/*
 * rps.c
 *
 * Computer Science 50, Fall 2011
 * section6
 *
 * Practice with enumerated types && have fun!
 */

#include <cs50.h>
#include <stdio.h>
#include <time.h>

// define an enumerated type with typedef
typedef enum
{
    WIN,
    LOSE,
    DRAW
} outcome;

// define an enumerated type without typedef
enum move {rock, paper, scissors};

// function prototype
outcome play_round(char c);

int
main(void)
{
    // save player's move and the score
    char choice;
    int score = 0, opp_score = 0;
    
    // get player's move and determine the round's result    
    do
    {
        printf("\nRock, paper, scissors, shoot...\n");
        printf("(play with 'r', 'p', 's' or type 'q' to quit)\n");
        printf("Score: %02d\nComputer's Score: %02d\n", score, opp_score);
        choice = GetChar();
        if(choice != 'q' &&
           (choice == 'r' || choice == 'p' || choice == 's'))
        {
            outcome result = play_round(choice);
            if(result == WIN)
            {
                printf("You win!\n");
                score++;
            }
            else if(result == LOSE)
            {
                printf("You lose!\n");
                opp_score++;
            }
            else
                printf("You draw!\n");
        }
    } while(choice != 'q');

    // success
    return 0;
}

// plays a round
outcome
play_round(char c)
{
    // initalize random seed
    srand(time(NULL));
    
    // generate random number
    int x = rand() % 3;
    
    // figure out the opponent's move
    enum move opp_move;
    
    if(x == 0)
    {
        opp_move = rock;
        printf("The computer picked rock.\n");
    }
    else if(x == 1)
    {
        opp_move = paper;
        printf("The computer picked paper.\n");
    }
    else
    {
        opp_move = scissors;
        printf("The computer picked scissors.\n");
    }
    
    // figure out what happened in the round
    switch(c)
    {
        case 'r':
            if(opp_move == rock)
                return DRAW;
            else if(opp_move == paper)
                return LOSE;
            else
                return WIN;
        
        case 'p':
            if(opp_move == rock)
                return WIN;
            else if(opp_move == paper)
                return DRAW;
            else
                return LOSE;
        
        default: // should only ever be 's'
            if(opp_move == rock)
                return LOSE;
            else if(opp_move == paper)
                return WIN;
            else
                return DRAW;
    }
}