/*
    * 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 java.lang.reflect.InvocationTargetException;
  import java.util.function.BiConsumer;
  import java.util.function.Consumer;
  import java.util.function.Function;
  import java.util.stream.Collector;
  import javax.annotation.Nullable;
  import javax.annotation.concurrent.GuardedBy;
  import javax.annotation.concurrent.ThreadSafe;
  import org.spf4j.log.Level;
  
  /**
   *
   * @author Zoltan Farkas
   */
  @ThreadSafe
  final class LogCollectorHandler<A, T> implements LogHandler, LogCollection<T> {
  
    private final Level fromLevel;
    private final Level toLevel;
    private final boolean passThrough;
    private final Object sync = new Object();
    @GuardedBy("sync")
    private A accObj;
    private final BiConsumer<A, TestLogRecord> acc;
    private final Function<A, T> finisher;
    private final Consumer<LogCollectorHandler<A, T>> onClose;
    private boolean isClosed;
  
    LogCollectorHandler(final Level fromLevel, final Level toLevel,
            final boolean passThrough,
            final Collector<TestLogRecord, A, T> collector, final Consumer<LogCollectorHandler<A, T>> onClose) {
      this.fromLevel = fromLevel;
      this.toLevel = toLevel;
      this.passThrough = passThrough;
      this.accObj = collector.supplier().get();
      this.acc = collector.accumulator();
      this.finisher = collector.finisher();
      this.onClose = onClose;
      this.isClosed = false;
    }
  
    @Override
    public LogHandler.Handling handles(final Level level) {
      if (level.ordinal() >= fromLevel.ordinal() && level.ordinal() <= toLevel.ordinal()) {
        return passThrough ? LogHandler.Handling.HANDLE_PASS : LogHandler.Handling.HANDLE_CONSUME;
      } else {
        return LogHandler.Handling.NONE;
      }
    }
  
    @Override
    @Nullable
    public TestLogRecord handle(final TestLogRecord record) {
      synchronized (sync) {
        if (!isClosed) {
          acc.accept(accObj, record);
        }
      }
      if (passThrough) {
        return record;
      } else {
        return null;
      }
    }
  
    @Override
    public T get() {
      synchronized (sync) {
        T result = finisher.apply(accObj);
        if (result == accObj) {
          try {
            return (T) result.getClass().getMethod("clone").invoke(result);
          } catch (NoSuchMethodException | SecurityException | IllegalAccessException  | InvocationTargetException ex) {
            throw new RuntimeException(ex);
          }
        }
        return result;
      }
    }
  
  
    @Override
   public void close() {
     synchronized (sync) {
       if (!isClosed) {
         try {
           onClose.accept(this);
         } finally {
           isClosed = true;
         }
       }
     }
   }
 
   @Override
   public String toString() {
     return "LogCollectorHandler{" + "accObj=" + accObj + ", fromLevel="
             + fromLevel + ", toLevel=" + toLevel + ", passThrough=" + passThrough + '}';
   }
 
 }