# This program is a simple simulation of the racquetball game.

# Racquetball is a sport played between two players using racquets
# to strike a ball in a four-walled court.
# To start the game, one of the players puts the ball into play
# (called serving). The players then alternate hitting the ball
# to keep it in play. This is a rally. The rally ends when one of
# the players fails to hit a legal shot. The player who misses
# the shot loses the rally. If the loser is the player who served,
# then service passes to the other player.
# If the server wins the rally, a point is awarded.
# Players can only score points during their own service. 
# The first player to reach 15 points wins the game.
#
#
# Convention:
#               in our simulation the ability-level of players
#               will be represented by the probability that the
#               player wins the rally when he or she serves.
#
#   Pa – the probability that the player A wins on his/her serve
#   Pb – the probability that the player B wins on his/her serve
#
# Assumption:
#   in each game player A serves first

def main():
    Intro() # print an introduction

    Pa, Pb, n = getInput() # getting input from the user
    print("Got it! Starting the simulation....")
   
    # simulating n games, returning the result of simulation
    WinsA, WinsB = simNgames(n,Pa,Pb)

    report(n,WinsA,WinsB) # reporting back to the user

def Intro():
    print('Hello, this is a simulation of the racquetball game.')
    print('Racuetball is a game for two players: Player A and Player B')

def getInput():
    ProbA = float(input('Please, input  the probability that\n player \
A wins on his/her serve (i.e. Ability-level) as %:'))
    print("You entered {0} %".format(ProbA))

    ProbB = float(input('Please, input  the probability that\n player \
B wins on his/her serve  (i.e. Ability-level) as %:'))
    print("You entered {0} %".format(ProbB))

    n = int(input('Input the number of games you\'d like to simulate:'))

    return ProbA/100, ProbB/100, n

def report(n,wA,wB):
    print("\t REPORT:")
    print("{0:0d} games are simulated".format(n))
    
    PercentA = wA*100.0/n
    print("Player A won {0} games, which is {1:0.1f} %".format(wA,PercentA))
    
    PercentB = wB*100.0/n
    print("Player B won {0} games, which is {1:0.1f} %".format(wB,PercentB))

    print("Have a good day!")

def simNgames(n,Pa,Pb):
    #print("Entering simNgames....")
    
    WinsA = 0
    WinsB = 0

    for i in range(n):   # loop n times to simulate n games
        result = simOneGame(Pa,Pb) # simulate one game, get the result
        #print("i=",i)
        if result == 1: # Player A won
            WinsA = WinsA+1
        else: # Player B won
            WinsB = WinsB+1
            
    return WinsA, WinsB

def simOneGame(Pa,Pb):
    """ simulation of one game
    takes Pa (probability of Player A to win at his/her serve), and
    Pb (probability of Player B to win at his/her serve);
    returns 1 if Player A wins, and 0 is Player B wins """
    #print("entering simOneGame...")

    from random import random
    serving = 'A' # Assuming that Player A serves at the beginning of each game
    scoreA, scoreB = 0, 0 # initializing scores to 0

    while scoreA < 15 and scoreB < 15: # the game is played until a player reaches the score of 15
        if serving == 'A':          # A is serving
            if random() < Pa:  # A wins the serve
                scoreA = scoreA+1     
            else:   # A loses the serve
                serving = 'B'  # change the serve
        else:   # B is serving
            if random() < Pb:   # B wins the serve
                scoreB = scoreB+1
            else:   # B loses the serve
                serving = 'A'  # change the serve
                
        #print("scoreA={0:0d}, scoreB={1:0d}".format(scoreA,scoreB))
                
    if scoreA == 15:
        return 1
    
    else:
        return 0

main()