module Smaak

# File lib/smaak.rb, line 25
def self.adaptors
  @@adaptors
end

# File lib/smaak.rb, line 29
def self.add_request_adaptor(request_clazz, adaptor_clazz)
  @@adaptors[request_clazz] = adaptor_clazz
end

# File lib/smaak.rb, line 33
def self.create_adaptor(request)
  @@adaptors.each do |r, a|
    return a.new(request) if request.is_a? r
  end
  raise ArgumentError.new("Unknown request class #{request.class}. Add an adaptor using Smaak.add_request_adaptor.")
end

# File lib/smaak.rb, line 15
def self.headers_to_be_signed
  [ "x-smaak-recipient",
    "x-smaak-identifier",
    "x-smaak-route-info",
    "x-smaak-psk",
    "x-smaak-expires",
    "x-smaak-nonce",
    "x-smaak-encrypt" ]
end

# File lib/smaak.rb, line 40
def self.select_specification(adaptor, specification)
  raise ArgumentError.new("Adaptor must be provided") if adaptor.nil?
  return Cavage04.new(adaptor) if specification == Smaak::Cavage04::SPECIFICATION
  raise ArgumentError.new("Unknown specification")
end

# File lib/smaak.rb, line 46
def self.sign_authorization_headers(key, auth_message, adaptor, specification = Smaak::Cavage04::SPECIFICATION)
  specification = Smaak.select_specification(adaptor, specification)

  signature_headers = specification.compile_signature_headers(auth_message)
  signature_data = Smaak::Crypto.sign_data(signature_headers, key)
  signature = Smaak::Crypto.encode64(signature_data)
  specification.compile_auth_header(signature)
  specification.adaptor
end

# File lib/smaak.rb, line 56
def self.verify_authorization_headers(adaptor, pubkey)
  raise ArgumentError.new("Key is required") if pubkey.nil?
  signature_headers, signature = Smaak.get_signature_data_from_request(adaptor)
  if signature.nil?
    puts "[smaak error]: could not extract signature"
    return false
  end
  if signature_headers.nil?
    puts "[smaak error]: could not extract signature headers"
    return false
  end
  verified = Smaak::Crypto.verify_signature(signature, Smaak::Crypto.encode64(signature_headers), pubkey)
  puts "[smaak error]: verification of headers and signature using pubkey failed" unless verified
  verified
end

# File lib/smaak.rb, line 74
def self.get_signature_data_from_request(adaptor, specification = Smaak::Cavage04::SPECIFICATION)
  specification = Smaak.select_specification(adaptor, specification)

  signature_headers = specification.extract_signature_headers
  signature = specification.extract_signature

  return signature_headers, Smaak::Crypto.decode64(signature)
end