cli: --forecast adds periodic transactions to reports

Ledger-style periodic transactions, previously supported only by
hledger-budget, have landed as a first-class feature.  The --forecast
flag activates them, so that any transactions they generate are
included in reports.

bin/hledger-budget.hs

@@ -13,7 +13,6 @@ import Data.List
 import Data.String.Here
 import System.Console.CmdArgs
 import Hledger.Cli
-import Hledger.Data.AutoTransaction
 
 -- hledger-budget REPORT-COMMAND [--no-offset] [--no-buckets] [OPTIONS...]
 

hledger-lib/Hledger/Data.hs

@@ -22,6 +22,7 @@ module Hledger.Data (
                module Hledger.Data.StringFormat,
                module Hledger.Data.Timeclock,
                module Hledger.Data.Transaction,
+               module Hledger.Data.AutoTransaction,
                module Hledger.Data.Types,
                tests_Hledger_Data
               )
@@ -42,6 +43,7 @@ import Hledger.Data.RawOptions
 import Hledger.Data.StringFormat
 import Hledger.Data.Timeclock
 import Hledger.Data.Transaction
+import Hledger.Data.AutoTransaction
 import Hledger.Data.Types
 
 tests_Hledger_Data :: Test

hledger-lib/Hledger/Reports/ReportOptions.hs

@@ -104,6 +104,7 @@ data ReportOpts = ReportOpts {
       -- eg in the income section of an income statement, this helps --sort-amount know
       -- how to sort negative numbers.
     ,color_          :: Bool
+    ,forecast_       :: Bool
  } deriving (Show, Data, Typeable)
 
 instance Default ReportOpts where def = defreportopts
@@ -134,6 +135,7 @@ defreportopts = ReportOpts
     def
     def
     def
+    def
 
 rawOptsToReportOpts :: RawOpts -> IO ReportOpts
 rawOptsToReportOpts rawopts = checkReportOpts <$> do
@@ -164,6 +166,7 @@ rawOptsToReportOpts rawopts = checkReportOpts <$> do
     ,sort_amount_ = boolopt "sort-amount" rawopts'
     ,pretty_tables_ = boolopt "pretty-tables" rawopts'
     ,color_       = color
+    ,forecast_    = boolopt "forecast" rawopts'
     }
 
 -- | Do extra validation of raw option values, raising an error if there's a problem.

hledger/Hledger/Cli/CliOptions.hs

@@ -155,6 +155,7 @@ reportflags = [
  ,flagNone ["empty","E"]     (setboolopt "empty") "show items with zero amount, normally hidden"
  ,flagNone ["cost","B"]      (setboolopt "cost") "convert amounts to their cost at transaction time (using the transaction price, if any)"
  ,flagNone ["value","V"]     (setboolopt "value") "convert amounts to their market value on the report end date (using the most recent applicable market price, if any)"
+ ,flagNone ["forecast"] (\opts -> setboolopt "forecast" opts) "generate forecast transactions"
  ]
 
 -- | Common output-related flags: --output-file, --output-format...

hledger/Hledger/Cli/Utils.hs

@@ -31,7 +31,7 @@ import Data.List
 import Data.Maybe
 import qualified Data.Text as T
 import qualified Data.Text.IO as T
-import Data.Time (Day)
+import Data.Time (Day, addDays)
 import Data.Word
 import Numeric
 import Safe (readMay)
@@ -70,6 +70,7 @@ withJournalDo opts cmd = do
           . anonymiseByOpts opts
           . journalApplyAliases (aliasesFromOpts opts)
         <=< journalApplyValue (reportopts_ opts)
+        <=< journalAddForecast opts
   either error' f ej
 
 -- | Apply the pivot transformation on a journal, if option is present.
@@ -117,6 +118,29 @@ journalApplyValue ropts j = do
                 = id
     return $ convert j
 
+-- | Run PeriodicTransactions from journal from today or journal end to requested end day.
+-- Add generated transactions to the journal
+journalAddForecast :: CliOpts -> Journal -> IO Journal
+journalAddForecast opts j = do
+  today <- getCurrentDay
+  -- Create forecast starting from end of journal + 1 day, and until the end of requested reporting period
+  -- If end is not provided, do 180 days of forecast.
+  -- Note that jdatespan already returns last day + 1
+  let startDate = fromMaybe today $ spanEnd (jdatespan j) 
+      endDate = fromMaybe (addDays 180 today) $ periodEnd (period_ ropts)
+      dates = DateSpan (Just startDate) (Just endDate)
+      withForecast = [makeForecast t | pt <- jperiodictxns j, t <- runPeriodicTransaction pt dates, spanContainsDate dates (tdate t) ] ++ (jtxns j)
+      makeForecast t = txnTieKnot $ t { tdescription = T.pack "Forecast transaction" }
+      ropts = reportopts_ opts
+  if forecast_ ropts 
+    then return $ journalBalanceTransactions' opts j { jtxns = withForecast }
+    else return j
+  where      
+    journalBalanceTransactions' opts j =
+      let assrt = not . ignore_assertions_ $ inputopts_ opts
+      in
+       either error' id $ journalBalanceTransactions assrt j
+
 -- | Write some output to stdout or to a file selected by --output-file.
 -- If the file exists it will be overwritten.
 writeOutput :: CliOpts -> String -> IO ()

tests/budget/forecast.test

@@ -0,0 +1,102 @@
+# Test --forecast switch
+hledger bal -M -b 2016-11 -e 2017-02 -f - --forecast
+<<<
+2016/12/31
+    expenses:housing  $600
+    assets:cash
+
+~ monthly from 2016/1
+    income  $-1000
+    expenses:food     $20
+    expenses:leisure  $15
+    expenses:grocery  $30
+    assets:cash
+>>>
+Balance changes in 2016/12/01-2017/01/31:
+
+                  || 2016/12  2017/01 
+==================++==================
+ assets:cash      ||   $-600     $935 
+ expenses:food    ||       0      $20 
+ expenses:grocery ||       0      $30 
+ expenses:housing ||    $600        0 
+ expenses:leisure ||       0      $15 
+ income           ||       0   $-1000 
+------------------++------------------
+                  ||       0        0 
+
+>>>2
+>>>=0
+
+
+hledger print -b 2016-11 -e 2017-02 -f - --forecast
+<<<
+2016/12/31
+    expenses:housing  $600
+    assets:cash
+
+~ monthly from 2016/1
+    income  $-1000
+    expenses:food     $20
+    expenses:leisure  $15
+    expenses:grocery  $30
+    assets:cash
+>>>
+2016/12/31
+    expenses:housing            $600
+    assets:cash
+
+2017/01/01 Forecast transaction
+    income                    $-1000
+    expenses:food                $20
+    expenses:leisure             $15
+    expenses:grocery             $30
+    assets:cash
+
+>>>2
+>>>=0
+
+
+hledger register -b 2016-11 -e 2017-02 -f - --forecast
+<<<
+2016/12/31
+    expenses:housing  $600
+    assets:cash
+
+~ monthly from 2016/1
+    income  $-1000
+    expenses:food     $20
+    expenses:leisure  $15
+    expenses:grocery  $30
+    assets:cash
+>>>
+2016/12/31                      expenses:housing              $600          $600
+                                assets:cash                  $-600             0
+2017/01/01 Forecast transact..  income                      $-1000        $-1000
+                                expenses:food                  $20         $-980
+                                expenses:leisure               $15         $-965
+                                expenses:grocery               $30         $-935
+                                assets:cash                   $935             0
+>>>2
+>>>=0
+
+# Check that --forecast generates transactions only after last transaction in journal
+hledger register -b 2015-12 -e 2017-02 -f - assets:cash --forecast
+<<<
+2016/01/01
+    expenses:fun  $10 ; more fireworks
+    assets:cash
+
+2016/12/02
+    expenses:housing  $600
+    assets:cash
+
+~ yearly from 2016
+    income  $-10000 ; bonus
+    assets:cash
+>>>
+2016/01/01                      assets:cash                   $-10          $-10
+2016/12/02                      assets:cash                  $-600         $-610
+2017/01/01 Forecast transact..  assets:cash                 $10000         $9390
+>>>2
+>>>=0