'''lecture_21_racquetball.py
Build a terminal-based racquetball game simulation using top-down design
Oliver W. Layton
CS 151: Computational Thinking: Visual Media
Spring 2021

Rules:
- Players hit ball back and forth in the count.
- Game starts by a player serving, like tennis.
- Game played by players hitting ball back and forth (player A hits, then B, then A, then B...)
Back and forth is called rally (like in Tennis).
- The rally ends when one player fails to hit the ball during a rally
- The point ends when the rally ends.
    - The loser was the one who failed to hit ball back during the rally.
    - Score only increases by 1 if winner also served.
    - If the loser was the one who served, the other player serves now.
        - e.g. if B was serving and fails to hit ball, now A serves.
- IMPORTANT: Game ends when one player gets 15 points.
- Rule: Player A always starts serving

Question: If player A and B played in a championship (many games) who would win?

'''
import random


def printInstructions():
    '''Task 1 from main'''
    print('This program simulates a game of racquetball between two',
        'players called A and B. The abilities of each player is',
        'indicated by a probability (number between 0 and 1) that',
        'the player wins the point when serving. Player A always',
        'has the first serve.')


def getUserInput():
    '''Task 2 from main'''
    playerAProbWin = float(input('Enter the chance that Player A wins a point: '))
    playerBProbWin = float(input('Enter the chance that Player B wins a point: '))
    numGames = int(input('Enter the number of games in the championship: '))
    
    return playerAProbWin, playerBProbWin, numGames


def printResults(gamesAWon, gamesBWon):
    '''Task 4 from main'''
    totalNumGames = gamesAWon + gamesBWon
    print('Player A won', gamesAWon, 'games (', 100*gamesAWon/totalNumGames, 'percent of games)')
    print('Player B won', gamesBWon, 'games (', 100*gamesBWon/totalNumGames, 'percent of games)')

    if gamesAWon > gamesBWon:
        print('Player A is the winner!')
    else:
        print('Player B is the winner!')


def simulateNGames(playerAProbWin, playerBProbWin, numGames):
    '''Task 3 of main'''
    gamesAWon = 0
    gamesBWon = 0

    for g in range(numGames):
        scoreA, scoreB = simulateOneGame(playerAProbWin, playerBProbWin)

        # Determine the winner of the game
        if scoreA > scoreB:
            gamesAWon = gamesAWon + 1
        else:
            gamesBWon = gamesBWon + 1

    return gamesAWon, gamesBWon


def simulateOneGame(playerAProbWin, playerBProbWin):
    scoreA = 0
    scoreB = 0
    server = 'A'

    # play the game, have player A serve, play until rally ends, etc.
    while not gameOver(scoreA, scoreB):
        if server == 'A':
            if random.random() < playerAProbWin:
                # A wins
                scoreA = scoreA + 1
            else:
                # A loses
                server = 'B'
        # B serving
        else:
            if random.random() < playerBProbWin:
                # B wins
                scoreB = scoreB + 1
            else:
                # B loses
                server = 'A'
    
    return scoreA, scoreB

# We need to record who wins particulars and who is serving

def main():
    # 1. We need to print instructions to the user about what the program is doing
    # DONE!
    printInstructions()

    # 2. We need user input from the Terminal
    # DONE!
    playerAProbWin, playerBProbWin, numGames = getUserInput() 

    # 3. Have Player A and Player B play some number of games
    gamesAWon, gamesBWon = simulateNGames(playerAProbWin, playerBProbWin, numGames)

    # 4. Print out the results to show how many games Player A and B won (who won the championship)
    printResults(gamesAWon, gamesBWon)


if __name__ == '__main__':
    main()