content: /*
   * 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
   *
   *     https://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.avro.tool;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.PrintStream;
  import java.nio.charset.StandardCharsets;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.trevni.Input;
  import org.apache.trevni.ColumnFileReader;
  import org.apache.trevni.MetaData;
  import org.apache.trevni.ColumnMetaData;
  
  import com.fasterxml.jackson.core.JsonFactory;
  import com.fasterxml.jackson.core.JsonGenerator;
  import com.fasterxml.jackson.core.JsonEncoding;
  import com.fasterxml.jackson.core.util.MinimalPrettyPrinter;
  
  /** Tool to print Trevni file metadata as JSON. */
  public class TrevniMetadataTool implements Tool {
    static final JsonFactory FACTORY = new JsonFactory();
  
    private JsonGenerator generator;
  
    @Override
    public String getName() {
      return "trevni_meta";
    }
  
    @Override
    public String getShortDescription() {
      return "Dumps a Trevni file's metadata as JSON.";
    }
  
    @Override
    public int run(InputStream stdin, PrintStream out, PrintStream err, List<String> args) throws Exception {
      String filename;
      boolean pretty = false;
      if (args.size() == 2 && "-pretty".equals(args.get(0))) {
        pretty = true;
        filename = args.get(1);
      } else if (args.size() == 1) {
        filename = args.get(0);
      } else {
        err.println("Usage: [-pretty] input");
        return 1;
      }
  
      dump(TrevniUtil.input(filename), out, pretty);
  
      return 0;
    }
  
    /** Read a Trevni file and print each row as a JSON object. */
    public void dump(Input input, PrintStream out, boolean pretty) throws IOException {
      this.generator = FACTORY.createGenerator(out, JsonEncoding.UTF8);
      if (pretty) {
        generator.useDefaultPrettyPrinter();
      } else { // ensure newline separation
        MinimalPrettyPrinter pp = new MinimalPrettyPrinter();
        pp.setRootValueSeparator(System.getProperty("line.separator"));
        generator.setPrettyPrinter(pp);
      }
  
      ColumnFileReader reader = new ColumnFileReader(input);
  
      generator.writeStartObject();
      generator.writeNumberField("rowCount", reader.getRowCount());
      generator.writeNumberField("columnCount", reader.getColumnCount());
  
      generator.writeFieldName("metadata");
      dump(reader.getMetaData());
  
      generator.writeFieldName("columns");
      generator.writeStartArray();
      for (ColumnMetaData c : reader.getColumnMetaData())
        dump(c);
      generator.writeEndArray();
  
      generator.writeEndObject();
  
      generator.flush();
      out.println();
      reader.close();
    }
  
    private void dump(MetaData<?> meta) throws IOException {
      generator.writeStartObject();
      for (Map.Entry<String, byte[]> e : meta.entrySet())
        generator.writeStringField(e.getKey(), new String(e.getValue(), StandardCharsets.ISO_8859_1));
      generator.writeEndObject();
    }
  
  }
  