/*
 * This file is a part of morm
 * and is distributed under the 2-Clause BSD licence.
 * Author: Tomasz Sowa <t.sowa@ttmath.org>
 */

/*
 * Copyright (c) 2018, Tomasz Sowa
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include "postgresqlconnector.h"
#include "utf8/utf8.h"
#include "postgresqlexpression.h"


namespace morm
{

PostgreSQLConnector::PostgreSQLConnector()
{
	pg_conn = nullptr;
	log_queries = false;
	last_status = PGRES_EMPTY_QUERY;
	last_result = nullptr;
}

PostgreSQLConnector::~PostgreSQLConnector()
{
}


void PostgreSQLConnector::allocate_default_expression()
{
	deallocate_expression();
	db_expression = new PostgreSQLExpression();
	expression_allocated = true;
}



void PostgreSQLConnector::set_log_queries(bool log_queries)
{
	this->log_queries = log_queries;
}


bool PostgreSQLConnector::query(const char * query_str)
{
//	if( log_queries )
//		log << log1 << "Db: executing query: " << q << logend;

	last_status = PGRES_EMPTY_QUERY;
	last_result = PQexec(pg_conn, query_str);

	if( !last_result )
	{
		if( PQstatus(pg_conn) != CONNECTION_OK )
		{
			//AssertConnection();
			last_result = PQexec(pg_conn, query_str);
		}
	}

	if( last_result )
	{
		last_status = PQresultStatus(last_result);
	}
	else
	{
//		log << log1 << "Db: Problem with this query: \"" << q << '\"' << logend;
//		log << log1 << "Db: " << PQerrorMessage(db_conn->GetPgConn()) << logend;
	}

return last_result != nullptr;
}


bool PostgreSQLConnector::query_select(const char * query_str)
{
	return (query(query_str) && last_status == PGRES_TUPLES_OK);
}

bool PostgreSQLConnector::query_update(const char * query_str)
{
	return (query(query_str) && last_status == PGRES_COMMAND_OK);
}

bool PostgreSQLConnector::query_insert(const char * query_str)
{
	return (query(query_str) && last_status == PGRES_COMMAND_OK);
}


//Error PostgreSQLConnector::DoCommand(const char * command)
//{
//	PGresult * r = 0;
//	Error status = WINIX_ERR_OK;
//
//	try
//	{
//		r = AssertQuery(command);
//		AssertResult(r, PGRES_COMMAND_OK);
//	}
//	catch(const Error & e)
//	{
//		status = e;
//	}
//
//	ClearResult(r);
//
//return status;
//}




bool PostgreSQLConnector::is_last_result(ExecStatusType t)
{
	return (last_result && PQresultStatus(last_result) == t);
}



int PostgreSQLConnector::get_column_index(const char * column_name)
{
	int c = PQfnumber(last_result, column_name);
	// returns -1 if there is no such a column

return c;
}



const char * PostgreSQLConnector::get_value(int row, int col)
{
	const char * res = PQgetvalue(last_result, row, col);
	// can return a null pointer if there is no such an item in the last result

return res;
}


bool PostgreSQLConnector::get_value(int row, int col, std::string & result, bool clear_string)
{
	if( clear_string )
		result.clear();

	const char * raw_result = get_value(row, col);

	if( raw_result )
	{
		result += raw_result;
	}

	return raw_result != nullptr;
}


bool PostgreSQLConnector::get_value(int row, int col, std::wstring & result, bool clear_string)
{
	if( clear_string )
		result.clear();

	const char * raw_result = get_value(row, col);

	if( raw_result )
	{
		PT::UTF8ToWide(raw_result, result);
	}

	return raw_result != nullptr;
}



//void PostgreSQLConnector::get_value_bin(int row, int col, std::string & result, bool clear_string)
//{
//	if( clear_string )
//		result.clear();
//
//	const char * raw_result = get_value(row, col);
//
//	if( raw_result )
//	{
//		int len = PQgetlength(last_result, row, col);
//
//		if( len > 0 )
//		{
//			unescape_bin(raw_result, len, result);
//		}
//	}
//}



//long PostgreSQLConnector::AssertValueLong(PGresult * r, int row, int col)
//{
//	return strtol( AssertValue(r, row, col), 0, 10 );
//}
//
//
//int PostgreSQLConnector::AssertValueInt(PGresult * r, int row, int col)
//{
//	return (int)strtol( AssertValue(r, row, col), 0, 10 );
//}
//
//
//bool PostgreSQLConnector::AssertValueBool(PGresult * r, int row, int col)
//{
//	const char * s = AssertValue(r, row, col);
//	return (s[0]=='t' || s[0]=='y' || s[0]=='1');
//}
//
//
//unsigned long PostgreSQLConnector::AssertValueULong(PGresult * r, int row, int col)
//{
//	return strtoul( AssertValue(r, row, col), 0, 10 );
//}
//
//
//unsigned int PostgreSQLConnector::AssertValueUInt(PGresult * r, int row, int col)
//{
//	return (unsigned int)strtoul( AssertValue(r, row, col), 0, 10 );
//}
//
//
//
//PT::Date PostgreSQLConnector::AssertValueDate(PGresult * r, int row, int col)
//{
//	PT::Date date = AssertValue(r, row, col);
//
//return date;
//}
//
//
//bool PostgreSQLConnector::AssertValueSpace(PGresult * r, int row, int col, PT::Space & space)
//{
//	const char * res = AssertValue(r, row, col);
//
//	conf_parser.SetSpace(space);
//	space.Clear();
//
//	PT::SpaceParser::Status status = conf_parser.ParseString(res);
//
//	if( status != PT::SpaceParser::ok )
//	{
//		log << log1 << "Db: a problem with parsing a PT::Space";
//
//		if( status == PT::SpaceParser::syntax_error )
//			log << ", syntax error at line: " << conf_parser.line;
//
//		log << logend;
//
//		space.Clear();
//		return false;
//	}
//
//return true;
//}
//
//



void PostgreSQLConnector::clear_result()
{
	if( last_result )
	{
		PQclear(last_result);
		last_result = nullptr;
	}
}


bool PostgreSQLConnector::is_null(int row, int col)
{
	if( last_result )
	{
		return PQgetisnull(last_result, row, col) == 1;
	}

	return true;
}


//int PostgreSQLConnector::Rows(PGresult * r)
//{
//	// PQntuples - Returns the number of rows (tuples) in the query result. Because it returns
//	// an integer result, large result sets might overflow the return value on 32-bit operating systems.
//	return PQntuples(r);
//}


//int PostgreSQLConnector::Cols(PGresult * r)
//{
//	// PQnfields - Returns the number of columns (fields) in each row of the query result.
//	return PQnfields(r);
//}


//long PostgreSQLConnector::AffectedRows(PGresult * r)
//{
//	// PQcmdTuples - This function returns a string containing the number of rows affected by the SQL
//	// statement that generated the PGresult. This function can only be used following the execution
//	// of an INSERT, UPDATE, DELETE, MOVE, FETCH, or COPY statement, or [...]
//	char * rows_str = PQcmdTuples(r); // can be an empty string
//	long rows = 0;
//
//	if( rows_str )
//	{
//		rows = strtol(rows_str, 0, 10);
//		// strtol - If an overflow or underflow occurs, errno is set to ERANGE
//		// and the function return value is clamped according to the following table:
//		//   Function       underflow    overflow
//		//   strtol()       LONG_MIN     LONG_MAX
//
//		if( rows < 0 )
//			rows = 0;
//	}
//
//return rows;
//}


//long PostgreSQLConnector::AssertCurrval(const char * table)
//{
//	PGresult * r;
//
//	bquery.Clear();
//	bquery << R("select currval(")
//		   << table
//		   << R(");");
//
//	r = AssertQuery(bquery);
//	AssertResult(r, PGRES_TUPLES_OK);
//
//	if( Rows(r) != 1 )
//	{
//		log << log1 << "Db: error (currval) for table: " << table << ", " << PQerrorMessage(db_conn->GetPgConn()) << logend;
//		throw Error(WINIX_ERR_DB_ERR_CURRVAL);
//	}
//
//return AssertValueLong(r, 0, 0);
//}
//








//void PostgreSQLConnector::CreateIdList(const std::vector<long> & id_tab, std::wstring & list, bool add_parentheses)
//{
//wchar_t buffer[50];
//size_t buffer_len = sizeof(buffer) / sizeof(wchar_t);
//
//	list.clear();
//
//	if( add_parentheses )
//		list += '(';
//
//	for(size_t i=0 ; i<id_tab.size() ; ++i)
//	{
//		Toa((unsigned long)id_tab[i], buffer, buffer_len);
//		list += buffer;
//
//		if( i+1 < id_tab.size() )
//			list += ',';
//	}
//
//	if( add_parentheses )
//		list += ')';
//}




//Error PostgreSQLConnector::BeginTrans()
//{
//	return DoCommand("BEGIN;");
//}
//
//
//
//Error PostgreSQLConnector::RollbackTrans()
//{
//	return DoCommand("ROLLBACK;");
//}
//
//
//
//Error PostgreSQLConnector::CommitTrans()
//{
//	return DoCommand("COMMIT;");
//}
//
//
//
//bool PostgreSQLConnector::EndTrans(bool everything_ok)
//{
//bool result;
//
//	if( everything_ok )
//	{
//		result = (CommitTrans() == WINIX_ERR_OK);
//	}
//	else
//	{
//		RollbackTrans();
//		// we return the old err code
//		result = false;
//	}
//
//return result;
//}
//
//
//Error PostgreSQLConnector::EndTrans(Error err)
//{
//	if( err == WINIX_ERR_OK )
//	{
//		err = CommitTrans();
//	}
//	else
//	{
//		// we return the old err code
//		RollbackTrans();
//	}
//
//return err;
//}






/*
	converting from a bytea
	the old way (escape format)
*/
/*
int PostgreSQLConnector::CharToInt(char c)
{
	return (int)(unsigned char)(c-'0');
}

bool PostgreSQLConnector::IsCorrectOctalDigit(char c)
{
	return c>='0' && c<='7';
}

// moves 'i' at least once
// return -1 if there is en error
int PostgreSQLConnector::UnescapeBin(const char * str, size_t & i, size_t len)
{
	if( str[i] != '\\' )
		return str[i++];

	i += 1;

	if( i >= len )
		return -1;

	if( str[i] == '\\' )
		return str[i++];

	if( i+2 >= len )
	{
		i = len;
		return -1;
	}

	if( !IsCorrectOctalDigit(str[i])   ||
		!IsCorrectOctalDigit(str[i+1]) ||
		!IsCorrectOctalDigit(str[i+2]) )
	{
		i += 3;
		return -1;
	}

	int c = 8*8*CharToInt(str[i]) + 8*CharToInt(str[i+1]) + CharToInt(str[i+2]);

	i += 3;

	if( c<0 || c>255 )
		return -1;

return c;
}

void PostgreSQLConnector::UnescapeBin(const char * str, size_t len, std::string & out, bool clear_out)
{
int c;
size_t i = 0;

	if( clear_out )
		out.clear();

	while( i < len )
	{
		c = UnescapeBin(str, i, len);

		if( c != -1 )
			out += c;
	}
}
*/





/*
	converting from a bytea
	the new way (hex format)
*/


//char PostgreSQLConnector::UnescapeBinHexToDigit(char hex)
//{
//	if( hex>='0' && hex<='9' )
//		return hex - '0';
//
//	if( hex>='a' && hex<='z' )
//		return hex - 'a' + 10;
//
//	if( hex>='A' && hex<='Z' )
//		return hex - 'A' + 10;
//
//return 0;
//}
//
//
//void PostgreSQLConnector::UnescapeBin(const char * str, size_t len, std::string & out, bool clear_out)
//{
//	if( clear_out )
//		out.clear();
//
//	if( len < 2 || str[0]!='\\' || str[1]!='x' )
//	{
//		log << log1 << "Db: unsupported binary format (skipping)" << logend;
//		return;
//	}
//
//	for(size_t i=2 ;  i + 1 < len ; i+=2 )
//	{
//		int c1 = UnescapeBinHexToDigit(str[i]);
//		int c2 = UnescapeBinHexToDigit(str[i+1]);
//
//		out += ((c1 << 4) | c2);
//	}
//}



//void PostgreSQLConnector::SetConnParam(const std::wstring & database_name, const std::wstring & user, const std::wstring & pass)
//{
//	db_database = database_name;
//	db_user     = user;
//	db_pass     = pass;
//}
//
//
//
//void PostgreSQLConnector::Connect()
//{
//	Close();
//
//	conn_info.Clear();
//	conn_info.SetExtented(false);
//
//	conn_info << R("dbname=")    << db_database
//			  << R(" user=")     << db_user
//			  << R(" password=") << db_pass;
//
//	pg_conn = PQconnectdb(conn_info.CStr());
//
//	// warning! pg_conn can be not null but there cannnot be a connection established
//	// use PQstatus(pg_conn) to check whether the connection works fine
//}
//
//
//
//void PostgreSQLConnector::LogConnectionSocket()
//{
//	log << log2 << "Db: connection to the database works fine" << logend;
//	log << log3 << "Db: connection socket: " << PQsocket(pg_conn) << logend;
//}
//
//
//
//void PostgreSQLConnector::WaitForConnection()
//{
//	if( !pg_conn || PQstatus(pg_conn) != CONNECTION_OK )
//	{
//		log << log3 << "Db: waiting for the db to be ready...." << logend << logsave;
//
//		while( !AssertConnection(false, false) )
//			sleep(5);
//
//		LogConnectionSocket();
//	}
//}
//
//
//
//void PostgreSQLConnector::Close()
//{
//	if( pg_conn )
//	{
//		PQfinish(pg_conn);
//		pg_conn = 0;
//	}
//}
//
//
//
//bool PostgreSQLConnector::AssertConnection(bool put_log, bool throw_if_no_connection)
//{
//bool was_connection = true;
//
//
//	if( !pg_conn )
//	{
//		was_connection = false;
//		Connect();
//	}
//	else
//	if( PQstatus(pg_conn) != CONNECTION_OK )
//	{
//		if( put_log )
//			log << log2 << "Db: connection to the database is lost, trying to recover" << logend;
//
//		was_connection = false;
//		PQreset(pg_conn);
//	}
//
//
//	if( pg_conn && PQstatus(pg_conn) == CONNECTION_OK )
//	{
//		if( !was_connection )
//		{
//			if( put_log )
//				LogConnectionSocket();
//
//			SetDbParameters();
//		}
//
//		return true;
//	}
//	else
//	{
//		if( put_log )
//			log << log1 << "Db: connection to db server cannot be established" << logend;
//
//		if( throw_if_no_connection )
//			throw Error(WINIX_ERR_DB_FATAL_ERROR_DURING_CONNECTING);
//
//		return false;
//	}
//}
//
//
//
//void PostgreSQLConnector::SetDbParameters()
//{
//	if( PQsetClientEncoding(pg_conn, "UTF8") == -1 )
//		log << log1 << "Db: Can't set the proper client encoding" << logend;
//}


}