#ifndef MESSAGE_H_
#define MESSAGE_H_

#include <string>

using namespace std;

class Message
{
private:
    int id;
    string *textptr;

    static int instance;  // identify Message instantiations

public:
    Message() : id(++instance), textptr(nullptr)
    {
        cout << "*** Default constructor: " << *this << endl;
    }

    Message(string text) : id(++instance), textptr(new string(text))
    {
        cout << "*** Constructor(" << text << "): " << *this << endl;
    }

    virtual ~Message()
    {
        cout << "*** Destructor: " << *this << endl;
        delete textptr;
    }

    Message(const Message& other)
    {
        id = ++instance;

        // Copy the other's resources.
        textptr = new string(*other.textptr);

        cout << "*** Copy constructor(" << other << "): " << *this << endl;
    }

    Message(Message&& other)
    {
        // Steal the other's resources.
        id = other.id;
        textptr = other.textptr;

        cout << "*** Move constructor(" << other << "): " << *this << endl;

        // The other's resources are now stolen.
        other.id = -other.id;
        other.textptr = nullptr;
    }

    Message& operator =(const Message& other)
    {
        if (this != &other)
        {
            // Copy the other's resources.
            textptr = new string(*other.textptr);
        }

        cout << "*** Copy assignment(" << other << "): " << *this << endl;
        return *this;
    }

    Message& operator =(Message&& other)
    {
        if (this != &other)
        {
            // Steal the other's resources.
            id = other.id;
            textptr = other.textptr;

            cout << "*** Move assignment(" << other << "): " << *this << endl;

            // The other's resources are now stolen.
            other.id = -other.id;
            other.textptr = nullptr;
        }
        return *this;
    }

    friend Message operator +(Message& msg1, Message& msg2)
    {
        Message sum = Message(*msg1.textptr + " " + *msg2.textptr);

        cout << "*** Operator + returns: " << sum << endl;
        return sum;  // returns an rvalue
    }

    friend Message add(Message& msg1, Message& msg2)
    {
        Message sum = Message(*msg1.textptr + " " + *msg2.textptr);

        cout << "*** Function add returns: " << sum << endl;
        return sum;  // returns an rvalue
    }

    friend ostream& operator <<(ostream& outs, const Message& msg)
    {
        cout << "[" << msg.id << "]";
        if (msg.textptr != nullptr) cout << *msg.textptr;
        else                        cout << "<empty>";

        return outs;
    }
};

#endif /* MESSAGE_H_ */