), guessed.end(), ostream_iterator<char>(cout, " "));
        cout << "nMisses: " << misses << endl;
        cout << "Remaining guesses " << max_misses - misses << endl;
        cout << "Guess a letter.nn ";
        cout << display << "nn";
        cin >> guess;
        cout << endl;

        // Checks input for errors such as capitalization
        // of if it's even a number.
        guess = tolower(guess);

        if (!isalpha(guess))
        {
            cout << "That is not a letter!n";
            continue;
        }

        bool right = false;

        //Checks if input has already been entered.
        if (guessed.find(guess) != guessed.end())
        {
            cout << guess << " has already been guessed.n";
            right = true;
        }

        guessed.insert(guess);

        // Compares guess with each char of word and
        // updates display accordingly.
        for (int i = 0; i < word_size; ++i)
        {
            if (guess == word[i])
            {
                display[i] = word[i];
                exposed++;
                right = true;
            }
        }

        // Checks the boolian value to determine
        // whether or not to subtract a guess.
        if (!right)
        {
            misses++;
            cout << guess << " is not in the word." << endl;
        }
    }

    // Displays final stat of game
    // and prompts the user for another try.
    cout << "That's right! The word was " << word << endl;
    cout << "You missed " << misses << " times!n";


    return 0;
}


int main()
{
    // Calls the hangman function which functions as the hangman game itself
    cout << "---------- Welcome to Hangman! ----------" << endl;
    hang_man(pick_word(rand_word));

    char answer;
    char yes = 'y';

    // Prompts the user for another game.
    cout << " Would you like to play again?" << endl;
    cout << " Press y to play again or anything else to exit. " << endl;
    cin >> answer;
    if (answer != yes)
    {
        cout << "Okay! See you next time!" << endl;

        return 0;
    }
    // Calls the hangman function for another game.
    else
        while (answer = yes)
        {
            hang_man(pick_word(rand_word));

            cout << " Would you like to play again?" << endl;
            cout << " Press y to play again or anything else to exit. " << endl;
            cin >> answer;
            if (answer != yes)
            {
                cout << "Okay! See you next time!" << endl;
                return 0;
            }

        }
    return 0;
}