'use strict';

////////////////////////////////////////////////////////////////////////////////
/// @brief Replication management
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2012 triagens GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is triAGENS GmbH, Cologne, Germany
///
/// @author Jan Steemann
/// @author Copyright 2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

var internal = require("internal");
var arangosh = require("@arangodb/arangosh");



var logger  = { };
var applier = { };

////////////////////////////////////////////////////////////////////////////////
/// @brief return the replication logger state
////////////////////////////////////////////////////////////////////////////////

logger.state = function () {
  var db = internal.db;

  var requestResult = db._connection.GET("/_api/replication/logger-state");
  arangosh.checkRequestResult(requestResult);

  return requestResult;
};

////////////////////////////////////////////////////////////////////////////////
/// @brief return the tick ranges that can be provided by the replication logger
////////////////////////////////////////////////////////////////////////////////

logger.tickRanges = function () {
  var db = internal.db;

  var requestResult = db._connection.GET("/_api/replication/logger-tick-ranges");
  arangosh.checkRequestResult(requestResult);

  return requestResult;
};

////////////////////////////////////////////////////////////////////////////////
/// @brief return the first tick that can be provided by the replication logger
////////////////////////////////////////////////////////////////////////////////

logger.firstTick = function () {
  var db = internal.db;

  var requestResult = db._connection.GET("/_api/replication/logger-first-tick");
  arangosh.checkRequestResult(requestResult);

  return requestResult.firstTick;
};

////////////////////////////////////////////////////////////////////////////////
/// @brief starts the replication applier
////////////////////////////////////////////////////////////////////////////////

applier.start = function (initialTick) {
  var db = internal.db;
  var append = "";

  if (initialTick !== undefined) {
    append = "?from=" + encodeURIComponent(initialTick);
  }

  var requestResult = db._connection.PUT("/_api/replication/applier-start" + append, "");
  arangosh.checkRequestResult(requestResult);

  return requestResult;
};

////////////////////////////////////////////////////////////////////////////////
/// @brief stops the replication applier
////////////////////////////////////////////////////////////////////////////////

applier.stop = applier.shutdown = function () {
  var db = internal.db;

  var requestResult = db._connection.PUT("/_api/replication/applier-stop", "");
  arangosh.checkRequestResult(requestResult);

  return requestResult;
};

////////////////////////////////////////////////////////////////////////////////
/// @brief return the replication applier state
////////////////////////////////////////////////////////////////////////////////

applier.state = function () {
  var db = internal.db;

  var requestResult = db._connection.GET("/_api/replication/applier-state");
  arangosh.checkRequestResult(requestResult);

  return requestResult;
};

////////////////////////////////////////////////////////////////////////////////
/// @brief stop the replication applier state and "forget" all state
////////////////////////////////////////////////////////////////////////////////

applier.forget = function () {
  var db = internal.db;

  var requestResult = db._connection.DELETE("/_api/replication/applier-state");
  arangosh.checkRequestResult(requestResult);

  return requestResult;
};

////////////////////////////////////////////////////////////////////////////////
/// @brief configures the replication applier
////////////////////////////////////////////////////////////////////////////////

applier.properties = function (config) {
  var db = internal.db;

  var requestResult;
  if (config === undefined) {
    requestResult = db._connection.GET("/_api/replication/applier-config");
  }
  else {
    requestResult = db._connection.PUT("/_api/replication/applier-config",
      JSON.stringify(config));
  }

  arangosh.checkRequestResult(requestResult);

  return requestResult;
};


////////////////////////////////////////////////////////////////////////////////
/// @brief performs a one-time synchronization with a remote endpoint
////////////////////////////////////////////////////////////////////////////////

var sync = function (config) {
  var db = internal.db;

  var body = JSON.stringify(config || { });
  var requestResult;
  if (config.async) {
    var headers = { "X-Arango-Async" : "store" };
    requestResult = db._connection.PUT_RAW("/_api/replication/sync", body, headers);
  }
  else {
    requestResult = db._connection.PUT("/_api/replication/sync", body);
  }

  arangosh.checkRequestResult(requestResult);
  if (config.async) {
    return requestResult.headers["x-arango-async-id"];
  }

  return requestResult;
};

////////////////////////////////////////////////////////////////////////////////
/// @brief performs a one-time synchronization with a remote endpoint, for
/// a single collection
////////////////////////////////////////////////////////////////////////////////

var syncCollection = function (collection, config) {
  var db = internal.db;

  config = config || { };
  config.restrictType = "include";
  config.restrictCollections = [ collection ];
  config.includeSystem = true;
  var body = JSON.stringify(config);
  var requestResult;
  if (config.async) {
    var headers = { "X-Arango-Async" : "store" };
    requestResult = db._connection.PUT_RAW("/_api/replication/sync", body, headers);
  }
  else {
    requestResult = db._connection.PUT("/_api/replication/sync", body);
  }

  arangosh.checkRequestResult(requestResult);
  if (config.async) {
    return requestResult.headers["x-arango-async-id"];
  }

  return requestResult;
};

var getSyncResult = function (id) {
  var db = internal.db;

  var requestResult = db._connection.PUT_RAW("/_api/job/" + encodeURIComponent(id), "");
  arangosh.checkRequestResult(requestResult);

  if (requestResult.headers.hasOwnProperty("x-arango-async-id")) {
    return JSON.parse(requestResult.body);
  }

  return false;
};

////////////////////////////////////////////////////////////////////////////////
/// @brief fetches a server's id
////////////////////////////////////////////////////////////////////////////////

var serverId = function () {
  var db = internal.db;

  var requestResult = db._connection.GET("/_api/replication/server-id");

  arangosh.checkRequestResult(requestResult);

  return requestResult.serverId;
};


exports.logger          = logger;
exports.applier         = applier;
exports.sync            = sync;
exports.syncCollection  = syncCollection;
exports.getSyncResult   = getSyncResult;
exports.serverId        = serverId;