//---------------------------------------------------------------------------
// Perform
// Preconditions: Movie exists, Movie Count is not 0, Customer doen't have
// the movie
// Postconditions: Customer has the movie, movie count is decremented
// Overrides Transactions virtual Perform. Before Performing the transaction
// the fucntion checks for validity. Then adds the movie to customer sets
// performed variable to true and adds the transaction to the transaction
// list
//---------------------------------------------------------------------------
bool Borrow::Perform(Store& store)
{
store.getInventory().Retrieve(*tempMovie, movie);
if (movie == NULL)
{
performed = false;
return false;
}
else if (movie->getCount() < 1)
{
performed = false;
return false;
}
else if (customer->HasMovie(movie))
{
performed = false;
return false;
}
else if (!movie->DecrementCount())
return false;
else
{
customer->AddMovie(movie);
performed = true;
customer->getTransactionList().Insert(this);
return true;
}
}
//--------------------------------Execute---------------------------------//
//this method performs the actions for the Borrow object, using the
//store as a parameter to access the inventory and alter accordingly
//it also uses the file stream to read in the information
//according to formatting specifications, setting it for this specified
//derived transaction class
bool Borrow::execute(ifstream& file, Store& st)
{
int custIdx;
file >> custIdx;
Customer* cust = st.getCustomer(custIdx);
//read the custtomer index and get the customer at that index
//from the store, if the store doesn't have the customer at that
//spot then the customer has not been created and we cannot do anything
if (cust == NULL)
{
cout << "Invalid Customer ID. Transaction could not be executed.\n";
//no need for clean up since Customer is still NULL
return false;
}
else
{
char format;
file >> format;
//read in the format, the format is specified to only be DVDs
if (format != 'D')
{
cout << "Invalid format. Transaction could not be executed.\n";
//no need for clean up since Formaat is not dynamic
return false;
}
else
{
char genre;
file >> genre;
//read in the genre and then use the stores movie factory
//to create a temporary movie of this genre,
//however, if the genre did not correspond to an appropriate
//movie, return false
Movie* tempMov = st.getMovieFact().createIt(genre);
if (tempMov == NULL)
{
cout << "Invalid movie. Transaction could not be "
<< "executed.\n";
//no need for clean up since tempMov is still NULL
return false;
}
else
{
//everything worked, now we try to set the data
//from the format specifications of a borrow
//movie, and if this didn't work, the movie was
//created so we must clean this up. otherwise, we try
//to borrow the movie from the inventory
if (!tempMov->readTrans(file))
{
delete tempMov;
tempMov = NULL;
return false;
}
else
{
Movie* mov = NULL;
//use a movie locator and a movie return value
//to try to borrow the movie from the stores
//inventory, if the borrow couldn't occur
//we must delete the temporary movie
if (!st.getInventory().borrowMovie(mov, tempMov))
{
cout << "Invalid movie. Transaction could not be "
<< "executed.\n";
delete tempMov;
tempMov = NULL;
return false;
}
else
{
//otherwise everything has worked out so far
//so we set the data of the borrow transaction
//because we already know the movie
//and the customer is accurate
setData(cust, mov);
//if we couldn't borrow we must clean up
if (!cust->borrowMovie(mov))
{
cout << "Invalid movie." <<
"Transaction could not be "
<< "executed.\n";
delete tempMov;
tempMov = NULL;
return false;
}
//otherwise everything worked out perfectly
//so the data is set and the customer
//adds this transaction to his/her trans hist
//and clean up our temp mov
cust->addTransaction(this);
delete tempMov;
tempMov = NULL;
return true;
}
}
}
}
}
}