refactor: imporve this plugin file framework

lua/Trans/query/offline.lua

@@ -0,0 +1,38 @@
+local _, db = pcall(require, 'sqlite.db')
+if not _ then
+    error('Please check out sqlite.lua')
+end
+
+-- INFO : init database
+local path = require('Trans').conf.db_path
+local dict = db:open(path)
+
+vim.api.nvim_create_autocmd('VimLeavePre', {
+    group = require("Trans").augroup,
+    callback = function()
+        if db:isopen() then
+            db:close()
+        end
+    end
+})
+
+return function(word)
+    local res = dict:select('stardict', {
+        where = {
+            word = word,
+        },
+        keys = {
+            'word',
+            'phonetic',
+            'definition',
+            'translation',
+            'pos',
+            'collins',
+            'oxford',
+            'tag',
+            'exchange',
+        },
+        limit = 1,
+    })
+    return res[1]
+end