package org.activityinfo.ui.client.page.entry.grouping;

/*
 * #%L
 * ActivityInfo Server
 * %%
 * Copyright (C) 2009 - 2013 UNICEF
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the 
 * License, or (at your option) any later version.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public 
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/gpl-3.0.html>.
 * #L%
 */

import com.extjs.gxt.ui.client.data.*;
import com.extjs.gxt.ui.client.event.Events;
import com.extjs.gxt.ui.client.event.FieldEvent;
import com.extjs.gxt.ui.client.event.Listener;
import com.extjs.gxt.ui.client.store.ListStore;
import com.extjs.gxt.ui.client.widget.form.ComboBox;
import com.google.common.collect.Lists;
import com.google.gwt.user.client.rpc.AsyncCallback;
import org.activityinfo.legacy.client.Dispatcher;
import org.activityinfo.legacy.shared.command.DimensionType;
import org.activityinfo.legacy.shared.command.Filter;
import org.activityinfo.legacy.shared.command.GetSchema;
import org.activityinfo.legacy.shared.model.ActivityDTO;
import org.activityinfo.legacy.shared.model.ActivityFormDTO;
import org.activityinfo.legacy.shared.model.AdminLevelDTO;
import org.activityinfo.legacy.shared.model.SchemaDTO;

import java.util.Collections;
import java.util.List;

public class GroupingComboBox extends ComboBox<GroupingModelData> {

    private final Dispatcher dispatcher;
    private Filter currentFilter = new Filter();

    public GroupingComboBox(Dispatcher dispatcher) {
        this.dispatcher = dispatcher;
        ListLoader<ListLoadResult<GroupingModelData>> loader = new BaseListLoader<ListLoadResult<GroupingModelData>>
                (new GroupingProxy());
        ListStore<GroupingModelData> store = new ListStore<GroupingModelData>(loader);

        setStore(store);
        setUseQueryCache(false);
        setDisplayField("label");
        setValue(GroupingModelData.NONE);
    }

    public GroupingComboBox withSelectionListener(Listener<FieldEvent> listener) {
        addListener(Events.Select, listener);
        return this;
    }

    public void setFilter(Filter filter) {
        assert filter != null;
        currentFilter = filter;
    }

    public GroupingModel getGroupingModel() {
        return getValue().getModel();
    }

    private class GroupingProxy extends RpcProxy<ListLoadResult<GroupingModelData>> {

        @Override
        protected void load(Object loadConfig, final AsyncCallback<ListLoadResult<GroupingModelData>> callback) {

            dispatcher.execute(new GetSchema(), new AsyncCallback<SchemaDTO>() {

                @Override
                public void onFailure(Throwable caught) {
                    callback.onFailure(caught);
                }

                @Override
                public void onSuccess(SchemaDTO result) {
                    List<GroupingModelData> models = Lists.newArrayList();
                    models.add(GroupingModelData.NONE);
                    models.add(GroupingModelData.TIME);
                    for (AdminLevelDTO level : adminLevels(result)) {
                        models.add(new GroupingModelData(level.getName(), new AdminGroupingModel(level.getId())));
                    }
                    callback.onSuccess(new BaseListLoadResult<>(models));
                }
            });
        }

        private List<AdminLevelDTO> adminLevels(SchemaDTO schema) {
            if (currentFilter.getRestrictions(DimensionType.Activity).size() == 1) {
                int activityId = currentFilter.getRestrictedCategory(DimensionType.Activity);
                ActivityDTO activity = schema.getActivityById(activityId);
                List<AdminLevelDTO> levels = Lists.newArrayList(activity.getAdminLevels());
                if (activity.getLocationType().isAdminLevel()) {
                    // since the location type is actually bound to the leaf
                    // here,
                    // we don't want to repeat it in the hierarchy
                    levels.remove(levels.size() - 1);
                }
                return levels;
            } else if (currentFilter.getRestrictions(DimensionType.Database).size() == 1) {
                int databaseId = currentFilter.getRestrictedCategory(DimensionType.Database);
                return schema.getDatabaseById(databaseId).getCountry().getAdminLevels();
            } else if (schema.getCountries().size() == 1) {
                return schema.getDatabases().get(0).getCountry().getAdminLevels();
            } else {
                return Collections.emptyList();
            }
        }
    }
}