// Copyright 2017 The Nomulus 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 google.registry.tools;

import static google.registry.persistence.transaction.TransactionManagerFactory.tm;
import static google.registry.util.CollectionUtils.isNullOrEmpty;

import com.beust.jcommander.Parameter;
import com.beust.jcommander.Parameters;
import com.google.common.collect.ImmutableList;
import google.registry.model.common.Cursor;
import google.registry.model.common.Cursor.CursorType;
import google.registry.model.tld.Tld;
import google.registry.tools.params.InstantParameter;
import java.time.Instant;
import java.util.List;

/** Modifies {@link Cursor} timestamps used by locking rolling cursor tasks, like in RDE. */
@Parameters(separators = " =", commandDescription = "Modifies cursor timestamps used by LRC tasks")
final class UpdateCursorsCommand extends ConfirmingCommand implements Command {

  @Parameter(description = "TLDs on which to operate. Omit for global cursors.")
  private List<String> tlds;

  @Parameter(names = "--type", description = "Which cursor to update.", required = true)
  private CursorType cursorType;

  @Parameter(
      names = "--timestamp",
      description = "The new timestamp to set.",
      converter = InstantParameter.class,
      required = true)
  private Instant newTimestamp;

  ImmutableList<Cursor> cursorsToUpdate;

  @Override
  protected void init() {
    ImmutableList.Builder<Cursor> result = new ImmutableList.Builder<>();
    if (isNullOrEmpty(tlds)) {
      result.add(Cursor.createGlobal(cursorType, newTimestamp));
    } else {
      for (String tldStr : tlds) {
        Tld tld = Tld.get(tldStr);
        result.add(Cursor.createScoped(cursorType, newTimestamp, tld));
      }
    }
    cursorsToUpdate = result.build();
  }

  @Override
  protected String execute() {
    tm().transact(() -> tm().putAll(cursorsToUpdate));
    return String.format("Updated %d cursors.\n", cursorsToUpdate.size());
  }

  /** Returns the changes that have been staged thus far. */
  @Override
  protected String prompt() {
    StringBuilder changes = new StringBuilder();
    if (cursorsToUpdate.isEmpty()) {
      return "No cursor changes to apply.";
    }
    cursorsToUpdate.forEach(cursor -> changes.append(getChangeString(cursor)));
    return changes.toString();
  }

  private String getChangeString(Cursor cursor) {
    return String.format(
        "Change cursorTime of %s for Scope:%s to %s\n",
        cursor.getType(), cursor.getScope(), cursor.getCursorTime());
  }
}
