/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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
 *
 *    https://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.grails.build.logging;

import groovy.ant.AntBuilder;

import org.apache.tools.ant.BuildEvent;
import org.apache.tools.ant.BuildLogger;
import org.apache.tools.ant.DefaultLogger;
import org.apache.tools.ant.MagicNames;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.ProjectHelper;
import org.apache.tools.ant.types.LogLevel;
import org.apache.tools.ant.util.StringUtils;

import grails.build.logging.GrailsConsole;

/**
 * Silences ant builder output.
 *
 * @author Graeme Rocher
 * @since 2.0
 */
public class GrailsConsoleAntBuilder extends AntBuilder {

    public GrailsConsoleAntBuilder(Project project) {
        super(project);
    }

    public GrailsConsoleAntBuilder() {
        super(createAntProject());
    }

    /**
     * @return Factory method to create new Project instances
     */
    @SuppressWarnings("unchecked")
    protected static Project createAntProject() {
        final Project project = new Project();

        final ProjectHelper helper = ProjectHelper.getProjectHelper();
        project.addReference(MagicNames.REFID_PROJECT_HELPER, helper);
        helper.getImportStack().addElement("AntBuilder"); // import checks that stack is not empty

        addGrailsConsoleBuildListener(project);

        project.init();
        project.getBaseDir();
        return project;
    }

    public static void addGrailsConsoleBuildListener(Project project) {
        final BuildLogger logger = new GrailsConsoleLogger();

        logger.setMessageOutputLevel(Project.MSG_INFO);
        logger.setOutputPrintStream(System.out);
        logger.setErrorPrintStream(System.err);

        project.addBuildListener(logger);

        GrailsConsole instance = GrailsConsole.getInstance();
        project.addBuildListener(new GrailsConsoleBuildListener(instance));

        if (!instance.isVerbose()) {
            for (Object buildListener : project.getBuildListeners()) {
                if (buildListener instanceof BuildLogger) {
                    ((BuildLogger) buildListener).setMessageOutputLevel(LogLevel.ERR.getLevel());
                }
            }
        }
    }

    private static class GrailsConsoleLogger extends DefaultLogger {
        /**
         * Name of the current target, if it should
         * be displayed on the next message. This is
         * set when a target starts building, and reset
         * to <code>null</code> after the first message for
         * the target is logged.
         */
        protected String targetName;
        protected GrailsConsole console = GrailsConsole.getInstance();

        /**
         * Notes the name of the target so it can be logged
         * if it generates any messages.
         *
         * @param event A BuildEvent containing target information.
         *              Must not be <code>null</code>.
         */
        @Override
        public void targetStarted(BuildEvent event) {
            targetName = event.getTarget().getName();
        }

        /**
         * Resets the current target name to <code>null</code>.
         *
         * @param event Ignored in this implementation.
         */
        @Override
        public void targetFinished(BuildEvent event) {
            targetName = null;
        }

        /**
         * Logs a message for a target if it is of an appropriate
         * priority, also logging the name of the target if this
         * is the first message which needs to be logged for the
         * target.
         *
         * @param event A BuildEvent containing message information.
         *              Must not be <code>null</code>.
         */
        @Override
        public void messageLogged(BuildEvent event) {
            if (event.getPriority() > msgOutputLevel ||
                    null == event.getMessage() ||
                    "".equals(event.getMessage().trim())) {
                return;
            }

            if (null != targetName) {
                console.verbose(System.lineSeparator() + targetName + ":");
                targetName = null;
            }
        }
    }
}
