//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2018
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include "td/telegram/TdDb.h"

#include "td/telegram/DialogDb.h"
#include "td/telegram/files/FileDb.h"
#include "td/telegram/logevent/LogEvent.h"
#include "td/telegram/MessagesDb.h"
#include "td/telegram/TdParameters.h"

#include "td/actor/actor.h"
#include "td/actor/MultiPromise.h"

#include "td/db/BinlogKeyValue.h"

#include "td/utils/logging.h"
#include "td/utils/port/path.h"
#include "td/utils/Random.h"

namespace td {
namespace {
std::string get_binlog_path(const TdParameters &parameters) {
  return PSTRING() << parameters.database_directory << "td" << (parameters.use_test_dc ? "_test" : "") << ".binlog";
}

std::string get_sqlite_path(const TdParameters &parameters) {
  const string db_name = "db" + (parameters.use_test_dc ? string("_test") : string());
  return parameters.database_directory + db_name + ".sqlite";
}

Result<EncryptionInfo> check_encryption(string path) {
  Binlog binlog;
  auto status = binlog.init(path, Binlog::Callback());
  if (status.is_error() && status.code() != Binlog::Error::WrongPassword) {
    return std::move(status);
  }
  EncryptionInfo info;
  info.is_encrypted = binlog.get_info().wrong_password;
  binlog.close(false /*need_sync*/).ensure();
  return info;
}

Status init_binlog(Binlog &binlog, string path, BinlogKeyValue<Binlog> &binlog_pmc, BinlogKeyValue<Binlog> &config_pmc,
                   TdDb::Events &events, DbKey key) {
  auto callback = [&](const BinlogEvent &event) {
    switch (event.type_) {
      case LogEvent::HandlerType::SecretChats:
        events.to_secret_chats_manager.push_back(event.clone());
        break;
      case LogEvent::HandlerType::Users:
        events.user_events.push_back(event.clone());
        break;
      case LogEvent::HandlerType::Chats:
        events.chat_events.push_back(event.clone());
        break;
      case LogEvent::HandlerType::Channels:
        events.channel_events.push_back(event.clone());
        break;
      case LogEvent::HandlerType::SecretChatInfos:
        events.secret_chat_events.push_back(event.clone());
        break;
      case LogEvent::HandlerType::WebPages:
        events.web_page_events.push_back(event.clone());
        break;
      case LogEvent::HandlerType::SendMessage:
      case LogEvent::HandlerType::DeleteMessage:
      case LogEvent::HandlerType::DeleteMessagesFromServer:
      case LogEvent::HandlerType::ReadHistoryOnServer:
      case LogEvent::HandlerType::ReadMessageContentsOnServer:
      case LogEvent::HandlerType::ForwardMessages:
      case LogEvent::HandlerType::SendBotStartMessage:
      case LogEvent::HandlerType::SendScreenshotTakenNotificationMessage:
      case LogEvent::HandlerType::SendInlineQueryResultMessage:
      case LogEvent::HandlerType::DeleteDialogHistoryFromServer:
      case LogEvent::HandlerType::ReadAllDialogMentionsOnServer:
      case LogEvent::HandlerType::DeleteAllChannelMessagesFromUserOnServer:
      case LogEvent::HandlerType::ToggleDialogIsPinnedOnServer:
      case LogEvent::HandlerType::ReorderPinnedDialogsOnServer:
      case LogEvent::HandlerType::SaveDialogDraftMessageOnServer:
      case LogEvent::HandlerType::GetChannelDifference:
        events.to_messages_manager.push_back(event.clone());
        break;
      case LogEvent::HandlerType::BinlogPmcMagic:
        binlog_pmc.external_init_handle(event);
        break;
      case LogEvent::HandlerType::ConfigPmcMagic:
        config_pmc.external_init_handle(event);
        break;
      default:
        LOG(FATAL) << "Unsupported logevent type " << event.type_;
    }
  };

  auto binlog_info = binlog.init(std::move(path), callback, std::move(key));
  if (binlog_info.is_error()) {
    return binlog_info.move_as_error();
  }
  return Status::OK();
}

Status init_db(SqliteDb &db) {
  TRY_STATUS(db.exec("PRAGMA encoding=\"UTF-8\""));
  TRY_STATUS(db.exec("PRAGMA journal_mode=WAL"));

  TRY_STATUS(db.exec("PRAGMA synchronous=NORMAL"));
  TRY_STATUS(db.exec("PRAGMA temp_store=MEMORY"));
  TRY_STATUS(db.exec("PRAGMA secure_delete=1"));

  return Status::OK();
}

}  // namespace

std::shared_ptr<FileDbInterface> TdDb::get_file_db_shared() {
  return file_db_;
}
std::shared_ptr<SqliteConnectionSafe> &TdDb::get_sqlite_connection_safe() {
  return sql_connection_;
}
ConcurrentBinlog *TdDb::get_binlog() {
  CHECK(binlog_);
  return binlog_.get();
}
BinlogPmc TdDb::get_binlog_pmc_shared() {
  return binlog_pmc_;
}
BinlogPmcPtr TdDb::get_binlog_pmc() {
  CHECK(binlog_pmc_);
  return binlog_pmc_.get();
}
BinlogPmcPtr TdDb::get_config_pmc() {
  CHECK(config_pmc_);
  return config_pmc_.get();
}

BigPmcPtr TdDb::get_sqlite_sync_pmc() {
  CHECK(common_kv_safe_);
  return &common_kv_safe_->get();
}

SqliteKeyValueAsyncInterface *TdDb::get_sqlite_pmc() {
  CHECK(common_kv_async_);
  return common_kv_async_.get();
}

MessagesDbSyncInterface *TdDb::get_messages_db_sync() {
  return &messages_db_sync_safe_->get();
}
MessagesDbAsyncInterface *TdDb::get_messages_db_async() {
  return messages_db_async_.get();
}
DialogDbSyncInterface *TdDb::get_dialog_db_sync() {
  return &dialog_db_sync_safe_->get();
}
DialogDbAsyncInterface *TdDb::get_dialog_db_async() {
  return dialog_db_async_.get();
}

CSlice TdDb::binlog_path() const {
  return binlog_->get_path();
}
CSlice TdDb::sqlite_path() const {
  return sqlite_path_;
}

void TdDb::flush_all() {
  if (messages_db_async_) {
    messages_db_async_->force_flush();
  }
  binlog_->force_flush();
}
void TdDb::close_all(Promise<> on_finished) {
  do_close(std::move(on_finished), false /*destroy_flag*/);
}

void TdDb::close_and_destroy_all(Promise<> on_finished) {
  do_close(std::move(on_finished), true /*destroy_flag*/);
}
void TdDb::do_close(Promise<> on_finished, bool destroy_flag) {
  MultiPromiseActorSafe mpas;
  mpas.add_promise(PromiseCreator::lambda(
      [promise = std::move(on_finished), sql_connection = std::move(sql_connection_), destroy_flag](Unit) mutable {
        if (sql_connection) {
          CHECK(sql_connection.unique()) << sql_connection.use_count();
          if (destroy_flag) {
            sql_connection->close_and_destroy();
          } else {
            sql_connection->close();
          }
          sql_connection.reset();
        }
        promise.set_value(Unit());
      }));
  auto lock = mpas.get_promise();

  if (file_db_) {
    file_db_->close(mpas.get_promise());
    file_db_.reset();
  }

  common_kv_safe_.reset();
  if (common_kv_async_) {
    common_kv_async_->close(mpas.get_promise());
  }

  messages_db_sync_safe_.reset();
  if (messages_db_async_) {
    messages_db_async_->close(mpas.get_promise());
  }

  dialog_db_sync_safe_.reset();
  if (dialog_db_async_) {
    dialog_db_async_->close(mpas.get_promise());
  }

  // binlog_pmc is dependent on binlog_ and anyway it doesn't support close_and_destroy
  CHECK(binlog_pmc_.unique());
  binlog_pmc_.reset();
  CHECK(config_pmc_.unique());
  config_pmc_.reset();

  if (binlog_) {
    if (destroy_flag) {
      binlog_->close_and_destroy(mpas.get_promise());
    } else {
      binlog_->close(mpas.get_promise());
    }
    binlog_.reset();
  }
}

Status TdDb::init_sqlite(int32 scheduler_id, const TdParameters &parameters, DbKey key, DbKey old_key,
                         BinlogKeyValue<Binlog> &binlog_pmc) {
  CHECK(!parameters.use_message_db || parameters.use_chat_info_db);
  CHECK(!parameters.use_chat_info_db || parameters.use_file_db);

  const string sql_db_name = get_sqlite_path(parameters);

  bool use_sqlite = parameters.use_file_db;
  bool use_file_db = parameters.use_file_db;
  bool use_dialog_db = parameters.use_message_db;
  bool use_message_db = parameters.use_message_db;
  if (!use_sqlite) {
    unlink(sql_db_name).ignore();
    return Status::OK();
  }

  sqlite_path_ = sql_db_name;
  TRY_STATUS(SqliteDb::change_key(sqlite_path_, key, old_key));
  sql_connection_ = std::make_shared<SqliteConnectionSafe>(sql_db_name, key);
  auto &db = sql_connection_->get();

  TRY_STATUS(init_db(db));

  // Init databases
  // Do initialization once and before everything else to avoid "database is locked" error.
  // Must be in a transaction

  // NB: when database is dropped we should also drop corresponding binlog events
  TRY_STATUS(db.exec("BEGIN TRANSACTION"));

  // Get 'PRAGMA user_version'
  TRY_RESULT(user_version, db.user_version());
  LOG(WARNING) << "got PRAGMA user_version = " << user_version;

  // init DialogDb
  bool dialog_db_was_created = false;
  if (use_dialog_db) {
    TRY_STATUS(init_dialog_db(db, user_version, dialog_db_was_created));
  } else {
    TRY_STATUS(drop_dialog_db(db, user_version));
  }

  // init MessagesDb
  if (use_message_db) {
    TRY_STATUS(init_messages_db(db, user_version));
  } else {
    TRY_STATUS(drop_messages_db(db, user_version));
  }

  // init filesDb
  if (use_file_db) {
    TRY_STATUS(init_file_db(db, user_version));
  } else {
    TRY_STATUS(drop_file_db(db, user_version));
  }

  // Update 'PRAGMA user_version'
  auto db_version = current_db_version();
  if (db_version != user_version) {
    LOG(WARNING) << "set PRAGMA user_version = " << db_version;
    TRY_STATUS(db.set_user_version(db_version));
  }

  if (dialog_db_was_created) {
    binlog_pmc.erase("unread_message_count");
    binlog_pmc.erase("last_server_dialog_date");
  }
  if (db_version == 0) {
    binlog_pmc.erase_by_prefix("top_dialogs");
    binlog_pmc.erase("next_contacts_sync_date");
  }
  binlog_pmc.force_sync({});

  TRY_STATUS(db.exec("COMMIT TRANSACTION"));

  file_db_ = create_file_db(sql_connection_, scheduler_id);

  common_kv_safe_ = std::make_shared<SqliteKeyValueSafe>("common", sql_connection_);
  common_kv_async_ = create_sqlite_key_value_async(common_kv_safe_, scheduler_id);

  if (use_dialog_db) {
    dialog_db_sync_safe_ = create_dialog_db_sync(sql_connection_);
    dialog_db_async_ = create_dialog_db_async(dialog_db_sync_safe_, scheduler_id);
  }

  if (use_message_db) {
    messages_db_sync_safe_ = create_messages_db_sync(sql_connection_);
    messages_db_async_ = create_messages_db_async(messages_db_sync_safe_, scheduler_id);
  }

  return Status::OK();
}

Status TdDb::init(int32 scheduler_id, const TdParameters &parameters, DbKey key, Events &events) {
  // Init pmc
  Binlog *binlog_ptr = nullptr;
  auto binlog = std::shared_ptr<Binlog>(new Binlog, [&](Binlog *ptr) { binlog_ptr = ptr; });

  auto binlog_pmc = std::make_unique<BinlogKeyValue<Binlog>>();
  auto config_pmc = std::make_unique<BinlogKeyValue<Binlog>>();
  binlog_pmc->external_init_begin(static_cast<int32>(LogEvent::HandlerType::BinlogPmcMagic));
  config_pmc->external_init_begin(static_cast<int32>(LogEvent::HandlerType::ConfigPmcMagic));

  bool encrypt_binlog = !key.is_empty();
  TRY_STATUS(init_binlog(*binlog, get_binlog_path(parameters), *binlog_pmc, *config_pmc, events, std::move(key)));

  binlog_pmc->external_init_finish(binlog);
  config_pmc->external_init_finish(binlog);

  DbKey new_sqlite_key;
  DbKey old_sqlite_key;
  bool encrypt_sqlite = encrypt_binlog;
  bool drop_sqlite_key = false;
  auto sqlite_key = binlog_pmc->get("sqlite_key");
  if (encrypt_sqlite) {
    if (sqlite_key.empty()) {
      sqlite_key = string(32, ' ');
      Random::secure_bytes(sqlite_key);
      binlog_pmc->set("sqlite_key", sqlite_key);
      binlog_pmc->force_sync(Auto());
    }
    new_sqlite_key = DbKey::raw_key(std::move(sqlite_key));
  } else {
    if (!sqlite_key.empty()) {
      old_sqlite_key = DbKey::raw_key(std::move(sqlite_key));
      drop_sqlite_key = true;
    }
  }
  auto init_sqlite_status = init_sqlite(scheduler_id, parameters, new_sqlite_key, old_sqlite_key, *binlog_pmc);
  if (init_sqlite_status.is_error()) {
    LOG(ERROR) << "Destroy bad sqlite db because of: " << init_sqlite_status;
    SqliteDb::destroy(get_sqlite_path(parameters)).ignore();
    TRY_STATUS(init_sqlite(scheduler_id, parameters, new_sqlite_key, old_sqlite_key, *binlog_pmc));
  }
  if (drop_sqlite_key) {
    binlog_pmc->erase("sqlite_key");
    binlog_pmc->force_sync(Auto());
  }

  auto concurrent_binlog_pmc = std::make_shared<BinlogKeyValue<ConcurrentBinlog>>();
  concurrent_binlog_pmc->external_init_begin(binlog_pmc->get_magic());
  concurrent_binlog_pmc->external_init_handle(std::move(*binlog_pmc));

  auto concurrent_config_pmc = std::make_shared<BinlogKeyValue<ConcurrentBinlog>>();
  concurrent_config_pmc->external_init_begin(config_pmc->get_magic());
  concurrent_config_pmc->external_init_handle(std::move(*config_pmc));

  binlog.reset();
  binlog_pmc.reset();
  config_pmc.reset();

  CHECK(binlog_ptr != nullptr);
  auto concurrent_binlog = std::make_shared<ConcurrentBinlog>(std::unique_ptr<Binlog>(binlog_ptr), scheduler_id);

  concurrent_binlog_pmc->external_init_finish(concurrent_binlog);
  concurrent_config_pmc->external_init_finish(concurrent_binlog);

  binlog_pmc_ = std::move(concurrent_binlog_pmc);
  config_pmc_ = std::move(concurrent_config_pmc);
  binlog_ = std::move(concurrent_binlog);

  return Status::OK();
}

TdDb::TdDb() = default;
TdDb::~TdDb() = default;

Result<std::unique_ptr<TdDb>> TdDb::open(int32 scheduler_id, const TdParameters &parameters, DbKey key,
                                         Events &events) {
  auto db = std::make_unique<TdDb>();
  TRY_STATUS(db->init(scheduler_id, parameters, std::move(key), events));
  return std::move(db);
}
Result<EncryptionInfo> TdDb::check_encryption(const TdParameters &parameters) {
  return ::td::check_encryption(get_binlog_path(parameters));
}
void TdDb::change_key(DbKey key, Promise<> promise) {
  get_binlog()->change_key(std::move(key), std::move(promise));
}
Status TdDb::destroy(const TdParameters &parameters) {
  SqliteDb::destroy(get_sqlite_path(parameters)).ignore();
  Binlog::destroy(get_binlog_path(parameters)).ignore();
  return Status::OK();
}
void TdDb::with_db_path(std::function<void(CSlice)> callback) {
  SqliteDb::with_db_path(sqlite_path(), callback);
  callback(binlog_path());
}
}  // namespace td