w20-cv5

gistfile1.coffee

http = require "http"
crypto = require "crypto"

hash = (text) -> crypto.createHash("md5").update(text).digest("hex")
all = (array, fn) ->
	for value in array
		return false unless fn(value)
	return true
any = (array, fn) ->
	for value in array
		return true if fn(value)
	return false

DB = 
	customers : []
	addCustomer : (name) ->
		DB.customers.push 
			id : DB.customers.length
			name : name
			modified : new Date().getTime()
			orders : []

DB.addCustomer "aaa"
DB.addCustomer "bbb"

server = http.createServer (req, res) -> 
	res.setHeader 'Content-Type', 'application/json'
	if req.url == "/customers"
		strong = "\""+(hash(JSON.stringify DB.customers))+"\""
		weak = "\"W/"+(hash JSON.stringify (DB.customers.map (x) -> {id : x.id, name: x.name}))+"\""
		res.setHeader "ETag", strong+", "+weak
		if (!!(etags = req.headers["if-none-match"]) and any (etags.split(",").map (x) -> x.trim()), (x)-> x == strong or x == weak) or 
		   (!!(date = req.headers["if-modified-since"]) and !!(date = Date.parse(date)) and (all DB.customers, (x) -> x.modified <= date ))
				res.statusCode = 304
				res.end()
				return
		
		res.write JSON.stringify DB.customers
	res.end()
server.listen 8080