hledger/hledger-lib/Hledger/Data/TransactionModifier.hs
Simon Michael a771c8fc19 imp: revert 2b5194238 imp: generate auto postings on forecast transactions by default (#2027)
I found at least one user for whom this would be a breaking change
(they generate forecast txns, and have auto posting rules, but don't
want the latter applied to the former). I guess it's better to keep
things as they were for now: if you need auto postings on your
forecast txns you must use two flags, --forecast --auto.
2023-04-30 08:08:26 -10:00

157 lines
7.7 KiB
Haskell

{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ViewPatterns #-}
{-|
A 'TransactionModifier' is a rule that modifies certain 'Transaction's,
typically adding automated postings to them.
-}
module Hledger.Data.TransactionModifier (
modifyTransactions
)
where
import Prelude hiding (Applicative(..))
import Control.Applicative (Applicative(..), (<|>))
import Data.Function ((&))
import qualified Data.Map as M
import Data.Maybe (catMaybes)
import qualified Data.Text as T
import Data.Time.Calendar (Day)
import Hledger.Data.Types
import Hledger.Data.Amount
import Hledger.Data.Dates
import Hledger.Data.Transaction (txnTieKnot)
import Hledger.Query (Query, filterQuery, matchesAmount, matchesPostingExtra,
parseQuery, queryIsAmt, queryIsSym, simplifyQuery)
import Hledger.Data.Posting (commentJoin, commentAddTag, postingAddTags, postingApplyCommodityStyles)
import Hledger.Utils (dbg6, wrap)
-- $setup
-- >>> :set -XOverloadedStrings
-- >>> import Hledger.Data.Posting
-- >>> import Hledger.Data.Transaction
-- >>> import Hledger.Data.Journal
-- | Apply all the given transaction modifiers, in turn, to each transaction.
-- Or if any of them fails to be parsed, return the first error. A reference
-- date is provided to help interpret relative dates in transaction modifier
-- queries.
modifyTransactions :: (AccountName -> Maybe AccountType)
-> (AccountName -> [Tag])
-> M.Map CommoditySymbol AmountStyle
-> Day -> Bool -> [TransactionModifier] -> [Transaction]
-> Either String [Transaction]
modifyTransactions atypes atags styles d verbosetags tmods ts = do
fs <- mapM (transactionModifierToFunction atypes atags styles d verbosetags) tmods -- convert modifiers to functions, or return a parse error
let
modifytxn t = t''
where
t' = foldr (flip (.)) id fs t -- apply each function in turn
t'' = if t' == t
then t'
else t'{tcomment=tcomment t' & (if verbosetags then (`commentAddTag` ("modified","")) else id)
,ttags=ttags t' & (("_modified","") :) & (if verbosetags then (("modified","") :) else id)
}
Right $ map modifytxn ts
-- | Converts a 'TransactionModifier' to a 'Transaction'-transforming function
-- which applies the modification(s) specified by the TransactionModifier.
-- Or, returns the error message there is a problem parsing the TransactionModifier's query.
-- A reference date is provided to help interpret relative dates in the query.
--
-- The postings of the transformed transaction will reference it in the usual
-- way (ie, 'txnTieKnot' is called).
--
-- Currently the only kind of modification possible is adding automated
-- postings when certain other postings are present.
--
-- >>> import qualified Data.Text.IO as T
-- >>> t = nulltransaction{tpostings=["ping" `post` usd 1]}
-- >>> tmpost acc amt = TMPostingRule (acc `post` amt) False
-- >>> test = either putStr (T.putStr.showTransaction) . fmap ($ t) . transactionModifierToFunction (const Nothing) (const []) mempty nulldate True
-- >>> test $ TransactionModifier "" ["pong" `tmpost` usd 2]
-- 0000-01-01
-- ping $1.00
-- pong $2.00 ; generated-posting: =
-- <BLANKLINE>
-- >>> test $ TransactionModifier "miss" ["pong" `tmpost` usd 2]
-- 0000-01-01
-- ping $1.00
-- <BLANKLINE>
-- >>> test $ TransactionModifier "ping" [("pong" `tmpost` nullamt{aquantity=3}){tmprIsMultiplier=True}]
-- 0000-01-01
-- ping $1.00
-- pong $3.00 ; generated-posting: = ping
-- <BLANKLINE>
--
transactionModifierToFunction :: (AccountName -> Maybe AccountType)
-> (AccountName -> [Tag])
-> M.Map CommoditySymbol AmountStyle
-> Day -> Bool -> TransactionModifier
-> Either String (Transaction -> Transaction)
transactionModifierToFunction atypes atags styles refdate verbosetags TransactionModifier{tmquerytxt, tmpostingrules} = do
q <- simplifyQuery . fst <$> parseQuery refdate tmquerytxt
let
fs = map (\tmpr -> addAccountTags . tmPostingRuleToFunction verbosetags styles q tmquerytxt tmpr) tmpostingrules
addAccountTags p = p `postingAddTags` atags (paccount p)
generatePostings p = p : map ($ p) (if matchesPostingExtra atypes q p then fs else [])
Right $ \t@(tpostings -> ps) -> txnTieKnot t{tpostings=concatMap generatePostings ps}
-- | Converts a 'TransactionModifier''s posting rule to a 'Posting'-generating function,
-- which will be used to make a new posting based on the old one (an "automated posting").
-- The new posting's amount can optionally be the old posting's amount multiplied by a constant.
-- If the old posting had a total-priced amount, the new posting's multiplied amount will be unit-priced.
-- The new posting will have a hidden _generated-posting: tag added,
-- and with a true first argument, also a visible generated-posting: tag.
-- The provided TransactionModifier's query text is saved as the tags' value.
tmPostingRuleToFunction :: Bool -> M.Map CommoditySymbol AmountStyle -> Query -> T.Text -> TMPostingRule -> (Posting -> Posting)
tmPostingRuleToFunction verbosetags styles query querytxt tmpr =
\p -> postingApplyCommodityStyles styles . renderPostingCommentDates $ pr
{ pdate = pdate pr <|> pdate p
, pdate2 = pdate2 pr <|> pdate2 p
, pamount = amount' p
, pcomment = pcomment pr & (if verbosetags then (`commentAddTag` ("generated-posting",qry)) else id)
, ptags = ptags pr
& (("_generated-posting",qry) :)
& (if verbosetags then (("generated-posting", qry) :) else id)
}
where
pr = tmprPosting tmpr
qry = "= " <> querytxt
symq = filterQuery (liftA2 (||) queryIsSym queryIsAmt) query
amount' = case postingRuleMultiplier tmpr of
Nothing -> const $ pamount pr
Just n -> \p ->
-- Multiply the old posting's amount by the posting rule's multiplier.
let
pramount = dbg6 "pramount" . head . amountsRaw $ pamount pr
matchedamount = dbg6 "matchedamount" . filterMixedAmount (symq `matchesAmount`) $ pamount p
-- Handle a matched amount with a total price carefully so as to keep the transaction balanced (#928).
-- Approach 1: convert to a unit price and increase the display precision slightly
-- Mixed as = dbg6 "multipliedamount" $ n `multiplyMixedAmount` mixedAmountTotalPriceToUnitPrice matchedamount
-- Approach 2: multiply the total price (keeping it positive) as well as the quantity
as = dbg6 "multipliedamount" $ multiplyMixedAmount n matchedamount
in
case acommodity pramount of
"" -> as
-- TODO multipliers with commodity symbols are not yet a documented feature.
-- For now: in addition to multiplying the quantity, it also replaces the
-- matched amount's commodity, display style, and price with those of the posting rule.
c -> mapMixedAmount (\a -> a{acommodity = c, astyle = astyle pramount, aprice = aprice pramount}) as
postingRuleMultiplier :: TMPostingRule -> Maybe Quantity
postingRuleMultiplier tmpr = case amountsRaw . pamount $ tmprPosting tmpr of
[a] | tmprIsMultiplier tmpr -> Just $ aquantity a
_ -> Nothing
renderPostingCommentDates :: Posting -> Posting
renderPostingCommentDates p = p { pcomment = comment' }
where
dates = T.concat $ catMaybes [showDate <$> pdate p, ("=" <>) . showDate <$> pdate2 p]
comment'
| T.null dates = pcomment p
| otherwise = (wrap "[" "]" dates) `commentJoin` pcomment p