// This may look like C code, but it's really -*- C++ -*-
/*
 * Copyright (C) 2008 Emweb bvba, Kessel-Lo, Belgium.
 *
 * See the LICENSE file for terms of use.
 */
#ifndef WT_DBO_BACKEND_SQLITE3_H_
#define WT_DBO_BACKEND_SQLITE3_H_

#include <Wt/Dbo/SqlConnection>
#include <Wt/Dbo/SqlStatement>
#include <Wt/Dbo/backend/WDboSqlite3DllDefs.h>

extern "C" {
  struct sqlite3;
}

namespace Wt {
  namespace Dbo {
    namespace backend {

/*! \class Sqlite3 Wt/Dbo/backend/Sqlite3 Wt/Dbo/backend/Sqlite3
 *  \brief An SQLite3 connection
 *
 * This class provides the backend implementation for SQLite3 databases.
 *
 * \ingroup dbo
 */
class WTDBOSQLITE3_API Sqlite3 : public SqlConnection
{
public:
  /*! \brief Configuration of date time storage.
   *
   * SQlite3 does not provide real type support for date time. Instead,
   * it offers 3 choices for storing a date time, each of these compatible
   * with the use of the built-in arithmetic functions.
   */
  enum DateTimeStorage {
    /*!
     * As 'text' in ISO8601 format.
     *
     * This also interprets correctly dates stored in the database
     * using the PseudoISO8601AsText format.
     */
    ISO8601AsText,

    /*!
     * As 'text' in ISO8601-like format, but using a space (' ')
     * instead of 'T' as a separator character between date and time. This is the
     * behaviour of Wt::Dbo prior to Wt 3.2.3.
     *
     * This also interprets correctly dates stored in the database
     * using the ISO8601AsText format.
     */
    PseudoISO8601AsText,

    /*!
     * As 'real', the number of julian days. Note that this does not support
     * second accuracy for a date time, but is the preferred format for a
     * plain date.
     */
    JulianDaysAsReal,

    /*!
     * As 'integer', number of seconds since UNIX Epoch.
     */
    UnixTimeAsInteger
  };

  /*! \brief Opens a new SQLite3 backend connection.
   *
   * The \p db may be any of the values supported by sqlite3_open().
   */
  Sqlite3(const std::string& db);

  /*! \brief Copies an SQLite3 connection.
   */
  Sqlite3(const Sqlite3& other);

  /*! \brief Destructor.
   *
   * Closes the connection.
   */
  ~Sqlite3();

  virtual Sqlite3 *clone() const;

  /*! \brief Returns the underlying connection.
   */
  sqlite3 *connection() { return db_; }

  /*! \brief Returns the underlying connection string.
   */
  std::string connectionString() { return conn_; }

  /*! \brief Configures how to store date or date time.
   *
   * The default format is ISO8601AsText.
   */
  void setDateTimeStorage(SqlDateTimeType type, DateTimeStorage format);

  /*! \brief Returns the date time storage.
   */
  DateTimeStorage dateTimeStorage(SqlDateTimeType type) const;

  virtual void startTransaction();
  virtual void commitTransaction();
  virtual void rollbackTransaction();

  virtual SqlStatement *prepareStatement(const std::string& sql);
  
  /** @name Methods that return dialect information
   */
  //@{
  virtual std::string autoincrementSql() const;
  virtual std::vector<std::string> 
    autoincrementCreateSequenceSql(const std::string &table,
				   const std::string &id) const;
  virtual std::vector<std::string> 
    autoincrementDropSequenceSql(const std::string &table,
				 const std::string &id) const;
  virtual std::string autoincrementType() const;
  virtual std::string autoincrementInsertSuffix(const std::string& id) const;
  virtual const char *dateTimeType(SqlDateTimeType type) const;
  virtual const char *blobType() const;
  virtual bool supportDeferrableFKConstraint() const;
  //@}
private:
  DateTimeStorage dateTimeStorage_[2];

  std::string conn_;
  sqlite3 *db_;

  void init();
};

    }
  }
}

#endif // WT_DBO_BACKEND_SQLITE3_H_
