// Copyright (C) 2020 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
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//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
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package com.google.gerrit.acceptance.testsuite.change;

import com.google.gerrit.entities.Change;
import com.google.gerrit.entities.PatchSet;

/**
 * An aggregation of operations on changes for test purposes.
 *
 * <p>To execute the operations, no Gerrit permissions are necessary.
 *
 * <p><strong>Note:</strong> This interface is not implemented using the REST or extension API.
 * Hence, it cannot be used for testing those APIs.
 */
public interface ChangeOperations {

  /**
   * Starts the fluent chain for querying or modifying a change. Please see the methods of {@link
   * PerChangeOperations} for details on possible operations.
   *
   * @return an aggregation of operations on a specific change
   */
  PerChangeOperations change(Change.Id changeId);

  /**
   * Starts the fluent chain to create a change. The returned builder can be used to specify the
   * attributes of the new change. To create the change for real, {@link
   * TestChangeCreation.Builder#create()} must be called.
   *
   * <p>Example:
   *
   * <pre>
   * Change.Id createdChangeId = changeOperations
   *     .newChange()
   *     .file("file1")
   *     .content("Line 1\nLine2\n")
   *     .create();
   * </pre>
   *
   * <p><strong>Note:</strong> There must be at least one existing user and repository.
   *
   * @return a builder to create the new change
   */
  TestChangeCreation.Builder newChange();

  /** An aggregation of methods on a specific change. */
  interface PerChangeOperations {

    /**
     * Checks whether the change exists.
     *
     * @return {@code true} if the change exists
     */
    boolean exists();

    /**
     * Retrieves the change.
     *
     * <p><strong>Note:</strong> This call will fail with an exception if the requested change
     * doesn't exist. If you want to check for the existence of a change, use {@link #exists()}
     * instead.
     *
     * @return the corresponding {@code TestChange}
     */
    TestChange get();

    /**
     * Starts the fluent chain to create a new patchset. The returned builder can be used to specify
     * the attributes of the new patchset. To create the patchset for real, {@link
     * TestPatchsetCreation.Builder#create()} must be called.
     *
     * <p>Example:
     *
     * <pre>
     * PatchSet.Id createdPatchsetId = changeOperations
     *     .change(changeId)
     *     .newPatchset()
     *     .file("file1")
     *     .content("Line 1\nLine2\n")
     *     .create();
     * </pre>
     *
     * @return builder to create a new patchset
     */
    TestPatchsetCreation.Builder newPatchset();

    /**
     * Starts the fluent chain for querying or modifying a patchset. Please see the methods of
     * {@link PerPatchsetOperations} for details on possible operations.
     *
     * @return an aggregation of operations on a specific patchset
     */
    PerPatchsetOperations patchset(PatchSet.Id patchsetId);

    /**
     * Like {@link #patchset(PatchSet.Id)} but for the current patchset.
     *
     * @return an aggregation of operations on a specific patchset
     */
    PerPatchsetOperations currentPatchset();
  }
}