{-|

A 'Ledger' is derived from a 'Journal' by applying a filter specification
to select 'Transaction's and 'Posting's of interest. It contains the
filtered journal and knows the resulting chart of accounts, account
balances, and postings in each account.

-}

module Hledger.Data.Ledger
where
import Data.Map (Map, findWithDefault, fromList)
import Hledger.Data.Utils
import Hledger.Data.Types
import Hledger.Data.Account (nullacct)
import Hledger.Data.AccountName
import Hledger.Data.Journal
import Hledger.Data.Posting


instance Show Ledger where
    show l = printf "Ledger with %d transactions, %d accounts\n%s"
             (length (jtxns $ journal l) +
              length (jmodifiertxns $ journal l) +
              length (jperiodictxns $ journal l))
             (length $ accountnames l)
             (showtree $ accountnametree l)

nullledger :: Ledger
nullledger = Ledger{
      journal = nulljournal,
      accountnametree = nullaccountnametree,
      accountmap = fromList []
    }

-- | Filter a journal's transactions as specified, and then process them
-- to derive a ledger containing all balances, the chart of accounts,
-- canonicalised commodities etc.
journalToLedger :: FilterSpec -> Journal -> Ledger
journalToLedger fs j = nullledger{journal=j',accountnametree=t,accountmap=m}
    where j' = filterJournalPostings fs{depth=Nothing} j
          (t, m) = journalAccountInfo j'

-- | List a ledger's account names.
ledgerAccountNames :: Ledger -> [AccountName]
ledgerAccountNames = drop 1 . flatten . accountnametree

-- | Get the named account from a ledger.
ledgerAccount :: Ledger -> AccountName -> Account
ledgerAccount l a = findWithDefault nullacct a $ accountmap l

-- | List a ledger's accounts, in tree order
ledgerAccounts :: Ledger -> [Account]
ledgerAccounts = drop 1 . flatten . ledgerAccountTree 9999

-- | List a ledger's top-level accounts, in tree order
ledgerTopAccounts :: Ledger -> [Account]
ledgerTopAccounts = map root . branches . ledgerAccountTree 9999

-- | Accounts in ledger whose name matches the pattern, in tree order.
ledgerAccountsMatching :: [String] -> Ledger -> [Account]
ledgerAccountsMatching pats = filter (matchpats pats . aname) . accounts

-- | List a ledger account's immediate subaccounts
ledgerSubAccounts :: Ledger -> Account -> [Account]
ledgerSubAccounts l Account{aname=a} = 
    map (ledgerAccount l) $ filter (`isSubAccountNameOf` a) $ accountnames l

-- | List a ledger's postings, in the order parsed.
ledgerPostings :: Ledger -> [Posting]
ledgerPostings = journalPostings . journal

-- | Get a ledger's tree of accounts to the specified depth.
ledgerAccountTree :: Int -> Ledger -> Tree Account
ledgerAccountTree depth l = treemap (ledgerAccount l) $ treeprune depth $ accountnametree l

-- | Get a ledger's tree of accounts rooted at the specified account.
ledgerAccountTreeAt :: Ledger -> Account -> Maybe (Tree Account)
ledgerAccountTreeAt l acct = subtreeat acct $ ledgerAccountTree 9999 l

-- | The (fully specified) date span containing all the ledger's (filtered) transactions,
-- or DateSpan Nothing Nothing if there are none.
ledgerDateSpan :: Ledger -> DateSpan
ledgerDateSpan = postingsDateSpan . ledgerPostings

-- | Convenience aliases.
accountnames :: Ledger -> [AccountName]
accountnames = ledgerAccountNames

account :: Ledger -> AccountName -> Account
account = ledgerAccount

accounts :: Ledger -> [Account]
accounts = ledgerAccounts

topaccounts :: Ledger -> [Account]
topaccounts = ledgerTopAccounts

accountsmatching :: [String] -> Ledger -> [Account]
accountsmatching = ledgerAccountsMatching

subaccounts :: Ledger -> Account -> [Account]
subaccounts = ledgerSubAccounts

postings :: Ledger -> [Posting]
postings = ledgerPostings

commodities :: Ledger -> Map String Commodity
commodities = journalCanonicalCommodities . journal

accounttree :: Int -> Ledger -> Tree Account
accounttree = ledgerAccountTree

accounttreeat :: Ledger -> Account -> Maybe (Tree Account)
accounttreeat = ledgerAccountTreeAt

-- datespan :: Ledger -> DateSpan
-- datespan = ledgerDateSpan

rawdatespan :: Ledger -> DateSpan
rawdatespan = journalDateSpan . journal

ledgeramounts :: Ledger -> [MixedAmount]
ledgeramounts = journalAmounts . journal