{-|

A 'Journal' is a set of transactions, plus optional related data.  This is
hledger's primary data object. It is usually parsed from a journal file or
other data format (see "Hledger.Read").

-}

module Hledger.Data.Journal (
  -- * Parsing helpers
  addHistoricalPrice,
  addModifierTransaction,
  addPeriodicTransaction,
  addTimeLogEntry,
  addTransaction,
  journalApplyAliases,
  journalBalanceTransactions,
  journalCanonicaliseAmounts,
  journalConvertAmountsToCost,
  journalFinalise,
  journalSelectingDate,
  -- * Filtering
  filterJournalPostings,
  filterJournalTransactions,
  -- * Querying
  journalAccountInfo,
  journalAccountNames,
  journalAccountNamesUsed,
  journalAmountAndPriceCommodities,
  journalAmounts,
  journalCanonicalCommodities,
  journalDateSpan,
  journalFilePath,
  journalFilePaths,
  journalPostings,
  -- * Standard account types
  journalBalanceSheetAccountQuery,
  journalProfitAndLossAccountQuery,
  journalIncomeAccountQuery,
  journalExpenseAccountQuery,
  journalAssetAccountQuery,
  journalLiabilityAccountQuery,
  journalEquityAccountQuery,
  journalCashAccountQuery,
  -- * Misc
  groupPostings,
  matchpats,
  nullctx,
  nulljournal,
  -- * Tests
  samplejournal,
  tests_Hledger_Data_Journal,
)
where
import Data.List
import Data.Map (findWithDefault, (!), toAscList)
import Data.Ord
import Data.Time.Calendar
import Data.Time.LocalTime
import Data.Tree
import Safe (headDef)
import System.Time (ClockTime(TOD))
import Test.HUnit
import Text.Printf
import qualified Data.Map as Map

import Hledger.Utils
import Hledger.Data.Types
import Hledger.Data.AccountName
import Hledger.Data.Account()
import Hledger.Data.Amount
import Hledger.Data.Commodity
import Hledger.Data.Dates
import Hledger.Data.Transaction
import Hledger.Data.Posting
import Hledger.Data.TimeLog
import Hledger.Query


instance Show Journal where
    show j = printf "Journal %s with %d transactions, %d accounts: %s"
             (journalFilePath j)
             (length (jtxns j) +
              length (jmodifiertxns j) +
              length (jperiodictxns j))
             (length accounts)
             (show accounts)
             -- ++ (show $ journalTransactions l)
             where accounts = flatten $ journalAccountNameTree j

-- showJournalDebug j = unlines [
--                       show j
--                      ,show (jtxns j)
--                      ,show (jmodifiertxns j)
--                      ,show (jperiodictxns j)
--                      ,show $ open_timelog_entries j
--                      ,show $ historical_prices j
--                      ,show $ final_comment_lines j
--                      ,show $ jContext j
--                      ,show $ map fst $ files j
--                      ]

nulljournal :: Journal
nulljournal = Journal { jmodifiertxns = []
                      , jperiodictxns = []
                      , jtxns = []
                      , open_timelog_entries = []
                      , historical_prices = []
                      , final_comment_lines = []
                      , jContext = nullctx
                      , files = []
                      , filereadtime = TOD 0 0
                      }

nullctx :: JournalContext
nullctx = Ctx { ctxYear = Nothing, ctxCommodity = Nothing, ctxAccount = [], ctxAliases = [] }

journalFilePath :: Journal -> FilePath
journalFilePath = fst . mainfile

journalFilePaths :: Journal -> [FilePath]
journalFilePaths = map fst . files

mainfile :: Journal -> (FilePath, String)
mainfile = headDef ("", "") . files

addTransaction :: Transaction -> Journal -> Journal
addTransaction t l0 = l0 { jtxns = t : jtxns l0 }

addModifierTransaction :: ModifierTransaction -> Journal -> Journal
addModifierTransaction mt l0 = l0 { jmodifiertxns = mt : jmodifiertxns l0 }

addPeriodicTransaction :: PeriodicTransaction -> Journal -> Journal
addPeriodicTransaction pt l0 = l0 { jperiodictxns = pt : jperiodictxns l0 }

addHistoricalPrice :: HistoricalPrice -> Journal -> Journal
addHistoricalPrice h l0 = l0 { historical_prices = h : historical_prices l0 }

addTimeLogEntry :: TimeLogEntry -> Journal -> Journal
addTimeLogEntry tle l0 = l0 { open_timelog_entries = tle : open_timelog_entries l0 }

journalPostings :: Journal -> [Posting]
journalPostings = concatMap tpostings . jtxns

-- | All account names used in this journal.
journalAccountNamesUsed :: Journal -> [AccountName]
journalAccountNamesUsed = sort . accountNamesFromPostings . journalPostings

journalAccountNames :: Journal -> [AccountName]
journalAccountNames = sort . expandAccountNames . journalAccountNamesUsed

journalAccountNameTree :: Journal -> Tree AccountName
journalAccountNameTree = accountNameTreeFrom . journalAccountNames

-- standard account types

-- | A query for Profit & Loss accounts in this journal.
-- Cf <http://en.wikipedia.org/wiki/Chart_of_accounts#Profit_.26_Loss_accounts>.
journalProfitAndLossAccountQuery  :: Journal -> Query
journalProfitAndLossAccountQuery j = Or [journalIncomeAccountQuery j
                                               ,journalExpenseAccountQuery j
                                               ]

-- | A query for Income (Revenue) accounts in this journal.
-- This is currently hard-coded to the case-insensitive regex @^(income|revenue)s?(:|$)@.
journalIncomeAccountQuery  :: Journal -> Query
journalIncomeAccountQuery _ = Acct "^(income|revenue)s?(:|$)"

-- | A query for Expense accounts in this journal.
-- This is currently hard-coded to the case-insensitive regex @^expenses?(:|$)@.
journalExpenseAccountQuery  :: Journal -> Query
journalExpenseAccountQuery _ = Acct "^expenses?(:|$)"

-- | A query for Asset, Liability & Equity accounts in this journal.
-- Cf <http://en.wikipedia.org/wiki/Chart_of_accounts#Balance_Sheet_Accounts>.
journalBalanceSheetAccountQuery  :: Journal -> Query
journalBalanceSheetAccountQuery j = Or [journalAssetAccountQuery j
                                              ,journalLiabilityAccountQuery j
                                              ,journalEquityAccountQuery j
                                              ]

-- | A query for Asset accounts in this journal.
-- This is currently hard-coded to the case-insensitive regex @^assets?(:|$)@.
journalAssetAccountQuery  :: Journal -> Query
journalAssetAccountQuery _ = Acct "^assets?(:|$)"

-- | A query for Liability accounts in this journal.
-- This is currently hard-coded to the case-insensitive regex @^liabilit(y|ies)(:|$)@.
journalLiabilityAccountQuery  :: Journal -> Query
journalLiabilityAccountQuery _ = Acct "^liabilit(y|ies)(:|$)"

-- | A query for Equity accounts in this journal.
-- This is currently hard-coded to the case-insensitive regex @^equity(:|$)@.
journalEquityAccountQuery  :: Journal -> Query
journalEquityAccountQuery _ = Acct "^equity(:|$)"

-- | A query for Cash (-equivalent) accounts in this journal (ie,
-- accounts which appear on the cashflow statement.)  This is currently
-- hard-coded to be all the Asset accounts except for those containing the
-- case-insensitive regex @(receivable|A/R)@.
journalCashAccountQuery  :: Journal -> Query
journalCashAccountQuery j = And [journalAssetAccountQuery j, Not $ Acct "(receivable|A/R)"]

-- Various kinds of filtering on journals. We do it differently depending
-- on the command.

-------------------------------------------------------------------------------
-- filtering V2

-- | Keep only postings matching the query expression.
-- This can leave unbalanced transactions.
filterJournalPostings :: Query -> Journal -> Journal
filterJournalPostings q j@Journal{jtxns=ts} = j{jtxns=map filtertransactionpostings ts}
    where
      filtertransactionpostings t@Transaction{tpostings=ps} = t{tpostings=filter (q `matchesPosting`) ps}

-- | Keep only transactions matching the query expression.
filterJournalTransactions :: Query -> Journal -> Journal
filterJournalTransactions q j@Journal{jtxns=ts} = j{jtxns=filter (q `matchesTransaction`) ts}

{-
-------------------------------------------------------------------------------
-- filtering V1

-- | Keep only transactions we are interested in, as described by the
-- filter specification.
filterJournalTransactions :: FilterSpec -> Journal -> Journal
filterJournalTransactions FilterSpec{datespan=datespan
                                    ,cleared=cleared
                                    -- ,real=real
                                    -- ,empty=empty
                                    ,acctpats=apats
                                    ,descpats=dpats
                                    ,depth=depth
                                    ,fMetadata=md
                                    } =
    filterJournalTransactionsByClearedStatus cleared .
    filterJournalPostingsByDepth depth .
    filterJournalTransactionsByAccount apats .
    filterJournalTransactionsByMetadata md .
    filterJournalTransactionsByDescription dpats .
    filterJournalTransactionsByDate datespan

-- | Keep only postings we are interested in, as described by the filter
-- specification. This can leave unbalanced transactions.
filterJournalPostings :: FilterSpec -> Journal -> Journal
filterJournalPostings FilterSpec{datespan=datespan
                                ,cleared=cleared
                                ,real=real
                                ,empty=empty
                                ,acctpats=apats
                                ,descpats=dpats
                                ,depth=depth
                                ,fMetadata=md
                                } =
    filterJournalPostingsByRealness real .
    filterJournalPostingsByClearedStatus cleared .
    filterJournalPostingsByEmpty empty .
    filterJournalPostingsByDepth depth .
    filterJournalPostingsByAccount apats .
    filterJournalTransactionsByMetadata md .
    filterJournalTransactionsByDescription dpats .
    filterJournalTransactionsByDate datespan

-- | Keep only transactions whose metadata matches all metadata specifications.
filterJournalTransactionsByMetadata :: [(String,String)] -> Journal -> Journal
filterJournalTransactionsByMetadata pats j@Journal{jtxns=ts} = j{jtxns=filter matchmd ts}
    where matchmd t = all (`elem` tmetadata t) pats

-- | Keep only transactions whose description matches the description patterns.
filterJournalTransactionsByDescription :: [String] -> Journal -> Journal
filterJournalTransactionsByDescription pats j@Journal{jtxns=ts} = j{jtxns=filter matchdesc ts}
    where matchdesc = matchpats pats . tdescription

-- | Keep only transactions which fall between begin and end dates.
-- We include transactions on the begin date and exclude transactions on the end
-- date, like ledger.  An empty date string means no restriction.
filterJournalTransactionsByDate :: DateSpan -> Journal -> Journal
filterJournalTransactionsByDate (DateSpan begin end) j@Journal{jtxns=ts} = j{jtxns=filter match ts}
    where match t = maybe True (tdate t>=) begin && maybe True (tdate t<) end

-- | Keep only transactions which have the requested cleared/uncleared
-- status, if there is one.
filterJournalTransactionsByClearedStatus :: Maybe Bool -> Journal -> Journal
filterJournalTransactionsByClearedStatus Nothing j = j
filterJournalTransactionsByClearedStatus (Just val) j@Journal{jtxns=ts} = j{jtxns=filter match ts}
    where match = (==val).tstatus

-- | Keep only postings which have the requested cleared/uncleared status,
-- if there is one.
filterJournalPostingsByClearedStatus :: Maybe Bool -> Journal -> Journal
filterJournalPostingsByClearedStatus Nothing j = j
filterJournalPostingsByClearedStatus (Just c) j@Journal{jtxns=ts} = j{jtxns=map filterpostings ts}
    where filterpostings t@Transaction{tpostings=ps} = t{tpostings=filter ((==c) . postingCleared) ps}

-- | Strip out any virtual postings, if the flag is true, otherwise do
-- no filtering.
filterJournalPostingsByRealness :: Bool -> Journal -> Journal
filterJournalPostingsByRealness False j = j
filterJournalPostingsByRealness True j@Journal{jtxns=ts} = j{jtxns=map filterpostings ts}
    where filterpostings t@Transaction{tpostings=ps} = t{tpostings=filter isReal ps}

-- | Strip out any postings with zero amount, unless the flag is true.
filterJournalPostingsByEmpty :: Bool -> Journal -> Journal
filterJournalPostingsByEmpty True j = j
filterJournalPostingsByEmpty False j@Journal{jtxns=ts} = j{jtxns=map filterpostings ts}
    where filterpostings t@Transaction{tpostings=ps} = t{tpostings=filter (not . isEmptyPosting) ps}

-- -- | Keep only transactions which affect accounts deeper than the specified depth.
-- filterJournalTransactionsByDepth :: Maybe Int -> Journal -> Journal
-- filterJournalTransactionsByDepth Nothing j = j
-- filterJournalTransactionsByDepth (Just d) j@Journal{jtxns=ts} =
--     j{jtxns=(filter (any ((<= d+1) . accountNameLevel . paccount) . tpostings) ts)}

-- | Strip out any postings to accounts deeper than the specified depth
-- (and any transactions which have no postings as a result).
filterJournalPostingsByDepth :: Maybe Int -> Journal -> Journal
filterJournalPostingsByDepth Nothing j = j
filterJournalPostingsByDepth (Just d) j@Journal{jtxns=ts} =
    j{jtxns=filter (not . null . tpostings) $ map filtertxns ts}
    where filtertxns t@Transaction{tpostings=ps} =
              t{tpostings=filter ((<= d) . accountNameLevel . paccount) ps}

-- | Keep only postings which affect accounts matched by the account patterns.
-- This can leave transactions unbalanced.
filterJournalPostingsByAccount :: [String] -> Journal -> Journal
filterJournalPostingsByAccount apats j@Journal{jtxns=ts} = j{jtxns=map filterpostings ts}
    where filterpostings t@Transaction{tpostings=ps} = t{tpostings=filter (matchpats apats . paccount) ps}

-- | Keep only transactions which affect accounts matched by the account patterns.
-- More precisely: each positive account pattern excludes transactions
-- which do not contain a posting to a matched account, and each negative
-- account pattern excludes transactions containing a posting to a matched
-- account.
filterJournalTransactionsByAccount :: [String] -> Journal -> Journal
filterJournalTransactionsByAccount apats j@Journal{jtxns=ts} = j{jtxns=filter tmatch ts}
    where
      tmatch t = (null positives || any positivepmatch ps) && (null negatives || not (any negativepmatch ps)) where ps = tpostings t
      positivepmatch p = any (`amatch` a) positives where a = paccount p
      negativepmatch p = any (`amatch` a) negatives where a = paccount p
      amatch pat a = regexMatchesCI (abspat pat) a
      (negatives,positives) = partition isnegativepat apats

-}

-- | Convert this journal's transactions' primary date to either the
-- actual or effective date.
journalSelectingDate :: WhichDate -> Journal -> Journal
journalSelectingDate ActualDate j = j
journalSelectingDate EffectiveDate j =
    j{jtxns=map (journalTransactionWithDate EffectiveDate) $ jtxns j}

-- | Apply additional account aliases (eg from the command-line) to all postings in a journal.
journalApplyAliases :: [(AccountName,AccountName)] -> Journal -> Journal
journalApplyAliases aliases j@Journal{jtxns=ts} = j{jtxns=map fixtransaction ts}
    where
      fixtransaction t@Transaction{tpostings=ps} = t{tpostings=map fixposting ps}
      fixposting p@Posting{paccount=a} = p{paccount=accountNameApplyAliases aliases a}

-- | Do post-parse processing on a journal to make it ready for use: check
-- all transactions balance, canonicalise amount formats, close any open
-- timelog entries and so on.
journalFinalise :: ClockTime -> LocalTime -> FilePath -> String -> JournalContext -> Journal -> Either String Journal
journalFinalise tclock tlocal path txt ctx j@Journal{files=fs} =
    journalBalanceTransactions $
    journalCanonicaliseAmounts $
    journalCloseTimeLogEntries tlocal
    j{files=(path,txt):fs, filereadtime=tclock, jContext=ctx}

-- | Fill in any missing amounts and check that all journal transactions
-- balance, or return an error message. This is done after parsing all
-- amounts and working out the canonical commodities, since balancing
-- depends on display precision. Reports only the first error encountered.
journalBalanceTransactions :: Journal -> Either String Journal
journalBalanceTransactions j@Journal{jtxns=ts} =
  case sequence $ map balance ts of Right ts' -> Right j{jtxns=ts'}
                                    Left e    -> Left e
      where balance = balanceTransaction (Just $ journalCanonicalCommodities j)

-- | Convert all the journal's posting amounts (not price amounts) to
-- their canonical display settings. Ie, all amounts in a given
-- commodity will use (a) the display settings of the first, and (b)
-- the greatest precision, of the posting amounts in that commodity.
journalCanonicaliseAmounts :: Journal -> Journal
journalCanonicaliseAmounts j@Journal{jtxns=ts} = j{jtxns=map fixtransaction ts}
    where
      fixtransaction t@Transaction{tpostings=ps} = t{tpostings=map fixposting ps}
      fixposting p@Posting{pamount=a} = p{pamount=fixmixedamount a}
      fixmixedamount (Mixed as) = Mixed $ map fixamount as
      fixamount a@Amount{commodity=c} = a{commodity=fixcommodity c}
      fixcommodity c@Commodity{symbol=s} = findWithDefault c s canonicalcommoditymap
      canonicalcommoditymap = journalCanonicalCommodities j

-- -- | Apply this journal's historical price records to unpriced amounts where possible.
-- journalApplyHistoricalPrices :: Journal -> Journal
-- journalApplyHistoricalPrices j@Journal{jtxns=ts} = j{jtxns=map fixtransaction ts}
--     where
--       fixtransaction t@Transaction{tdate=d, tpostings=ps} = t{tpostings=map fixposting ps}
--        where
--         fixposting p@Posting{pamount=a} = p{pamount=fixmixedamount a}
--         fixmixedamount (Mixed as) = Mixed $ map fixamount as
--         fixamount = fixprice
--         fixprice a@Amount{price=Just _} = a
--         fixprice a@Amount{commodity=c} = a{price=maybe Nothing (Just . UnitPrice) $ journalHistoricalPriceFor j d c}

-- -- | Get the price for a commodity on the specified day from the price database, if known.
-- -- Does only one lookup step, ie will not look up the price of a price.
-- journalHistoricalPriceFor :: Journal -> Day -> Commodity -> Maybe MixedAmount
-- journalHistoricalPriceFor j d Commodity{symbol=s} = do
--   let ps = reverse $ filter ((<= d).hdate) $ filter ((s==).hsymbol) $ sortBy (comparing hdate) $ historical_prices j
--   case ps of (HistoricalPrice{hamount=a}:_) -> Just a
--              _ -> Nothing

-- | Close any open timelog sessions in this journal using the provided current time.
journalCloseTimeLogEntries :: LocalTime -> Journal -> Journal
journalCloseTimeLogEntries now j@Journal{jtxns=ts, open_timelog_entries=es} =
  j{jtxns = ts ++ (timeLogEntriesToTransactions now es), open_timelog_entries = []}

-- | Convert all this journal's amounts to cost by applying their prices, if any.
journalConvertAmountsToCost :: Journal -> Journal
journalConvertAmountsToCost j@Journal{jtxns=ts} = j{jtxns=map fixtransaction ts}
    where
      -- similar to journalCanonicaliseAmounts
      fixtransaction t@Transaction{tpostings=ps} = t{tpostings=map fixposting ps}
      fixposting p@Posting{pamount=a} = p{pamount=fixmixedamount a}
      fixmixedamount (Mixed as) = Mixed $ map fixamount as
      fixamount = canonicaliseAmountCommodity (Just $ journalCanonicalCommodities j) . costOfAmount

-- | Get this journal's unique, display-preference-canonicalised commodities, by symbol.
journalCanonicalCommodities :: Journal -> Map.Map String Commodity
journalCanonicalCommodities j = canonicaliseCommodities $ journalAmountCommodities j

-- | Get all this journal's amounts' commodities, in the order parsed.
journalAmountCommodities :: Journal -> [Commodity]
journalAmountCommodities = map commodity . concatMap amounts . journalAmounts

-- | Get all this journal's amount and price commodities, in the order parsed.
journalAmountAndPriceCommodities :: Journal -> [Commodity]
journalAmountAndPriceCommodities = concatMap amountCommodities . concatMap amounts . journalAmounts

-- | Get this amount's commodity and any commodities referenced in its price.
amountCommodities :: Amount -> [Commodity]
amountCommodities Amount{commodity=c,price=p} =
    case p of Nothing -> [c]
              Just (UnitPrice ma)  -> c:(concatMap amountCommodities $ amounts ma)
              Just (TotalPrice ma) -> c:(concatMap amountCommodities $ amounts ma)

-- | Get all this journal's amounts, in the order parsed.
journalAmounts :: Journal -> [MixedAmount]
journalAmounts = map pamount . journalPostings

-- | The (fully specified) date span containing this journal's transactions,
-- or DateSpan Nothing Nothing if there are none.
journalDateSpan :: Journal -> DateSpan
journalDateSpan j
    | null ts = DateSpan Nothing Nothing
    | otherwise = DateSpan (Just $ tdate $ head ts) (Just $ addDays 1 $ tdate $ last ts)
    where
      ts = sortBy (comparing tdate) $ jtxns j

-- Misc helpers

-- | Check if a set of hledger account/description filter patterns matches the
-- given account name or entry description.  Patterns are case-insensitive
-- regular expressions. Prefixed with not:, they become anti-patterns.
matchpats :: [String] -> String -> Bool
matchpats pats str =
    (null positives || any match positives) && (null negatives || not (any match negatives))
    where
      (negatives,positives) = partition isnegativepat pats
      match "" = True
      match pat = regexMatchesCI (abspat pat) str

negateprefix = "not:"

isnegativepat = (negateprefix `isPrefixOf`)

abspat pat = if isnegativepat pat then drop (length negateprefix) pat else pat

-- | Calculate the account tree and all account balances from a journal's
-- postings, returning the results for efficient lookup.
journalAccountInfo :: Journal -> (Tree AccountName, Map.Map AccountName Account)
journalAccountInfo j = (ant, amap)
    where
      (ant, psof, _, inclbalof) = (groupPostings . journalPostings) j
      amap = Map.fromList [(a, acctinfo a) | a <- flatten ant]
      acctinfo a = Account a (psof a) (inclbalof a)

tests_journalAccountInfo = [
 "journalAccountInfo" ~: do
   let (t,m) = journalAccountInfo samplejournal
   assertEqual "account tree"
    (Node "top" [
      Node "assets" [
       Node "assets:bank" [
        Node "assets:bank:checking" [],
        Node "assets:bank:saving" []
        ],
       Node "assets:cash" []
       ],
      Node "expenses" [
       Node "expenses:food" [],
       Node "expenses:supplies" []
       ],
      Node "income" [
       Node "income:gifts" [],
       Node "income:salary" []
       ],
      Node "liabilities" [
       Node "liabilities:debts" []
       ]
      ]
     )
    t
   mapM_ 
         (\(e,a) -> assertEqual "" e a)
         (zip [
               ("assets",Account "assets" [] (Mixed [dollars (-1)]))
              ,("assets:bank",Account "assets:bank" [] (Mixed [dollars 1]))
              ,("assets:bank:checking",Account "assets:bank:checking" [
                  Posting {
                    pstatus=False,
                    paccount="assets:bank:checking",
                    pamount=(Mixed [dollars 1]),
                    pcomment="",
                    ptype=RegularPosting,
                    ptags=[],
                    ptransaction=Nothing
                  },
                  Posting {
                    pstatus=False,
                    paccount="assets:bank:checking",
                    pamount=(Mixed [dollars 1]),
                    pcomment="",
                    ptype=RegularPosting,
                    ptags=[],
                    ptransaction=Nothing
                  },
                  Posting {
                    pstatus=False,
                    paccount="assets:bank:checking",
                    pamount=(Mixed [dollars (-1)]),
                    pcomment="",
                    ptype=RegularPosting,
                    ptags=[],
                    ptransaction=Nothing
                  },
                  Posting {
                    pstatus=False,
                    paccount="assets:bank:checking",
                    pamount=(Mixed [dollars (-1)]),
                    pcomment="",
                    ptype=RegularPosting,
                    ptags=[],
                    ptransaction=Nothing
                  }
                  ] (Mixed [nullamt]))
              ,("assets:bank:saving",Account "assets:bank:saving" [
                  Posting {
                    pstatus=False,
                    paccount="assets:bank:saving",
                    pamount=(Mixed [dollars 1]),
                    pcomment="",
                    ptype=RegularPosting,
                    ptags=[],
                    ptransaction=Nothing
                  }
                  ] (Mixed [dollars 1]))
              ,("assets:cash",Account "assets:cash" [
                  Posting {
                    pstatus=False,
                    paccount="assets:cash",
                    pamount=(Mixed [dollars (-2)]),
                    pcomment="",
                    ptype=RegularPosting,
                    ptags=[],
                    ptransaction=Nothing
                  }
                ] (Mixed [dollars (-2)]))
              ,("expenses",Account "expenses" [] (Mixed [dollars 2]))
              ,("expenses:food",Account "expenses:food" [
                  Posting {
                    pstatus=False,
                    paccount="expenses:food",
                    pamount=(Mixed [dollars 1]),
                    pcomment="",
                    ptype=RegularPosting,
                    ptags=[],
                    ptransaction=Nothing
                  }
                ] (Mixed [dollars 1]))
              ,("expenses:supplies",Account "expenses:supplies" [
                  Posting {
                    pstatus=False,
                    paccount="expenses:supplies",
                    pamount=(Mixed [dollars 1]),
                    pcomment="",
                    ptype=RegularPosting,
                    ptags=[],
                    ptransaction=Nothing
                  }
                ] (Mixed [dollars 1]))
              ,("income",Account "income" [] (Mixed [dollars (-2)]))
              ,("income:gifts",Account "income:gifts" [
                  Posting {
                    pstatus=False,
                    paccount="income:gifts",
                    pamount=(Mixed [dollars (-1)]),
                    pcomment="",
                    ptype=RegularPosting,
                    ptags=[],
                    ptransaction=Nothing
                  }
                ] (Mixed [dollars (-1)]))
              ,("income:salary",Account "income:salary" [
                  Posting {
                    pstatus=False,
                    paccount="income:salary",
                    pamount=(Mixed [dollars (-1)]),
                    pcomment="",
                    ptype=RegularPosting,
                    ptags=[],
                    ptransaction=Nothing
                  }
                  ] (Mixed [dollars (-1)]))
              ,("liabilities",Account "liabilities" [] (Mixed [dollars 1]))
              ,("liabilities:debts",Account "liabilities:debts" [
                  Posting {
                    pstatus=False,
                    paccount="liabilities:debts",
                    pamount=(Mixed [dollars 1]),
                    pcomment="",
                    ptype=RegularPosting,
                    ptags=[],
                    ptransaction=Nothing
                  }
                ] (Mixed [dollars 1]))
              ,("top",Account "top" [] (Mixed [nullamt]))
             ]
             (toAscList m)
         )
 ]

-- | Given a list of postings, return an account name tree and three query
-- functions that fetch postings, subaccount-excluding-balance and
-- subaccount-including-balance by account name.
groupPostings :: [Posting] -> (Tree AccountName,
                               (AccountName -> [Posting]),
                               (AccountName -> MixedAmount),
                               (AccountName -> MixedAmount))
groupPostings ps = (ant, psof, exclbalof, inclbalof)
    where
      anames = sort $ nub $ map paccount ps
      ant = accountNameTreeFrom $ expandAccountNames anames
      allanames = flatten ant
      pmap = Map.union (postingsByAccount ps) (Map.fromList [(a,[]) | a <- allanames])
      psof = (pmap !)
      balmap = Map.fromList $ flatten $ calculateBalances ant psof
      exclbalof = fst . (balmap !)
      inclbalof = snd . (balmap !)

-- | Add subaccount-excluding and subaccount-including balances to a tree
-- of account names somewhat efficiently, given a function that looks up
-- transactions by account name.
calculateBalances :: Tree AccountName -> (AccountName -> [Posting]) -> Tree (AccountName, (MixedAmount, MixedAmount))
calculateBalances ant psof = addbalances ant
    where
      addbalances (Node a subs) = Node (a,(bal,bal+subsbal)) subs'
          where
            bal         = sumPostings $ psof a
            subsbal     = sum $ map (snd . snd . root) subs'
            subs'       = map addbalances subs

-- | Convert a list of postings to a map from account name to that
-- account's postings.
postingsByAccount :: [Posting] -> Map.Map AccountName [Posting]
postingsByAccount ps = m'
    where
      sortedps = sortBy (comparing paccount) ps
      groupedps = groupBy (\p1 p2 -> paccount p1 == paccount p2) sortedps
      m' = Map.fromList [(paccount $ head g, g) | g <- groupedps]

-- debug helpers
-- traceAmountPrecision a = trace (show $ map (precision . commodity) $ amounts a) a
-- tracePostingsCommodities ps = trace (show $ map ((map (precision . commodity) . amounts) . pamount) ps) ps

-- tests

-- A sample journal for testing, similar to data/sample.journal:
--
-- 2008/01/01 income
--     assets:bank:checking  $1
--     income:salary
--
-- 2008/06/01 gift
--     assets:bank:checking  $1
--     income:gifts
--
-- 2008/06/02 save
--     assets:bank:saving  $1
--     assets:bank:checking
--
-- 2008/06/03 * eat & shop
--     expenses:food      $1
--     expenses:supplies  $1
--     assets:cash
--
-- 2008/12/31 * pay off
--     liabilities:debts  $1
--     assets:bank:checking
--
Right samplejournal = journalBalanceTransactions $ Journal
          [] 
          [] 
          [
           txnTieKnot $ Transaction {
             tdate=parsedate "2008/01/01",
             teffectivedate=Nothing,
             tstatus=False,
             tcode="",
             tdescription="income",
             tcomment="",
             ttags=[],
             tpostings=[
              Posting {
                pstatus=False,
                paccount="assets:bank:checking",
                pamount=(Mixed [dollars 1]),
                pcomment="",
                ptype=RegularPosting,
                ptags=[],
                ptransaction=Nothing
              },
              Posting {
                pstatus=False,
                paccount="income:salary",
                pamount=(missingmixedamt),
                pcomment="",
                ptype=RegularPosting,
                ptags=[],
                ptransaction=Nothing
              }
             ],
             tpreceding_comment_lines=""
           }
          ,
           txnTieKnot $ Transaction {
             tdate=parsedate "2008/06/01",
             teffectivedate=Nothing,
             tstatus=False,
             tcode="",
             tdescription="gift",
             tcomment="",
             ttags=[],
             tpostings=[
              Posting {
                pstatus=False,
                paccount="assets:bank:checking",
                pamount=(Mixed [dollars 1]),
                pcomment="",
                ptype=RegularPosting,
                ptags=[],
                ptransaction=Nothing
              },
              Posting {
                pstatus=False,
                paccount="income:gifts",
                pamount=(missingmixedamt),
                pcomment="",
                ptype=RegularPosting,
                ptags=[],
                ptransaction=Nothing
              }
             ],
             tpreceding_comment_lines=""
           }
          ,
           txnTieKnot $ Transaction {
             tdate=parsedate "2008/06/02",
             teffectivedate=Nothing,
             tstatus=False,
             tcode="",
             tdescription="save",
             tcomment="",
             ttags=[],
             tpostings=[
              Posting {
                pstatus=False,
                paccount="assets:bank:saving",
                pamount=(Mixed [dollars 1]),
                pcomment="",
                ptype=RegularPosting,
                ptags=[],
                ptransaction=Nothing
              },
              Posting {
                pstatus=False,
                paccount="assets:bank:checking",
                pamount=(Mixed [dollars (-1)]),
                pcomment="",
                ptype=RegularPosting,
                ptags=[],
                ptransaction=Nothing
              }
             ],
             tpreceding_comment_lines=""
           }
          ,
           txnTieKnot $ Transaction {
             tdate=parsedate "2008/06/03",
             teffectivedate=Nothing,
             tstatus=True,
             tcode="",
             tdescription="eat & shop",
             tcomment="",
             ttags=[],
             tpostings=[
              Posting {
                pstatus=False,
                paccount="expenses:food",
                pamount=(Mixed [dollars 1]),
                pcomment="",
                ptype=RegularPosting,
                ptags=[],
                ptransaction=Nothing
              },
              Posting {
                pstatus=False,
                paccount="expenses:supplies",
                pamount=(Mixed [dollars 1]),
                pcomment="",
                ptype=RegularPosting,
                ptags=[],
                ptransaction=Nothing
              },
              Posting {
                pstatus=False,
                paccount="assets:cash",
                pamount=(missingmixedamt),
                pcomment="",
                ptype=RegularPosting,
                ptags=[],
                ptransaction=Nothing
              }
             ],
             tpreceding_comment_lines=""
           }
          ,
           txnTieKnot $ Transaction {
             tdate=parsedate "2008/12/31",
             teffectivedate=Nothing,
             tstatus=False,
             tcode="",
             tdescription="pay off",
             tcomment="",
             ttags=[],
             tpostings=[
              Posting {
                pstatus=False,
                paccount="liabilities:debts",
                pamount=(Mixed [dollars 1]),
                pcomment="",
                ptype=RegularPosting,
                ptags=[],
                ptransaction=Nothing
              },
              Posting {
                pstatus=False,
                paccount="assets:bank:checking",
                pamount=(Mixed [dollars (-1)]),
                pcomment="",
                ptype=RegularPosting,
                ptags=[],
                ptransaction=Nothing
              }
             ],
             tpreceding_comment_lines=""
           }
          ]
          []
          []
          ""
          nullctx
          []
          (TOD 0 0)

tests_Hledger_Data_Journal = TestList $
    tests_journalAccountInfo
  -- [
  -- "query standard account types" ~:
  --  do
  --   let j = journal1
  --   journalBalanceSheetAccountNames j `is` ["assets","assets:a","equity","equity:q","equity:q:qq","liabilities","liabilities:l"]
  --   journalProfitAndLossAccountNames j `is` ["expenses","expenses:e","income","income:i"]
 -- ]