EnumParser.java

/*
 * Copyright 2015 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * 
 *      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.drools.workbench.screens.enums.client.editor;

import java.util.ArrayList;
import java.util.List;

/**
 * Utility methods to parse Enums.
 */
public class EnumParser {

    private EnumParser() {
    }

    /**
     * Parse enum definitions from a String
     * @param content
     * @return A List of Enum definitions
     */
    public static List<EnumRow> fromString( final String content ) {
        final List<EnumRow> enums = new ArrayList<EnumRow>();

        if ( content == null || content.isEmpty() ) {
            return enums;

        } else {
            final String[] lines = content.split( "\\n" );
            for ( int i = 0; i < lines.length; i++ ) {
                final String line = lines[ i ].trim();
                final EnumRow er = parseEnum( line );
                if ( er != null ) {
                    enums.add( er );
                }
            }
        }
        return enums;
    }

    private static EnumRow parseEnum( final String line ) {
        if ( line.equals( "" ) || line.startsWith( "#" ) || line.startsWith( "//" ) ) {
            return null;
        }

        final int colonIndex = line.indexOf( ":" );
        if ( colonIndex < 0 ) {
            return new EnumRow( line );
        }
        String factField = line.substring( 0,
                                           colonIndex );
        factField = factField.trim();
        final int dotIndex = factField.indexOf( "." );
        if ( dotIndex < 0 ) {
            return new EnumRow( line );
        }

        String factName = factField.substring( 0,
                                               dotIndex );
        factName = factName.trim();
        String fieldName = factField.substring( dotIndex + 1,
                                                factField.length() );
        fieldName = fieldName.trim();

        if ( !factName.startsWith( "'" ) ) {
            return new EnumRow( line );
        }
        if ( !fieldName.endsWith( "'" ) ) {
            return new EnumRow( line );
        }
        factName = factName.substring( 1 ).trim();
        fieldName = fieldName.substring( 0, fieldName.length() - 1 ).trim();

        final String context = line.substring( colonIndex + 1 ).trim();

        final EnumRow er = new EnumRow( factName,
                                        fieldName,
                                        context );
        if ( !er.isValid() ) {
            return new EnumRow( line );
        }
        return er;
    }

    /**
     * Parse enum definitions to String
     * @param content
     * @return A String representing the Enum definitions
     */
    public static String toString( final List<EnumRow> content ) {
        if ( content == null || content.isEmpty() ) {
            return "";
        }
        final StringBuilder sb = new StringBuilder();
        for ( final EnumRow enumRow : content ) {
            sb.append( enumRow.toString() ).append( "\n" );
        }
        return sb.toString();
    }

}