// This Source Code is in the Public Domain per: http://unlicense.org
package org.litesoft.GWT.client.view;

import org.litesoft.commonfoundation.typeutils.Objects;
import org.litesoft.security.*;
import org.litesoft.uispecification.*;

import com.google.gwt.user.client.*;

import java.util.*;

/**
 * Controls which screen is showing. Coordinates w/ the GWT {@link History}
 * mechanism.
 */
public abstract class AbstractViewManager implements ViewManager {
    protected final ViewAccessControlManager mAccessControlManager;
    private final Map<String, ViewDef> mScreenDefs = new HashMap<String, ViewDef>();
    private final Map<String, ViewFactory> mViewFactories = new HashMap<String, ViewFactory>();

    AbstractViewManager( ViewAccessControlManager pAccessControlManager, ViewFactory... pFactories ) {
        Objects.assertNotNull( "AccessControlManager", mAccessControlManager = pAccessControlManager );
        add( pFactories );
    }

    @Override
    public ViewFactory getViewFactory( ViewDef pDef ) {
        if ( pDef == null ) {
            return null;
        }
        return mAccessControlManager.allowAccessTo( pDef ) ? mViewFactories.get( pDef.getFragmentID() ) : ViewFactory.NO_ACCESS;
    }

    protected ViewDef getViewDef( String pViewDefId ) {
        ViewDef zDef = mScreenDefs.get( pViewDefId );
        return mAccessControlManager.allowAccessTo( zDef ) ? zDef : null;
    }

    /**
     * Use this to add a navigable screen.
     *
     * @param pFactories
     */
    @Override
    public void add( ViewFactory... pFactories ) {
        if ( pFactories != null ) {
            for ( ViewFactory zFactory : pFactories ) {
                if ( zFactory != null ) {
                    ViewDef zDef = zFactory.getViewDef();
                    mViewFactories.put( zDef.getFragmentID(), zFactory );
                    mScreenDefs.put( zDef.getFragmentID(), zDef );
                }
            }
        }
    }

    /**
     * Use this to add placeholder(e.g. for displaying a disabled button).
     *
     * @param pViewDefs
     */
    @Override
    public void add( ViewDef... pViewDefs ) {
        if ( pViewDefs != null ) {
            for ( ViewDef zDef : pViewDefs ) {
                if ( zDef != null ) {
                    mScreenDefs.put( zDef.getFragmentID(), zDef );
                }
            }
        }
    }
}