fixed 16-color detection

nvim/lua/darcula/utils/init.lua

@@ -156,6 +156,35 @@ local function iff(b, l, r)
   return r
 end
 
+local detect_termguicolors = function()
+  local term = (vim.env.TERM or ""):lower()
+  if term == "ansi" or
+    term == "cons25" or
+    term == "dumb" or
+    term == "linux" or
+    term:match("^vt%d+$") or
+    term:find("16color", 1, true) then
+    return false
+  end
+
+  local colorterm = (vim.env.COLORTERM or ""):lower()
+  if colorterm == "24bit" or colorterm == "truecolor" then
+    return true
+  end
+
+  if vim.fn.executable("tput") == 1 then
+    local output = vim.fn.system({"tput", "colors"})
+    if vim.v.shell_error == 0 then
+      local color_count = tonumber(output:match("%d+"))
+      if color_count and color_count <= 16 then
+        return false
+      end
+    end
+  end
+
+  return true
+end
+
 local parse_env = function(var, def)
   if vim.env[var] ~= nil then
     if type(def) == "boolean" then
@@ -222,6 +251,7 @@ return {
   copy_file = copy_file,
   create_vert_display = create_vert_display,
   cword = cword,
+  detect_termguicolors = detect_termguicolors,
   file_exists = file_exists,
   get_current_filename = get_current_filename,
   get_files_sorted_without_extension = get_files_sorted_without_extension,