fix: trouble extension. Support Trouble.nvim v3 and keep backward com…

…patibility

lua/lualine/extensions/trouble.lua

@@ -1,22 +1,40 @@
 local M = {}
 
-local function get_trouble_mode()
-  local opts = require('trouble.config').options
-
-  local words = vim.split(opts.mode, '[%W]')
+---Format mode, eg: lsp_document_symbols -> Lsp Document Symbols
+---@param mode string
+---@return string
+local function _format_mode(mode)
+  local words = vim.split(mode, '[%W]')
   for i, word in ipairs(words) do
     words[i] = word:sub(1, 1):upper() .. word:sub(2)
   end
 
   return table.concat(words, ' ')
 end
 
+local function get_trouble_mode()
+  local opts = require('trouble.config').options
+  if opts ~= nil and opts.mode ~= nil then
+    return _format_mode(opts.mode)
+  end
+
+  local win = vim.api.nvim_get_current_win()
+  if vim.w[win] ~= nil then
+    local trouble = vim.w[win].trouble
+    if trouble ~= nil and trouble.mode ~= nil then
+      return _format_mode(trouble.mode)
+    end
+  end
+
+  return ''
+end
+
 M.sections = {
   lualine_a = {
     get_trouble_mode,
   },
 }
 
-M.filetypes = { 'Trouble' }
+M.filetypes = { 'trouble', 'Trouble' }
 
 return M