#include "pq-cursorselectcommand.h"
#include "pq-connection.h"
#include "pq-error.h"
#include <compileTimeFormatter.h>

AdHocFormatter(PQCursorSelectDeclare, "DECLARE %? CURSOR FOR ");
AdHocFormatter(PQCursorSelectFetch, "FETCH %? IN %?");
AdHocFormatter(PQCursorSelectClose, "CLOSE %?");

PQ::CursorSelectCommand::CursorSelectCommand(Connection * conn, const std::string & sql, unsigned int no, const PQ::CommandOptions * pqco) :
	DB::Command(sql),
	PQ::SelectBase(sql),
	PQ::Command(conn, sql, no),
	executed(false),
	txOpened(false),
	fTuples(pqco ? pqco->fetchTuples : 35),
	s_fetch(PQCursorSelectFetch::get(fTuples, stmntName)),
	s_close(PQCursorSelectClose::get(stmntName))
{
}

PQ::CursorSelectCommand::~CursorSelectCommand()
{
	if (executed && PQtransactionStatus(c->conn) != PQTRANS_INERROR) {
		c->checkResultFree((PQexec(c->conn, s_close.c_str())), PGRES_COMMAND_OK);
	}
	if (txOpened) {
		c->commitTx();
	}
}

std::string
PQ::CursorSelectCommand::mkdeclare() const
{
	std::stringstream psql;
	PQCursorSelectDeclare::write(psql, stmntName);
	prepareSql(psql, sql);
	return psql.str();
}

void
PQ::CursorSelectCommand::execute()
{
	if (!executed) {
		if (!c->inTx()) {
			c->beginTx();
			txOpened = true;
		}
		if (s_declare.empty()) {
			s_declare = mkdeclare();
		}
		c->checkResultFree(
				PQexecParams(c->conn, s_declare.c_str(), values.size(), NULL, &values.front(), &lengths.front(), NULL, 0),
				PGRES_COMMAND_OK);
		fetchTuples();
		createColumns(execRes);
		executed = true;
	}
}

void
PQ::CursorSelectCommand::fetchTuples()
{
	execRes = c->checkResult(PQexec(c->conn, s_fetch.c_str()), PGRES_TUPLES_OK);
	nTuples = PQntuples(execRes);
	tuple = -1;
}

bool
PQ::CursorSelectCommand::fetch()
{
	execute();
	if ((tuple >= (nTuples - 1)) && (nTuples == fTuples)) {
		// Delete the previous result set
		PQclear(execRes);
		execRes = NULL;
		fetchTuples();
	}
	if (tuple++ < (nTuples - 1)) {
		return true;
	}
	else {
		PQclear(PQexec(c->conn, s_close.c_str()));
		PQclear(execRes);
		execRes = NULL;
		executed = false;
		return false;
	}
}