Configliere.use :config_file, :define, :crypter

module Configliere
  module EncryptedParam
    # The password used in encrypting params during serialization
    attr_accessor :encrypt_pass

    # decrypts any encrypted params
    # then calls the next step in the resolve! chain.
    def resolve!
      resolve_encrypted!
      begin ; super() ; rescue NoMethodError ; nil ; end
      self
    end

    # import values, decrypting all params marked as encrypted
    def resolve_encrypted!
      remove_and_adopt_encrypt_pass_param_if_any!
      encrypted_params.each do |param|
        encrypted_val = deep_delete(*dotted_to_encrypted_keys(param)) or next
        self[param] = self.decrypted(encrypted_val)
      end
    end

  protected

    # @example
    #   Settings.defaults :username=>"mysql_username", :password=>"mysql_password"
    #   Settings.define :password, :encrypted => true
    #   Settings.exportable
    #     #=> {:username => 'mysql_username', :password=>"\345?r`\222\021"\210\312\331\256\356\351\037\367\326" }
    def export
      hsh = super()
      encrypted_params.each do |param|
        val = hsh.deep_delete(*dotted_to_deep_keys(param)) or next
        hsh.deep_set( *(dotted_to_encrypted_keys(param) | [encrypted(val)]) )
      end
      hsh
    end

    # if :encrypted_pass was set as a param, remove it from the hash and set it as an attribute
    def remove_and_adopt_encrypt_pass_param_if_any!
      @encrypt_pass = self.delete(:encrypt_pass) if self[:encrypt_pass]
    end

    # the chain of symbol keys for a dotted path key,
    # prefixing the last one with "encrypted_"
    #
    # @example
    #    dotted_to_encrypted_keys('amazon.api.key')
    #    #=> [:amazon, :api, :encrypted_key]
    def dotted_to_encrypted_keys param
      encrypted_path = dotted_to_deep_keys(param).dup
      encrypted_path[-1] = "encrypted_#{encrypted_path.last}".to_sym
      encrypted_path
    end

    # list of all params to encrypt on serialization
    def encrypted_params
      params_with(:encrypted)
    end

    def decrypted val
      return val if val.blank?
      Configliere::Crypter.decrypt(val, encrypt_pass)
    end

    def encrypted val
      return unless val
      Configliere::Crypter.encrypt(val, encrypt_pass)
    end
  end

  class Param
    include EncryptedParam
  end
end