typedef struct PGconn PGconn;

#define PG_FUNCS \
    X(PQconnectdb, PGconn *, const char *) \
    X(PQerrorMessage, char *, const PGconn *) \
    X(PQfinish, void, PGconn *) \
    X(PQlibVersion, int, void) \
    X(PQserverVersion, int, const PGconn *) \
    X(PQstatus, int, const PGconn *)

#define X(n, r, ...) static r (*n)(__VA_ARGS__);
PG_FUNCS
#undef X

static void fupg_load() {
    void *handle = dlopen("libpq.so", RTLD_LAZY);
    if (!handle) croak("Unable to load libpq: %s", dlerror());
#define X(n, ...) if (!(n = dlsym(handle, #n))) croak("Unable to load libpq: %s", dlerror());
PG_FUNCS
#undef X
}

#undef PG_FUNCS


typedef struct {
    PGconn *conn;
} fupg_conn;

fupg_conn *fupg_connect(pTHX_ const char *str) {
    SV *sv;
    PGconn *conn = PQconnectdb(str);
    if (PQstatus(conn) != 0) {
        sv = newSVpvf("FU::PG connection error: %s", PQerrorMessage(conn));
        PQfinish(conn);
        croak_sv(sv);
    }

    fupg_conn *c = safecalloc(1, sizeof(fupg_conn));
    c->conn = conn;
    return c;
}

static void fupg_destroy(fupg_conn *c) {
    PQfinish(c->conn);
    safefree(c);
}