#ifndef EVSQL_H
#define EVSQL_H

/*
 * An event-based (Postgre)SQL client API using libevent
 */

// XXX: libpq
#include <postgresql/libpq-fe.h>
#include <event2/event.h>

/*
 * The generic context handle
 */
struct evsql;

/*
 * A query handle
 */
struct evsql_query;

/*
 * Query parameter info
 * /
struct evsql_query_params {
    int count;
    const char * const *values;
    const int *lengths;
    const int *formats;
    int result_format;
}; */

/*
 * Result type
 */
struct evsql_result_info {
    struct evsql *evsql;
    
    int error;

    union {
        // XXX: libpq
        PGresult *pq;

    } result;
};

/*
 * Callback for handling query-level errors.
 *
 * The query has completed, either succesfully or unsuccesfully (look at info.error).
 * info.result contains the result à la the evsql's type.
 */
typedef void (*evsql_query_cb)(struct evsql_result_info info, void *arg);

/*
 * Callback for handling connection-level errors.
 *
 * The SQL context/connection suffered an error. It is not valid anymore, and may not be used.
 */
typedef void (*evsql_error_cb)(struct evsql *evsql, void *arg);

/*
 * Create a new PostgreSQL/libpq(evpq) -based evsql using the given conninfo.
 */
struct evsql *evsql_new_pq (struct event_base *ev_base, const char *pq_conninfo, evsql_error_cb error_fn, void *cb_arg);

/*
 * Queue the given query for execution.
 */
struct evsql_query *evsql_query (struct evsql *evsql, const char *command, evsql_query_cb query_fn, void *cb_arg);

/*
 * Close a connection. Callbacks for waiting queries will not be run.
 *
 * XXX: not implemented yet.
 */
void evsql_close (struct evsql *evsql);

#endif /* EVSQL_H */