script:balance-as-budget-multi.hs

Like balance-as-budged, but many times

bin/README.md

@@ -431,6 +431,17 @@ shows balance reports for two different periods side by side.
 [`hledger-balance-as-budget.hs`](https://github.com/simonmichael/hledger/blob/master/bin/hledger-balance-as-budget.hs)
 uses one balance report to set budget goals for another balance report.
 
+This is useful for compare-and-contrast reports. You can, for example, use a previous year as a budget for this year, and see
+how this year spending compares to your past spending.
+
+### hledger-balance-as-budget-multi
+
+[`hledger-balance-as-budget.hs`](https://github.com/simonmichael/hledger/blob/master/bin/hledger-balance-as-budget-multi.hs)
+uses one balance report to set budget goals for another balance report, and allows you to run multiple balance commands on them.
+
+Like `hledger run`, this will load journals only once, and will be significantly faster than calling `hledger-balance-as-budget`
+multiple times.
+
 ### hledger-smooth
 
 [`hledger-smooth.hs`](https://github.com/simonmichael/hledger/blob/master/bin/hledger-smooth.hs)

bin/hledger-balance-as-budget-multi.hs

@@ -0,0 +1,57 @@
+#!/usr/bin/env stack
+-- stack runghc --verbosity info --package hledger
+-- Run from inside the hledger source tree, or compile with compile.sh.
+-- See hledger-check-fancyassertions.hs.
+
+-- {-# OPTIONS_GHC -Wno-missing-signatures #-}
+
+{-| Construct two balance reports for two different time periods and use one of the as "budget" for
+    the other, thus comparing them
+-}
+import qualified Data.Text.Lazy.IO as TL
+import System.Environment (getArgs)
+import Hledger.Cli.Script
+import Hledger.Cli.Commands.Balance
+
+------------------------------------------------------------------------------
+cmdmode = hledgerCommandMode
+  (unlines ["balance-as-budget-multi"
+           ,"Read two journal files and generate multiple balance reports that use first of them as budget for the second."
+           ," "
+           ,"Pass two journal names and a file that contains sets of 'hledger balance'-compatible options, one per line"
+           ,"For example, to use Jan 2019 as budget for Jan 2020, use:"
+           ,"2019.journal 2020.journal commands.txt"
+           ,"and put '\"assets\" --depth 3 --value=$,then' in the commands.txt"
+           ])
+  [] 
+  [generalflagsgroup1]
+  []
+  ([], Just $ argsFlag "BUDGET_JOURNAL ACTUAL_JOURNAL COMMAND_FILE")
+------------------------------------------------------------------------------
+
+main :: IO ()
+main = do
+  args <- getArgs
+  case args of
+    [budget_f, real_f, commands_f] -> runAllCommands budget_f real_f commands_f
+    _ -> error' "expected exactly three arguments"
+
+runAllCommands :: String -> String -> String -> IO ()
+runAllCommands budget_f real_f commands_f = do
+  d <- getCurrentDay
+  budget <- readJournalFile' budget_f
+  real <- readJournalFile' real_f
+  let styles = journalCommodityStylesWith HardRounding real
+  commands <- lines <$> readFile commands_f
+  forM_ commands $ \command -> do
+    let args = words' command
+    case args of
+      [] -> return ()
+      "echo":args -> putStrLn $ unwords args
+      _ -> do
+        opts@CliOpts{reportspec_=rspec} <- getHledgerCliOpts' balancemode args 
+        let b = multiBalanceReport rspec budget
+        let r = multiBalanceReport rspec real
+        let reportopts = _rsReportOpts rspec
+        let combined = combineBudgetAndActual reportopts real b{prDates=prDates r} r
+        writeOutputLazyText opts $ budgetReportAsText reportopts $ styleAmounts styles $ combined