/*
 * Copyright 2019 Immutables Authors and Contributors
 *
 * 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.immutables.criteria.geode;

import org.apache.geode.cache.Region;
import org.immutables.criteria.backend.StandardOperations;
import org.immutables.criteria.backend.WriteResult;

import java.util.Map;
import java.util.concurrent.Callable;
import java.util.stream.Collectors;

class SyncUpdate implements Callable<WriteResult> {

  private final GeodeBackend.Session session;
  private final StandardOperations.Update operation;
  private final Region<Object, Object> region;

  SyncUpdate(GeodeBackend.Session session, StandardOperations.Update operation) {
    this.session = session;
    this.operation = operation;
    this.region = session.region;
  }

  @Override
  public WriteResult call() throws Exception {
    if (operation.values().isEmpty()) {
      return WriteResult.empty();
    }

    Map<Object, Object> toInsert = operation.values().stream().collect(Collectors.toMap(session.idExtractor::extract, x -> x));
    Region<Object, Object> region = this.region;

    // use putAll for upsert
    if (operation.upsert()) {
      region.putAll(toInsert);
      return WriteResult.unknown();
    }

    long inserted = 0;
    long updated = 0;
    for (Map.Entry<Object, Object> entry: toInsert.entrySet()) {
      if (region.replace(entry.getKey(), entry.getValue()) == null) {
        inserted++;
      } else {
        updated++;
      }
    }

    return GeodeWriteResult.of().withInsertedCount(inserted).withUpdatedCount(updated);
  }
}

@@ -1667,64 +1667,28 @@
   re
-gion.putAll(toInsert);%0A      return WriteResult.unknown(
+turn upsert(toInsert
 );%0A 
@@ -1809,20 +1809,124 @@
 %7B%0A      
-if (
+// need to iterate because update semantics which translates into map.replace()%0A      boolean wasInserted = 
 region.r
@@ -1973,16 +1973,39 @@
  == null
+;%0A      if (wasInserted
 ) %7B%0A    
@@ -2160,11 +2160,624 @@
 ed);%0A  %7D
+%0A%0A  private WriteResult upsert(Map%3CObject, Object%3E toUpsert) %7B%0A    if (toUpsert.size() == 1) %7B%0A      // for single value upsert one can return more meaningful WriteResult%0A      Map.Entry%3CObject, Object%3E entry = toUpsert.entrySet().iterator().next();%0A      Object result = region.put(entry.getKey(), entry.getValue());%0A      return result == null ? GeodeWriteResult.of().withInsertedCount(1) : GeodeWriteResult.of().withUpdatedCount(1);%0A    %7D%0A%0A    // generic case upsert in bulk%0A    // we don't really know how many records were inserted / updated%0A    region.putAll(toUpsert);%0A    return WriteResult.unknown();%0A  %7D
 %0A%7D%0A

Return better statistics for single value upsert in Geode