gnucash/libgnucash/engine/cap-gains.h
Geert Janssens 83d14e1c1c Restructure the src directory
It is split into
- /libgnucash (for the non-gui bits)
- /gnucash (for the gui)
- /common (misc source files used by both)
- /bindings (currently only holds python bindings)

This is the first step in restructuring the code. It will need much
more fine tuning later on.
2017-08-10 18:45:00 +02:00

213 lines
10 KiB
C

/********************************************************************\
* cap-gains.h -- Automatically Compute Capital Gains/Losses *
* *
* 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 gnu@gnu.org *
\********************************************************************/
/** @addtogroup Engine
* @{ */
/** @addtogroup CapGains Cap Gains
* This file implements the various routines to automatically
* compute and handle Cap Gains/Losses resulting from trading
* activities. Some of these routines might have broader
* applicability, for handling depreciation & etc.
*
* This code is under development, and is 'beta': we think we're
* mostly done, and we've tested and "things work for us", but there
* may still be something missing, and there might still be some
* bugs.
*
* This code does not currently handle tax distinctions, e.g
* the different tax treatment that short-term and long-term
* cap gains have.
*
* The computation of (Realized) Gains/Losses is performed automatically by
* the lot "scrub" routines, using a "double-balance" algorithm. Every
* split has two numbers associated with it: an "amount", which is the
* number of items that a split describes, and the "value", which is the
* cost of those items. In a closed lot, the grand-total amount of items in
* the lot is zero: the number of items bought equals the number of items
* sold; thus the amount-balance is zero. But since the purchase/sale of
* the items in the lot typically happen at different prices, there will
* typically be a gain/loss. This gain/loss is the grand-total value of all
* the items in the lot (total costs minus total income).
*
* In order to properly account for the gains/losses, an "adjusting split"
* is added that brings the total gains/losses back to exactly zero (this
* is the second "balance" of "double balance"). This adjusting split will
* have an amount of zero (no items are involved) but have a non-zero value
* (equal to the total gain/loss). This split can then participate in a
* "gains transaction" which records the gains in another account. Thus,
* for example, if you record $300 in your bank account due to the purchase
* and then the sale of some item, the "gains transaction" will record $300
* in income in an income account. Thus, the change in the bank balance is
* always reflected by an equal change in income, assuring that the books
* are balanced.
*
* Notes about auto-recompute: If the amount in a split is changed,
* then the lot has to be recomputed.
* This has a potential trickle-through effect on all later lots.
* Ideally, later lots are dissolved, and recomputed. However, some
* lots may have been user-hand-built. These should be left alone.
*
ToDo:
o XXX Need to create a data-integrity scrubber, tht makes sure that
the various flags, and pointers & etc. match.
* @{ */
/** @file cap-gains.h
* @brief Utilities to Automatically Compute Capital Gains/Losses.
* @author Created by Linas Vepstas August 2003
* @author Copyright (c) 2003,2004 Linas Vepstas <linas@linas.org>
*/
#ifndef XACC_CAP_GAINS_H
#define XACC_CAP_GAINS_H
#include "gnc-engine.h"
/** The xaccSplitGetCapGains() method returns the value of
* capital gains (if any) associated with the indicated
* split. In order for there to be any capital gains,
* several things must hold true about this split:
* (1) It must have been involved in trading (for aexample,
* by belonging to a stock or trading account)
* (2) It must have been assigned to a lot.
* (3) It cannot be the opening split of a lot; that
* is, it must be a matching sale of an earlier purchase
* (or vice versa).
*/
gnc_numeric xaccSplitGetCapGains(Split *);
/** The xaccAccountHasTrades() method checks to see if the
* indicated account is used in the trading of commodities.
* A 'trading' account will contain transactions whose
* transaction currency is not the same as the account
* commodity. The existence of such transactions is
* the very definition of a 'trade'. This routine returns
* TRUE if this is a trading account, else it returns
* FALSE.
*/
gboolean xaccAccountHasTrades (const Account *);
/** The xaccAccountFindEarliestOpenLot() method is a handy
* utility routine for finding the earliest open lot in
* an account whose lot balance is *opposite* to the
* passed argument 'sign'. By 'earliest lot', we mean
* the lot that has a split with the earliest 'date_posted'.
* The sign comparison helps identify a lot that can be
* added to: usually, one wants to add splits to a lot so
* that the balance only decreases.
* If 'currency' is non-null, then this attempts to find
* a lot whose opening transaction has the same currency.
*/
GNCLot * xaccAccountFindEarliestOpenLot (Account *acc,
gnc_numeric sign,
gnc_commodity *currency);
GNCLot * xaccAccountFindLatestOpenLot (Account *acc,
gnc_numeric sign,
gnc_commodity *currency);
/** The xaccSplitGetCapGainsSplit() routine returns the split
* that records the cap gains for this split. It returns NULL
* if not found. This routine does nothing more than search for
* the split recorded in the KVP key "/gains-split"
*/
Split * xaccSplitGetCapGainsSplit (const Split *);
/** The xaccSplitGetGainsSourceSplit() routine returns the split
* that is the source of the cap gains in this split. It returns
* NULL if not found. This routine does nothing more than search
* for the split recorded in the KVP key "/gains-source"
*/
Split * xaccSplitGetGainsSourceSplit (const Split *);
/** The`xaccSplitAssign() routine will take the indicated
* split and, if it doesn't already belong to a lot, it will attempt
* to assign it to an appropriate lot.
* If the split already belongs to a Lot, this routine does nothing.
* If there are no open Lots, this routine will create a new lot
* and place the split into it. If there's an open lot, and its
* big enough to accept the split in it's entirety, then the split
* will be placed into that lot. If the split is too big to fit
* into the currently open lot, it will be busted up into two
* (or more) pieces, and each placed into a lot accordingly.
* If the split needed to be broken up into several pieces, this
* routine will return TRUE, else it returns FALSE.
*
* If the split had to be broken up, kvp markup in the "/lot-split"
* directory is used to identify the peers. 'gemini'-style kvp's
* are used.
*
* This routine uses the "FIFOPolicy" callback, and thus
* implements a "FIFO" First-In First-Out accounting policy.
* This is currently the only implemented policy; adding new
* policies should be 'easy'; read the source luke.
*/
gboolean xaccSplitAssign (Split *split);
/** The xaccSplitAssignToLot() routine will fit the indicated split
* into the indicated lot, with the goal of closing the lot, or
* at least bringing the lot balance closer to closure. (A closed
* lot has a balance of zero). To make this "fit", a variety of
* checks and actions are performed. First, the lot must be open,
* and the sign of the split amount must be opposite to the sign
* of the lot balance. The 'opposite-sign' requirement is so that
* inserting the split will cause the size of the lot to decrease.
* If the amount of the split is too small, or is just right to
* close the lot, the split is added, and NULL is returned. If
* the split is larger than the lot balance, the split will be
* divided into sub-splits, one of which is just right to close
* the lot. A pointer to the other sub-split will be returned.
*
* If the split had to be broken up, kvp markup in the "/lot-split"
* directory is used to identify the peers. 'gemini'-style kvp's
* are used.
*/
Split * xaccSplitAssignToLot (Split *split, GNCLot *lot);
/** The xaccSplitComputeCapGains() routine computes the cap gains
* or losses for the indicated split. The gains are placed into
* the 'gains_acct'. If the gains_acct is NULL, then the appropriate
* default account is used (and created, if needed).
*
* To compute the gains, the split must belong to a lot. If the
* split is the 'opening split', i.e. the earliest split in the
* lot, then nothing is done, as there are no gains/losses (something
* must be bought *and* sold for there to be a gain/loss).
*
* Note also: the 'amount' of the split must be of opposite sign,
* and must be equal to or smaller, than the 'amount' of the opening
* split; its an error otherwise. If the 'amount' of the split is
* less than the opening amount, the gains are pro-rated.
*
* The xaccLotComputeCapGains() routine merely invokes the above on
* each split in the lot.
*/
void xaccSplitComputeCapGains(Split *split, Account *gain_acc);
void xaccLotComputeCapGains (GNCLot *lot, Account *gain_acc);
#endif /* XACC_CAP_GAINS_H */
/** @} */
/** @} */
/* =========================== END OF FILE ======================= */