# tossing.py, a disc-tossing simulation.
# By Dustin Freeman, dustinfreeman.org, Sept 28, 2009.
from array import array
import random
random.seed()

#I make no excuse for messy code practices. Love, Dustin.

num_tossers = 6
init_tossers = array ('c',['w','d','d','d','w','w'])
# w - waiting
# d - has a disc
# t - just threw a disc
# c - just caught a disc
# f - just dropped a disc. Will pick it up for next turn
tosser_type = array('c',['r','r','r','r','r','r'])
# j - jerk
# r - reluctant
tosser_waiting = array ('i',[0,0,0,0,0,0])
# how many turns a tosser has waited.

incoming_discs_init = array ('i',[0,0,0,0,0,0])
# the number of discs incoming to each person. >1 is a fail state.

tossers = array('i')
incoming_discs_prev= array('i')
incoming_discs_curr= array('i')
num_collisions = 0
num_tosses = 0


def initialize():
        global tossers
        tossers = init_tossers[:]
        
        global incoming_discs_prev
        incoming_discs_prev = incoming_discs_init[:]
        global incoming_discs_curr
        incoming_discs_curr = incoming_discs_init[:]
        
def toss(i):
        global tossers
        global incoming_discs_curr
        global num_tosses
        reciever = random.randint(0,num_tossers-1)
        while ((tossers[reciever] != 'w') & (incoming_discs_curr[reciever] == 0)):       
                reciever = random.randint(0,num_tossers-1)
        incoming_discs_curr[reciever] +=1
        tossers[i] = 't'
        num_tosses += 1
        tosser_waiting[i]= 0

def toss_decision(i):
        global num_tossers
        global tossers
        global tosser_type
        
        if (tosser_type[i] == 'j'):
                #jerks toss right away.
                toss(i)
        elif (tosser_waiting[i] < 3):
                wait = False
                for j in range(0,num_tossers):
                        if ((tossers[j] == 'c') | (tossers[j] == 'd')):
                                wait=True
                                
                if (wait):
                        tossers[i] = 'd'
                        tosser_waiting[i] +=1
                        
                else:
                        toss(i)
        else:
                if (random.random() > 0.5):
                        toss(i)



failure_rate = 0.1
Its = 10000
verbose = False

initialize()
#main simulation loop
for it in range(0, Its):
        if (verbose):
                print (it , ': ' , tossers.tostring(), incoming_discs_prev)
                num_discs = 0
                for i in range(0,num_tossers):
                #error checking to make sure I don't "lose" discs.
                        if ((tossers[i] == 't') | (tossers[i] == 'f') | (tossers[i] == 'c')| (tossers[i] == 'd')):
                                num_discs +=1
                        
                print ('num discs ', num_discs)
                
        for i in range(0,num_tossers):
                if tossers[i] == 'w':
                        if incoming_discs_prev[i] > 1:
                                if (verbose):
                                        print ('collision!')
                                num_collisions+=1
                                initialize()
                                
                                        
                                break
                        elif incoming_discs_prev[i] ==1:
                                tossers[i] = 'c'
                                
                elif tossers[i] == 't':
                        
                        tossers[i] = 'w'
                        
                elif tossers[i] == 'c':
                        if incoming_discs_prev[i] > 0:
                                if (verbose):
                                        print ('collision!')
                                num_collisions+=1
                                initialize()
                                break
                        if (random.random() < failure_rate):
                        
                                #dropped the disc
                                tossers[i] = 'f' 
                                
                        else:
                                toss_decision(i)
                elif tossers[i] == 'f':
                        toss_decision(i)
                elif tossers[i] == 'd':
                        toss_decision(i)
                
        incoming_discs_prev = incoming_discs_curr[:]
        incoming_discs_curr = incoming_discs_init[:]


#results                
print ('Its: ', Its, 'Num Collisions: ' , num_collisions, 'Num Tosses: ',num_tosses, 'Coll per Toss: ', num_collisions/float(num_tosses))