/*
 * This file is part of the OpenSCADA project
 * Copyright (C) 2006-2010 TH4 SYSTEMS GmbH (http://th4-systems.com)
 *
 * OpenSCADA is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 3
 * only, as published by the Free Software Foundation.
 *
 * OpenSCADA is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License version 3 for more details
 * (a copy is included in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3 along with OpenSCADA. If not, see
 * <http://opensource.org/licenses/lgpl-3.0.html> for a copy of the LGPLv3 License.
 */

package org.openscada.opc.lib.da.browser;

import java.net.UnknownHostException;
import java.util.Collection;
import java.util.EnumSet;
import java.util.LinkedList;

import org.jinterop.dcom.common.JIException;
import org.jinterop.dcom.core.JIVariant;
import org.openscada.opc.dcom.da.OPCBROWSEDIRECTION;
import org.openscada.opc.dcom.da.OPCBROWSETYPE;
import org.openscada.opc.dcom.da.impl.OPCBrowseServerAddressSpace;

/**
 * Browse through the hierarchical server namespace.
 * <br/>
 * The operations on the address space browser browser are not synchronized
 * as is the TreeBrowser itself. The user must take care of preventing
 * simultanious access to this instance and the server address space browser.
 * @author Jens Reimann <jens.reimann@th4-systems.com>
 *
 */
public class TreeBrowser extends BaseBrowser
{

    private String _filterCriteria = "";

    private EnumSet<Access> _accessMask = EnumSet.noneOf ( Access.class );

    private int _variantType = JIVariant.VT_EMPTY;

    /**
     * Browse for all items without search parameters.
     * <br/>
     * This will actually call:
     * <br/>
     * <code>
     * TreeBrowser ( browser, "", EnumSet.noneOf ( Access.class ), JIVariant.VT_EMPTY );
     * </code>
     * @param browser The browser to use for browsing
     */
    public TreeBrowser ( final OPCBrowseServerAddressSpace browser )
    {
        super ( browser );
    }

    /**
     * Browse for items with search parameters.
     * @param browser The browser to use
     * @param filterCriteria The filter criteria. It is specific to the server you use.
     * @param accessMask The access mask (use <code>EnumSet.noneOf ( Access.class )</code> for all)
     * @param variantType The variant type (use <code>JIVariant.VT_EMPTY</code> for all)
     */
    public TreeBrowser ( final OPCBrowseServerAddressSpace browser, final String filterCriteria, final EnumSet<Access> accessMask, final int variantType )
    {
        super ( browser );
        this._filterCriteria = filterCriteria;
        this._accessMask = accessMask;
        this._variantType = variantType;
    }

    /**
     * Move the tree browser to the root folder
     * @throws JIException
     */
    protected void moveToRoot () throws JIException
    {
        this._browser.changePosition ( null, OPCBROWSEDIRECTION.OPC_BROWSE_TO );
    }

    /**
     * Move the tree browser to a branch
     * @param branch The branch to move to
     * @throws JIException
     */
    protected void moveToBranch ( final Branch branch ) throws JIException
    {
        Collection<String> branchStack = branch.getBranchStack ();

        moveToRoot ();
        for ( String branchName : branchStack )
        {
            this._browser.changePosition ( branchName, OPCBROWSEDIRECTION.OPC_BROWSE_DOWN );
        }
    }

    /**
     * Browse the root branch for its sub-branches.
     * @return The list of sub branches
     * @throws JIException
     * @throws IllegalArgumentException
     * @throws UnknownHostException
     */
    public Branch browseBranches () throws JIException, IllegalArgumentException, UnknownHostException
    {
        Branch branch = new Branch ();
        fillBranches ( branch );
        return branch;
    }

    /**
     * Browse the root branch for this leaves.
     * @return The list of leaves
     * @throws IllegalArgumentException
     * @throws UnknownHostException
     * @throws JIException
     */
    public Branch browseLeaves () throws IllegalArgumentException, UnknownHostException, JIException
    {
        Branch branch = new Branch ();
        fillLeaves ( branch );
        return branch;
    }

    /**
     * Fill the branch list of the provided branch.
     * @param branch The branch to fill.
     * @throws JIException
     * @throws IllegalArgumentException
     * @throws UnknownHostException
     */
    public void fillBranches ( final Branch branch ) throws JIException, IllegalArgumentException, UnknownHostException
    {
        moveToBranch ( branch );
        browse ( branch, false, true, false );
    }

    /**
     * Fill the leaf list of the provided branch. 
     * @param branch The branch to fill.
     * @throws IllegalArgumentException
     * @throws UnknownHostException
     * @throws JIException
     */
    public void fillLeaves ( final Branch branch ) throws IllegalArgumentException, UnknownHostException, JIException
    {
        moveToBranch ( branch );
        browse ( branch, true, false, false );
    }

    /**
     * Browse through all levels of the tree browser.
     * @return The whole expanded server address space
     * @throws JIException
     * @throws IllegalArgumentException
     * @throws UnknownHostException
     */
    public Branch browse () throws JIException, IllegalArgumentException, UnknownHostException
    {
        Branch branch = new Branch ();
        fill ( branch );
        return branch;
    }

    /**
     * Fill the leaves and branches of the branch provided branches including
     * alls sub-branches. 
     * @param branch The branch to fill.
     * @throws IllegalArgumentException
     * @throws UnknownHostException
     * @throws JIException
     */
    public void fill ( final Branch branch ) throws IllegalArgumentException, UnknownHostException, JIException
    {
        moveToBranch ( branch );
        browse ( branch, true, true, true );
    }

    /**
     * Fill the branch object with the leaves of this currently selected branch.
     * <br/>
     * The server object is not located to the branch before browsing!
     * @param branch The branch to fill
     * @throws IllegalArgumentException
     * @throws UnknownHostException
     * @throws JIException
     */
    protected void browseLeaves ( final Branch branch ) throws IllegalArgumentException, UnknownHostException, JIException
    {
        branch.setLeaves ( new LinkedList<Leaf> () );

        for ( String item : browse ( OPCBROWSETYPE.OPC_LEAF, this._filterCriteria, this._accessMask, this._variantType ) )
        {
            Leaf leaf = new Leaf ( branch, item, this._browser.getItemID ( item ) );
            branch.getLeaves ().add ( leaf );
        }
    }

    protected void browseBranches ( final Branch branch, final boolean leaves, final boolean descend ) throws IllegalArgumentException, UnknownHostException, JIException
    {
        branch.setBranches ( new LinkedList<Branch> () );

        for ( String item : browse ( OPCBROWSETYPE.OPC_BRANCH, this._filterCriteria, this._accessMask, this._variantType ) )
        {
            Branch subBranch = new Branch ( branch, item );
            // descend only if we should
            if ( descend )
            {
                this._browser.changePosition ( item, OPCBROWSEDIRECTION.OPC_BROWSE_DOWN );
                browse ( subBranch, leaves, true, true );
                this._browser.changePosition ( null, OPCBROWSEDIRECTION.OPC_BROWSE_UP );
            }
            branch.getBranches ().add ( subBranch );
        }
    }

    protected void browse ( final Branch branch, final boolean leaves, final boolean branches, final boolean descend ) throws IllegalArgumentException, UnknownHostException, JIException
    {
        // process leaves
        if ( leaves )
        {
            browseLeaves ( branch );
        }

        // process branches
        if ( branches )
        {
            browseBranches ( branch, leaves, descend );
        }
    }
}
