/*
    * Copyright 2018 SPF4J.
    *
    * Licensed 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.spf4j.test.log;
  
  import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  import java.util.EnumMap;
  import java.util.Map;
  import java.util.function.Supplier;
  import javax.annotation.concurrent.ThreadSafe;
  import org.slf4j.Logger;
  import org.slf4j.Marker;
  import org.spf4j.log.Level;
  //CHECKSTYLE:OFF
  import sun.misc.Contended;
  //CHECKSTYLE:ON
  
  /**
   * @author Zoltan Farkas
   */
  @ThreadSafe
  public final class TestLogger implements Logger {
  
    private final String name;
  
    private final Supplier<LogConfig> cfgSource;
  
    private final Map<Level, Supplier<LogConsumer>> consumers;
  
  
    private static final class LogConfigConsumer {
  
      private static final LogConfigConsumer NULL = new LogConfigConsumer(null, null);
  
      private final LogConfig cfg;
  
      private final LogConsumer consumer;
  
      LogConfigConsumer(final LogConfig cfg, final LogConsumer consumer) {
        this.cfg = cfg;
        this.consumer = consumer;
      }
  
    }
  
    @ThreadSafe
    private final class ConsumerSupplier implements Supplier<LogConsumer> {
  
      private final Level level;
  
      @Contended
      private volatile LogConfigConsumer cfgConsumer;
  
      ConsumerSupplier(final Level level) {
        this.level = level;
        this.cfgConsumer = LogConfigConsumer.NULL;
      }
  
      @Override
      @SuppressFBWarnings("NOS_NON_OWNED_SYNCHRONIZATION") //its a private class
      public LogConsumer get() {
        LogConfig nCfg = cfgSource.get();
        LogConfigConsumer curCfgConsumer = cfgConsumer;
        if (nCfg == curCfgConsumer.cfg) {
          return curCfgConsumer.consumer;
        } else {
          synchronized (this) {
            nCfg = cfgSource.get();
            curCfgConsumer = cfgConsumer;
            if (nCfg == curCfgConsumer.cfg) {
              return curCfgConsumer.consumer;
            } else {
              LogConsumer nCons = nCfg.getLogConsumer(name, level);
              cfgConsumer = new LogConfigConsumer(nCfg, nCons);
              return nCons;
            }
          }
        }
      }
  
    }
  
    public TestLogger(final String name, final Supplier<LogConfig> configSource) {
      this.name = name;
      this.cfgSource = configSource;
      this.consumers = new EnumMap<>(Level.class);
      for (Level level : Level.values()) {
       consumers.put(level, new ConsumerSupplier(level));
     }
   }
 
   @Override
   public String getName() {
     return name;
   }
 
   public void log(final Level level, final Marker marker, final String msg, final Object... args) {
     LogConsumer consumer = consumers.get(level).get();
     if (consumer != null) {
       consumer.accept(new TestLogRecordImpl(name, level, marker, msg, args));
     }
   }
 
   @Override
   public boolean isTraceEnabled() {
     return consumers.get(Level.TRACE).get() != null;
   }
 
   @Override
   public void trace(final String msg) {
     log(Level.TRACE, null, msg);
   }
 
 
   @Override
   public void trace(final String format, final Object arg) {
     log(Level.TRACE, null, format, arg);
   }
 
   @Override
   public void trace(final String format, final Object arg1, final Object arg2) {
     log(Level.TRACE, null, format, arg1, arg2);
   }
 
   @Override
   public void trace(final String format, final Object... arguments) {
     log(Level.TRACE, null, format, arguments);
   }
 
   @Override
   public void trace(final String msg, final Throwable t) {
     log(Level.TRACE, null, msg, t);
   }
 
   @Override
   public boolean isTraceEnabled(final Marker marker) {
     return isTraceEnabled();
   }
 
   @Override
   public void trace(final Marker marker, final String msg) {
      log(Level.TRACE, marker, msg);
   }
 
   @Override
   public void trace(final Marker marker, final String format, final Object arg) {
      log(Level.TRACE, marker, format, arg);
   }
 
   @Override
   public void trace(final Marker marker, final String format, final Object arg1, final Object arg2) {
     log(Level.TRACE, marker, format, arg1, arg2);
   }
 
   @Override
   public void trace(final Marker marker, final String format, final Object... argArray) {
     log(Level.TRACE, marker, format, argArray);
   }
 
   @Override
   public void trace(final Marker marker, final String msg, final Throwable t) {
     log(Level.TRACE, marker, msg, t);
   }
 
   @Override
   public boolean isDebugEnabled() {
     return  consumers.get(Level.DEBUG).get() != null;
   }
 
   @Override
   public void debug(final String msg) {
     log(Level.DEBUG, null, msg);
   }
 
   @Override
   public void debug(final String format, final Object arg) {
     log(Level.DEBUG, null, format, arg);
   }
 
   @Override
   public void debug(final String format, final Object arg1, final Object arg2) {
     log(Level.DEBUG, null, format, arg1, arg2);
   }
 
   @Override
   public void debug(final String format, final Object... arguments) {
     log(Level.DEBUG, null, format, arguments);
   }
 
   @Override
   public void debug(final String msg, final Throwable t) {
     log(Level.DEBUG, null, msg, t);
   }
 
   @Override
   public boolean isDebugEnabled(final Marker marker) {
     return isDebugEnabled();
   }
 
   @Override
   public void debug(final Marker marker, final String msg) {
     log(Level.DEBUG, marker, msg);
   }
 
   @Override
   public void debug(final Marker marker, final String format, final Object arg) {
     log(Level.DEBUG, marker, format, arg);
   }
 
   @Override
   public void debug(final Marker marker, final String format, final Object arg1, final Object arg2) {
     log(Level.DEBUG, marker, format, arg1, arg2);
   }
 
   @Override
   public void debug(final Marker marker, final String format, final Object... arguments) {
     log(Level.DEBUG, marker, format, arguments);
   }
 
   @Override
   public void debug(final Marker marker, final String msg, final Throwable t) {
     log(Level.DEBUG, marker, msg, t);
   }
 
   @Override
   public boolean isInfoEnabled() {
     return consumers.get(Level.INFO).get() != null;
   }
 
   @Override
   public void info(final String msg) {
     log(Level.INFO, null, msg);
   }
 
   @Override
   public void info(final String format, final Object arg) {
     log(Level.INFO, null, format, arg);
   }
 
   @Override
   public void info(final String format, final Object arg1, final Object arg2) {
     log(Level.INFO, null, format, arg1, arg2);
   }
 
   @Override
   public void info(final String format, final Object... arguments) {
     log(Level.INFO, null, format, arguments);
   }
 
   @Override
   public void info(final String msg, final Throwable t) {
     log(Level.INFO, null, msg, t);
   }
 
   @Override
   public boolean isInfoEnabled(final Marker marker) {
     return isInfoEnabled();
   }
 
   @Override
   public void info(final Marker marker, final String msg) {
     log(Level.INFO, marker, msg);
   }
 
   @Override
   public void info(final Marker marker, final String format, final Object arg) {
     log(Level.INFO, marker, format, arg);
   }
 
   @Override
   public void info(final Marker marker, final String format, final Object arg1, final Object arg2) {
     log(Level.INFO, marker, format, arg1, arg2);
   }
 
   @Override
   public void info(final Marker marker, final String format, final Object... arguments) {
     log(Level.INFO, marker, format, arguments);
   }
 
   @Override
   public void info(final Marker marker, final String msg, final Throwable t) {
     log(Level.INFO, marker, msg, t);
   }
 
   @Override
   public boolean isWarnEnabled() {
     return consumers.get(Level.WARN).get() != null;
   }
 
   @Override
   public void warn(final String msg) {
     log(Level.WARN, null, msg);
   }
 
   @Override
   public void warn(final String format, final Object arg) {
     log(Level.WARN, null, format, arg);
   }
 
   @Override
   public void warn(final String format, final Object... arguments) {
     log(Level.WARN, null, format, arguments);
   }
 
   @Override
   public void warn(final String format, final Object arg1, final Object arg2) {
     log(Level.WARN, null, format, arg1, arg2);
   }
 
   @Override
   public void warn(final String msg, final Throwable t) {
     log(Level.WARN, null, msg, t);
   }
 
   @Override
   public boolean isWarnEnabled(final Marker marker) {
     return isWarnEnabled();
   }
 
   @Override
   public void warn(final Marker marker, final String msg) {
     log(Level.WARN, marker, msg);
   }
 
   @Override
   public void warn(final Marker marker, final String format, final Object arg) {
     log(Level.WARN, marker, format, arg);
   }
 
   @Override
   public void warn(final Marker marker, final String format, final Object arg1, final Object arg2) {
     log(Level.WARN, marker, format, arg1, arg2);
   }
 
   @Override
   public void warn(final Marker marker, final String format, final Object... arguments) {
     log(Level.WARN, marker, format, arguments);
   }
 
   @Override
   public void warn(final Marker marker, final String msg, final Throwable t) {
     log(Level.WARN, marker, msg, t);
   }
 
   @Override
   public boolean isErrorEnabled() {
     return consumers.get(Level.ERROR).get() != null;
   }
 
   @Override
   public void error(final String msg) {
     log(Level.ERROR, null, msg);
   }
 
   @Override
   public void error(final String format, final Object arg) {
     log(Level.ERROR, null, format, arg);
   }
 
   @Override
   public void error(final String format, final Object arg1, final Object arg2) {
     log(Level.ERROR, null, format, arg1, arg2);
   }
 
   @Override
   public void error(final String format, final Object... arguments) {
     log(Level.ERROR, null, format, arguments);
   }
 
   @Override
   public void error(final String msg, final Throwable t) {
     log(Level.ERROR, null, msg, t);
   }
 
   @Override
   public boolean isErrorEnabled(final Marker marker) {
     return isErrorEnabled();
   }
 
   @Override
   public void error(final Marker marker, final String msg) {
     log(Level.ERROR, marker, msg);
   }
 
   @Override
   public void error(final Marker marker, final String format, final Object arg) {
     log(Level.ERROR, marker, format, arg);
   }
 
   @Override
   public void error(final Marker marker, final String format, final Object arg1, final Object arg2) {
     log(Level.ERROR, marker, format, arg1, arg2);
   }
 
   @Override
   public void error(final Marker marker, final String format, final Object... arguments) {
     log(Level.ERROR, marker, format, arguments);
   }
 
   @Override
   public void error(final Marker marker, final String msg, final Throwable t) {
     log(Level.ERROR, marker, msg, t);
   }
 
   @Override
   public String toString() {
     return "TestLogger{" + "name=" + name + '}';
   }
 
 }