/*
 * 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
 *
 *      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.apache.logging.log4j.core.appender;

import org.apache.logging.log4j.core.Appender;
import org.apache.logging.log4j.core.Core;
import org.apache.logging.log4j.core.Filter;
import org.apache.logging.log4j.core.Layout;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.appender.rolling.DefaultRolloverStrategy;
import org.apache.logging.log4j.core.appender.rolling.DirectFileRolloverStrategy;
import org.apache.logging.log4j.core.appender.rolling.DirectWriteRolloverStrategy;
import org.apache.logging.log4j.core.appender.rolling.RollingRandomAccessFileManager;
import org.apache.logging.log4j.core.appender.rolling.RolloverStrategy;
import org.apache.logging.log4j.core.appender.rolling.TriggeringPolicy;
import org.apache.logging.log4j.core.net.Advertiser;
import org.apache.logging.log4j.plugins.Plugin;
import org.apache.logging.log4j.plugins.PluginBuilderAttribute;
import org.apache.logging.log4j.plugins.PluginElement;
import org.apache.logging.log4j.plugins.PluginFactory;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.zip.Deflater;

/**
 * An appender that writes to random access files and can roll over at
 * intervals.
 */
@Plugin(name = "RollingRandomAccessFile", category = Core.CATEGORY_NAME, elementType = Appender.ELEMENT_TYPE, printObject = true)
public final class RollingRandomAccessFileAppender extends AbstractOutputStreamAppender<RollingRandomAccessFileManager> {

    public static class Builder<B extends Builder<B>> extends AbstractOutputStreamAppender.Builder<B>
            implements org.apache.logging.log4j.plugins.util.Builder<RollingRandomAccessFileAppender> {

        public Builder() {
            super();
            setBufferSize(RollingRandomAccessFileManager.DEFAULT_BUFFER_SIZE);
            setIgnoreExceptions(true);
            setImmediateFlush(true);
        }

        @PluginBuilderAttribute("fileName")
        private String fileName;

        @PluginBuilderAttribute("filePattern")
        private String filePattern;

        @PluginBuilderAttribute("append")
        private boolean append = true;

        @PluginElement("Policy")
        private TriggeringPolicy policy;

        @PluginElement("Strategy")
        private RolloverStrategy strategy;

        @PluginBuilderAttribute("advertise")
        private boolean advertise;

        @PluginBuilderAttribute("advertiseURI")
        private String advertiseURI;

        @PluginBuilderAttribute
        private String filePermissions;

        @PluginBuilderAttribute
        private String fileOwner;

        @PluginBuilderAttribute
        private String fileGroup;

        @Override
        public RollingRandomAccessFileAppender build() {
            final String name = getName();
            if (name == null) {
                LOGGER.error("No name provided for FileAppender");
                return null;
            }

            if (strategy == null) {
                if (fileName != null) {
                    strategy = DefaultRolloverStrategy.newBuilder()
                            .setCompressionLevelStr(String.valueOf(Deflater.DEFAULT_COMPRESSION))
                            .setConfig(getConfiguration())
                            .build();
                } else {
                    strategy = DirectWriteRolloverStrategy.newBuilder()
                            .setCompressionLevelStr(String.valueOf(Deflater.DEFAULT_COMPRESSION))
                            .setConfig(getConfiguration())
                            .build();
                }
            } else if (fileName == null && !(strategy instanceof DirectFileRolloverStrategy)) {
                LOGGER.error("RollingFileAppender '{}': When no file name is provided a DirectFileRolloverStrategy must be configured", name);
                return null;
            }

            if (filePattern == null) {
                LOGGER.error("No filename pattern provided for FileAppender with name " + name);
                return null;
            }

            if (policy == null) {
                LOGGER.error("A TriggeringPolicy must be provided");
                return null;
            }

            final Layout<? extends Serializable> layout = getOrCreateLayout();

            final boolean immediateFlush = isImmediateFlush();
            final int bufferSize = getBufferSize();
            final RollingRandomAccessFileManager manager = RollingRandomAccessFileManager
                    .getRollingRandomAccessFileManager(fileName, filePattern, append, immediateFlush, bufferSize, policy,
                            strategy, advertiseURI, layout,
                            filePermissions, fileOwner, fileGroup, getConfiguration());
            if (manager == null) {
                return null;
            }

            manager.initialize();

            return new RollingRandomAccessFileAppender(name, layout,getFilter(), manager, fileName, filePattern,
                    isIgnoreExceptions(), immediateFlush, bufferSize, advertise ? getConfiguration().getAdvertiser() : null);
        }

        public B setFileName(final String fileName) {
            this.fileName = fileName;
            return asBuilder();
        }

        public B setFilePattern(final String filePattern) {
            this.filePattern = filePattern;
            return asBuilder();
        }

        public B setAppend(final boolean append) {
            this.append = append;
            return asBuilder();
        }

        public B setPolicy(final TriggeringPolicy policy) {
            this.policy = policy;
            return asBuilder();
        }

        public B setStrategy(final RolloverStrategy strategy) {
            this.strategy = strategy;
            return asBuilder();
        }

        public B setAdvertise(final boolean advertise) {
            this.advertise = advertise;
            return asBuilder();
        }

        public B setAdvertiseURI(final String advertiseURI) {
            this.advertiseURI = advertiseURI;
            return asBuilder();
        }

        public B setFilePermissions(final String filePermissions) {
            this.filePermissions = filePermissions;
            return asBuilder();
        }

        public B setFileOwner(final String fileOwner) {
            this.fileOwner = fileOwner;
            return asBuilder();
        }

        public B setFileGroup(final String fileGroup) {
            this.fileGroup = fileGroup;
            return asBuilder();
        }

    }
    
    private final String fileName;
    private final String filePattern;
    private final Object advertisement;
    private final Advertiser advertiser;

    private RollingRandomAccessFileAppender(final String name, final Layout<? extends Serializable> layout,
            final Filter filter, final RollingRandomAccessFileManager manager, final String fileName,
            final String filePattern, final boolean ignoreExceptions,
            final boolean immediateFlush, final int bufferSize, final Advertiser advertiser) {
        super(name, layout, filter, ignoreExceptions, immediateFlush, null, manager);
        if (advertiser != null) {
            final Map<String, String> configuration = new HashMap<>(layout.getContentFormat());
            configuration.put("contentType", layout.getContentType());
            configuration.put("name", name);
            advertisement = advertiser.advertise(configuration);
        } else {
            advertisement = null;
        }
        this.fileName = fileName;
        this.filePattern = filePattern;
        this.advertiser = advertiser;
    }

    @Override
    public boolean stop(final long timeout, final TimeUnit timeUnit) {
        setStopping();
        super.stop(timeout, timeUnit, false);
        if (advertiser != null) {
            advertiser.unadvertise(advertisement);
        }
        setStopped();
        return true;
    }

    /**
     * Write the log entry rolling over the file when required.
     *
     * @param event The LogEvent.
     */
    @Override
    public void append(final LogEvent event) {
        final RollingRandomAccessFileManager manager = getManager();
        manager.checkRollover(event);

        // Leverage the nice batching behaviour of async Loggers/Appenders:
        // we can signal the file manager that it needs to flush the buffer
        // to disk at the end of a batch.
        // From a user's point of view, this means that all log events are
        // _always_ available in the log file, without incurring the overhead
        // of immediateFlush=true.
        manager.setEndOfBatch(event.isEndOfBatch()); // FIXME manager's EndOfBatch threadlocal can be deleted

        // LOG4J2-1292 utilize gc-free Layout.encode() method: taken care of in superclass
        super.append(event);
    }

    /**
     * Returns the File name for the Appender.
     *
     * @return The file name.
     */
    public String getFileName() {
        return fileName;
    }

    /**
     * Returns the file pattern used when rolling over.
     *
     * @return The file pattern.
     */
    public String getFilePattern() {
        return filePattern;
    }

    /**
     * Returns the size of the file manager's buffer.
     * @return the buffer size
     */
    public int getBufferSize() {
        return getManager().getBufferSize();
    }

    @PluginFactory
    public static <B extends Builder<B>> B newBuilder() {
        return new Builder<B>().asBuilder();
    }

}