An advanced Garry's Mod server search query processor.

advanced_server_search_query.lua

local function parse_host_name_tags(host_name)
	local tags = {}
	local function add_tag(tag)
		tag = tag:Trim()
		if #tag > 1 and #tag < 15 then
			table.insert(tags, tag)
		end
	end

	local start_index, _ = host_name:find("[%|%,%-]")
	local end_index = 1
	while start_index do
		local tag = end_index == 1
			and host_name:sub(end_index, start_index - 1):Trim()
			or host_name:sub(end_index, start_index - 1):gsub("[%[%]%(%)]", ""):Trim()
			add_tag(tag)

		end_index = start_index + 1
		start_index, _ = host_name:find("[%|%,%-]", end_index)
	end

	local last_tag = host_name:sub(end_index, #host_name):gsub("[%[%]%(%)]", ""):Trim()
	add_tag(last_tag)

	local explicit_tag_patterns = {
		"%[(.+)%]", "%((.+)%)", "%{(.+)%}", "%<(.+)%>",
		"%[(.+)$", "%((.+)$", "%{(.+)$", "%<(.+)$",
	}

	local actual_host_name = (table.remove(tags, 1) or host_name)
	for _, tag_pattern in ipairs(explicit_tag_patterns) do
		actual_host_name = actual_host_name:gsub(tag_pattern, function(tag)
			add_tag(tag)
			return ""
		end)
	end

	if #tags <= 0 then
		add_tag("N/A")
	end

	return actual_host_name, tags
end

local valid_filters = {
	["host"] = "FullHostName",
	["tag"] = "Tags",
	["gm"] = "Description",
	["map"] = "Map",
	["ip"] = "IPAddress",
}

local function default_search_processor(server, search_query)
	local has_matching_tag = false
	for _, tag in ipairs(server.Tags) do
		if tag:lower():find(search_query, 1, true) then
			has_matching_tag = true
			break
		end
	end

	return server.FullHostName:lower():find(search_query, 1, true)
		or server.Description:lower():find(search_query, 1, true)
		or server.Map:lower():find(search_query, 1, true)
		or server.Gamemode:lower():find(search_query, 1, true)
		or server.IPAddress:find(search_query, 1, true)
		or has_matching_tag
end

local function parse_search_query(search_query)
	if not search_query or #search_query:Trim() <= 0 then
		return function(server) return true end
	end

	local filter_processors = {}
	local filters = search_query:Split(";")
	for _, filter in ipairs(filters) do
		local chunks = filter:Split("=")
		local has_valid_filter_value = chunks[2] and #chunks[2] > 0
		if has_valid_filter_value then
			local filter_type = chunks[1]:Trim():lower()
			local filter_value = chunks[2]:lower()
			if not valid_filters[filter_type] then
				table.insert(filter_processors, function(server) return false end)
				continue
			end

			table.insert(filter_processors, function(server)
				local server_value = server[valid_filters[filter_type]]
				if not server_value then
					return false
				end

				local server_value_type = type(server_value)
				if isstring(server_value) then
					return server_value:lower():find(filter_value, 1, true)
				elseif server_value_type == "table" then
					for _, value in ipairs(server_value) do
						if value:lower():find(filter_value, 1, true) then
							return true
						end
					end

					return false
				else
					return tostring(server_value):lower():find(filter_value, 1, true)
				end
			end)
		else
			table.insert(filter_processors, function(server) return default_search_processor(server, filter:Trim():lower()) end)
		end
	end

	return function(server)
		for _, filter_processor in ipairs(filter_processors) do
			if not filter_processor(server) then
				return false
			end
		end

		return true
	end
end

local function fetch_servers(srv_type, callback, search_query)
	serverlist.Query({
		Type = srv_type,
		Callback = function(ping, host_name, description, map_name, ply_count, max_ply_count, bot_ply_count, has_password, workshop_id, ip_address, gamemode)
			local actual_host_name, tags = parse_host_name_tags(host_name)
			local server = {
				Ping = ping,
				FullHostName = host_name,
				HostName = actual_host_name,
				Tags = tags,
				Description = description,
				Map = map_name,
				PlayerCount = ply_count,
				MaxPlayerCount = max_ply_count,
				BotPlayerCount = bot_ply_count,
				HasPassword = has_password,
				WorkshopID = workshop_id,
				IPAddress = ip_address,
				Gamemode = gamemode,
			}

			if search_query then
				local execute_query = parse_search_query(search_query:lower())
				if execute_query(server) then
					callback(server)
				end
			else
				callback(server)
			end
		end,
	})
end