/* vim: set sw=8: -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
#ifndef _GNM_FUNC_H_
# define _GNM_FUNC_H_

#include "gnumeric.h"
#include "dependent.h"

G_BEGIN_DECLS

/* Setup of the symbol table */
void functions_init     (void);
void functions_shutdown (void);

GPtrArray *gnm_func_enumerate (void);

/******************************************************************************/
/* Function group support */

struct _GnmFuncGroup {
	GOString *internal_name, *display_name;
	gboolean has_translation;
	GSList *functions;
	unsigned ref_count; /* boxed type */
};

GType gnm_func_group_get_type (void); /* boxed type */
GnmFuncGroup *gnm_func_group_get_nth (gint n);
GnmFuncGroup *gnm_func_group_fetch (char const *name,
				    char const *translation);

/******************************************************************************/

/*
 * Function registration routines
 *
 * Functions come in two fashions:  Those that only deal with
 * very specific data types and a constant number of arguments,
 * and those who don't.
 *
 * The former kind of functions receives a precomputed array of
 * GnmValue pointers.
 *
 * The latter sort of functions receives the plain ExprNodes and
 * it is up to that routine to do the value computations and range
 * processing.
 */

/*
 *  Argument tokens passed in 'args'
 *
 * With intersection and iteration support
 *	f : floating point	(no errors, string conversion attempted)
 *	b : boolean		(identical to f, Do we need this ?)
 *	s : string		(no errors)
 *	S : 'scalar': any non-error value
 *	E : scalar including errors
 * Without intersection or iteration support
 *	r : cell range	content is _NOT_ guaranteed to have been evaluated yet
 *	A : area	either range or array (as above)
 *	a : array
 *	? : anything
 *
 *  For optional arguments do:
 * "ff|ss" where the strings are optional
 */

typedef enum {
	GNM_FUNC_TYPE_ARGS,	/* Arguments get marshalled by type */
	GNM_FUNC_TYPE_NODES,	/* Takes unevaulated expers directly */

	/* implementation has not been loaded yet, but we know where it is */
	GNM_FUNC_TYPE_STUB
} GnmFuncType;

typedef enum {
	GNM_FUNC_SIMPLE			= 0,
	GNM_FUNC_VOLATILE		= 1 << 0, /* eg now(), today() */
	GNM_FUNC_RETURNS_NON_SCALAR	= 1 << 1, /* eg transpose(), mmult() */

	/* For functions that are not exactly compatible with various import
	 * formats.  We need to recalc their results to avoid changing values
	 * unexpectedly when we recalc later.  This probably needs to be done
	 * on a per import format basis.  It may not belong here.
	 */
/* 	GNM_FUNC_RECALC_ONLOAD		= 1 << 2, */

	/* an unknown function that will hopefully be defined later */
	GNM_FUNC_IS_PLACEHOLDER		= 1 << 3,
	GNM_FUNC_IS_WORKBOOK_LOCAL	= 1 << 5,
	GNM_FUNC_INTERNAL		= 1 << 6,

	GNM_FUNC_AUTO_UNKNOWN           = 0 << 8,
	GNM_FUNC_AUTO_MONETARY          = 1 << 8,  /* Like PV */
	GNM_FUNC_AUTO_DATE              = 2 << 8,  /* Like DATE */
	GNM_FUNC_AUTO_TIME              = 3 << 8,  /* Like TIME */
	GNM_FUNC_AUTO_PERCENT           = 4 << 8,  /* Like IRR */
	GNM_FUNC_AUTO_FIRST             = 5 << 8,  /* Like SUM */
	GNM_FUNC_AUTO_SECOND            = 6 << 8,  /* Like IF */
	GNM_FUNC_AUTO_UNITLESS          = 7 << 8,  /* Like COUNT */
	GNM_FUNC_AUTO_MASK              = 7 << 8   /* The bits we use for AUTO.  */
} GnmFuncFlags;

/* I do not like this.  It is going to be different for different apps probably
 * want to split it into bit file with our notion of its state, and 2 bits of
 * state per import format.
 */
typedef enum {
	GNM_FUNC_IMPL_STATUS_EXISTS = 0,
	GNM_FUNC_IMPL_STATUS_UNIMPLEMENTED,
	GNM_FUNC_IMPL_STATUS_SUBSET,
	GNM_FUNC_IMPL_STATUS_COMPLETE,
	GNM_FUNC_IMPL_STATUS_SUPERSET,
	GNM_FUNC_IMPL_STATUS_SUBSET_WITH_EXTENSIONS,
	GNM_FUNC_IMPL_STATUS_UNDER_DEVELOPMENT,
	GNM_FUNC_IMPL_STATUS_UNIQUE_TO_GNUMERIC
} GnmFuncImplStatus;

typedef enum {
	GNM_FUNC_TEST_STATUS_UNKNOWN = 0,
	GNM_FUNC_TEST_STATUS_NO_TESTSUITE,
	GNM_FUNC_TEST_STATUS_BASIC,
	GNM_FUNC_TEST_STATUS_EXHAUSTIVE,
	GNM_FUNC_TEST_STATUS_UNDER_DEVELOPMENT
} GnmFuncTestStatus;

typedef GnmValue	*(*GnmFuncArgs)	  (GnmFuncEvalInfo *ei, GnmValue const * const *args);
typedef GnmValue	*(*GnmFuncNodes)  (GnmFuncEvalInfo *ei,
					   int argc, GnmExprConstPtr const *argv);
typedef GnmDependentFlags (*GnmFuncLink)  (GnmFuncEvalInfo *ei, gboolean qlink);

typedef void	 (*GnmFuncUsageNotify) (GnmFunc *f, int refcount);
typedef gboolean (*GnmFuncLoadDesc)  (GnmFunc const *f, GnmFuncDescriptor *fd);

typedef enum {
	GNM_FUNC_HELP_END,		/* Format */
					/* ------ */
	GNM_FUNC_HELP_NAME,
	/* <NAME>:<1 SENTENCE DESCRIPTION> (translated) */

	GNM_FUNC_HELP_ARG,
	/* <NAME>:<1 SENTENCE DESCRIPTION> (translated) */

	GNM_FUNC_HELP_DESCRIPTION,
	/* <LONG DESCRIPTION (reference args using @{arg})> (translated) */

	GNM_FUNC_HELP_NOTE,
	/* <SPECIAL CASES (reference args using @{arg})> (translated) */

	GNM_FUNC_HELP_EXAMPLES,
	/*
	 * Either translated text, or a formula that is only marked for
	 * translation if it contains strings that need to be translated.
	 */

	GNM_FUNC_HELP_SEEALSO,
	/* name,name,name ...	(not translated) */

	GNM_FUNC_HELP_EXTREF,
	/*
	 * Link to external descriptions.  The following styles defined:
	 * wolfram:Sine.html
	 * wiki:en:Trigonometric_functions
	 */

	GNM_FUNC_HELP_EXCEL,
	/* <SPECIAL NOTE RE EXCEL (reference args using @{arg})> (translated) */

	GNM_FUNC_HELP_ODF
	/* <SPECIAL NOTE RE ODF (reference args using @{arg})> (translated) */
} GnmFuncHelpType;
typedef struct {
    GnmFuncHelpType	 type;
    char const		*text;
} GnmFuncHelp;

struct _GnmFuncDescriptor {
	char const *name;
	char const *arg_spec;
	GnmFuncHelp const *help;
	GnmFuncArgs	  fn_args;
	GnmFuncNodes	  fn_nodes;
	GnmFuncLink	  linker;
	GnmFuncUsageNotify usage_notify;
	GnmFuncFlags	  flags;
	GnmFuncImplStatus impl_status;
	GnmFuncTestStatus test_status;
};

struct _GnmFunc {
	char const *name;
	GPtrArray  *arg_names_p;
	GnmFuncHelp const *help;
	GOString *tdomain;
	char *localized_name;
	GnmFuncType fn_type;
	union {
		GnmFuncNodes nodes;
		struct {
			char const *arg_spec;
			GnmFuncArgs  func;
			int min_args, max_args;
			char *arg_types;
		} args;
		GnmFuncLoadDesc	load_desc;
	} fn;
	GnmFuncGroup		*fn_group; /* most recent it was assigned to */
	GnmFuncLink		 linker;
	GnmFuncUsageNotify	 usage_notify;
	GnmFuncImplStatus	 impl_status;
	GnmFuncTestStatus	 test_status;
	GnmFuncFlags		 flags;

	gint			 usage_count;
	gpointer		 user_data;
};

struct _GnmFuncEvalInfo {
	GnmEvalPos const *pos;
	GnmExprFunction const *func_call;
	GnmExprEvalFlags flags;
};

GType       gnm_func_get_type        (void);
void	    gnm_func_free	     (GnmFunc *func);
GnmFunc	   *gnm_func_ref	     (GnmFunc *func);
void	    gnm_func_unref	     (GnmFunc *func);
void        gnm_func_load_if_stub    (GnmFunc *func);
void	    gnm_func_load_stub	     (GnmFunc *fn_def);
char const *gnm_func_get_name	     (GnmFunc const *fn_def,
				      gboolean localized);
gpointer    gnm_func_get_user_data   (GnmFunc const *func);
void        gnm_func_set_user_data   (GnmFunc *func, gpointer user_data);
GnmFunc	   *gnm_func_lookup	     (char const *name, Workbook *scope);
GnmFunc    *gnm_func_lookup_localized (char const *name, Workbook *scope);
GSList	   *gnm_func_lookup_prefix   (char const *prefix, Workbook *scope,
				      gboolean trans);
GnmFunc    *gnm_func_add	     (GnmFuncGroup *group,
				      GnmFuncDescriptor const *descriptor,
				      const char *tdomain);
GnmFunc    *gnm_func_add_placeholder (Workbook *optional_scope,
				      char const *name,
				      char const *type);
GnmFunc    *gnm_func_add_placeholder_localized (char const *gname, char const *lname);
GnmFunc	   *gnm_func_lookup_or_add_placeholder (char const *name);
void        gnm_func_upgrade_placeholder
				      (GnmFunc *fd,
				       GnmFuncGroup *fn_group,
				       const char *tdomain,
				       GnmFuncLoadDesc load_desc,
				       GnmFuncUsageNotify opt_usage_notify);

/* TODO */
char const *gnm_func_get_description (GnmFunc const *fn_def);
void        function_def_count_args    (GnmFunc const *fn_def,
                                        gint *min, int *max);
char        function_def_get_arg_type  (GnmFunc const *fn_def,
                                        gint arg_idx);
char const *function_def_get_arg_type_string  (GnmFunc const *fn_def,
                                        gint arg_idx);
char       *function_def_get_arg_name  (GnmFunc const *fn_def,
                                        guint arg_idx);
char const *gnm_func_get_arg_description (GnmFunc const *fn_def,
                                        guint arg_idx);
char       *gnm_func_convert_markup_to_pango (char const *desc,
					      GtkWidget *target);

/*************************************************************************/

GnmValue *function_call_with_exprs	(GnmFuncEvalInfo *ei);
GnmValue *function_call_with_values     (GnmEvalPos const *ep, char const *name,
					 int argc, GnmValue const * const *values);
GnmValue *function_def_call_with_values (GnmEvalPos const *ep, GnmFunc const *fn,
					 int argc, GnmValue const * const *values);

/* Utilies to interate through ranges and argument lists */
typedef GnmValue * (*FunctionIterateCB) (GnmEvalPos const *ep, GnmValue const *value,
					 gpointer user_data);
GnmValue *function_iterate_argument_values (GnmEvalPos const *ep,
					    FunctionIterateCB callback,
					    gpointer callback_closure,
					    int argc,
					    GnmExprConstPtr const *argv,
					    gboolean strict,
					    CellIterFlags iter_flags);

G_END_DECLS

#endif /* _GNM_FUNC_H_ */
