// Copyright (C) 2013 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.
// 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.gerrit.pgm.init;

import com.google.common.collect.Iterables;
import com.google.gerrit.lucene.AbstractLuceneIndex;
import com.google.gerrit.pgm.init.api.ConsoleUI;
import com.google.gerrit.pgm.init.api.InitFlags;
import com.google.gerrit.pgm.init.api.InitStep;
import com.google.gerrit.pgm.init.api.Section;
import com.google.gerrit.server.config.SitePaths;
import com.google.gerrit.server.index.IndexModule;
import com.google.gerrit.server.index.IndexModule.IndexType;
import com.google.gerrit.server.index.SchemaDefinitions;
import com.google.inject.Inject;
import com.google.inject.Singleton;

import java.io.IOException;
import java.nio.file.DirectoryStream;
import java.nio.file.Files;
import java.nio.file.Path;

/** Initialize the {@code index} configuration section. */
@Singleton
class InitIndex implements InitStep {
  private final ConsoleUI ui;
  private final Section index;
  private final SitePaths site;
  private final InitFlags initFlags;
  private final Section gerrit;

  @Inject
  InitIndex(ConsoleUI ui,
      Section.Factory sections,
      SitePaths site,
      InitFlags initFlags) {
    this.ui = ui;
    this.index = sections.get("index", null);
    this.gerrit = sections.get("gerrit", null);
    this.site = site;
    this.initFlags = initFlags;
  }

  @Override
  public void run() throws IOException {
    IndexType type = IndexType.LUCENE;
    if (IndexType.values().length > 1) {
      ui.header("Index");
      type = index.select("Type", "type", type);
    }

    if ((site.isNew || isEmptySite()) && type == IndexType.LUCENE) {
      for (SchemaDefinitions<?> def : IndexModule.ALL_SCHEMA_DEFS) {
        AbstractLuceneIndex.setReady(
            site, def.getName(), def.getLatest().getVersion(), true);
      }
    } else {
      if (IndexType.values().length <= 1) {
        ui.header("Index");
      }
      String message = String.format(
        "\nThe index must be %sbuilt before starting Gerrit:\n"
        + "  java -jar gerrit.war reindex -d site_path\n",
        site.isNew ? "" : "re");
      ui.message(message);
      initFlags.autoStart = false;
    }
  }

  private boolean isEmptySite() {
    try (DirectoryStream<Path> files =
        Files.newDirectoryStream(site.resolve(gerrit.get("basePath")))) {
      return Iterables.isEmpty(files);
    } catch (IOException e) {
      return true;
    }
  }

  @Override
  public void postRun() throws Exception {
  }
}