/*
 * A program to illustrate the use of a generic Queue implemenation.
 * This is not adequate testing by any means.  The point here is to
 * illustrate the use of templates.
 *
 * Author:  Mark A. Sheldon, Tufts University, Fall 2016
 */
#include <iostream>
#include <string>
#include <stdexcept>

#include "Queue.h"

using namespace std;

/*
 * A struct that represents dogs.
 * This illustrates that the queue implementation can be used
 * for more than just basic types like int, double, etc.
 */
struct Dog
{
        string name;
        string owner;
};

/*
 * You can overload the stream insertion operator to make printing
 * easier on your own types!
 * This function says that if someone wants to print a dog using an
 * output stream, here's what you do.
 */
ostream &operator<<(ostream &s, Dog d)
{
        s << "[Dog \"" << d.name << "\" owned by \"" << d.owner << "\"]";
        return s;
}

/*
 * An example of using try-catch to verify that an implementation 
 * throws an exception when expected to.
 */
void test_cannot_dequeue_from_empty()
{
        Queue<int> intQ;
        int n;

        try {
                n = intQ.dequeue();  // should throw exception
        } catch (runtime_error &e) {
                cerr << "PASS:  dequeue from empty queue detected" << endl;
                return;
        }
        cerr << "FAIL:  queue does not detect dequeue from empty!" << endl;
}

int main()
{
        Queue<int> int_q;
        Queue<Dog> dog_q;

        test_cannot_dequeue_from_empty();

        /* Enqueue and dequeue 10 integers */
        for (int i = 0; i < 10; ++i)
                int_q.enqueue(i);

        for (int i = 0; i < 10; ++i)
                cout << int_q.dequeue() << ' ';
        cout << endl;

        /* Now use the queue on Dog instances */

        Dog dogs[] = {{"Humphrey", "Maya"},
                      {"Grey",     "Raina"},
                      {"Shorty",   "Mark"}};
        int n_dogs = sizeof(dogs) / sizeof(Dog);

        for (int i = 0; i < n_dogs; ++i)
                dog_q.enqueue(dogs[i]);

        while (not dog_q.is_empty())
                cout << dog_q.dequeue() << endl;

        return 0;
}