// FileManager.java
// program simulates a hard disk

import java.util.Vector;

public class FileManager
{
	private FileList fileList; // list of files
	private SectorList sectorList; // list of sectors represents the disk


	// constructor
	public FileManager()
	{
		FileList flist = new FileList();
		this.setFileList( flist );
		SectorList slist = new SectorList();
		this.setSectorList( slist );
	} // end constructor


	// constructor
	public FileManager( FileList f, SectorList s )
	{
		setFileList( f );
		setSectorList( s );
	} // end constructor


	// set the file list
	public void setFileList( FileList f )
	{
		fileList = f;
	} // end method setFileList


	// set the sector list
	public void setSectorList( SectorList s )
	{
		sectorList = s;
	} // end method setSectorList


	// get sector list
	public SectorList getSectorList()
	{
		return sectorList;
	} // end method getSectorList


	// get the file list
	public FileList getFileList()
	{
		return fileList;
	} // end method getFileList


	// create the sector list which represents the hard disk
	public void createSectors()
	{
		Sector sector; // sector object

		for( int count = 1; count <= 32; count++ )
		{
		 	sector = new Sector( count, true );
			sectorList.insertAtBack( sector );
		} // end for
		sectorList.setFreeSectors( sectorList.getSize() );
	} // end method createSectors


	// create Files--takes name and number of characters in Kbytes
	public void createFile( String name, int num )
	{
		File file = new File( name, num );
		fileList.insertAtBack( file );
		System.out.printf( "File %s created.\n", name );
	} // end method createFile


	// save files to disk
	public void saveFile( String name )
	{
		ListNode fileNode = fileList.findNode( name ); // return node in the file list
		File file = null;
		int sectorsRequired = 0;
		// int size = sectorList.getFreeSectors(); IGNORE THIS LINE
		Vector < ListNode > v = new Vector < ListNode > (); // vector object to hold sectors used

		// check for presence of file in the file list
		if( fileNode != null )
		{
			file = ( File ) fileNode.getObject(); // data portion of file node
			sectorsRequired = file.getSectorsNeeded(); // sectors needed to store file

			if( sectorsRequired <= sectorList.getFreeSpace() ) // checks available space on disk
			{
				ListNode current = sectorList.getFirstNode();

				// loop thru sector list, check if each node is available or occupied
				while ( current != null && sectorsRequired >= 1 )
				{
					Sector sec = ( Sector ) current.getObject();

					if( sec.getFree() ) // checks if sector is free or not
						{
							sec.setFree( false ); // change status of sector to occupied
							sectorsRequired--;
							// sectorList.setFreeSectors( size--); IGONRE THIS LINE
							v.add( current ); // adds node to vector that stores which sectors have file
						} // end if
					current = current.getNext();
				} // end while
			file.setSectorsUsed( v ); // store sectors occupied in vector & set data portion of file node
			file.setSaved( true ); // set saved to true in data portion of file node

			System.out.printf( "File %s saved.  File contains %d Kbytes.  %d sectors used.\n",
				name, file.getCharacters(), v.size() );
			} // end if
			else
				System.out.printf ( "Cannot save %s. %d sectors needed, %d are free.\n",
					name, file.getSectorsNeeded(), sectorList.getFreeSpace() );

		} // end if
		else
			System.out.printf( "Cannot save %s. File not found.\n", name );

	} // end method saveFile


	// delete a file
	public void deleteFile( String name )
	{
		ListNode fileNode = fileList.findNode( name ); // find node of particular file
		ListNode sectorNode;
		if ( fileNode != null )
		{
			// set number of characters to zero to indicate file empty
			File file = ( File ) fileNode.getObject();
			file.setCharacters( 0 );

			// read the nodes from the vector and change the sectors to indicate they are available
			Vector v = file.getSectorsUsed();
			Sector sec;
			int size = v.size();
			for ( int i = 0; i < size; i++ )
			{
				sectorNode = ( ListNode ) v.remove( 0 );
				sec = ( Sector ) sectorNode.getObject();
				sec.setFree( true );
				sectorNode.setData( sec );
			} // end for

			file.clearSectorsUsed(); // empty the vector so that points to no sectors in list
			file.setSaved( false );
			System.out.printf( "File %s deleted. %d sectors freed.\n", name, size );

		} // end if
		else
			System.out.printf( "Cannot delete %s. File not found.\n", name );
	} // end method deleteFile


	// print file usage report
	public void printReport()
	{
		System.out.println("\n");
		System.out.printf( "                              DISK USAGE\n" );

		System.out.printf( "%17s%60s\n", "Files Saved", "Sectors" );
		System.out.println( "******************************************" +
			"***********************************" );

		ListNode node; // file from current file list
		File file; // file object in file node
		Vector v; // vector object hold sectors used info
		Sector sec;

		node = fileList.getFirstNode();

		while ( node != null )
		{
			file = ( File ) node.getObject();
			if( file.getSaved() )
			{
				System.out.printf ( "%17s", file.getFileName() );
				System.out.printf ( "%60s\n", file.printSectorsUsed() );
			} // end if

			node = node.getNext();
		} // end while
		System.out.println( "******************************************" +
			"***********************************" );

		if ( sectorList.getFreeSpace() == 0 )
			System.out.printf( "%17s%60s\n", "AVAILABLE SPACE", "No sectors free" );
		else
			System.out.printf( "%17s%60s\n", "AVAILABLE SPACE", sectorList.sectorsAvailable() );

		System.out.println("\n");
	} // end method printReport


	// simulate creating, saving and deleting files
	public void fileDemo()
	{
		System.out.print ( "This program simulates the saving and deleting of files to a hard disk.\n");
		System.out.print ( "The disk contains 32 sectors." +
			"  Each sector can hold a maximum of 4 Kbytes.\n" );
		System.out.print ( "The total disk space is then 128 Kbytes.\n\n" );
		createSectors();
		createFile( "superman.jpg", 31 );
		createFile( "aquaman.jpg", 32 );
		createFile( "greenlantern.jpg", 13 );
		createFile( "dr.strange.jpg", 20 );
		createFile( "cyclops.jpg", 27);
		createFile( "ironman.jpg", 16 );
		createFile( "flash.jpg", 6);
		createFile( "daredevil.jpg", 22 );
		createFile( "hulk.jpg", 17 );
		createFile( "sinestro.jpg", 14 );

		saveFile( "superman.jpg" );
		saveFile( "aquaman.jpg" );
		saveFile( "ironman.jpg" );
		saveFile( "flash.jpg" );
		saveFile( "greenlantern.jpg" );
		saveFile( "dr.strange.jpg" );
		printReport();
		deleteFile( "flash.jpg" );
		printReport();
		saveFile( "dr.strange.jpg" );
		saveFile( "cyclop.jpg" );
		saveFile( "cyclops.jpg" );
		printReport();
		deleteFile( "dr.strange.jpg" );
		printReport();
		saveFile( "hulk.jpg" );
		saveFile( "sinestro.jpg" );
		printReport();
		deleteFile( "superman.jpg" );
		printReport();
		saveFile( "daredevil.jpg" );
		printReport();
		deleteFile( "iromnan.jpg" );
		deleteFile( "ironman.jpg" );
		printReport();
		saveFile( "dr.strange.jpg" );
		printReport();
		saveFile( "daredevil.jpg" );
		printReport();

	} // end method fileDemo

} // end class FileManager