#include <windows.h>
#include <SWI-Prolog.h>

#include "pl.h"

Query::Query(const module_t ctx, const predicate_t p, const term_t t0)
{
	m_q = PL_open_query(ctx, PL_Q_CATCH_EXCEPTION, p, t0);
}

Query::~Query()
{
	PL_cut_query(m_q);
}

int Query::Cut()
{
	if (PL_cut_query(m_q)) return 1;
	if (const term_t t = PL_exception(m_q)) throw t;
	return 0;
}

int Query::Close()
{
	if (PL_close_query(m_q)) return 1;
	if (const term_t t = PL_exception(m_q)) throw t;
	return 0;
}

int Query::NextSolution()
{
	if (PL_next_solution(m_q)) return 1;
	if (const term_t t = PL_exception(m_q)) throw t;
	return 0;
}

int PL_get_tchars(const term_t t, TCHAR** const pTsz, const int iFlags)
{
#ifdef UNICODE
	size_t len;
	if (!PL_get_wchars(t, &len, pTsz, iFlags))
		return 0;
	return len;
#else
	if (!PL_get_chars(t, pTsz, iFlags))
		return 0;
	return -1;
#endif
}

int Plx(const char* const szMod, const char* const szPred)
{
	const term_t t = PL_new_term_refs(0);
	Query q(NULL, PL_predicate(szPred, 0, szMod), t);
	return q.NextSolution();
}