// FILE: washing.h (part of the namespace main_savitch_8A)
// CLASSES PROVIDED: bool_source, averager, washer.
//
// CONSTRUCTOR for the bool_source class:
//   bool_source(double p = 0.5)
//     Precondition: 0 <= p <= 1.
//     Postcondition: The bool_source has been initialized so that p is the
//     approximate probability of returning true in any subsequent activation
//     of query( ).
//
// CONSTANT MEMBER FUNCTION for the bool_source class:
//   bool query( ) const
//     Postcondition: The return value is either true or false, with the
//     probability of a true value being approximately p (from the constructor).
//
// CONSTRUCTOR for the averager class:
//   averager( )
//     Postcondition: The averager has been initialized so that it
//     is ready to accept a sequence of numbers to average.
//
// MODIFICATION MEMBER FUNCTION for the averager class:
//   void next_number(double value)
//     Postcondition: The averager has accepted value as the next
//     number in the sequence of numbers which it is averaging.
//
// CONSTANT MEMBER FUNCTIONS for the averager class:
//   size_t how_many_numbers( ) const
//     Postcondition: The value returned is a count of how many
//     times next_number has been activated.
//
//   double average( ) const
//     Precondition: how_many_numbers > 0.
//     Postcondition: The value returned is the average of all the
//     numbers which have been given to the averager.
//
// CONSTRUCTOR for the washer class:
//   washer(unsigned int s = 60)
//     Precondition: The value of s is the number of seconds needed for
//     the completion of one wash cycle.
//     Postcondition: The washer has been initialized so that all
//     other member functions may be used.
//
// MODIFICATION MEMBER FUNCTIONS for the washer class:
//   void one_second( )
//     Postcondition: The washer has recorded (and simulated) the
//     passage of one more second of time.
//
//   void start_washing( )
//     Precondition: The washer is not busy.
//     Postcondition: The washer has started simulating one wash
//     cycle. Therefore, is_busy( ) will return true until
//     the required number of simulated seconds have occured.
//
// CONSTANT MEMBER FUNCTIONS for the washer class:
//   bool is_busy( ) const
//     Postcondition: Return value is true if the washer is busy
//     (in a wash cycle); otherwise the return value is false.
//
// VALUE SEMANTICS for the bool_source, averager, and washer classes:
//   Assignments and the copy constructor may be used with the three classes.
//

#ifndef MAIN_SAVITCH_WASHING_H
#define MAIN_SAVITCH_WASHING_H
#include <cstdlib> // Provides std::size_t

namespace main_savitch_8A
{
    class bool_source
    {
    public:
        // CONSTRUCTOR
        bool_source(double p = 0.5);
        // CONSTANT function
        bool query( ) const;
    private:
        double probability; // Probability of query( ) returning true
    };

    class averager
    {
    public:
        // CONSTRUCTOR
        averager( );
        // MODIFICATION function
        void next_number(double value);
        // CONSTANT functions
        std::size_t how_many_numbers( ) const { return count; }
        double average( ) const;
    private:
        std::size_t count; // How many numbers have been given to the averager
        double sum;   // Sum of all the numbers given to the averager
    };

    class washer
    {
    public:
        // CONSTRUCTOR
        washer(unsigned int s = 60);
        // MODIFICATION functions
        void one_second( );
        void start_washing( );
        // CONSTANT function
        bool is_busy( ) const { return (wash_time_left > 0); }
    private:
        unsigned int seconds_for_wash; // Seconds for a single wash
        unsigned int wash_time_left;   // Seconds until washer no longer busy
    };
}

#endif