package framework;

import java.io.*;

/**
 Responsible for saving the model to a file and for reading
 the model from a file.
 <p>
 This is used by the FileMenuController, but could be used
 in other places, too.
 */
public class FileSystemGateway {
    /**
     Reads a model from a specified file.

     @param fname  The name of the file containing the model.
     @return The saved model
     */
	public Model getModel(String fname) throws AppError {
		try {
			ObjectInputStream ois =
               new ObjectInputStream(new FileInputStream(fname));
               Model model = (Model) ois.readObject();
               model.setFname(fname); // just in case
               ois.close();
               return model;
		   } catch(Exception e) {
			   throw new AppError(e.getMessage());
		   }
	}

    /**
     Saves a model to a specified file.

     @param model  the model to be saved.
     @param fname  the name of the specified file
     */
	public void saveModelAs(Model model, String fname) throws AppError {
		try {
			model.setUnsavedChanges(false);
			model.setFname(fname); // needed?
			ObjectOutputStream obstream =
        	new ObjectOutputStream(
        		new FileOutputStream(fname));
        	obstream.writeObject(model);
        	obstream.flush();
        	obstream.close();
		} catch(Exception e) {
			throw new AppError(e.getMessage());
		}
	}
    /**
     Same as saveModelAs(m, m.getFname());

     @param m  the model to be saved.
     */
	public void saveModel(Model m) throws AppError {
		saveModelAs(m, m.getFname());
	}

}