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
   *
   *     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 accord.maelstrom;
  
  import java.io.IOException;
  import java.util.NavigableSet;
  import java.util.TreeSet;
  
  import accord.api.Key;
  import accord.local.Node;
  import accord.local.Node.Id;
  import accord.maelstrom.Packet.Type;
  import accord.messages.MessageType;
  import accord.messages.Reply;
  import accord.messages.ReplyContext;
  import accord.messages.Request;
  import accord.primitives.Keys;
  import accord.primitives.Txn;
  import com.google.gson.stream.JsonReader;
  import com.google.gson.stream.JsonToken;
  import com.google.gson.stream.JsonWriter;
  
  import static accord.utils.Invariants.illegalState;
  
  public class MaelstromRequest extends Body implements Request
  {
      final Txn txn;
  
      public MaelstromRequest(long msg_id, Txn txn)
      {
          super(Type.txn, msg_id, SENTINEL_MSG_ID);
          this.txn = txn;
      }
  
      @Override
      public void process(Node node, Id client, ReplyContext replyContext)
      {
          node.coordinate(txn).invoke((success, fail) -> {
              Reply reply = success != null ? new MaelstromReply(MaelstromReplyContext.messageIdFor(replyContext), (MaelstromResult) success) : null;
              node.reply(client, replyContext, reply, fail);
          });
      }
  
      @Override
      public MessageType type()
      {
          throw new UnsupportedOperationException();
      }
  
      @Override
      void writeBody(JsonWriter out) throws IOException
      {
          super.writeBody(out);
          out.name("txn");
          writeTxnExternal(out, txn);
      }
  
      static void writeTxnExternal(JsonWriter out, Txn txn) throws IOException
      {
          if (txn == null)
          {
              out.nullValue();
              return;
          }
  
          out.beginArray();
          Keys keys = (Keys)txn.keys();
          MaelstromRead read = (MaelstromRead) txn.read();
          MaelstromUpdate update = (MaelstromUpdate) txn.update();
          for (int i = 0 ; i < keys.size() ; ++i)
          {
              MaelstromKey.Key key = (MaelstromKey.Key) keys.get(i);
              if (read.readKeys.indexOf(key) >= 0)
              {
                  out.beginArray();
                  out.value("r");
                  key.datum.write(out);
                  out.nullValue();
                  out.endArray();
              }
              if (update.containsKey(key))
              {
                  out.beginArray();
                  out.value("append");
                  key.datum.write(out);
                  update.get(key).write(out);
                  out.endArray();
              }
          }
          out.endArray();
      }
  
      public static Txn readTxnExternal(JsonReader in, Node.Id client, long requestId) throws IOException
      {
          if (in.peek() == JsonToken.NULL)
              return null;
  
          NavigableSet<Key> buildReadKeys = new TreeSet<>();
          NavigableSet<Key> buildKeys = new TreeSet<>();
          MaelstromUpdate update = new MaelstromUpdate();
          in.beginArray();
          while (in.hasNext())
          {
              in.beginArray();
              String op = in.nextString();
              Key key = MaelstromKey.readKey(in);
              switch (op)
              {
                  default: throw illegalState("Invalid op: " + op);
                  case "r":
                      in.nextNull();
                      buildReadKeys.add(key);
                      break;
                  case "append":
                      Datum value = Datum.read(in);
                      buildKeys.add(key);
                      update.merge(key, new Value(value), Value::append);
              }
              in.endArray();
          }
          in.endArray();
  
          buildKeys.addAll(buildReadKeys);
          Keys readKeys = new Keys(buildReadKeys);
          Keys keys = new Keys(buildKeys);
          MaelstromRead read = new MaelstromRead(readKeys, keys);
          MaelstromQuery query = new MaelstromQuery(client, requestId);
  
          return new Txn.InMemory(keys, read, query, update);
      }
  
  }
  