require 'as_jwt_auth/version'
require 'as_jwt_auth/verify_jwt'
require 'as_jwt_auth/generate_jwt'
require 'as_jwt_auth/jwt_header'
require 'as_jwt_auth/railtie' if defined?(Rails)

module AsJWTAuth
  def self.generate_jwt(payload = {}, issuer: default_issuer, key: default_private_key)
    GenerateJWT.new(key: key, issuer: issuer).generate payload
  end

  def self.verify_jwt(jwt, key: )
    verifier = VerifyJWT.new(key)
    verifier.valid? jwt
  end

  def self.jwt_header(jwt)
    JWTHeader.call jwt
  end

  def self.default_issuer
    ENV.fetch('APP_NAME') do
      raise ArgumentError, 'Missing issuer. Either pass an issuer or define the environment variable APP_NAME'
    end
  end

  def self.default_private_key
    pem = ENV.fetch('PRIVATE_KEY') do
      raise ArgumentError, 'Missing private key. Either pass a key or define the environment variable PRIVATE_KEY'
    end

    # When pulling a private key from the environment, it is common to
    # accidentally have newlines escaped. This `gsub` will work when newlines
    # are correctly newlines and when newlines are escaped.
    OpenSSL::PKey::EC.new pem.gsub('\n', "\n")
  end
end