/*
 * Copyright 2000-2018 JetBrains s.r.o.
 *
 * 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 jetbrains.buildServer.buildTriggers.vcs.mercurial.command;

import com.intellij.openapi.util.Pair;
import jetbrains.buildServer.buildTriggers.vcs.mercurial.MercurialTemplate;
import jetbrains.buildServer.util.StringUtil;
import jetbrains.buildServer.vcs.VcsException;
import org.jetbrains.annotations.NotNull;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

public class LoadDagCommand extends VcsRootCommand {

  private final MercurialTemplate myDagLogTemplate;
  private int myMaxDagNodesCount;

  public LoadDagCommand(@NotNull CommandSettings commandSettings,
                        @NotNull String hgPath,
                        @NotNull File workingDir,
                        @NotNull AuthSettings authSettings,
                        @NotNull MercurialTemplate dagLogTemplate) {
    super(commandSettings, hgPath, workingDir, authSettings);
    myDagLogTemplate = dagLogTemplate;
  }

  public void setMaxDagNodesCount(int maxDagNodesCount) {
    myMaxDagNodesCount = maxDagNodesCount;
  }

  @NotNull
  public List<Pair<String, String>> call() throws VcsException {
    return myDagLogTemplate.withTemplate(new MercurialTemplate.WithTemplate<List<Pair<String, String>>>() {
      @NotNull
      public List<Pair<String, String>> action(@NotNull File template) throws VcsException {
        final List<Pair<String, String>> edges = new ArrayList<Pair<String, String>>();
        final MercurialCommandLine cli = createCommandLine();
        cli.addParameter("log");
        cli.addParameter("--style=" + template.getAbsolutePath());
        if (myMaxDagNodesCount > 0) {
          cli.addParameters("--limit", String.valueOf(myMaxDagNodesCount));
        }

        final CommandResult res = runCommand(cli);


        final String output = res.getRawStdout();
        String fromNode = null;
        for (String line : StringUtil.splitByLines(output)) {
          final String[] revs = line.split(" ");
          if (revs.length == 0) continue;

          if (fromNode != null) {
            edges.add(Pair.create(fromNode, revs[0]));
            fromNode = null;
          }

          if (revs.length == 1) {
            fromNode = revs[0];
          } else {
            edges.add(Pair.create(revs[0], revs[1]));
            if (revs.length == 3) {
              edges.add(Pair.create(revs[0], revs[2]));
            }
          }
        }
        return edges;
      }
    });
  }

  @NotNull
  @Override
  protected String getDescription() {
    return "hg log <dag>";
  }
}