/*
 * Created on 18.08.2003
 *
 */
package net.sourceforge.ganttproject.document;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URI;
import java.net.URL;

/**
 * This interface abstracts the details of file access. Implementations of this
 * interface provide methods to open streams to a project file, indepent of
 * storage location (filesystem / WebDAV).
 * 
 * @author Michael Haeusler (michael at akatose.de)
 */
public interface Document {

    /**
     * Gets the description of the document (can be displayed in the
     * application's titlebar).
     * 
     * @return the description of the document
     */
    public String getDescription();

    /**
     * Checks, wether the document is readable.
     * 
     * @return readability
     */
    public boolean canRead();

    /**
     * Checks, wether the document is writable.
     * 
     * @return writability
     */
    public boolean canWrite();

    /**
     * Checks, wether the document should appear in the MRU (list of <b>m</b>ost
     * <b>r</b>ecently <b>u</b>sed files).
     * 
     * @return validity for MRU
     */
    public boolean isValidForMRU();

    /**
     * Tries to acquire a lock. <br>
     * This method is optional. Storage containers, for which locking is
     * inappropriate, should always return true.
     * 
     * @return wether a lock could be successfully acquired
     * @see #releaseLock()
     */
    public boolean acquireLock();

    /**
     * Releases a previously acquired lock.
     * 
     * @see #acquireLock()
     */
    public void releaseLock();

    /**
     * Gets an InputStream, that allows to read from the document.
     * 
     * @return InputStream to read from
     */
    public InputStream getInputStream() throws IOException;

    /**
     * Gets an OutputStream, that allows to write to the document.
     * 
     * @return OutputStream to write to
     */
    public OutputStream getOutputStream() throws IOException;

    /**
     * Gets the path to the document.
     * 
     * @return the path to the document
     */
    public String getPath();

    /**
     * Gets the path to the document, if it is a file on a local file system
     * (can be used to initialize a JFileChooser).
     * 
     * @return the path, if the document is a local file; <code>null</code>,
     *         otherwise.
     */
    public String getFilePath();

    /**
     * Gets the path to the document, if it is a file on a server (can be used
     * to initialize an UrlChooser).
     * 
     * @return the path, if the document is a server file; <code>null</code>,
     *         otherwise.
     */
    public String getURLPath();

    /**
     * Gets the username used to authenticate to the storage container
     * 
     * @return username
     */
    public String getUsername();

    /**
     * Gets the password used to authenticate to the storage container
     * 
     * @return username
     */
    public String getPassword();

    /**
     * Sets the credentials used to authenticate to the storage container
     * 
     * @param user
     *            username
     * @param pass
     *            password
     */
    public void setUserInfo(String user, String pass);

    /**
     * Gets the last error
     * 
     * @return errormessage
     */
    public String getLastError();

    public void read() throws IOException;
    
    public void write() throws IOException;

    public URI getURI();
}
