/*
 *  Copyright (C) 2005-2018 Team Kodi
 *  This file is part of Kodi - https://kodi.tv
 *
 *  SPDX-License-Identifier: GPL-2.0-or-later
 *  See LICENSES/README.md for more information.
 */

#include "Database.h"
#include "settings/AdvancedSettings.h"
#include "filesystem/SpecialProtocol.h"
#include "profiles/ProfileManager.h"
#include "settings/SettingsComponent.h"
#include "utils/log.h"
#include "utils/SortUtils.h"
#include "utils/StringUtils.h"
#include "sqlitedataset.h"
#include "DatabaseManager.h"
#include "DbUrl.h"
#include "ServiceBroker.h"

#if defined(HAS_MYSQL) || defined(HAS_MARIADB)
#include "mysqldataset.h"
#endif

#ifdef TARGET_POSIX
#include "platform/posix/ConvUtils.h"
#endif

using namespace dbiplus;

#define MAX_COMPRESS_COUNT 20

void CDatabase::Filter::AppendField(const std::string &strField)
{
  if (strField.empty())
    return;

  if (fields.empty() || fields == "*")
    fields = strField;
  else
    fields += ", " + strField;
}

void CDatabase::Filter::AppendJoin(const std::string &strJoin)
{
  if (strJoin.empty())
    return;

  if (join.empty())
    join = strJoin;
  else
    join += " " + strJoin;
}

void CDatabase::Filter::AppendWhere(const std::string &strWhere, bool combineWithAnd /* = true */)
{
  if (strWhere.empty())
    return;

  if (where.empty())
    where = strWhere;
  else
  {
    where = "(" + where + ") ";
    where += combineWithAnd ? "AND" : "OR";
    where += " (" + strWhere + ")";
  }
}

void CDatabase::Filter::AppendOrder(const std::string &strOrder)
{
  if (strOrder.empty())
    return;

  if (order.empty())
    order = strOrder;
  else
    order += ", " + strOrder;
}

void CDatabase::Filter::AppendGroup(const std::string &strGroup)
{
  if (strGroup.empty())
    return;

  if (group.empty())
    group = strGroup;
  else
    group += ", " + strGroup;
}

void CDatabase::ExistsSubQuery::AppendJoin(const std::string &strJoin)
{
  if (strJoin.empty())
    return;

  if (join.empty())
    join = strJoin;
  else
    join += " " + strJoin;
}

void CDatabase::ExistsSubQuery::AppendWhere(const std::string &strWhere, bool combineWithAnd /* = true */)
{
  if (strWhere.empty())
    return;

  if (where.empty())
    where = strWhere;
  else
  {
    where += combineWithAnd ? " AND " : " OR ";
    where += strWhere;
  }
}

bool CDatabase::ExistsSubQuery::BuildSQL(std::string & strSQL)
{
  if (tablename.empty())
    return false;
  strSQL = "EXISTS (SELECT 1 FROM " + tablename;
  if (!join.empty())
    strSQL += " " + join;
  std::string strWhere;
  if (!param.empty())
    strWhere = param;
  if (!where.empty())
  {
    if (!strWhere.empty())
      strWhere += " AND ";
    strWhere += where;
  }
  if (!strWhere.empty())
    strSQL += " WHERE " + strWhere;

  strSQL += ")";
  return true;
}

CDatabase::DatasetLayout::DatasetLayout(size_t totalfields)
{
  m_fields.resize(totalfields, DatasetFieldInfo(false, false, -1));
}

void CDatabase::DatasetLayout::SetField(int fieldNo, const std::string &strField, bool bOutput /*= false*/)
{  
  if (fieldNo >= 0 && fieldNo < static_cast<int>(m_fields.size()))
  {
    m_fields[fieldNo].strField = strField;
    m_fields[fieldNo].fetch = true;
    m_fields[fieldNo].output = bOutput;
  }
}

void CDatabase::DatasetLayout::AdjustRecordNumbers(int offset)
{
  int recno = 0;
  for (auto& field : m_fields)
  {
    if (field.fetch)
    {
      field.recno = recno + offset;
      ++recno;
    }
  }
}

bool CDatabase::DatasetLayout::GetFetch(int fieldno)
{
  if (fieldno >= 0 && fieldno < static_cast<int>(m_fields.size()))
    return m_fields[fieldno].fetch;
  return false;
}

void CDatabase::DatasetLayout::SetFetch(int fieldno, bool bFetch /*= true*/)
{
  if (fieldno >= 0 && fieldno < static_cast<int>(m_fields.size()))
    m_fields[fieldno].fetch = bFetch;
}

bool CDatabase::DatasetLayout::GetOutput(int fieldno)
{
  if (fieldno >= 0 && fieldno < static_cast<int>(m_fields.size()))
    return m_fields[fieldno].output;
  return false;
}

int CDatabase::DatasetLayout::GetRecNo(int fieldno)
{
  if (fieldno >= 0 && fieldno < static_cast<int>(m_fields.size()))
    return m_fields[fieldno].recno;
  return -1;
}

const std::string CDatabase::DatasetLayout::GetFields()
{
  std::string strSQL;
  for (const auto& field : m_fields)
  {
    if (!field.strField.empty() && field.fetch)
    {
      if (strSQL.empty())
        strSQL = field.strField;
      else
        strSQL += ", " + field.strField;
    }
  }

  return strSQL;
}

bool CDatabase::DatasetLayout::HasFilterFields()
{
  for (const auto& field : m_fields)
  {
    if (field.fetch)
      return true;
  }
  return false;
}

CDatabase::CDatabase() :
  m_profileManager(*CServiceBroker::GetSettingsComponent()->GetProfileManager())
{
  m_openCount = 0;
  m_sqlite = true;
  m_bMultiWrite = false;
  m_multipleExecute = false;
}

CDatabase::~CDatabase(void)
{
  Close();
}

void CDatabase::Split(const std::string& strFileNameAndPath, std::string& strPath, std::string& strFileName)
{
  strFileName = "";
  strPath = "";
  int i = strFileNameAndPath.size() - 1;
  while (i > 0)
  {
    char ch = strFileNameAndPath[i];
    if (ch == ':' || ch == '/' || ch == '\\') break;
    else i--;
  }
  strPath = strFileNameAndPath.substr(0, i);
  strFileName = strFileNameAndPath.substr(i);
}

std::string CDatabase::PrepareSQL(std::string strStmt, ...) const
{
  std::string strResult = "";

  if (nullptr != m_pDB)
  {
    va_list args;
    va_start(args, strStmt);
    strResult = m_pDB->vprepare(strStmt.c_str(), args);
    va_end(args);
  }

  return strResult;
}

std::string CDatabase::GetSingleValue(const std::string &query, std::unique_ptr<Dataset> &ds)
{
  std::string ret;
  try
  {
    if (!m_pDB || !ds)
      return ret;

    if (ds->query(query) && ds->num_rows() > 0)
      ret = ds->fv(0).get_asString();

    ds->close();
  }
  catch(...)
  {
    CLog::Log(LOGERROR, "%s - failed on query '%s'", __FUNCTION__, query.c_str());
  }
  return ret;
}

std::string CDatabase::GetSingleValue(const std::string &strTable, const std::string &strColumn, const std::string &strWhereClause /* = std::string() */, const std::string &strOrderBy /* = std::string() */)
{
  std::string query = PrepareSQL("SELECT %s FROM %s", strColumn.c_str(), strTable.c_str());
  if (!strWhereClause.empty())
    query += " WHERE " + strWhereClause;
  if (!strOrderBy.empty())
    query += " ORDER BY " + strOrderBy;
  query += " LIMIT 1";
  return GetSingleValue(query, m_pDS);
}

std::string CDatabase::GetSingleValue(const std::string &query)
{
  return GetSingleValue(query, m_pDS);
}

bool CDatabase::DeleteValues(const std::string &strTable, const Filter &filter /* = Filter() */)
{
  std::string strQuery;
  BuildSQL(PrepareSQL("DELETE FROM %s ", strTable.c_str()), filter, strQuery);
  return ExecuteQuery(strQuery);
}

bool CDatabase::BeginMultipleExecute()
{
  m_multipleExecute = true;
  m_multipleQueries.clear();
  return true;
}

bool CDatabase::CommitMultipleExecute()
{
  m_multipleExecute = false;
  BeginTransaction();
  for (const auto& i : m_multipleQueries)
  {
    if (!ExecuteQuery(i))
    {
      RollbackTransaction();
      return false;
    }
  }
  m_multipleQueries.clear();
  return CommitTransaction();
}

bool CDatabase::ExecuteQuery(const std::string &strQuery)
{
  if (m_multipleExecute)
  {
    m_multipleQueries.push_back(strQuery);
    return true;
  }

  bool bReturn = false;

  try
  {
    if (nullptr == m_pDB)
      return bReturn;
    if (nullptr == m_pDS)
      return bReturn;
    m_pDS->exec(strQuery);
    bReturn = true;
  }
  catch (...)
  {
    CLog::Log(LOGERROR, "%s - failed to execute query '%s'",
        __FUNCTION__, strQuery.c_str());
  }

  return bReturn;
}

bool CDatabase::ResultQuery(const std::string &strQuery)
{
  bool bReturn = false;

  try
  {
    if (nullptr == m_pDB)
      return bReturn;
    if (nullptr == m_pDS)
      return bReturn;

    std::string strPreparedQuery = PrepareSQL(strQuery.c_str());

    bReturn = m_pDS->query(strPreparedQuery);
  }
  catch (...)
  {
    CLog::Log(LOGERROR, "%s - failed to execute query '%s'",
        __FUNCTION__, strQuery.c_str());
  }

  return bReturn;
}

bool CDatabase::QueueInsertQuery(const std::string &strQuery)
{
  if (strQuery.empty())
    return false;

  if (!m_bMultiWrite)
  {
    if (nullptr == m_pDB)
      return false;
    if (nullptr == m_pDS2)
      return false;

    m_bMultiWrite = true;
    m_pDS2->insert();
  }

  m_pDS2->add_insert_sql(strQuery);

  return true;
}

bool CDatabase::CommitInsertQueries()
{
  bool bReturn = true;

  if (m_bMultiWrite)
  {
    try
    {
      m_bMultiWrite = false;
      m_pDS2->post();
      m_pDS2->clear_insert_sql();
    }
    catch(...)
    {
      bReturn = false;
      CLog::Log(LOGERROR, "%s - failed to execute queries",
          __FUNCTION__);
    }
  }

  return bReturn;
}

bool CDatabase::Open()
{
  DatabaseSettings db_fallback;
  return Open(db_fallback);
}

bool CDatabase::Open(const DatabaseSettings &settings)
{
  if (IsOpen())
  {
    m_openCount++;
    return true;
  }

  // check our database manager to see if this database can be opened
  if (!CServiceBroker::GetDatabaseManager().CanOpen(GetBaseDBName()))
    return false;

  DatabaseSettings dbSettings = settings;
  InitSettings(dbSettings);

  std::string dbName = dbSettings.name;
  dbName += StringUtils::Format("%d", GetSchemaVersion());
  return Connect(dbName, dbSettings, false);
}

void CDatabase::InitSettings(DatabaseSettings &dbSettings)
{
  m_sqlite = true;

#if defined(HAS_MYSQL) || defined(HAS_MARIADB)
  if (dbSettings.type == "mysql")
  {
    // check we have all information before we cancel the fallback
    if ( ! (dbSettings.host.empty() ||
            dbSettings.user.empty() || dbSettings.pass.empty()) )
      m_sqlite = false;
    else
      CLog::Log(LOGINFO, "Essential mysql database information is missing. Require at least host, user and pass defined.");
  }
  else
#else
  if (dbSettings.type == "mysql")
    CLog::Log(LOGERROR, "MySQL library requested but MySQL support is not compiled in. Falling back to sqlite3.");
#endif
  {
    dbSettings.type = "sqlite3";
    if (dbSettings.host.empty())
      dbSettings.host = CSpecialProtocol::TranslatePath(m_profileManager.GetDatabaseFolder());
  }

  // use separate, versioned database
  if (dbSettings.name.empty())
    dbSettings.name = GetBaseDBName();
}

void CDatabase::CopyDB(const std::string& latestDb)
{
  m_pDB->copy(latestDb.c_str());
}

void CDatabase::DropAnalytics()
{
  m_pDB->drop_analytics();
}

bool CDatabase::Connect(const std::string &dbName, const DatabaseSettings &dbSettings, bool create)
{
  // create the appropriate database structure
  if (dbSettings.type == "sqlite3")
  {
    m_pDB.reset( new SqliteDatabase() ) ;
  }
#if defined(HAS_MYSQL) || defined(HAS_MARIADB)
  else if (dbSettings.type == "mysql")
  {
    m_pDB.reset( new MysqlDatabase() ) ;
  }
#endif
  else
  {
    CLog::Log(LOGERROR, "Unable to determine database type: %s", dbSettings.type.c_str());
    return false;
  }

  // host name is always required
  m_pDB->setHostName(dbSettings.host.c_str());

  if (!dbSettings.port.empty())
    m_pDB->setPort(dbSettings.port.c_str());

  if (!dbSettings.user.empty())
    m_pDB->setLogin(dbSettings.user.c_str());

  if (!dbSettings.pass.empty())
    m_pDB->setPasswd(dbSettings.pass.c_str());

  // database name is always required
  m_pDB->setDatabase(dbName.c_str());

  // set configuration regardless if any are empty
  m_pDB->setConfig(dbSettings.key.c_str(),
                   dbSettings.cert.c_str(),
                   dbSettings.ca.c_str(),
                   dbSettings.capath.c_str(),
                   dbSettings.ciphers.c_str(),
                   dbSettings.compression);

  // create the datasets
  m_pDS.reset(m_pDB->CreateDataset());
  m_pDS2.reset(m_pDB->CreateDataset());

  if (m_pDB->connect(create) != DB_CONNECTION_OK)
    return false;

  try
  {
    // test if db already exists, if not we need to create the tables
    if (!m_pDB->exists() && create)
    {
      if (dbSettings.type == "sqlite3")
      {
        //  Modern file systems have a cluster/block size of 4k.
        //  To gain better performance when performing write
        //  operations to the database, set the page size of the
        //  database file to 4k.
        //  This needs to be done before any table is created.
        m_pDS->exec("PRAGMA page_size=4096\n");

        //  Also set the memory cache size to 16k
        m_pDS->exec("PRAGMA default_cache_size=4096\n");
      }
      CreateDatabase();
    }

    // sqlite3 post connection operations
    if (dbSettings.type == "sqlite3")
    {
      m_pDS->exec("PRAGMA cache_size=4096\n");
      m_pDS->exec("PRAGMA synchronous='NORMAL'\n");
      m_pDS->exec("PRAGMA count_changes='OFF'\n");
    }
  }
  catch (DbErrors &error)
  {
    CLog::Log(LOGERROR, "%s failed with '%s'", __FUNCTION__, error.getMsg());
    m_openCount = 1; // set to open so we can execute Close()
    Close();
    return false;
  }

  m_openCount = 1; // our database is open
  return true;
}

int CDatabase::GetDBVersion()
{
  m_pDS->query("SELECT idVersion FROM version\n");
  if (m_pDS->num_rows() > 0)
    return m_pDS->fv("idVersion").get_asInt();
  return 0;
}

bool CDatabase::IsOpen()
{
  return m_openCount > 0;
}

void CDatabase::Close()
{
  if (m_openCount == 0)
    return;

  if (m_openCount > 1)
  {
    m_openCount--;
    return;
  }

  m_openCount = 0;
  m_multipleExecute = false;

  if (nullptr == m_pDB)
    return;
  if (nullptr != m_pDS)
    m_pDS->close();
  m_pDB->disconnect();
  m_pDB.reset();
  m_pDS.reset();
  m_pDS2.reset();
}

bool CDatabase::Compress(bool bForce /* =true */)
{
  if (!m_sqlite)
    return true;

  try
  {
    if (nullptr == m_pDB)
      return false;
    if (nullptr == m_pDS)
      return false;
    if (!bForce)
    {
      m_pDS->query("select iCompressCount from version");
      if (!m_pDS->eof())
      {
        int iCount = m_pDS->fv(0).get_asInt();
        if (iCount > MAX_COMPRESS_COUNT)
          iCount = -1;
        m_pDS->close();
        std::string strSQL=PrepareSQL("update version set iCompressCount=%i\n",++iCount);
        m_pDS->exec(strSQL);
        if (iCount != 0)
          return true;
      }
    }

    if (!m_pDS->exec("vacuum\n"))
      return false;
  }
  catch (...)
  {
    CLog::Log(LOGERROR, "%s - Compressing the database failed", __FUNCTION__);
    return false;
  }
  return true;
}

void CDatabase::Interrupt()
{
  m_pDS->interrupt();
}

void CDatabase::BeginTransaction()
{
  try
  {
    if (nullptr != m_pDB)
      m_pDB->start_transaction();
  }
  catch (...)
  {
    CLog::Log(LOGERROR, "database:begintransaction failed");
  }
}

bool CDatabase::CommitTransaction()
{
  try
  {
    if (nullptr != m_pDB)
      m_pDB->commit_transaction();
  }
  catch (...)
  {
    CLog::Log(LOGERROR, "database:committransaction failed");
    return false;
  }
  return true;
}

void CDatabase::RollbackTransaction()
{
  try
  {
    if (nullptr != m_pDB)
      m_pDB->rollback_transaction();
  }
  catch (...)
  {
    CLog::Log(LOGERROR, "database:rollbacktransaction failed");
  }
}

bool CDatabase::CreateDatabase()
{
  BeginTransaction();
  try
  {
    CLog::Log(LOGINFO, "creating version table");
    m_pDS->exec("CREATE TABLE version (idVersion integer, iCompressCount integer)\n");
    std::string strSQL=PrepareSQL("INSERT INTO version (idVersion,iCompressCount) values(%i,0)\n", GetSchemaVersion());
    m_pDS->exec(strSQL);

    CreateTables();
    CreateAnalytics();
  }
  catch (...)
  {
    CLog::Log(LOGERROR, "%s unable to create database:%i", __FUNCTION__, (int)GetLastError());
    RollbackTransaction();
    return false;
  }

  return CommitTransaction();
}

void CDatabase::UpdateVersionNumber()
{
  std::string strSQL=PrepareSQL("UPDATE version SET idVersion=%i\n", GetSchemaVersion());
  m_pDS->exec(strSQL);
}

bool CDatabase::BuildSQL(const std::string &strQuery, const Filter &filter, std::string &strSQL)
{
  strSQL = strQuery;

  if (!filter.join.empty())
    strSQL += filter.join;
  if (!filter.where.empty())
    strSQL += " WHERE " + filter.where;
  if (!filter.group.empty())
    strSQL += " GROUP BY " + filter.group;
  if (!filter.order.empty())
    strSQL += " ORDER BY " + filter.order;
  if (!filter.limit.empty())
    strSQL += " LIMIT " + filter.limit;

  return true;
}

bool CDatabase::BuildSQL(const std::string &strBaseDir, const std::string &strQuery, Filter &filter, std::string &strSQL, CDbUrl &dbUrl)
{
  SortDescription sorting;
  return BuildSQL(strBaseDir, strQuery, filter, strSQL, dbUrl, sorting);
}

bool CDatabase::BuildSQL(const std::string &strBaseDir, const std::string &strQuery, Filter &filter, std::string &strSQL, CDbUrl &dbUrl, SortDescription &sorting /* = SortDescription() */)
{
  // parse the base path to get additional filters
  dbUrl.Reset();
  if (!dbUrl.FromString(strBaseDir) || !GetFilter(dbUrl, filter, sorting))
    return false;

  return BuildSQL(strQuery, filter, strSQL);
}
