From 9c7144e9398a99d53a87aabd6f3f1d257a61e25d Mon Sep 17 00:00:00 2001
From: Simon Michael <simon@joyful.com>
Date: Thu, 26 Jan 2023 00:31:10 -1000
Subject: [PATCH] imp: cli: pick help accent color to contrast with terminal bg
 when possible

---
 hledger/Hledger/Cli/Commands.hs | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/hledger/Hledger/Cli/Commands.hs b/hledger/Hledger/Cli/Commands.hs
index df80110e6..7e6f10117 100644
--- a/hledger/Hledger/Cli/Commands.hs
+++ b/hledger/Hledger/Cli/Commands.hs
@@ -121,8 +121,6 @@ builtinCommands = [
   ,(testmode               , testcmd)
   ]
 
-accent = blue
-
 -- figlet -f FONTNAME hledger, then escape backslashes
 _banner_slant = drop 1 [""
     -----------------------------------------80-------------------------------------
@@ -134,7 +132,7 @@ _banner_slant = drop 1 [""
   ,"                   /____/             "
   ]
 
-_banner_smslant = map accent $ drop 1 [""
+_banner_smslant = drop 1 [""
   ,"   __   __       __            "
   ,"  / /  / /__ ___/ /__ ____ ____"
   ," / _ \\/ / -_) _  / _ `/ -_) __/"
@@ -151,6 +149,11 @@ _banner_speed = drop 1 [""
   ,"                         /____/               "
   ]
 
+-- | Choose and apply an accent color for hledger output, if possible
+-- picking one that will contrast with the current terminal background colour.
+accent :: String -> String
+accent = if terminalIsLight == Just False then yellow else blue
+
 highlightAddon = id
 
 -- | The commands list, showing command names, standard aliases,
@@ -174,7 +177,7 @@ highlightAddon = id
 commandsList :: String -> [String] -> Bool -> [String]
 commandsList progversion othercmds highlight =
   (if highlight then (map (\s -> if "+" `isPrefixOf` s then highlightAddon (' ' : drop 1 s) else s)) else id) $
-  _banner_smslant ++ [
+  map accent _banner_smslant ++ [
   -- keep synced with hledger.m4.md > PART 4: COMMANDS, Hledger/Cli/Commands > commands.m4 -->
     -----------------------------------------80-------------------------------------
    ""