#ifndef SG_SG_H_
#define SG_SG_H_

typedef long long int SgId;

#include <gu/exn.h>
#include <pgf/pgf.h>

typedef struct SgSG SgSG;

SgSG*
sg_open(const char *filename, GuExn* err);

void
sg_close(SgSG *sg, GuExn* err);

void
sg_begin_trans(SgSG* sg, GuExn* err);

void
sg_commit(SgSG* sg, GuExn* err);

void
sg_rollback(SgSG* sg, GuExn* err);


SgId
sg_insert_expr(SgSG *sg, PgfExpr expr, GuExn* err);

PgfExpr
sg_get_expr(SgSG *sg, SgId key, GuPool* out_pool, GuExn* err);


typedef PgfExpr SgTriple[3];

SgId
sg_insert_triple(SgSG *sg, SgTriple triple, GuExn* err);

int
sg_get_triple(SgSG *sg, SgId key, SgTriple triple,
                 GuPool* out_pool, GuExn* err);

typedef struct SgTripleResult SgTripleResult;

SgTripleResult*
sg_query_triple(SgSG *sg, SgTriple triple, GuExn* err);

int
sg_triple_result_fetch(SgTripleResult* tres, SgId* pKey, SgTriple triple,
                       GuPool* out_pool, GuExn* err);

void
sg_triple_result_get_query(SgTripleResult* tres, SgTriple triple);

void
sg_triple_result_close(SgTripleResult* tres, GuExn* err);

typedef int SgPattern[3];

typedef struct {
	SgId* sel;
	SgId* vars;
	size_t n_patterns;
	SgPattern patterns[];
} SgQuery;

typedef struct SgQueryResult SgQueryResult;

SgQueryResult*
sg_query(SgSG *sg, SgQuery* query, GuExn* err);

#endif