/**
 * 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.camel.processor;

import org.apache.camel.Exchange;
import org.apache.camel.Processor;
import org.apache.camel.impl.DefaultExchangeFormatter;
import org.apache.camel.model.LoggingLevel;
import org.apache.camel.processor.interceptor.ExchangeFormatter;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * A {@link Processor} which just logs to a {@link Log} object which can be used
 * as an exception handler instead of using a dead letter queue.
 *
 * @version $Revision: 1532 $
 */
public class Logger implements Processor {
    private Log log;
    private LoggingLevel level;
    private ExchangeFormatter formatter = DefaultExchangeFormatter.getInstance();

    public Logger() {
        this(LogFactory.getLog(Logger.class));
    }

    public Logger(Log log) {
        this(log, LoggingLevel.INFO);
    }

    public Logger(Log log, LoggingLevel level) {
        this.log = log;
        this.level = level;
    }

    public Logger(String logName) {
        this(LogFactory.getLog(logName));
    }

    public Logger(String logName, LoggingLevel level) {
        this(LogFactory.getLog(logName), level);
    }

    public Logger(Log log, ExchangeFormatter formatter) {
        this(log);
        this.formatter = formatter;
    }

    @Override
    public String toString() {
        return "Logger[" + log + "]";
    }

    public void process(Exchange exchange) {
        switch (level) {
        case DEBUG:
            if (log.isDebugEnabled()) {
                log.debug(logMessage(exchange));
            }
            break;
        case ERROR:
            if (log.isErrorEnabled()) {
                log.error(logMessage(exchange));
            }
            break;
        case FATAL:
            if (log.isFatalEnabled()) {
                log.fatal(logMessage(exchange));
            }
            break;
        case INFO:
            if (log.isInfoEnabled()) {
                log.info(logMessage(exchange));
            }
            break;
        case TRACE:
            if (log.isTraceEnabled()) {
                log.trace(logMessage(exchange));
            }
            break;
        case WARN:
            if (log.isWarnEnabled()) {
                log.warn(logMessage(exchange));
            }
            break;
        default:
            log.error("Unknown level: " + level + " when trying to log exchange: " + logMessage(exchange));
        }
    }

    public void process(Exchange exchange, Throwable exception) {
        switch (level) {
        case DEBUG:
            if (log.isDebugEnabled()) {
                log.debug(logMessage(exchange), exception);
            }
            break;
        case ERROR:
            if (log.isErrorEnabled()) {
                log.error(logMessage(exchange), exception);
            }
            break;
        case FATAL:
            if (log.isFatalEnabled()) {
                log.fatal(logMessage(exchange), exception);
            }
            break;
        case INFO:
            if (log.isInfoEnabled()) {
                log.info(logMessage(exchange), exception);
            }
            break;
        case TRACE:
            if (log.isTraceEnabled()) {
                log.trace(logMessage(exchange), exception);
            }
            break;
        case WARN:
            if (log.isWarnEnabled()) {
                log.warn(logMessage(exchange), exception);
            }
            break;
        default:
            log.error("Unknown level: " + level + " when trying to log exchange: " + logMessage(exchange));
        }
    }

    public void log(String message, LoggingLevel loggingLevel) {
        LoggingLevel oldLogLevel = getLevel();
        setLevel(loggingLevel);
        log(message);
        setLevel(oldLogLevel);
    }
    
    public void log(String message) {
        switch (level) {
        case DEBUG:
            if (log.isDebugEnabled()) {
                log.debug(message);
            }
            break;
        case ERROR:
            if (log.isErrorEnabled()) {
                log.error(message);
            }
            break;
        case FATAL:
            if (log.isFatalEnabled()) {
                log.fatal(message);
            }
            break;
        case INFO:
            if (log.isInfoEnabled()) {
                log.debug(message);
            }
            break;
        case TRACE:
            if (log.isTraceEnabled()) {
                log.trace(message);
            }
            break;
        case WARN:
            if (log.isWarnEnabled()) {
                log.warn(message);
            }
            break;
        default:
            log.error("Unknown level: " + level + " when trying to log exchange: " + message);
        }
    }

    public void log(String message, Throwable exception, LoggingLevel loggingLevel) {
        LoggingLevel oldLogLevel = getLevel();
        setLevel(loggingLevel);
        log(message, exception);
        setLevel(oldLogLevel);
    }   
    
    public void log(String message, Throwable exception) {
        switch (level) {
        case DEBUG:
            if (log.isDebugEnabled()) {
                log.debug(message, exception);
            }
            break;
        case ERROR:
            if (log.isErrorEnabled()) {
                log.error(message, exception);
            }
            break;
        case FATAL:
            if (log.isFatalEnabled()) {
                log.fatal(message, exception);
            }
            break;
        case INFO:
            if (log.isInfoEnabled()) {
                log.debug(message, exception);
            }
            break;
        case TRACE:
            if (log.isTraceEnabled()) {
                log.trace(message, exception);
            }
            break;
        case WARN:
            if (log.isWarnEnabled()) {
                log.warn(message, exception);
            }
            break;
        case OFF:
            break;
        default:
            log.error("Unknown level: " + level + " when trying to log exchange: " + message, exception);
        }
    }

    protected Object logMessage(Exchange exchange) {
        return formatter.format(exchange);
    }

    public Log getLog() {
        return log;
    }

    public void setLog(Log log) {
        this.log = log;
    }

    public LoggingLevel getLevel() {
        return level;
    }

    public void setLevel(LoggingLevel level) {
        this.level = level;
    }

    public void setFormatter(ExchangeFormatter formatter) {
        this.formatter = formatter;
    }
}
