/*
 * Copyright 2004-2009 the original author or authors.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.compass.spring.web.mvc;

import java.util.HashMap;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.compass.core.support.search.CompassSearchCommand;
import org.compass.core.support.search.CompassSearchHelper;
import org.compass.core.support.search.CompassSearchResults;
import org.springframework.util.StringUtils;
import org.springframework.validation.BindException;
import org.springframework.web.servlet.ModelAndView;

/**
 * <p> A general Spring's MVC Controller that perform the search operation of <code>Compass</code>.
 *
 * <p>Will perform the search operation on the <code>Compass</code> instance using the query supplied
 * by the {@link CompassSearchCommand}.
 *
 * <p>Pagination can be enabled by setting the <code>pageSize</code> property on the controller,
 * as well as providing the <code>page</code> number property on the {@link CompassSearchCommand}.
 *
 * <p>The controller has two views to be set, the <code>searchView</code>, which is the view that
 * holds the screen which the user will initiate the search operation, and the
 * <code>searchResultsView</code>, which will show the results of the search operation (they can be
 * the same page).
 *
 * <p>The results of the search operation will be saved under the <code>searchResultsName<code>,
 * which defaults to "searchResults".
 *
 * <p>In order to extend and execute additional operations during the search process
 * {@link org.compass.core.support.search.CompassSearchHelper} should be extended and
 * set using {@link #setSearchHelper(org.compass.core.support.search.CompassSearchHelper)}.
 *
 * @author kimchy
 */
public class CompassSearchController extends AbstractCompassCommandController {

    private String searchView;

    private String searchResultsView;

    private String searchResultsName = "searchResults";

    private Integer pageSize;

    private CompassSearchHelper searchHelper;

    public CompassSearchController() {
        setCommandClass(CompassSearchCommand.class);
    }

    public void afterPropertiesSet() throws Exception {
        super.afterPropertiesSet();
        if (searchView == null) {
            throw new IllegalArgumentException("Must set the searchView property");
        }
        if (searchResultsView == null) {
            throw new IllegalArgumentException("Must set the searchResultsView property");
        }
        if (searchHelper == null) {
            searchHelper = new CompassSearchHelper(getCompass(), getPageSize());
        }
    }

    protected ModelAndView handle(HttpServletRequest request, HttpServletResponse response, Object command,
                                  BindException errors) throws Exception {
        final CompassSearchCommand searchCommand = (CompassSearchCommand) command;
        if (!StringUtils.hasText(searchCommand.getQuery())) {
            return new ModelAndView(getSearchView(), getCommandName(), searchCommand);
        }
        CompassSearchResults searchResults = searchHelper.search(searchCommand);
        HashMap data = new HashMap();
        data.put(getCommandName(), searchCommand);
        data.put(getSearchResultsName(), searchResults);
        return new ModelAndView(getSearchResultsView(), data);
    }

    /**
     * Returns the view that holds the screen which the user will initiate the
     * search operation.
     */
    public String getSearchView() {
        return searchView;
    }

    /**
     * Sets the view that holds the screen which the user will initiate the
     * search operation.
     */
    public void setSearchView(String searchView) {
        this.searchView = searchView;
    }

    /**
     * Returns the name of the results that the {@link org.compass.core.support.search.CompassSearchResults}
     * will be saved under. Defaults to "searchResults".
     */
    public String getSearchResultsName() {
        return searchResultsName;
    }

    /**
     * Sets the name of the results that the {@link org.compass.core.support.search.CompassSearchResults} will
     * be saved under. Defaults to "searchResults".
     */
    public void setSearchResultsName(String searchResultsName) {
        this.searchResultsName = searchResultsName;
    }

    /**
     * Returns the view which will show the results of the search operation.
     */
    public String getSearchResultsView() {
        return searchResultsView;
    }

    /**
     * Sets the view which will show the results of the search operation.
     */
    public void setSearchResultsView(String resultsView) {
        this.searchResultsView = resultsView;
    }

    /**
     * Sets the page size for the pagination of the results. If not set, not
     * pagination will be used.
     */
    public Integer getPageSize() {
        return pageSize;
    }

    /**
     * Returns the page size for the pagination of the results. If not set, not
     * pagination will be used.
     *
     * @param pageSize The page size when using paginated results
     */
    public void setPageSize(Integer pageSize) {
        this.pageSize = pageSize;
    }

    /**
     * <p>The search helper is used to execute the actual search. By default (if not set)
     * the search controller will create a new search helper. If provided, the search
     * controller will use it to perform the search.
     *
     * <p>Mainly used to extend the search helper and execute additional operation within
     * specific calbacks the search helper exposes.
     *
     * @param searchHelper A specific search helper to use
     */
    public void setSearchHelper(CompassSearchHelper searchHelper) {
        this.searchHelper = searchHelper;
    }
}