/*
 * 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.
 */

/* $Rev$ $Date$ */

#ifndef tuscany_sca_util_logger_h
#define tuscany_sca_util_logger_h

#include "tuscany/sca/export.h"
#include "tuscany/sca/util/LogWriter.h"

namespace tuscany
{
    namespace sca
    {
        namespace util
        {
            /**
             * Provide a logging interface.
             */
            class Logger {
    
            public:
                /**
                 * Set the log writer to use.
                 * @param writer The writer to use for all subsequent logging.
                 */
                SCA_API static void setLogWriter(LogWriter* writer);
    
                /**
                 * Set or reset the logging level. Any message with a higher logging
                 * level than this value will be filtered (i.e. not shown).
                 * @param level The level of logging to use for all subsequent logging.
                 */
                SCA_API static void setLogging(int level);
    
                /**
                 * Log a message.
                 * @param level The log level of this message.
                 * @param msg The message to be logged.
                 */
                SCA_API static void log(int level, const char* msg);
    
                /**
                 * Log a message with variable arguments.
                 * @param level The log level of this message.
                 * @param msg The message to be logged. Must include template 
                 * characters as described in printf.
                 * @param ... Variable arguments.
                 */
                SCA_API static void logArgs(int level, const char* msg, ...);
                SCA_API static void logArgs0(const char* msg, ...);
                SCA_API static void logArgs1(const char* msg, ...);
                SCA_API static void logArgs2(const char* msg, ...);
    
                /**
                 * The currently set logging level
                 */
                SCA_API static int loggingLevel;
    
            private:
                /** 
                 * The current log writer.
                 */
                static LogWriter* logWriter;
                
                /**
                 * Get the current log writer.
                 * @return The current log writer.
                 */
                static LogWriter* getLogWriter();
    
                /**
                 * Retrieves the logging level set as an environment variable.
                 */
                static int setLogging();
                
                /**
                 * Print the current thread id into the given char buffer.
                 */
                static void formatThreadID(char* tid);

                /**
                 * Message buffer
                 */
                static char messageBuffer[4096];
                
            };
            
            class LogEntry
            {
            public:
            
                LogEntry(const char* func)
                    : funcName(func)
                {
                    if (Logger::loggingLevel >= 2)
                    {
                        Logger::logArgs(2, ">> %s", funcName);
                    }
                }
                
                ~LogEntry()
                {
                    if (Logger::loggingLevel >= 2)
                    {
                        Logger::logArgs(2, "<< %s", funcName);
                    }
                }
                
            private:
                const char *funcName;
            
            };
        
        } // End namespace util
    } // End namespace sca
} // End namespace tuscany

#endif // tuscany_sca_util_logger_h