From c98d28e118d4da9a4f99ca109106ca7721b58df4 Mon Sep 17 00:00:00 2001
From: Thijs <thijs@thijsschreijer.nl>
Date: Sun, 26 May 2024 00:31:29 +0200
Subject: [PATCH] feat: 'enable' function and improved Windows detection

Adds a method to manually enable/disable the functionality. And
adds better Windows detection when setting the default value for
`enabled`.
---
 README.textile | 13 ++++++++++++-
 ansicolors.lua | 27 +++++++++++++++++++++++----
 2 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/README.textile b/README.textile
index 4e37acf..dccda08 100644
--- a/README.textile
+++ b/README.textile
@@ -20,6 +20,11 @@ h2. Usage
   print(colors('%{red}hello'))
   print(colors('%{redbg}hello%{reset}'))
   print(colors('%{bright red underline}hello'))
+
+  colors.enable(false)
+  print(colors('%{red}this is printed plain since coloring is disabled'))
+  colors.enable(true)
+  print(colors('%{red}this is printed in red again'))
 </pre>
 
 The @colors@ function makes sure that color attributes are reset at each end of the generated string. If you want to generate complex strings piece-by-piece, use @colors.noReset@, which works exactly the same, but without adding the reset codes at each end of the string.
@@ -35,7 +40,13 @@ Notice that the tests will only work on an ANSI-compatible machine (windows isn'
 
 h2. Windows
 
-Windows console, by default, isn't capable of handling ANSI color codes correctly. This library tries to detect whether it is on a windows machine (by looking at package.path) and in that case it suppresses all ANSI control characters (the text appears devoid of color, but legible).
+Windows console, by default, isn't capable of handling ANSI color codes correctly. This library tries to detect whether it is on a Windows machine (by looking at package.path) and in that case it suppresses all ANSI control characters (the text appears devoid of color, but legible).
+
+By default coloring is disabled on Windows, except if:
+
+* Environment variable @ANSICON@ has been set
+* Module @luasystem@ is available and terminal processing has been enabled on @io.stdout@
+* It is manually enabled by calling @enable(true)@
 
 h2. Valid attribute list:
 
diff --git a/ansicolors.lua b/ansicolors.lua
index f474952..5f7ae0e 100644
--- a/ansicolors.lua
+++ b/ansicolors.lua
@@ -27,8 +27,20 @@ local function isWindows()
   return type(package) == 'table' and type(package.config) == 'string' and package.config:sub(1,1) == '\\'
 end
 
-local supported = not isWindows()
-if isWindows() then supported = os.getenv("ANSICON") end
+local enabled = not isWindows()
+if isWindows() then 
+  enabled = os.getenv("ANSICON") 
+  if not enabled then
+    local ok, sys = pcall(require, 'system')
+    if ok and sys.getconsoleflags then
+      local flags = sys.getconsoleflags(io.stdout)
+      if flags then
+        enabled = flags:has_all_of(sys.COF_VIRTUAL_TERMINAL_PROCESSING)
+      end
+    end
+  end
+end
+
 
 local keys = {
   -- reset
@@ -70,7 +82,7 @@ end
 
 local function escapeKeys(str)
 
-  if not supported then return "" end
+  if not enabled then return "" end
 
   local buffer = {}
   local number
@@ -97,4 +109,11 @@ local function ansicolors( str )
 end
 
 
-return setmetatable({noReset = replaceCodes}, {__call = function (_, str) return ansicolors (str) end})
+return setmetatable({
+  noReset = replaceCodes,
+  enable = function(val) enabled = not not val end,
+}, {
+  __call = function(_, str) 
+    return ansicolors(str) 
+  end,
+})