require "open-uri"
require "singleton"
require "timeout"
require "tempfile"

module RSpec
  class VaultServer
    include Singleton

    TOKEN_PATH = File.expand_path("~/.vault-token").freeze
    TOKEN_PATH_BKUP = "#{TOKEN_PATH}.bak".freeze

    def self.method_missing(m, *args, &block)
      self.instance.public_send(m, *args, &block)
    end

    attr_reader :token

    def initialize
      # If there is already a vault-token, we need to move it so we do not
      # clobber!
      if File.exist?(TOKEN_PATH)
        FileUtils.mv(TOKEN_PATH, TOKEN_PATH_BKUP)
        at_exit do
          FileUtils.mv(TOKEN_PATH_BKUP, TOKEN_PATH)
        end
      end

      io = Tempfile.new("vault-server")
      pid = Process.spawn({}, "vault server -dev", out: io.to_i, err: io.to_i)

      at_exit do
        Process.kill("INT", pid)
        Process.waitpid2(pid)

        io.close
        io.unlink
      end

      wait_for_ready do
        @token = File.read(TOKEN_PATH)
      end
    end

    def address
      "http://127.0.0.1:8200"
    end

    def wait_for_ready(&block)
      Timeout.timeout(5) do
        while !File.exist?(TOKEN_PATH)
          sleep(0.25)
        end
      end

      yield
    rescue Timeout::Error
      raise "Vault did not start in 5 seconds!"
    end
  end
end