/* (c) 2014 Open Source Geospatial Foundation - all rights reserved
 * (c) 2014 OpenPlans
 * This code is licensed under the GPL 2.0 license, available at the root
 * application directory.
 */
package org.geoserver.rest.web;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.logging.Logger;

import org.apache.wicket.markup.html.form.TextArea;
import org.apache.wicket.markup.html.form.TextField;
import org.apache.wicket.model.IModel;
import org.apache.wicket.model.PropertyModel;
import org.apache.wicket.validation.IValidatable;
import org.apache.wicket.validation.IValidator;
import org.geoserver.catalog.MetadataMap;
import org.geoserver.config.SettingsInfo;
import org.geoserver.rest.ecql.RESTUploadECQLPathMapper;
import org.geoserver.web.data.settings.SettingsPluginPanel;
import org.geoserver.web.util.MapModel;
import org.geoserver.web.util.MetadataMapModel;
import org.geotools.filter.FilterAttributeExtractor;
import org.geotools.filter.text.cql2.CQLException;
import org.geotools.filter.text.ecql.ECQL;
import org.geotools.util.logging.Logging;
import org.opengis.filter.expression.Expression;

/**
 * Simple Panel which adds a TextField for setting the ECQL expression for the WorkSpace or Global Settings.
 * 
 * @author Nicola Lagomarsini Geosolutions S.A.S.
 * 
 */
public class RESTECQLSettingsPanel extends SettingsPluginPanel {

    private static Logger LOGGER = Logging
            .getLogger("org.geoserver.rest.web.RESTECQLSettingsPanel");

    public RESTECQLSettingsPanel(String id, IModel<SettingsInfo> model) {
        super(id, model);

        // Selection of the IModel associated to the metadata map
        final PropertyModel<MetadataMap> metadata = new PropertyModel<MetadataMap>(model,
                "metadata");

        // TextField associated to the root directory to map
        TextArea ecqlexp = new TextArea("ecqlexp", new MetadataMapModel(metadata,
                RESTUploadECQLPathMapper.EXPRESSION_KEY,String.class));
        // Addition of the validator
        ecqlexp.add(new IValidator<String>() {

            @Override
            public void validate(IValidatable<String> validatable) {
                // Extraction of the expression for the validation
                String expression = validatable.getValue();

                Expression ecql = null;
                // First check on the Syntax of the expression
                try {
                    ecql = ECQL.toExpression(expression);
                } catch (CQLException e) {
                    LOGGER.info("Unable to parse the following Expression");
                    error("Unable to parse the following Expression:" + e.getSyntaxError());
                }

                // Selection of a FilterAttributeExtractor
                if (ecql != null) {
                    FilterAttributeExtractor filter = new FilterAttributeExtractor();
                    ecql.accept(filter, null);
                    // Extraction of the attributes
                    List<String> attributes = Arrays.asList(filter.getAttributeNames());
                    // Invalid Attributes
                    List<String> invalid = new ArrayList<String>();
                    // Check on the attributes
                    for(String attribute : attributes){
                        if(!(attribute.equalsIgnoreCase(RESTUploadECQLPathMapper.PATH) || 
                                attribute.equalsIgnoreCase(RESTUploadECQLPathMapper.NAME))){
                            invalid.add(attribute);
                        }
                    }
                    
                    //If and only if an invalid attribute is present
                    if(!invalid.isEmpty()){
                        
                      StringBuilder string = new StringBuilder("Invalid Attributes: ");

                        for(String attribute : invalid){
                            string.append(attribute);
                            string.append(", ");
                        }
                        
                        // Removal of the last 2 characters
                        string.setLength(string.length() - 2);
                        
                        // If invalid attributes have been found, they are reported
                        error(invalid.toString());  
                    }
                }
            }
        });
        add(ecqlexp);
    }
}