# CS2/examples/objects/OhMaybe.py                  David MacQuigg   8-Sept-07
'''Our new package of Coins has just arrived from the Coin Factory.  Let's see
if they followed our orders, and built every one to the correct interface.'''

import Coins

#**
def testCoin(coin, bias=0.75, numTrials=500):
    '''Toss a coin "numTrials" times.

Save all data (bias, numTrials, totalHeads, resultList) as attributes attached
to each coin, and return just the most important result, the percentage of heads
(a float).
    >>> Coins.random.seed(1234)
    >>> coin = Coins.BiasedCoin()  # an instance of BiasedCoin
    >>> testCoin(coin, bias=0.2, numTrials=200)
    22.5
    '''
    coin.bias = bias              # Data will be saved until this coin
    coin.numTrials = numTrials    #   goes to the garbage collector.
    
    totalHeads = 0; resultList = []
    for trial in range(numTrials):
        
        result = coin.toss()       # Each coin has its own toss method
        
        if result == True:         # Result is Heads
            resultList.append('H')
            totalHeads += 1
        elif result == False:      # Result is Tails
            resultList.append('-')
        else:                      # Result is something else
            resultList.append('*')

    percentHeads =  100.0 * totalHeads/numTrials  # 100.0 forces a float

    coin.resultList   = resultList
    coin.totalHeads   = totalHeads
    coin.percentHeads = percentHeads
    return percentHeads

#**
if __name__ == '__main__':
    ''' '''
    classList = Coins.__all__       # All public classes
    print classList                 # ['BiasedCoin', 'FairCoin']
    for name in classList:
        coin = eval('Coins.%s()' % name)  #  eval('Coins.BiasedCoin()')
        percentHeads = testCoin(coin, numTrials=200)
        print '%s: percentHeads = %s' % (name, percentHeads)
        print ' '.join(coin.resultList)

    from doctest import testmod
    testmod()


#**
'''So what is wrong with this?  We can now handle any object that follows the
interface of class Coin.  Coin is just a metaphor.  A 'coin' could represent
results of an experiment in biology, whatever.  The internals of a 'coin' are
now fully isolated from their environment.

We still have a lot of stuff at global scope, however.  If this module is to
be useful in a larger program, we might want to encapsulate testCoin() along
with some of the display stuff we see in the __main__ section above.  Let's
make a class call TestRunner with three different display methods, depending
on how much detail you want.
~'''
#**~