/*
    * 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.maven.cling.invoker.logging;
  
  import java.io.OutputStream;
  import java.io.PrintStream;
  import java.io.PrintWriter;
  import java.util.Objects;
  
  import org.apache.maven.api.annotations.Nullable;
  import org.apache.maven.api.cli.Logger;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * System {@link Logger}. Uses provided {@link PrintStream}s or {@link System#err} ones as fallback.
   * This logger is used in case of "early failures" (when no logging may be set up yet).
   */
  public class SystemLogger implements Logger {
      private final PrintWriter out;
      private final Level threshold;
  
      public SystemLogger(@Nullable OutputStream out) {
          this(out, null);
      }
  
      public SystemLogger(@Nullable OutputStream out, @Nullable Level threshold) {
          this.out = new PrintWriter(toPsOrDef(out, System.err), true);
          this.threshold = Objects.requireNonNullElse(threshold, Level.INFO);
      }
  
      private PrintStream toPsOrDef(OutputStream outputStream, PrintStream def) {
          if (outputStream == null) {
              return def;
          }
          if (outputStream instanceof PrintStream ps) {
              return ps;
          }
          return new PrintStream(outputStream, true);
      }
  
      @Override
      public void log(Level level, String message, Throwable error) {
          requireNonNull(level, "level");
          requireNonNull(message, "message");
          if (level.ordinal() >= threshold.ordinal()) {
              out.println("[" + level.name() + "] " + message);
              if (error != null) {
                  error.printStackTrace(out);
              }
          }
      }
  }