gncBillTerm.c

/********************************************************************\
 * gncBillTerm.c -- the Gnucash Billing Terms interface             *
 *                                                                  *
 * This program is free software; you can redistribute it and/or    *
 * modify it under the terms of the GNU General Public License as   *
 * published by the Free Software Foundation; either version 2 of   *
 * the License, or (at your option) any later version.              *
 *                                                                  *
 * This program is distributed in the hope that it will be useful,  *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of   *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the    *
 * GNU General Public License for more details.                     *
 *                                                                  *
 * You should have received a copy of the GNU General Public License*
 * along with this program; if not, contact:                        *
 *                                                                  *
 * Free Software Foundation           Voice:  +1-617-542-5942       *
 * 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652       *
 * Boston, MA  02110-1301,  USA       [email protected]                   *
 *                                                                  *
\********************************************************************/

/*
 * Copyright (C) 2002 Derek Atkins
 * Copyright (C) 2003 Linas Vepstas <[email protected]>
 * Author: Derek Atkins <[email protected]>
 */

#include <config.h>

#include <glib.h>
#include <qofinstance-p.h>

#include "gnc-engine.h"
#include "gncBillTermP.h"

struct _gncBillTerm
{
    QofInstance     inst;

    /* 'visible' data fields directly manipulated by user */
    char *          name;
    char *          desc;
    GncBillTermType type;
    gint            due_days;
    gint            disc_days;
    gnc_numeric     discount;
    gint            cutoff;

    /* Internal management fields */
    /* See src/doc/business.txt for an explanation of the following */
    /* Code that handles this is *identical* to that in gncTaxTable */
    gint64          refcount;
    GncBillTerm *   parent;      /* if non-null, we are an immutable child */
    GncBillTerm *   child;       /* if non-null, we have not changed */
    gboolean        invisible;
    GList *         children;    /* list of children for disconnection */
};

struct _gncBillTermClass
{
    QofInstanceClass parent_class;
};

struct _book_info
{
    GList *         terms;        /* visible terms */
};

static QofLogModule log_module = GNC_MOD_BUSINESS;

#define _GNC_MOD_NAME        GNC_ID_BILLTERM

#define SET_STR(obj, member, str) { \
        char * tmp; \
        \
        if (!g_strcmp0 (member, str)) return; \
        gncBillTermBeginEdit (obj); \
        tmp = CACHE_INSERT (str); \
        CACHE_REMOVE (member); \
        member = tmp; \
        }

AS_STRING_DEC(GncBillTermType, ENUM_TERMS_TYPE)
FROM_STRING_DEC(GncBillTermType, ENUM_TERMS_TYPE)

/* ============================================================== */
/* Misc inline utilities */

static inline void
mark_term (GncBillTerm *term)
{
    qof_instance_set_dirty(&term->inst);
    qof_event_gen (&term->inst, QOF_EVENT_MODIFY, NULL);
}

static inline void maybe_resort_list (GncBillTerm *term)
{
    struct _book_info *bi;

    if (term->parent || term->invisible) return;
    bi = qof_book_get_data (qof_instance_get_book(term), _GNC_MOD_NAME);
    bi->terms = g_list_sort (bi->terms, (GCompareFunc)gncBillTermCompare);
}

static inline void addObj (GncBillTerm *term)
{
    struct _book_info *bi;
    bi = qof_book_get_data (qof_instance_get_book(term), _GNC_MOD_NAME);
    bi->terms = g_list_insert_sorted (bi->terms, term,
                                      (GCompareFunc)gncBillTermCompare);
}

static inline void remObj (GncBillTerm *term)
{
    struct _book_info *bi;
    bi = qof_book_get_data (qof_instance_get_book(term), _GNC_MOD_NAME);
    bi->terms = g_list_remove (bi->terms, term);
}

static inline void
gncBillTermAddChild (GncBillTerm *table, GncBillTerm *child)
{
    g_return_if_fail(qof_instance_get_destroying(table) == FALSE);
    table->children = g_list_prepend(table->children, child);
}

static inline void
gncBillTermRemoveChild (GncBillTerm *table, GncBillTerm *child)
{
    if (qof_instance_get_destroying(table)) return;
    table->children = g_list_remove(table->children, child);
}

/* ============================================================== */

enum
{
    PROP_0,
    PROP_NAME
};

/* GObject Initialization */
G_DEFINE_TYPE(GncBillTerm, gnc_billterm, QOF_TYPE_INSTANCE);

static void
gnc_billterm_init(GncBillTerm* bt)
{
}

static void
gnc_billterm_dispose(GObject *btp)
{
    G_OBJECT_CLASS(gnc_billterm_parent_class)->dispose(btp);
}

static void
gnc_billterm_finalize(GObject* btp)
{
    G_OBJECT_CLASS(gnc_billterm_parent_class)->finalize(btp);
}

static void
gnc_billterm_get_property (GObject         *object,
                           guint            prop_id,
                           GValue          *value,
                           GParamSpec      *pspec)
{
    GncBillTerm *bt;

    g_return_if_fail(GNC_IS_BILLTERM(object));

    bt = GNC_BILLTERM(object);
    switch (prop_id)
    {
    case PROP_NAME:
        g_value_set_string(value, bt->name);
        break;
    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
        break;
    }
}

static void
gnc_billterm_set_property (GObject         *object,
                           guint            prop_id,
                           const GValue          *value,
                           GParamSpec      *pspec)
{
    GncBillTerm *bt;

    g_return_if_fail(GNC_IS_BILLTERM(object));

    bt = GNC_BILLTERM(object);
    g_assert (qof_instance_get_editlevel(bt));

    switch (prop_id)
    {
    case PROP_NAME:
        gncBillTermSetName(bt, g_value_get_string(value));
        break;
    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
        break;
    }
}

static GList*
impl_get_typed_referring_object_list(const QofInstance* inst, const QofInstance* ref)
{
    /* Bill term doesn't refer to anything except other billterms */
    return NULL;
}

static void
gnc_billterm_class_init (GncBillTermClass *klass)
{
    GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
    QofInstanceClass* qof_class = QOF_INSTANCE_CLASS(klass);

    gobject_class->dispose = gnc_billterm_dispose;
    gobject_class->finalize = gnc_billterm_finalize;
    gobject_class->set_property = gnc_billterm_set_property;
    gobject_class->get_property = gnc_billterm_get_property;

    qof_class->get_display_name = NULL;
    qof_class->refers_to_object = NULL;
    qof_class->get_typed_referring_object_list = impl_get_typed_referring_object_list;

    g_object_class_install_property
    (gobject_class,
     PROP_NAME,
     g_param_spec_string ("name",
                          "BillTerm Name",
                          "The bill term name is an arbitrary string "
                          "assigned by the user.  It is intended to "
                          "a short, 10 to 30 character long string "
                          "that is displayed by the GUI as the "
                          "billterm mnemonic.",
                          NULL,
                          G_PARAM_READWRITE));
}

/* Create/Destroy Functions */
GncBillTerm * gncBillTermCreate (QofBook *book)
{
    GncBillTerm *term;
    if (!book) return NULL;

    term = g_object_new (GNC_TYPE_BILLTERM, NULL);
    qof_instance_init_data(&term->inst, _GNC_MOD_NAME, book);
    term->name = CACHE_INSERT ("");
    term->desc = CACHE_INSERT ("");
    term->discount = gnc_numeric_zero ();
    addObj (term);
    qof_event_gen (&term->inst,  QOF_EVENT_CREATE, NULL);
    return term;
}

void gncBillTermDestroy (GncBillTerm *term)
{
    gchar guidstr[GUID_ENCODING_LENGTH+1];
    if (!term) return;
    guid_to_string_buff(qof_instance_get_guid(&term->inst),guidstr);
    DEBUG("destroying bill term %s (%p)", guidstr, term);
    qof_instance_set_destroying(term, TRUE);
    qof_instance_set_dirty (&term->inst);
    gncBillTermCommitEdit (term);
}

static void gncBillTermFree (GncBillTerm *term)
{
    GncBillTerm *child;
    GList *list;

    if (!term) return;

    qof_event_gen (&term->inst,  QOF_EVENT_DESTROY, NULL);
    CACHE_REMOVE (term->name);
    CACHE_REMOVE (term->desc);
    remObj (term);

    if (!qof_instance_get_destroying(term))
        PERR("free a billterm without do_free set!");

    /* disconnect from parent */
    if (term->parent)
        gncBillTermRemoveChild(term->parent, term);

    /* disconnect from the children */
    for (list = term->children; list; list = list->next)
    {
        child = list->data;
        gncBillTermSetParent(child, NULL);
    }
    g_list_free(term->children);

    /* qof_instance_release(&term->inst); */
    g_object_unref (term);
}

/* ============================================================== */
/* Set Functions */

void gncBillTermSetName (GncBillTerm *term, const char *name)
{
    if (!term || !name) return;
    SET_STR (term, term->name, name);
    mark_term (term);
    maybe_resort_list (term);
    gncBillTermCommitEdit (term);
}

void gncBillTermSetDescription (GncBillTerm *term, const char *desc)
{
    if (!term || !desc) return;
    SET_STR (term, term->desc, desc);
    mark_term (term);
    maybe_resort_list (term);
    gncBillTermCommitEdit (term);
}

void gncBillTermSetType (GncBillTerm *term, GncBillTermType type)
{
    if (!term) return;
    if (term->type == type) return;
    gncBillTermBeginEdit (term);
    term->type = type;
    mark_term (term);
    gncBillTermCommitEdit (term);
}

FROM_STRING_FUNC(GncBillTermType, ENUM_TERMS_TYPE)

static
void qofBillTermSetType (GncBillTerm *term, const char *type_label)
{
    GncBillTermType type;

    type = GncBillTermTypefromString(type_label);
    gncBillTermSetType(term, type);
}

void gncBillTermSetDueDays (GncBillTerm *term, gint days)
{
    if (!term) return;
    if (term->due_days == days) return;
    gncBillTermBeginEdit (term);
    term->due_days = days;
    mark_term (term);
    gncBillTermCommitEdit (term);
}

void gncBillTermSetDiscountDays (GncBillTerm *term, gint days)
{
    if (!term) return;
    if (term->disc_days == days) return;
    gncBillTermBeginEdit (term);
    term->disc_days = days;
    mark_term (term);
    gncBillTermCommitEdit (term);
}

void gncBillTermSetDiscount (GncBillTerm *term, gnc_numeric discount)
{
    if (!term) return;
    if (gnc_numeric_eq (term->discount, discount)) return;
    gncBillTermBeginEdit (term);
    term->discount = discount;
    mark_term (term);
    gncBillTermCommitEdit (term);
}

void gncBillTermSetCutoff (GncBillTerm *term, gint cutoff)
{
    if (!term) return;
    if (term->cutoff == cutoff) return;
    gncBillTermBeginEdit (term);
    term->cutoff = cutoff;
    mark_term (term);
    gncBillTermCommitEdit (term);
}

/* XXX this doesn't seem right. If the parent/child relationship
 * is a doubly-linked list, then there shouldn't be separate set-parent,
 * set-child routines, else misuse of the routines will goof up
 * relationships.  These ops should be atomic, I think.
 */
void gncBillTermSetParent (GncBillTerm *term, GncBillTerm *parent)
{
    if (!term) return;
    gncBillTermBeginEdit (term);
    if (term->parent)
        gncBillTermRemoveChild(term->parent, term);
    term->parent = parent;
    if (parent)
        gncBillTermAddChild(parent, term);
    term->refcount = 0;
    if ( parent != NULL )
    {
        gncBillTermMakeInvisible (term);
    }
    mark_term (term);
    gncBillTermCommitEdit (term);
}

void gncBillTermSetChild (GncBillTerm *term, GncBillTerm *child)
{
    if (!term) return;
    gncBillTermBeginEdit (term);
    term->child = child;
    mark_term (term);
    gncBillTermCommitEdit (term);
}

void gncBillTermIncRef (GncBillTerm *term)
{
    if (!term) return;
    if (term->parent || term->invisible) return;        /* children dont need refcounts */
    gncBillTermBeginEdit (term);
    term->refcount++;
    mark_term (term);
    gncBillTermCommitEdit (term);
}

void gncBillTermDecRef (GncBillTerm *term)
{
    if (!term) return;
    if (term->parent || term->invisible) return;        /* children dont need refcounts */
    g_return_if_fail (term->refcount >= 1);
    gncBillTermBeginEdit (term);
    term->refcount--;
    mark_term (term);
    gncBillTermCommitEdit (term);
}

void gncBillTermSetRefcount (GncBillTerm *term, gint64 refcount)
{
    if (!term) return;
    gncBillTermBeginEdit (term);
    term->refcount = refcount;
    mark_term (term);
    gncBillTermCommitEdit (term);
}

void gncBillTermMakeInvisible (GncBillTerm *term)
{
    if (!term) return;
    gncBillTermBeginEdit (term);
    term->invisible = TRUE;
    remObj (term);
    mark_term (term);
    gncBillTermCommitEdit (term);
}

void gncBillTermChanged (GncBillTerm *term)
{
    if (!term) return;
    term->child = NULL;
}

void gncBillTermBeginEdit (GncBillTerm *term)
{
    qof_begin_edit(&term->inst);
}

static void gncBillTermOnError (QofInstance *inst, QofBackendError errcode)
{
    PERR("BillTerm QofBackend Failure: %d", errcode);
    gnc_engine_signal_commit_error( errcode );
}

static void bill_free (QofInstance *inst)
{
    GncBillTerm *term = (GncBillTerm *) inst;
    gncBillTermFree(term);
}

static void on_done (QofInstance *inst) {}

void gncBillTermCommitEdit (GncBillTerm *term)
{
    if (!qof_commit_edit (QOF_INSTANCE(term))) return;
    qof_commit_edit_part2 (&term->inst, gncBillTermOnError,
                           on_done, bill_free);
}

/* Get Functions */

GncBillTerm *gncBillTermLookupByName (QofBook *book, const char *name)
{
    GList *list = gncBillTermGetTerms (book);

    for ( ; list; list = list->next)
    {
        GncBillTerm *term = list->data;
        if (!g_strcmp0 (term->name, name))
            return list->data;
    }
    return NULL;
}

GList * gncBillTermGetTerms (QofBook *book)
{
    struct _book_info *bi;
    if (!book) return NULL;

    bi = qof_book_get_data (book, _GNC_MOD_NAME);
    return bi->terms;
}

const char *gncBillTermGetName (const GncBillTerm *term)
{
    if (!term) return NULL;
    return term->name;
}

const char *gncBillTermGetDescription (const GncBillTerm *term)
{
    if (!term) return NULL;
    return term->desc;
}

GncBillTermType gncBillTermGetType (const GncBillTerm *term)
{
    if (!term) return 0;
    return term->type;
}

AS_STRING_FUNC(GncBillTermType, ENUM_TERMS_TYPE)

static
const char* qofBillTermGetType (const GncBillTerm *term)
{
    if (!term)
    {
        return NULL;
    }
    return GncBillTermTypeasString(term->type);
}

gint gncBillTermGetDueDays (const GncBillTerm *term)
{
    if (!term) return 0;
    return term->due_days;
}

gint gncBillTermGetDiscountDays (const GncBillTerm *term)
{
    if (!term) return 0;
    return term->disc_days;
}

gnc_numeric gncBillTermGetDiscount (const GncBillTerm *term)
{
    if (!term) return gnc_numeric_zero ();
    return term->discount;
}

gint gncBillTermGetCutoff (const GncBillTerm *term)
{
    if (!term) return 0;
    return term->cutoff;
}

static GncBillTerm *gncBillTermCopy (const GncBillTerm *term)
{
    GncBillTerm *t;

    if (!term) return NULL;
    t = gncBillTermCreate (qof_instance_get_book(term));

    gncBillTermBeginEdit(t);

    gncBillTermSetName (t, term->name);
    gncBillTermSetDescription (t, term->desc);

    t->type = term->type;
    t->due_days = term->due_days;
    t->disc_days = term->disc_days;
    t->discount = term->discount;
    t->cutoff = term->cutoff;

    mark_term (t);
    gncBillTermCommitEdit(t);

    return t;
}

GncBillTerm *gncBillTermReturnChild (GncBillTerm *term, gboolean make_new)
{
    GncBillTerm *child = NULL;

    if (!term) return NULL;
    if (term->child) return term->child;
    if (term->parent || term->invisible) return term;
    if (make_new)
    {
        child = gncBillTermCopy (term);
        gncBillTermSetChild (term, child);
        gncBillTermSetParent (child, term);
    }
    return child;
}

GncBillTerm *gncBillTermGetParent (const GncBillTerm *term)
{
    if (!term) return NULL;
    return term->parent;
}

gint64 gncBillTermGetRefcount (const GncBillTerm *term)
{
    if (!term) return 0;
    return term->refcount;
}

gboolean gncBillTermGetInvisible (const GncBillTerm *term)
{
    if (!term) return FALSE;
    return term->invisible;
}

int gncBillTermCompare (const GncBillTerm *a, const GncBillTerm *b)
{
    int ret;

    if (!a && !b) return 0;
    if (!a) return -1;
    if (!b) return 1;

    ret = g_strcmp0 (a->name, b->name);
    if (ret) return ret;

    return g_strcmp0 (a->desc, b->desc);
}

gboolean gncBillTermEqual(const GncBillTerm *a, const GncBillTerm *b)
{
    if (a == NULL && b == NULL) return TRUE;
    if (a == NULL || b == NULL) return FALSE;

    g_return_val_if_fail(GNC_IS_BILLTERM(a), FALSE);
    g_return_val_if_fail(GNC_IS_BILLTERM(b), FALSE);

    if (g_strcmp0(a->name, b->name) != 0)
    {
        PWARN("Names differ: %s vs %s", a->name, b->name);
        return FALSE;
    }

    if (g_strcmp0(a->desc, b->desc) != 0)
    {
        PWARN("Descriptions differ: %s vs %s", a->desc, b->desc);
        return FALSE;
    }

    if (a->type != b->type)
    {
        PWARN("Types differ");
        return FALSE;
    }

    if (a->due_days != b->due_days)
    {
        PWARN("Due days differ: %d vs %d", a->due_days, b->due_days);
        return FALSE;
    }

    if (a->disc_days != b->disc_days)
    {
        PWARN("Discount days differ: %d vs %d", a->disc_days, b->disc_days);
        return FALSE;
    }

    if (!gnc_numeric_equal(a->discount, b->discount))
    {
        PWARN("Discounts differ");
        return FALSE;
    }

    if (a->cutoff != b->cutoff)
    {
        PWARN("Cutoffs differ: %d vs %d", a->cutoff, b->cutoff);
        return FALSE;
    }

    if (a->invisible != b->invisible)
    {
        PWARN("Invisible flags differ");
        return FALSE;
    }

//    gint64          refcount;
//    GncBillTerm *   parent;      /* if non-null, we are an immutable child */
//    GncBillTerm *   child;       /* if non-null, we have not changed */
//    GList *         children;    /* list of children for disconnection */

    return TRUE;
}

gboolean gncBillTermIsFamily (const GncBillTerm *a, const GncBillTerm *b)
{
    if (!gncBillTermCompare (a, b))
        return TRUE;
    else
        return FALSE;
}

gboolean gncBillTermIsDirty (const GncBillTerm *term)
{
    if (!term) return FALSE;
    return qof_instance_get_dirty_flag(term);
}

/********************************************************/
/* functions to compute dates from Bill Terms           */

#define SECS_PER_DAY 86400

/* Based on the post date and a proximo type, compute the month and
 * year this is due.  The actual day is filled in below.
 *
 * A proximo billing term has multiple parameters:
 * * due day: day of the month the invoice/bill will be due
 * * cutoff: day of the month used to decide if the due date will be
 *           in the next month or in the month thereafter. This can be
 *           a negative number in which case the cutoff date is relative
 *           to the end of the month and counting backwards.
 *           Eg: cutoff = -3 would mean 25 in February or 28 in June
 *
 * How does it work:
 * Assume cutoff = 19 and due day = 20
 *
 * * Example 1 post date = 14-06-2010 (European date format)
 *   14 is less than the cutoff of 19, so the due date will be in the next
 *   month. Since the due day is set to 20, the due date will be
 *   20-07-2010
 *
 * * Example 2 post date = 22-06-2010 (European date format)
 *   22 is more than the cutoff of 19, so the due date will be in the month
 *   after next month. Since the due day is set to 20, the due date will be
 *   20-02-2010
 *
 */
static void
compute_monthyear (const GncBillTerm *term, Timespec post_date,
                   int *month, int *year)
{
    int iday, imonth, iyear;
    int cutoff = term->cutoff;

    g_return_if_fail (term->type == GNC_TERM_TYPE_PROXIMO);

    gnc_timespec2dmy (post_date, &iday, &imonth, &iyear);

    if (cutoff <= 0)
        cutoff += gnc_date_get_last_mday (imonth, iyear);

    if (iday <= cutoff)
    {
        /* We apply this to next month */
        imonth++;
    }
    else
    {
        /* We apply to the following month */
        imonth += 2;
    }

    if (imonth > 12)
    {
        iyear++;
        imonth -= 12;
    }

    if (month) *month = imonth;
    if (year) *year = iyear;
}

/* There are two types of billing terms:
 *
 * Type DAYS defines a due date to be a fixed number of days passed the post
 * date. This is a straightforward calculation.
 *
 * The other type PROXIMO defines the due date as a fixed day of the month
 * (like always the 15th of the month). The proximo algorithm determines which
 * month based on the cutoff day and the post date. See above for a more
 * detailed explanation of proximo.
 */

static Timespec
compute_time (const GncBillTerm *term, Timespec post_date, int days)
{
    Timespec res = post_date;
    int day, month, year;

    switch (term->type)
    {
    case GNC_TERM_TYPE_DAYS:
        res.tv_sec += (SECS_PER_DAY * days);
        break;
    case GNC_TERM_TYPE_PROXIMO:
        compute_monthyear (term, post_date, &month, &year);
        day = gnc_date_get_last_mday (month, year);
        if (days < day)
            day = days;
        res = gnc_dmy2timespec (day, month, year);
        break;
    }
    return res;
}

Timespec
gncBillTermComputeDueDate (const GncBillTerm *term, Timespec post_date)
{
    Timespec res = post_date;
    if (!term) return res;

    return compute_time (term, post_date, term->due_days);
}
/* Package-Private functions */

static void _gncBillTermCreate (QofBook *book)
{
    struct _book_info *bi;

    if (!book) return;

    bi = g_new0 (struct _book_info, 1);
    qof_book_set_data (book, _GNC_MOD_NAME, bi);
}

static void _gncBillTermDestroy (QofBook *book)
{
    struct _book_info *bi;

    if (!book) return;

    bi = qof_book_get_data (book, _GNC_MOD_NAME);

    g_list_free (bi->terms);
    g_free (bi);
}

static QofObject gncBillTermDesc =
{
    DI(.interface_version = ) QOF_OBJECT_VERSION,
    DI(.e_type            = ) _GNC_MOD_NAME,
    DI(.type_label        = ) "Billing Term",
    DI(.create            = ) (gpointer)gncBillTermCreate,
    DI(.book_begin        = ) _gncBillTermCreate,
    DI(.book_end          = ) _gncBillTermDestroy,
    DI(.is_dirty          = ) qof_collection_is_dirty,
    DI(.mark_clean        = ) qof_collection_mark_clean,
    DI(.foreach           = ) qof_collection_foreach,
    DI(.printable         = ) NULL,
    DI(.version_cmp       = ) (int (*)(gpointer, gpointer)) qof_instance_version_cmp,
};

gboolean gncBillTermRegister (void)
{
    static QofParam params[] =
    {
        { GNC_BILLTERM_NAME,            QOF_TYPE_STRING,  (QofAccessFunc)gncBillTermGetName,                    (QofSetterFunc)gncBillTermSetName },
        { GNC_BILLTERM_DESC,            QOF_TYPE_STRING,  (QofAccessFunc)gncBillTermGetDescription,             (QofSetterFunc)gncBillTermSetDescription },
        { GNC_BILLTERM_TYPE, QOF_TYPE_STRING, (QofAccessFunc)qofBillTermGetType, (QofSetterFunc)qofBillTermSetType },
        { GNC_BILLTERM_DUEDAYS,         QOF_TYPE_INT32,   (QofAccessFunc)gncBillTermGetDueDays,                 (QofSetterFunc)gncBillTermSetDueDays },
        { GNC_BILLTERM_DISCDAYS,        QOF_TYPE_INT32,   (QofAccessFunc)gncBillTermGetDiscountDays,    (QofSetterFunc)gncBillTermSetDiscountDays },
        { GNC_BILLTERM_DISCOUNT,        QOF_TYPE_NUMERIC, (QofAccessFunc)gncBillTermGetDiscount,                (QofSetterFunc)gncBillTermSetDiscount },
        { GNC_BILLTERM_CUTOFF,          QOF_TYPE_INT32,   (QofAccessFunc)gncBillTermGetCutoff,                  (QofSetterFunc)gncBillTermSetCutoff },
        { GNC_BILLTERM_REFCOUNT,        QOF_TYPE_INT64,   (QofAccessFunc)gncBillTermGetRefcount,                NULL },
        { QOF_PARAM_BOOK,                       QOF_ID_BOOK,      (QofAccessFunc)qof_instance_get_book,                 NULL },
        { QOF_PARAM_GUID,                       QOF_TYPE_GUID,    (QofAccessFunc)qof_instance_get_guid,                 NULL },
        { NULL },
    };

    qof_class_register (_GNC_MOD_NAME, (QofSortFunc)gncBillTermCompare, params);

    return qof_object_register (&gncBillTermDesc);
}