convert command for transforming bank CSV exports to ledger format

AddCommand.hs

@@ -34,12 +34,10 @@ getAndAddTransactions l = (do
   today <- getCurrentDay
   date <- liftM (fixSmartDate today . fromparse . parse smartdate "" . lowercase)
          $ askFor "date" (Just $ showDate today)
-  -- cleared' <- askFor "cleared, y/n" (Just "n")
-  -- let cleared = if cleared' == "y" then True else False
   description <- askFor "description" Nothing
   ps <- getPostings []
   let t = nullledgertxn{ltdate=date
-                       ,ltstatus=False -- cleared
+                       ,ltstatus=False
                        ,ltdescription=description
                        ,ltpostings=ps
                        }

ConvertCommand.hs

@@ -0,0 +1,96 @@
+{-|
+
+Convert account data in CSV format (eg downloaded from a bank) to ledger
+format, and print it on stdout.
+
+Usage: hledger convert CSVFILE ACCOUNTNAME RULESFILE
+
+ACCOUNTNAME is the base account to use for transactions.  RULESFILE
+provides some rules to help convert the data. It should contain paragraphs
+separated by one blank line.  The first paragraph is a single line of five
+comma-separated numbers, which are the csv field positions corresponding
+to the ledger transaction's date, status, code, description, and amount.
+All other paragraphs specify one or more regular expressions, followed by
+the ledger account to use when a transaction's description matches any of
+them. Here's an example rules file:
+
+> 0,2,3,4,1
+>
+> ATM DEPOSIT
+> assets:bank:checking
+>
+> (TO|FROM) SAVINGS
+> assets:bank:savings
+>
+> ITUNES
+> BLOCKBUSTER
+> expenses:entertainment
+
+Roadmap: 
+Support for other formats will be added. To update a ledger file, pipe the
+output into the import command. The rules will move to a hledger config
+file. When no rule matches, accounts will be guessed based on similarity
+to descriptions in the current ledger, with interactive prompting and
+optional rule saving.
+
+-}
+
+module ConvertCommand where
+import Data.Maybe (isJust)
+import Data.List.Split (splitOn)
+import Options (Opt)
+import Ledger.Types (Ledger)
+import Ledger.Utils (strip)
+import System (getArgs)
+import Text.CSV (parseCSVFromFile, Record)
+import Text.Printf (printf)
+import Text.Regex.PCRE ((=~))
+import Data.Maybe
+import Ledger.Dates (firstJust, showDate)
+import System.Locale (defaultTimeLocale)
+import Data.Time.Format (parseTime)
+import Control.Monad (when)
+
+
+convert :: [Opt] -> [String] -> Ledger -> IO ()
+convert opts args l = do
+  when (length args /= 3) (error "please specify a csv file, base account, and import rules file.")
+  let [csvfile,baseacct,rulesfile] = args
+  rulesstr <- readFile rulesfile
+  (fieldpositions,rules) <- parseRules rulesstr
+  parse <- parseCSVFromFile csvfile
+  let records = case parse of
+                  Left e -> error $ show e
+                  Right rs -> reverse rs
+  mapM_ (print_ledger_txn (baseacct,fieldpositions,rules)) records
+
+parseRules s = do
+  let ls = map strip $ lines s
+  let paras = splitOn [""] ls
+  let fieldpositions = map read $ splitOn "," $ head $ head paras
+  let rules = [(last p,init p) | p <- tail paras]
+  return (fieldpositions,rules)
+
+print_ledger_txn (baseacct,fieldpositions,rules) record@(a:b:c:d:e) = do
+  let [date,cleared,number,description,amount] = map (record !!) fieldpositions
+      amount' = strnegate amount where strnegate ('-':s) = s
+                                       strnegate s = '-':s
+      unknownacct | (read amount' :: Double) < 0 = "income:unknown"
+                  | otherwise = "expenses:unknown"
+  putStrLn $ printf "%s%s %s" (fixdate date) (if not (null number) then printf " (%s)" number else "") description
+  putStrLn $ printf "    %-30s  %15s" (fromMaybe unknownacct $ choose_acct rules description) (printf "$%s" amount' :: String)
+  putStrLn $ printf "    %s\n" baseacct
+print_ledger_txn _ _ = return ()
+
+choose_acct rules description | null matches = Nothing
+                              | otherwise = Just $ fst $ head $ matches
+                              where matches = filter (any (description =~) . snd) rules
+
+fixdate :: String -> String
+fixdate s = maybe "0000/00/00" showDate $ 
+              firstJust
+              [parseTime defaultTimeLocale "%Y/%m/%d" s
+              ,parseTime defaultTimeLocale "%Y-%m-%d" s
+              ,parseTime defaultTimeLocale "%m/%d/%Y" s
+              ,parseTime defaultTimeLocale "%m-%d-%Y" s
+              ]

Options.hs

@@ -25,15 +25,17 @@ timeprogname  = "hours"
 usagehdr = (
   "Usage: hledger [OPTIONS] [COMMAND [PATTERNS]]\n" ++
   "       hours   [OPTIONS] [COMMAND [PATTERNS]]\n" ++
+  "       hledger convert CSVFILE ACCOUNTNAME RULESFILE\n" ++
   "\n" ++
   "When invoked as \"hours\", uses your timelog and --period today as defaults.\n" ++
   "\n" ++
   "COMMAND is one of (may be abbreviated):\n" ++
-  "  add       - read new transactions interactively\n" ++
-  "  balance   - show account balances\n" ++
-  "  histogram - show transaction counts per reporting interval\n" ++
-  "  print     - show transactions as formatted data\n" ++
-  "  register  - show transactions as a register\n" ++
+  "  add       - prompt for new transactions and add them to the ledger\n" ++
+  "  balance   - show accounts, with balances\n" ++
+  "  convert   - convert CSV data to ledger format and print on stdout\n" ++
+  "  histogram - show transaction counts per day or other interval\n" ++
+  "  print     - show transactions in ledger format\n" ++
+  "  register  - show transactions as a register with running balance\n" ++
 #ifdef VTY
   "  ui        - run a simple curses-based text ui\n" ++
 #endif

hledger.cabal

@@ -52,7 +52,8 @@ Executable hledger
 
   Build-Depends:  base, containers, haskell98, directory, parsec,
                   regex-compat, regexpr>=0.5.1, old-locale, time,
-                  HUnit, mtl, bytestring, filepath, process, testpack
+                  HUnit, mtl, bytestring, filepath, process, testpack,
+                  regex-pcre, csv, split
 
   Other-Modules:  
                   BalanceCommand

hledger.hs

@@ -38,6 +38,7 @@ module Main (
              module Utils,
              module Options,
              module BalanceCommand,
+             module ConvertCommand,
              module PrintCommand,
              module RegisterCommand,
              module HistogramCommand,
@@ -60,6 +61,7 @@ import Utils (withLedgerDo)
 import Options
 import Tests
 import BalanceCommand
+import ConvertCommand
 import PrintCommand
 import RegisterCommand
 import HistogramCommand
@@ -81,6 +83,7 @@ main = do
        | Help `elem` opts             = putStr $ usage
        | Version `elem` opts          = putStr versionmsg
        | cmd `isPrefixOf` "balance"   = withLedgerDo opts args balance
+       | cmd `isPrefixOf` "convert"   = withLedgerDo opts args convert
        | cmd `isPrefixOf` "print"     = withLedgerDo opts args print'
        | cmd `isPrefixOf` "register"  = withLedgerDo opts args register
        | cmd `isPrefixOf` "histogram" = withLedgerDo opts args histogram