#include "PgsqlConn.h"

#include <stdexcept>


using namespace Pgsql;

namespace  {

	void set_stdstring_with_charptr(std::string &s, const char *p)
	{
		if (p) {
			s = p;
		}
		else {
			s.clear();
		}
	}

} // einde unnamed namespace

ErrorDetails ErrorDetails::createErrorDetailsFromPGresult(const PGresult *result)
{
	ErrorDetails r;
	set_stdstring_with_charptr(r.state,             PQresultErrorField(result, PG_DIAG_SQLSTATE)); ///< PG_DIAG_SQLSTATE Error code as listed in	https://www.postgresql.org/docs/9.5/static/errcodes-appendix.html
	set_stdstring_with_charptr(r.severity,          PQresultErrorField(result, PG_DIAG_SEVERITY));
	set_stdstring_with_charptr(r.messagePrimary,    PQresultErrorField(result, PG_DIAG_MESSAGE_PRIMARY));
	set_stdstring_with_charptr(r.messageDetail,     PQresultErrorField(result, PG_DIAG_MESSAGE_DETAIL));
	set_stdstring_with_charptr(r.messageHint,       PQresultErrorField(result, PG_DIAG_MESSAGE_HINT));
	const char * p = PQresultErrorField(result, PG_DIAG_STATEMENT_POSITION);
	r.statementPosition = p != nullptr ? atoi(p) : -1; ///< First character is one, measured in characters not bytes!
	p = PQresultErrorField(result, PG_DIAG_INTERNAL_POSITION);
	r.internalPosition  = p != nullptr ? atoi(p) : -1;
	set_stdstring_with_charptr(r.internalQuery,     PQresultErrorField(result, PG_DIAG_INTERNAL_QUERY));
	set_stdstring_with_charptr(r.context,           PQresultErrorField(result, PG_DIAG_CONTEXT));
	set_stdstring_with_charptr(r.schemaName,        PQresultErrorField(result, PG_DIAG_SCHEMA_NAME));
	set_stdstring_with_charptr(r.tableName,         PQresultErrorField(result, PG_DIAG_TABLE_NAME));
	set_stdstring_with_charptr(r.columnName,        PQresultErrorField(result, PG_DIAG_COLUMN_NAME));
	set_stdstring_with_charptr(r.datatypeName,      PQresultErrorField(result, PG_DIAG_DATATYPE_NAME));
	set_stdstring_with_charptr(r.constraintName,    PQresultErrorField(result, PG_DIAG_CONSTRAINT_NAME));
	set_stdstring_with_charptr(r.sourceFile,        PQresultErrorField(result, PG_DIAG_SOURCE_FILE));
	set_stdstring_with_charptr(r.sourceLine,        PQresultErrorField(result, PG_DIAG_SOURCE_LINE));
	set_stdstring_with_charptr(r.sourceFunction,    PQresultErrorField(result, PG_DIAG_SOURCE_FUNCTION));
	return r;
}

Result::Result(PGresult *res)
	: result(res)
{
	if (res == nullptr) {
		throw std::runtime_error("Passing nullptr to Result::Result is not allowed");
	}
}

Result::~Result()
{
	PQclear(result);
}


Result::Result(Result &&rhs)
	: result(rhs.result)
{
	rhs.result = nullptr;
}

Result& Result::operator=(Result &&rhs)
{
	if (result) {
		PQclear(result);
	}
	result = rhs.result;
	rhs.result = nullptr;
	return *this;
}

Result::operator bool() const
{
	return result != nullptr;
}

ExecStatusType Result::resultStatus()
{
	return PQresultStatus(result);
}

std::string Result::getResStatus()
{
//    return PQresStatus(result);
		return "";
}

std::string Result::diagSqlState()
{
	std::string s(PQresultErrorField(result, PG_DIAG_SQLSTATE));
	return s;
}


ErrorDetails Result::diagDetails()
{
//	ErrorDetails r;
//	r.state             = PQresultErrorField(result, PG_DIAG_SQLSTATE); ///< PG_DIAG_SQLSTATE Error code as listed in	https://www.postgresql.org/docs/9.5/static/errcodes-appendix.html
//	r.severity          = PQresultErrorField(result, PG_DIAG_SEVERITY);
//	r.messagePrimary    = PQresultErrorField(result, PG_DIAG_MESSAGE_PRIMARY);
//	r.messageDetail     = PQresultErrorField(result, PG_DIAG_MESSAGE_DETAIL);
//	r.messageHint       = PQresultErrorField(result, PG_DIAG_MESSAGE_HINT);
//	r.statementPosition = atoi(PQresultErrorField(result, PG_DIAG_STATEMENT_POSITION)); ///< First character is one, measured in characters not bytes!
//	r.internalPosition  = atoi(PQresultErrorField(result, PG_DIAG_INTERNAL_POSITION));
//	r.internalQuery     = PQresultErrorField(result, PG_DIAG_INTERNAL_QUERY);
//	r.context           = PQresultErrorField(result, PG_DIAG_CONTEXT);
//	r.schemaName        = PQresultErrorField(result, PG_DIAG_SCHEMA_NAME);
//	r.tableName         = PQresultErrorField(result, PG_DIAG_TABLE_NAME);
//	r.columnName        = PQresultErrorField(result, PG_DIAG_COLUMN_NAME);
//	r.datatypeName      = PQresultErrorField(result, PG_DIAG_DATATYPE_NAME);
//	r.constraintName    = PQresultErrorField(result, PG_DIAG_CONSTRAINT_NAME);
//	r.sourceFile        = PQresultErrorField(result, PG_DIAG_SOURCE_FILE);
//	r.sourceLine        = PQresultErrorField(result, PG_DIAG_SOURCE_LINE);
//	r.sourceFunction    = PQresultErrorField(result, PG_DIAG_SOURCE_FUNCTION);

//	return r;
	return ErrorDetails::createErrorDetailsFromPGresult(result);
}


int Result::getRows() const
{
	return PQntuples(result);
}

int Result::getCols() const
{
	return PQnfields(result);
}

const char* const Result::getColName(int idx) const
{
	return PQfname(result, idx);
}

const char * Result::getVal(int col, int row) const
{
    return PQgetvalue(result, row, col);
}


Canceller::Canceller(PGcancel *c)
	: m_cancel(c)
{}

Canceller::Canceller(Canceller&& rhs)
	: m_cancel(rhs.m_cancel)
{
	rhs.m_cancel = nullptr;
}

Canceller& Canceller::operator=(Canceller&& rhs)
{
	if (m_cancel) {
		PQfreeCancel(m_cancel);
	}
	m_cancel = rhs.m_cancel;
	rhs.m_cancel = nullptr;
	return *this;
}

Canceller::~Canceller()
{
	if (m_cancel) {
		PQfreeCancel(m_cancel);
	}
}

void Canceller::cancel()
{
	const int errbuf_size = 256;
	char errbuf[errbuf_size];
	PQcancel(m_cancel, errbuf, errbuf_size);
}



Connection::Connection() = default;

Connection::~Connection()
{
	close();
}

Connection::Connection(Connection &&rhs)
	: conn(rhs.conn)
{
	rhs.conn = nullptr;
}

Connection& Connection::operator=(Connection &&rhs)
{
	close();
	conn = rhs.conn;
	rhs.conn = nullptr;
    return *this;
}

void Connection::close()
{
	if (conn) {
		PQfinish(conn);
		conn = nullptr;
	}
}

Canceller Connection::getCancel()
{
	Canceller c(PQgetCancel(conn));
	return c;
}

bool Connection::connect(const char *params)
{
	bool result = false;
	conn = PQconnectdb(params);
	if (conn) {
		ConnStatusType status = PQstatus(conn);
		result = (status == CONNECTION_OK);
	}
    return result;
}

bool Connection::connectStart(const char* params)
{
	conn = PQconnectStart(params);
	return conn != nullptr;
}

PostgresPollingStatusType Connection::connectPoll()
{
	return PQconnectPoll(conn);
}

ConnStatusType Connection::status()
{
	return PQstatus(conn);
}

int Connection::socket()
{
	return PQsocket(conn);
}

std::string Connection::getErrorMessage() const
{
	std::string result;
	if (conn) {
		result = PQerrorMessage(conn);
	}
	else {
		result = "no connection";
	}
	return result;
}

Result Connection::query(const char * command)
{
	PGresult *result = PQexec(conn, command);
	return Result(result);
}


bool Connection::sendQuery(const char *query)
{
	int res = PQsendQuery(conn, query);
	return res == 1;
}

std::unique_ptr<Result> Connection::getResult()
{
	PGresult *r = PQgetResult(conn);
	if (r) {
		return std::make_unique<Result>(r);
	}
	else {
		return nullptr;
	}
}

bool Connection::consumeInput()
{
	int res = PQconsumeInput(conn);
	return res == 1;
}

bool Connection::isBusy()
{
	int res = PQisBusy(conn);
	return res == 1;
}

void Connection::setNoticeReceiver(std::function<void(const PGresult *)> callback)
{
	notifyReceiver = callback;
	PQsetNoticeReceiver(conn,
		Connection::notifyReceiveFunc
		, reinterpret_cast<void*>(this));
}

void Connection::notifyReceiveFunc(void *arg, const PGresult *result)
{
	Connection *c = reinterpret_cast<Connection *>(arg);
	c->notifyReceiver(result);
}