/*
 * 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.polaris.persistence.nosql.testextension;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkState;

import jakarta.annotation.Nonnull;
import java.util.ArrayList;
import java.util.List;
import java.util.ServiceLoader;
import java.util.function.Predicate;

public final class BackendTestFactoryLoader {
  private BackendTestFactoryLoader() {}

  @Nonnull
  public static BackendTestFactory findFactoryByName(@Nonnull String name) {
    return findFactory(f -> f.name().equals(name));
  }

  @Nonnull
  public static BackendTestFactory findAny() {
    return findFactory(x -> true);
  }

  @Nonnull
  public static BackendTestFactory findFactory(@Nonnull Predicate<BackendTestFactory> filter) {
    ServiceLoader<BackendTestFactory> loader = ServiceLoader.load(BackendTestFactory.class);
    List<BackendTestFactory> candidates = new ArrayList<>();
    boolean any = false;
    for (BackendTestFactory backendFactory : loader) {
      any = true;
      if (filter.test(backendFactory)) {
        candidates.add(backendFactory);
      }
    }
    checkState(any, "No BackendFactory on class path");
    checkArgument(!candidates.isEmpty(), "No BackendFactory matched the given filter");
    checkState(candidates.size() == 1, "More than one BackendFactory matched the given filter");

    return candidates.getFirst();
  }
}
