/*
    * Copyright 2012-2025 CodeLibs Project and the Others.
    *
    * 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 org.codelibs.fess.app.web.api.admin.backup;
  
  import static org.codelibs.core.stream.StreamUtil.stream;
  import static org.codelibs.fess.app.web.admin.backup.AdminBackupAction.NDJSON_EXTENTION;
  import static org.codelibs.fess.app.web.admin.backup.AdminBackupAction.getBackupItems;
  import static org.codelibs.fess.app.web.admin.backup.AdminBackupAction.getClickLogNdjsonWriteCall;
  import static org.codelibs.fess.app.web.admin.backup.AdminBackupAction.getFavoriteLogNdjsonWriteCall;
  import static org.codelibs.fess.app.web.admin.backup.AdminBackupAction.getSearchLogNdjsonWriteCall;
  import static org.codelibs.fess.app.web.admin.backup.AdminBackupAction.getUserInfoNdjsonWriteCall;
  
  import java.io.BufferedWriter;
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStreamWriter;
  import java.io.Writer;
  import java.util.List;
  import java.util.Map;
  import java.util.function.Consumer;
  
  import org.apache.commons.text.StringEscapeUtils;
  import org.codelibs.core.exception.IORuntimeException;
  import org.codelibs.fess.Constants;
  import org.codelibs.fess.app.web.api.ApiResult;
  import org.codelibs.fess.app.web.api.ApiResult.ApiBackupFilesResponse;
  import org.codelibs.fess.app.web.api.admin.FessApiAdminAction;
  import org.codelibs.fess.mylasta.direction.FessConfig;
  import org.codelibs.fess.util.ComponentUtil;
  import org.codelibs.fess.util.SearchEngineUtil;
  import org.lastaflute.web.Execute;
  import org.lastaflute.web.response.JsonResponse;
  import org.lastaflute.web.response.StreamResponse;
  
  /**
   * API action for admin backup.
   *
   */
  public class ApiAdminBackupAction extends FessApiAdminAction {
  
      /**
       * Default constructor.
       */
      public ApiAdminBackupAction() {
          super();
      }
  
      /**
       * Retrieves a list of available backup files.
       *
       * @return JSON response with backup file list
       */
      // GET /api/admin/backup/files
      @Execute
      public JsonResponse<ApiResult> files() {
          final List<Map<String, String>> list = getBackupItems();
          return asJson(new ApiBackupFilesResponse().files(list).total(list.size()).status(ApiResult.Status.OK).result());
      }
  
      /**
       * Downloads a specific backup file by ID.
       * Supports various backup formats including system properties, bulk data, and NDJSON logs.
       *
       * @param id the backup file ID to download
       * @return stream response containing the backup file data
       */
      // GET /api/admin/backup/file/{id}
      @Execute
      public StreamResponse get$file(final String id) {
          final FessConfig fessConfig = ComponentUtil.getFessConfig();
          if (stream(fessConfig.getIndexBackupAllTargets()).get(stream -> stream.anyMatch(s -> s.equals(id)))) {
              if ("system.properties".equals(id)) {
                  return asStream(id).contentTypeOctetStream().stream(out -> {
                      try (final ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
                          ComponentUtil.getSystemProperties().store(baos, id);
                          try (final InputStream in = new ByteArrayInputStream(baos.toByteArray())) {
                              out.write(in);
                          }
                      }
                  });
              }
              if (!id.endsWith(NDJSON_EXTENTION)) {
                  final String index;
                  final String filename;
                 if (id.endsWith(".bulk")) {
                     index = id.substring(0, id.length() - 5);
                     filename = id;
                 } else {
                     index = id;
                     filename = id + ".bulk";
                 }
                 return asStream(filename).contentTypeOctetStream().stream(out -> {
                     try (final BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(out.stream(), Constants.CHARSET_UTF_8))) {
                         SearchEngineUtil.scroll(index, hit -> {
                             try {
                                 writer.write("{\"index\":{\"_index\":\"" + index + "\",\"_id\":\""
                                         + StringEscapeUtils.escapeJson(hit.getId()) + "\"}}\n");
                                 writer.write(hit.getSourceAsString());
                                 writer.write("\n");
                             } catch (final IOException e) {
                                 throw new IORuntimeException(e);
                             }
                             return true;
                         });
                         writer.flush();
                     }
                 });
             }
             final String name = id.substring(0, id.length() - NDJSON_EXTENTION.length());
             if ("search_log".equals(name)) {
                 return writeNdjsonResponse(id, getSearchLogNdjsonWriteCall());
             }
             if ("user_info".equals(name)) {
                 return writeNdjsonResponse(id, getUserInfoNdjsonWriteCall());
             }
             if ("click_log".equals(name)) {
                 return writeNdjsonResponse(id, getClickLogNdjsonWriteCall());
             }
             if ("favorite_log".equals(name)) {
                 return writeNdjsonResponse(id, getFavoriteLogNdjsonWriteCall());
             }
         }
 
         throwValidationErrorApi(messages -> messages.addErrorsCouldNotFindBackupIndex(GLOBAL));
         return StreamResponse.asEmptyBody(); // no-op
     }
 
     private StreamResponse writeNdjsonResponse(final String id, final Consumer<Writer> writeCall) {
         return asStream(id)//
                 .header("Pragma", "no-cache")//
                 .header("Cache-Control", "no-cache")//
                 .header("Expires", "Thu, 01 Dec 1994 16:00:00 GMT")//
                 .header("Content-Type", "application/x-ndjson")//
                 .stream(out -> {
                     try (final Writer writer = new BufferedWriter(new OutputStreamWriter(out.stream(), Constants.CHARSET_UTF_8))) {
                         writeCall.accept(writer);
                         writer.flush();
                     }
                 });
     }
 }