#!/usr/bin/env ruby

########################################
# Main
########################################

require "webrick"

# Color
BOLD  = "\x1b[1;30m"
RED   = "\x1b[0;35m"
CLEAR = "\x1b[0m"

http_config = {
  :Port          => 80,
  :RequestCallback => lambda {|req, res|
    puts req.header.map{|k, v|
      "#{BOLD}#{k}#{CLEAR}: #{RED}#{v.join(" ")}#{CLEAR}"
    }.join("\n")
    puts "\n"
  }
}

server = WEBrick::HTTPServer.new(http_config)

# /favicon.ico
server.mount("/favicon.ico", WEBrick::HTTPServlet::FileHandler, "#{__dir__}/../favicon.ico")

# /
server.mount_proc('/', Proc.new{|req, res|
  host = req.header["host"].first

  case host
  when "intra.example" then
    res.content_type = "text/html"
    res.body = File.open("./intra.html").read
  when "sns.example" then
    res.content_type = "text/html"
    res.body = File.open("./sns.html").read
  when "attack.example" then
    res.content_type = "text/html"
    res.body = File.open("./attack.html").read
  end
})

# /jxck/123456
class Preflight < WEBrick::HTTPServlet::AbstractServlet
  def do_OPTIONS(req, res)
    host = req.header["host"].first
    unless host == "sns.example"
      return res.status = 404
    end

    origin         = req.header.fetch("origin", []).first
    request_method = req.header.fetch("access-control-request-method", []).first

    if origin == "http://intra.example" and request_method == "DELETE"
      res.header['access-control-allow-origin']  = origin
      res.header['access-control-allow-methods'] = request_method
      return res.status = 200
    end

    ## OPTIONS は Preflight 以外にも使われ
    ## 通常は Allow ヘッダで有効なメソッドを伝える
    res["allow"] = ["OPTIONS", "HEAD", "GET", "POST", "DELETE", "PUT"].join(",")
    res.status = 200
  end
  def do_DELETE(req, res)
    host = req.header["host"].first
    unless host == "sns.example"
      return res.status = 404
    end

    origin = req.header.fetch("origin", []).first

    if origin == "http://intra.example"
      res.header['access-control-allow-origin'] = origin
      return res.status = 204
    end

    return res.status = 400
  end
end

server.mount('/jxck/123456', Preflight)
Signal.trap("INT") { server.shutdown }
server.start