// Copyright 2010 The Bazel Authors. All Rights Reserved.
//
// 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 com.google.testing.junit.runner.junit4;

import com.google.common.base.Preconditions;
import com.google.common.base.Supplier;
import com.google.inject.Singleton;
import com.google.testing.junit.runner.model.TestSuiteModel;
import com.google.testing.junit.runner.model.TestSuiteModel.Builder;

import org.junit.runner.Description;
import org.junit.runner.Request;

import javax.inject.Inject;

/**
 * Builds a {@link TestSuiteModel} for JUnit4 tests.
 */
@Singleton
class JUnit4TestModelBuilder implements Supplier<TestSuiteModel> {
  private final Request request;
  private final String suiteName;
  private final Builder builder;

  @Inject
  public JUnit4TestModelBuilder(Request request, @TopLevelSuite String suiteName, Builder builder) {
    this.request = request;
    this.suiteName = suiteName;
    this.builder = builder;
  }

  /**
   * Creates a model for a JUnit4 suite. This can be expensive; callers should
   * consider memoizing the result.
   *
   * @return model.
   */
  @Override
  public TestSuiteModel get() {
    Description root = request.getRunner().getDescription();
    Preconditions.checkArgument(root.isSuite(), "Top test must be a suite");
    return builder.build(suiteName, root);
  }
}