/*
 * This file and its contents are licensed under the Apache License 2.0.
 * Please see the included NOTICE for copyright information and
 * LICENSE-APACHE for a copy of the license.
 */
#ifndef TIMESCALEDB_FUNC_CACHE_H
#define TIMESCALEDB_FUNC_CACHE_H

#include <postgres.h>
#include <nodes/primnodes.h>

#include "export.h"

#define FUNC_CACHE_MAX_FUNC_ARGS 10

typedef Expr *(*sort_transform_func)(FuncExpr *func);
typedef double (*group_estimate_func)(PlannerInfo *root, FuncExpr *expr, double path_rows);

/* Describes the function origin */
typedef enum
{
	/*
	 * Function is provided by PostgreSQL.
	 */
	ORIGIN_POSTGRES = 0,
	/*
	 * Function is provided by TimescaleDB.
	 */
	ORIGIN_TIMESCALE = 1,
	/*
	 * Fuction is provided by TimescaleDB and is experimental.
	 * It should be looked for in the experimental schema.
	 */
	ORIGIN_TIMESCALE_EXPERIMENTAL = 2,
} FuncOrigin;

typedef struct FuncInfo
{
	const char *funcname;
	FuncOrigin origin;
	bool is_bucketing_func;
	bool allowed_in_cagg_definition;
	int nargs;
	Oid arg_types[FUNC_CACHE_MAX_FUNC_ARGS];
	group_estimate_func group_estimate;
	sort_transform_func sort_transform;
} FuncInfo;

extern TSDLLEXPORT FuncInfo *ts_func_cache_get(Oid funcid);
extern TSDLLEXPORT FuncInfo *ts_func_cache_get_bucketing_func(Oid funcid);

#endif /* TIMESCALEDB_FUNC_CACHE_H */