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.io.parsing;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.avro.Schema;
  import org.apache.avro.Schema.Field;
  
  /**
   * The class that generates a grammar suitable to parse Avro data in JSON
   * format.
   */
  
  public class JsonGrammarGenerator extends ValidatingGrammarGenerator {
    /**
     * Returns the non-terminal that is the start symbol for the grammar for the
     * grammar for the given schema <tt>sc</tt>.
     */
    @Override
    public Symbol generate(Schema schema) {
      return Symbol.root(generate(schema, new HashMap<>()));
    }
  
    /**
     * Returns the non-terminal that is the start symbol for grammar of the given
     * schema <tt>sc</tt>. If there is already an entry for the given schema in the
     * given map <tt>seen</tt> then that entry is returned. Otherwise a new symbol
     * is generated and an entry is inserted into the map.
     * 
     * @param sc   The schema for which the start symbol is required
     * @param seen A map of schema to symbol mapping done so far.
     * @return The start symbol for the schema
     */
    @Override
    public Symbol generate(Schema sc, Map<LitS, Symbol> seen) {
      switch (sc.getType()) {
      case NULL:
      case BOOLEAN:
      case INT:
      case LONG:
      case FLOAT:
      case DOUBLE:
      case STRING:
      case BYTES:
      case FIXED:
      case UNION:
        return super.generate(sc, seen);
      case ENUM:
        return Symbol.seq(Symbol.enumLabelsAction(sc.getEnumSymbols()), Symbol.ENUM);
      case ARRAY:
        return Symbol.seq(Symbol.repeat(Symbol.ARRAY_END, Symbol.ITEM_END, generate(sc.getElementType(), seen)),
            Symbol.ARRAY_START);
      case MAP:
        return Symbol.seq(Symbol.repeat(Symbol.MAP_END, Symbol.ITEM_END, generate(sc.getValueType(), seen),
            Symbol.MAP_KEY_MARKER, Symbol.STRING), Symbol.MAP_START);
      case RECORD: {
        LitS wsc = new LitS(sc);
        Symbol rresult = seen.get(wsc);
        if (rresult == null) {
          Symbol[] production = new Symbol[sc.getFields().size() * 3 + 2];
          rresult = Symbol.seq(production);
          seen.put(wsc, rresult);
  
          int i = production.length;
          int n = 0;
          production[--i] = Symbol.RECORD_START;
          for (Field f : sc.getFields()) {
            production[--i] = Symbol.fieldAdjustAction(n, f.name(), f.aliases());
            production[--i] = generate(f.schema(), seen);
            production[--i] = Symbol.FIELD_END;
            n++;
          }
          production[--i] = Symbol.RECORD_END;
        }
        return rresult;
      }
      default:
        throw new RuntimeException("Unexpected schema type");
      }
    }
  }
  