fix: ensure that dir exists before creating files

lua/chatgpt_nvim/handler.lua

@@ -1,17 +1,35 @@
 local M = {}
+local uv = vim.loop
+
+local function ensure_dir(path)
+  local st = uv.fs_stat(path)
+  if st and st.type == 'directory' then
+    return true
+  end
+  local parent = path:match("(.*)/")
+  if parent and parent ~= "" then
+    ensure_dir(parent)
+  end
+  uv.fs_mkdir(path, 511)
+  return true
+end
 
 function M.get_clipboard_content()
   return vim.fn.getreg('+')
 end
 
 function M.write_file(filepath, content)
-  local fd = vim.loop.fs_open(filepath, "w", 438)
+  local dir = filepath:match("(.*)/")
+  if dir and dir ~= "" then
+    ensure_dir(dir)
+  end
+  local fd = uv.fs_open(filepath, "w", 438)
   if not fd then
     vim.api.nvim_err_writeln("Could not open file for writing: " .. filepath)
     return
   end
-  vim.loop.fs_write(fd, content, -1)
-  vim.loop.fs_close(fd)
+  uv.fs_write(fd, content, -1)
+  uv.fs_close(fd)
 end
 
 function M.finish()