////////////////////////////////////////////////////////////////////////
// OpenTibia - an opensource roleplaying game
////////////////////////////////////////////////////////////////////////
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
////////////////////////////////////////////////////////////////////////

#ifndef __DATABASE__
#define __DATABASE__
#include "otsystem.h"

#include "enums.h"
#include <sstream>

#ifdef MULTI_SQL_DRIVERS
#define DATABASE_VIRTUAL virtual
#define DATABASE_CLASS _Database
#define DBRES_CLASS _DBResult
class _Database;
class _DBResult;
#else
#define DATABASE_VIRTUAL

#if defined(__USE_MYSQL__)
#define DATABASE_CLASS DatabaseMySQL
#define DBRES_CLASS MySQLResult
class DatabaseMySQL;
class MySQLResult;

#elif defined(__USE_SQLITE__)
#define DATABASE_CLASS DatabaseSQLite
#define DBRES_CLASS SQLiteResult
class DatabaseSQLite;
class SQLiteResult;

#elif defined(__USE_ODBC__)
#define DATABASE_CLASS DatabaseODBC
#define DBRES_CLASS ODBCResult
class DatabaseODBC;
class ODBCResult;

#elif defined(__USE_PGSQL__)
#define DATABASE_CLASS DatabasePgSQL
#define DBRES_CLASS PgSQLResult
class DatabasePgSQL;
class PgSQLResult;

#endif
#endif

#ifndef DATABASE_CLASS
#error "You have to compile with at least one database driver!"
#define DBResult void
#define DBInsert void*
#define Database void
#else
typedef DATABASE_CLASS Database;
typedef DBRES_CLASS DBResult;

class DBQuery;
enum DBParam_t
{
	DBPARAM_MULTIINSERT = 1
};

class _Database
{
	public:
		/**
		* Singleton implementation.
		*
		* Retruns instance of database handler. Don't create database (or drivers) instances in your code - instead of it use Database::getInstance(). This method stores static instance of connection class internaly to make sure exacly one instance of connection is created for entire system.
		*
		* @return database connection handler singletor
		*/
		static Database* getInstance();

		/**
		* Database information.
		*
		* Returns currently used database attribute.
		*
		* @param DBParam_t parameter to get
		* @return suitable for given parameter
		*/
		DATABASE_VIRTUAL bool getParam(DBParam_t param) {return false;}

		/**
		* Database connected.
		*
		* Returns whether or not the database is connected.
		*
		* @return whether or not the database is connected.
		*/
		DATABASE_VIRTUAL bool isConnected() {return m_connected;}

		/**
		* Database ...
		*/
		DATABASE_VIRTUAL void use() {m_use = time(NULL);}

	protected:
		/**
		* Transaction related methods.
		*
		* Methods for starting, commiting and rolling back transaction. Each of the returns boolean value.
		*
		* @return true on success, false on error
		* @note
		*	If your database system doesn't support transactions you should return true - it's not feature test, code should work without transaction, just will lack integrity.
		*/
		friend class DBTransaction;

		DATABASE_VIRTUAL bool beginTransaction() {return 0;}
		DATABASE_VIRTUAL bool rollback() {return 0;}
		DATABASE_VIRTUAL bool commit() {return 0;}

	public:
		/**
		* Executes command.
		*
		* Executes query which doesn't generates results (eg. INSERT, UPDATE, DELETE...).
		*
		* @param std::string query command
		* @return true on success, false on error
		*/
		DATABASE_VIRTUAL bool executeQuery(const std::string &query) {return 0;}

		/**
		* Queries database.
		*
		* Executes query which generates results (mostly SELECT).
		*
		* @param std::string query
		* @return results object (null on error)
		*/
		DATABASE_VIRTUAL DBResult* storeQuery(const std::string &query) {return 0;}

		/**
		* Escapes string for query.
		*
		* Prepares string to fit SQL queries including quoting it.
		*
		* @param std::string string to be escaped
		* @return quoted string
		*/
		DATABASE_VIRTUAL std::string escapeString(const std::string &s) {return "''";}

		/**
		* Escapes binary stream for query.
		*
		* Prepares binary stream to fit SQL queries.
		*
		* @param char* binary stream
		* @param long stream length
		* @return quoted string
		*/
		DATABASE_VIRTUAL std::string escapeBlob(const char* s, uint32_t length) {return "''";}

		/**
		 * Retrieve id of last inserted row
		 *
		 * @return id on success, 0 if last query did not result on any rows with auto_increment keys
		 */
		DATABASE_VIRTUAL uint64_t getLastInsertId() {return 0;}

		/**
		* Get case insensitive string comparison operator
		*
		* @return the case insensitive operator
		*/
		DATABASE_VIRTUAL std::string getStringComparison() {return "=";}
		DATABASE_VIRTUAL std::string getUpdateLimiter() {return " LIMIT 1";}

		/**
		* Get database engine
		*
		* @return the database engine type
		*/
		DATABASE_VIRTUAL DatabaseEngine_t getDatabaseEngine() {return DATABASE_ENGINE_NONE;}

	protected:
		_Database() {}
		DATABASE_VIRTUAL ~_Database() {}

		DBResult* verifyResult(DBResult* result);

		bool m_connected;
		time_t m_use;

	private:
		static Database* _instance;
};

class _DBResult
{
	public:
		/** Get the Integer value of a field in database
		*\returns The Integer value of the selected field and row
		*\param s The name of the field
		*/
		DATABASE_VIRTUAL int32_t getDataInt(const std::string &s) {return 0;}

		/** Get the Long value of a field in database
		*\returns The Long value of the selected field and row
		*\param s The name of the field
		*/
		DATABASE_VIRTUAL int64_t getDataLong(const std::string &s) {return 0;}

		/** Get the String of a field in database
		*\returns The String of the selected field and row
		*\param s The name of the field
		*/
		DATABASE_VIRTUAL std::string getDataString(const std::string &s) {return "''";}

		/** Get the blob of a field in database
		*\returns a PropStream that is initiated with the blob data field, if not exist it returns NULL.
		*\param s The name of the field
		*/
		DATABASE_VIRTUAL const char* getDataStream(const std::string &s, uint64_t &size) {return 0;}

		/** Result freeing
		*/
		DATABASE_VIRTUAL void free() {/*delete this;*/}

		/** Moves to next result in set
		*\returns true if moved, false if there are no more results.
		*/
		DATABASE_VIRTUAL bool next() {return false;}

	protected:
		_DBResult() {}
		DATABASE_VIRTUAL ~_DBResult() {}
};

/**
 * Thread locking hack.
 *
 * By using this class for your queries you lock and unlock database for threads.
*/
class DBQuery : public std::stringstream
{
	friend class _Database;
	public:
		DBQuery() {OTSYS_THREAD_LOCK(databaseLock, "");}
		virtual ~DBQuery() {str(""); OTSYS_THREAD_UNLOCK(databaseLock, "");}

	protected:
		static OTSYS_THREAD_LOCKVAR databaseLock;
};

/**
 * INSERT statement.
 *
 * Gives possibility to optimize multiple INSERTs on databases that support multiline INSERTs.
 */
class DBInsert
{
	public:
		/**
		* Associates with given database handler.
		*
		* @param Database* database wrapper
		*/
		DBInsert(Database* db);
		virtual ~DBInsert() {}

		/**
		* Sets query prototype.
		*
		* @param std::string& INSERT query
		*/
		void setQuery(const std::string& query);

		/**
		* Adds new row to INSERT statement.
		*
		* On databases that doesn't support multiline INSERTs it simply execute INSERT for each row.
		*
		* @param std::string& row data
		*/
		bool addRow(const std::string& row);
		/**
		* Allows to use addRow() with stringstream as parameter.
		*/
		bool addRow(std::stringstream& row);

		/**
		* Executes current buffer.
		*/
		bool execute();

	protected:
		Database* m_db;

		bool m_multiLine;
		uint32_t m_rows;
		std::string m_query, m_buf;
};


#ifndef MULTI_SQL_DRIVERS
#if defined(__USE_MYSQL__)
#include "databasemysql.h"
#elif defined(__USE_SQLITE__)
#include "databasesqlite.h"
#elif defined(__USE_ODBC__)
#include "databaseodbc.h"
#elif defined(__USE_PGSQL__)
#include "databasepgsql.h"
#endif
#endif

class DBTransaction
{
	public:
		DBTransaction(Database* database)
		{
			m_database = database;
			m_state = STATE_NO_START;
		}

		virtual ~DBTransaction()
		{
			if(m_state == STATE_START)
				m_database->rollback();
		}

		bool begin()
		{
			m_state = STATE_START;
			return m_database->beginTransaction();
		}

		bool commit()
		{
			if(m_state != STATE_START)
				return false;

			m_state = STEATE_COMMIT;
			return m_database->commit();
		}

	private:
		enum TransactionStates_t
		{
			STATE_NO_START,
			STATE_START,
			STEATE_COMMIT
		};

		TransactionStates_t m_state;
		Database* m_database;
};
#endif
#endif