package com.redhat.thermostat.tools.eclipse.plugin.editor;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import org.eclipse.jface.viewers.ArrayContentProvider;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.IStructuredContentProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Table;
import org.eclipse.ui.forms.IManagedForm;
import org.eclipse.ui.forms.MasterDetailsBlock;
import org.eclipse.ui.forms.SectionPart;
import org.eclipse.ui.forms.widgets.FormToolkit;
import org.eclipse.ui.forms.widgets.Section;

import com.redhat.thermostat.tools.eclipse.plugin.Messages;
import com.redhat.thermostat.tools.eclipse.plugin.model.Plugin;

public abstract class BaseMasterDetailsBlock extends MasterDetailsBlock {

    protected Plugin model;

    protected SectionPart sectionPart;

    public void setModel(Plugin model) {
        this.model = model;
    }

    @Override
    protected void createToolBarActions(IManagedForm managedForm) {
        // no-op
    }

    @Override
    protected void createMasterPart(final IManagedForm managedForm, final Composite parent) {
        FormToolkit toolkit = managedForm.getToolkit();
        final Section section = toolkit.createSection(parent, Section.TITLE_BAR | Section.DESCRIPTION);
        section.setText(getSectionTitle());
        section.setDescription(getSectionDescription());

        sectionPart = new SectionPart(section);
        managedForm.addPart(sectionPart);

        Composite sectionContents = toolkit.createComposite(section);
        GridLayout layout = new GridLayout(2, false);
        sectionContents.setLayout(layout);

        section.setClient(sectionContents);

        Table list = toolkit.createTable(sectionContents, SWT.BORDER | SWT.V_SCROLL);
        list.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
        final TableViewer viewer = new TableViewer(list);
        viewer.addSelectionChangedListener(new ISelectionChangedListener() {
            @Override
            public void selectionChanged(SelectionChangedEvent event) {
                managedForm.fireSelectionChanged(sectionPart, event.getSelection());
            }
        });
        IStructuredContentProvider contentProvider = ArrayContentProvider.getInstance();
        viewer.setContentProvider(contentProvider);
        viewer.setInput(getListViewModel());
        model.addPropertyChangeListener(new PropertyChangeListener() {
            @Override
            public void propertyChange(PropertyChangeEvent arg0) {
                viewer.setInput(getListViewModel());
                viewer.refresh();
            }
        });

        Composite buttons = toolkit.createComposite(sectionContents);
        GridData buttonCompositeLayoutData = new GridData(SWT.FILL, SWT.FILL, false, true);
        buttonCompositeLayoutData.verticalAlignment = SWT.BEGINNING;
        buttons.setLayoutData(buttonCompositeLayoutData);

        buttons.setLayout(new GridLayout(1, false));
        GridData buttonLayoutData = new GridData(SWT.FILL, SWT.BEGINNING, true, false);

        Button add = toolkit.createButton(buttons, Messages.BaseMasterDetailsBlock_add, SWT.NONE);
        add.setLayoutData(buttonLayoutData);
        add.addSelectionListener(new SelectionAdapter() {
            @Override
            public void widgetSelected(SelectionEvent e) {
                addButtonSelected(parent.getShell());

                Object lastElement = viewer.getElementAt(viewer.getTable().getItemCount() - 1);
                if (lastElement != null) {
                    viewer.setSelection(new StructuredSelection(lastElement));
                }
            }

        });

        Button remove = toolkit.createButton(buttons, Messages.BaseMasterDetailsBlock_remove, SWT.NONE);
        remove.setLayoutData(buttonLayoutData);
        remove.addSelectionListener(new SelectionAdapter() {
            @Override
            public void widgetSelected(SelectionEvent e) {
                Object selectedItem = ((IStructuredSelection)viewer.getSelection()).getFirstElement();
                removeButtonSelected(selectedItem);
            }
        });
    }

    /** Return the name of the section containing the model list */
    abstract String getSectionTitle();
    /** Return the description for the section containing the model list*/
    abstract String getSectionDescription();

    /** Return the model object to use in the master list */
    abstract Object[] getListViewModel();

    /** Invoked when the 'add' button is selected */
    abstract void addButtonSelected(Shell shell);

    /**
     * Invoked when the remove button is selected. The {@code selectedItem}
     * should be removed from the model.
     *
     * @param selectedItem
     *            the item currently selected.
     */
    abstract void removeButtonSelected(Object selectedItem);
}