update fire calculations, merge with overview script

1 files changed, 125 insertions, 36 deletions

diff --git a/hledger-overview.hs b/hledger-overview.hs
index c97dee6..bdddff4 100755
--- a/hledger-overview.hs
+++ b/hledger-overview.hs
@@ -1,48 +1,86 @@
 #!/usr/bin/env runhaskell
 
+{-# LANGUAGE OverloadedStrings #-}
+
 -- | Calculates and displays an overview of my finances.
 module Main where
 
-import Data.Decimal (Decimal)
+import Data.Decimal (Decimal (..), DecimalRaw (..), divide, roundTo)
 import Data.Either (fromRight)
-import Data.Text (pack)
-import Data.Time.Calendar (Day)
+import Data.Function ((&))
+import qualified Data.List as List
+import Data.Text (Text, pack)
+import qualified Data.Text as T
+import qualified Data.Text.IO as IO
+import Data.Time.Calendar (Day, toGregorian)
 import Data.Time.Clock (UTCTime (utctDay), getCurrentTime)
 import Hledger
 
+data Config = Config
+  { age :: Decimal
+  }
+
 main = do
   j <- getJournal
   today <- getCurrentTime >>= return . utctDay
-  let bal = getTotal j today Nothing
-  let balUSD = getTotal j today $ Just $ pack "USD"
+  let bal = getTotal j today $ defreportopts
+  let balUSD = getTotal j today $ defreportopts {value_ = inUsd}
   sec "cash balances"
-  row "simple" (bal "^as:me:cash:simple status:! status:*") Nothing
-  row "wallet" (bal "^as:me:cash:wallet") Nothing
-  row "  disc" (bal "^li:me:cred:discover status:*") Nothing
-  row "  citi" (bal "^li:me:cred:citi status:*") Nothing
-  row "   btc" (bal "^as cur:BTC") Nothing
+  row "simple" (prn $ bal "^as:me:cash:simple status:! status:*") Nothing
+  row "wallet" (prn $ bal "^as:me:cash:wallet") Nothing
+  row "  disc" (prn $ bal "^li:me:cred:discover status:*") Nothing
+  row "  citi" (prn $ bal "^li:me:cred:citi status:*") Nothing
+  row "   btc" (prn $ bal "^as cur:BTC") Nothing
 
   sec "metrics"
-  let netLiquid = bal "^as:me:cash ^li:me:cred cur:USD"
-  let netWorth = balUSD "^as ^li"
-  row "  in - ex" (bal "^in ^ex cur:USD -p thismonth") $ Just "keep this negative to make progress"
-  row "cred load" netLiquid $ Just "net liquid: credit spending minus cash assets. keep it positive"
-  row "net worth" netWorth Nothing
-  row "    level" (level netWorth) Nothing
+  let netLiquid = roundTo 2 $ bal "^as:me:cash ^li:me:cred cur:USD"
+  let netWorth = roundTo 2 $ balUSD "^as ^li"
+  row "  in - ex" (prn $ bal "^in ^ex cur:USD") $ Just "keep this negative to make progress"
+  row "cred load" (prn netLiquid) $ Just "net liquid: credit spending minus cash assets. keep it positive"
+  row "net worth" (prn netWorth) Nothing
+  row "    level" (pr $ level netWorth) Nothing
 
   sec "trivials"
-  let trivialWorth = trivial * netWorth
-  let trivialLiquid = trivial * netLiquid
-  row "   net" trivialWorth Nothing
-  row "liquid" trivialLiquid Nothing
+  let trivialWorth = roundTo 2 $ trivial * netWorth
+  let trivialLiquid = roundTo 2 $ trivial * netLiquid
+  row "   net" (pr trivialWorth) Nothing
+  row "liquid" (pr trivialLiquid) Nothing
+
+  sec "fire"
+  let (thisyear, _, _) = toGregorian today
+  let cfg = Config {age = (fromInteger thisyear) - 1992}
+  let n = whenFreedom j today
+  let ageFree = roundTo 1 $ (n / 12) + (age cfg)
+  row "savings rate" (pr $ savingsRate j today) Nothing
+  row " target fund" (prn $ roundTo 2 $ targetFund j today) Nothing
+  row "   when free" ((pr n) <> " months") $ Just $ "I'll be " <> pr ageFree <> " years old"
 
+sec :: String -> IO ()
 sec label = putStrLn $ "\n" <> label <> ":"
 
-row label value Nothing = putStrLn $ gap <> label <> ":" <> gap <> show value
-row label value (Just nb) = putStrLn $ gap <> label <> ":" <> gap <> show value <> gap <> "\t(" <> nb <> ")"
+pr :: Show s => s -> Text
+pr = pack . show
 
+row :: Text -> Text -> Maybe Text -> IO ()
+row label value Nothing = IO.putStrLn $ gap <> label <> ":" <> gap <> value
+row label value (Just nb) = IO.putStrLn $ gap <> label <> ":" <> gap <> value <> gap <> "\t(" <> nb <> ")"
+
+gap :: Text
 gap = "  "
 
+-- Pretty-print a number. From https://stackoverflow.com/a/61070523/1146898
+prn :: Quantity -> Text
+prn d = T.intercalate "." $ case T.splitOn "." $ T.pack $ show d of
+  x : xs -> (T.pack . reverse . go . reverse . T.unpack) x : xs
+  xs -> xs
+  where
+    go (x : y : z : []) = x : y : z : []
+    go (x : y : z : ['-']) = x : y : z : ['-']
+    go (x : y : z : xs) = x : y : z : ',' : go xs
+    go xs = xs
+
+-- | There's levels to life, a proxy metric for what level you're at is your net
+-- worth rounded down to the nearest power of 10.
 level :: Decimal -> Integer
 level = floor . logBase 10 . realToFrac
 
@@ -50,23 +88,21 @@ level = floor . logBase 10 . realToFrac
 -- uses the upper bound of that range.
 --
 -- From <https://ofdollarsanddata.com/climbing-the-wealth-ladder/>
+trivial :: Quantity
 trivial = 0.001
 
-getTotal :: Journal -> Day -> Maybe CommoditySymbol -> String -> Quantity
-getTotal j d commodity q = sum $ map aquantity $ total
+inUsd :: Maybe ValuationType
+inUsd = Just $ AtNow $ Just "USD"
+
+getTotal :: Journal -> Day -> ReportOpts -> String -> Quantity
+getTotal j d opts q = sum $ map aquantity $ total
   where
-    value = case commodity of
-      Nothing -> Nothing
-      Just txt -> Just $ AtNow $ Just txt
-    opts =
-      defreportopts
-        { balancetype_ = CumulativeChange,
-          real_ = True,
-          today_ = Just d,
-          value_ = value
+    opts' =
+      opts
+        { today_ = Just d
         }
     (query, _) = parseQuery d $ pack q
-    (_, (Mixed total)) = balanceReport opts query j
+    (_, (Mixed total)) = balanceReport opts' query j
 
 getJournal :: IO Journal
 getJournal = do
@@ -75,6 +111,59 @@ getJournal = do
   ej <- readJournalFile opts jp
   return $ fromRight undefined ej
 
+-- | These are the accounts that I consider a part of my savings and not my
+-- cash-spending accounts.
+savingsAccounts :: [String]
+savingsAccounts =
+  ["as:me:save", "as:me:vest"]
+
+-- | Savings rate is a FIRE staple. Basically take your savings and divide it by
+-- your income on a monthly basis.
+savingsRate :: Journal -> Day -> Quantity
+savingsRate j d = roundTo 2 $ allSavings / allIncome
+  where
+    allSavings = getTotal j d (defreportopts {value_ = inUsd}) query
+    query = List.intercalate " " $ savingsAccounts
+    -- gotta flip the sign because income is negative
+    allIncome = - getTotal j d (defreportopts {value_ = inUsd}) "^in"
+
+-- | The target fund is simply 25x your annual expenditure.
+--
+-- This is going to be incomplete until I have a full year of
+-- expenses.. currently, I just use my most recent quarter times 4 as a proxy
+-- for the yearly expenses.
+--
+-- Assumptions: 4% withdrawal rate, 3-5% return on investments.
+targetFund :: Journal -> Day -> Quantity
+targetFund j d = 25 * yearlyExpenses
+  where
+    yearlyExpenses = sum $ map aquantity $ total
+    (query, _) = parseQuery d $ pack "^ex"
+    (_, (Mixed total)) = balanceReport opts query j
+    opts =
+      defreportopts
+        { -- idk what the '2020 4' is for, but this actually results in the yearly
+          -- report for some reason
+          period_ = QuarterPeriod 2020 4,
+          value_ = Just $ AtNow $ Just "USD",
+          today_ = Just d
+        }
+
+-- | How long until I can live off of my savings and investment returns?
+--
+-- Return integer is number of months until I'm free.
+whenFreedom :: Journal -> Day -> Quantity
+whenFreedom j d = roundTo 1 $ targetFund j d / monthlySavings
+  where
+    (year, month, _) = toGregorian d
+    -- I have data going back to 2018.12
+    monthsSinceBeginning = fromInteger $ (year - 2019) * 12 + toInteger month + 1
+    monthlySavings =
+      savingsAccounts
+        & map (getTotal j d (defreportopts {value_ = inUsd, period_ = MonthPeriod 2020 10}))
+        & sum
+        & \n -> (n / monthsSinceBeginning)
+
 -- | Escape velocity:
 --
 -- In physics it is basically the movement of an object away from the earth,
@@ -92,9 +181,9 @@ getJournal = do
 --
 -- v = sqrt(2 * 3% * li / net_worth)
 --
--- v = sqrt(2 * 3% * 18534.54 / 17580.93)
+-- v = sqrt(2 * 3% * 20,000 / 100,000)
 --
--- v = 0.25
+-- v = 0.1095
 --
 -- I don't know what this means... maybe my money must be growing at a 25% rate in
 -- order to cover the debt? I need to think about this equation some more.