Server utils for love2d presentation https://github.com/Kyonru/love2d-barcamp

server_utils.lua

---@diagnostic disable: invisible

--- From https://github.com/rxi/json.lua
local json = require("json")

local server = {}

function server.allowedHeaders()
	local response = [[
HTTP/1.1 204 No Content
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET, POST, OPTIONS, PUT
Access-Control-Allow-Headers: x-api-key
Access-Control-Max-Age: 86400
Content-Length: 0

]]

	return response
end

---@param body string
function server.buildResponse(body)
	local response = table.concat({
		"HTTP/1.1 200 OK",
		"Content-Type: application/json",
		"Access-Control-Allow-Origin: *",
		"Access-Control-Allow-Headers: Content-Type,  x-api-key, X-Requested-With, Access-Control-Request-Headers",
		"Access-Control-Allow-Methods: GET, POST, PUT, OPTIONS",
		"Content-Length: " .. #body,
		"",
		body,
	}, "\r\n")

	return response
end

--- @class FeatherRequest
--- @field method string
--- @field path string
--- @field params table
--- @field headers table

--- Builds a request object from a raw request string
--- @param client table
--- @return FeatherRequest
function server.buildRequest(client)
	local request = client:receive()

	local method, pathWithQuery = request:match("^(%u+)%s+([^%s]+)")
	local path, queryString = pathWithQuery:match("^([^?]+)%??(.*)$")
	local function parseQuery(qs)
		local params = {}
		for key, val in qs:gmatch("([^&=?]+)=([^&=?]+)") do
			params[key] = val
		end
		return params
	end

	local params = parseQuery(queryString)

	local line = client:receive()
	local raw_headers = line
	while line ~= "" do
		raw_headers = raw_headers .. "\n" .. line

		line = client:receive()
	end

	local headers = {}
	for header in raw_headers:gmatch("[^\r\n]+") do
		local key, value = header:match("^([^:]+):%s*(.*)$")
		if key and value then
			headers[key] = value
		end
	end

	return {
		method = method,
		path = path,
		params = params,
		headers = headers,
	}
end

--- check if the given address is in the whitelist
---@param addr string
---@param whitelist table
function server.isInWhitelist(addr, whitelist)
	for _, a in pairs(whitelist) do
		local ptn = "^" .. a:gsub("%.", "%%."):gsub("%*", "%%d*") .. "$"
		if addr:match(ptn) then
			return true
		end
	end
	return false
end

function server.createResponse(body)
	return server.buildResponse(json.encode(body))
end

--- Handle get request
local function handleGetRequest(request, dt)
	local data = {}

	if request.path == "/checkout" and request.params.commit then
		local commit = request.params.commit
		--- @type boolean | nil
		local success = false
		if commit:match("^[0-9a-fA-F]+$") then
			success = os.execute(string.format("cd ./creating-games-with-love-demo && git checkout %s", commit))
		end

		if success then
			love.event.quit("restart")
		end
	end

	return data
end

-- Handle a request from a client
---@param client table
function server.handleRequest(client, whitelist, dt)
	if client then
		client:settimeout(1)

		local request = server.buildRequest(client)

		local addr = client:getsockname()
		if not server.isInWhitelist(addr, whitelist) then
			print("non-whitelisted connection attempt: ", addr)
			client:close()
		end

		if request then
			local response = {}

			if request.method == "OPTIONS" then
				local optionsResponse = server.allowedHeaders()

				client:send(optionsResponse)
				client:close()
				return
			end

			if request.method == "GET" then
				response.data = handleGetRequest(request, dt)
			end

			client:send(server.createResponse(response.data or {}))
		end

		client:close()
	end
end

return server