make the first worked autocomplete for Tarantool box submodule

Just uses Tarantool internal submodule for autocompletion.
Parse current string, select current selected token for completion
and call Tarantool internals.

bin/tarantool-lsp

@@ -13,6 +13,7 @@ box.cfg {
     log = fio.pathjoin(source_root, 'log.txt'),
     log_level = 6,
 
+    checkpoint_interval = 0,
     wal_mode = 'none',
 }
 

tarantool-lsp/analyze.lua

@@ -593,9 +593,9 @@ function analyze.refresh(document)
 	document.lines = lines
 
 	local start_time = os.clock()
-	log.info('ast start build! %s %s', document.text, document.uri)
+	-- log.info('ast start build! %s %s', document.text, document.uri)
 	local ast, err = parser.parse(document.text, document.uri, Config.language)
-	log.info('ast builded!')
+	-- log.info('ast builded!')
 	if ast then
 		document.ast = ast
 		document.validtext = document.text

tarantool-lsp/loop.lua

@@ -33,7 +33,6 @@ local function main(_)
 	while not Shutdown do
 		-- header
 		local data, err = rpc.decode()
-		log.info('new request %t', data)
 		if _G.Config.debugMode then
 			reload_all()
 		end

tarantool-lsp/lua-parser/parser.lua

@@ -604,7 +604,6 @@ function parser.parse(subject, filename, version)
   local errorinfo = { subject = subject, filename = filename }
   lpeg.setmaxstack(1000)
   local ast, label, errpos = lpeg.match(G["5.3"], subject, nil, errorinfo)
-  require('log').info('hello')
   if not ast then
     local errmsg = labels[label][2]
     return ast, syntaxerror(errorinfo, errpos, errmsg)

tarantool-lsp/methods.lua

@@ -6,10 +6,12 @@ local utf     = require 'tarantool-lsp.unicode'
 local json    = require 'json'
 local unpack  = table.unpack or unpack
 
+local fun = require('fun')
+local console = require('console')
 local method_handlers = {}
 
 function method_handlers.initialize(params, id)
-	if Initialized then
+	if _G.Initialized then
 		error("already initialized!")
 	end
 	Config.root  = params.rootPath or params.rootUri
@@ -600,9 +602,30 @@ method_handlers["textDocument/completion"] = function(params, id)
 		end
 	end
 
-	-- Add Tarantool box.* space fields
-	for key, _ in pairs(box) do
-		table.insert(items, { label = key} )
+	local current_line = document.lines[params.position.line + 1]["text"]
+	local left_part = current_line:sub(0, params.position.character)
+	local last_token = left_part:match("[%w.:_]*$")
+	if last_token then
+		local completions = console.completion_handler(last_token, 0, last_token:len()) or {}
+		-- Completion handler returns input string at the first element
+		for _, cmplt in fun.tail(completions) do
+			local showedCmplt = cmplt
+			local insertedCmplt = cmplt
+			local cmpltKind = completionKinds["Field"]
+
+			if cmplt:find("[(]") then
+				cmpltKind = completionKinds["Function"]
+				showedCmplt = cmplt:gsub("%(", "")
+			end
+
+			table.insert(items, {
+				label = showedCmplt,
+				kind = cmpltKind,
+				insertText = insertedCmplt,
+				-- documentation = "box.cfg{} option",
+				detail = "detail information"
+			})
+		end
 	end
 
 	return rpc.respond(id, {