# Copyright (c) 2008-13 Peter H. Boling of RailsBling.com
# Released under the MIT license

module SanitizeEmail
  # SanitizeEmail::Bleach determines whether to sanitize the headers of an email, and does so when appropriate.
  class Bleach

    # Can override global configs at the instance level.
    attr_accessor :engage, # Turn sanitization on or off just for this instance
                  :overridden_addresses

    def initialize(args = {})
      # Not using extract_options! because non-rails compatibility is a goal
      @engage = args[:engage] || SanitizeEmail::Config.config[:engage]
    end

    # If all recipient addresses are white-listed the field is left alone.
    def delivering_email(message)
      if self.sanitize_engaged?(message)
        SanitizeEmail::MailHeaderTools.add_original_addresses_as_headers(message)
        SanitizeEmail::MailHeaderTools.prepend_custom_subject(message)

        o = SanitizeEmail::OverriddenAddresses.new(message)

        message.to = o.overridden_to
        message.cc = o.overridden_cc
        message.bcc = o.overridden_bcc
      end
    end

    # This method will be called by the Hook to determine if an override should occur
    # There are four ways SanitizeEmail can be turned on; in order of precedence they are:
    #
    # 1. SanitizeEmail.force_sanitize = true # by default it is nil
    #   Only useful for local context.  Inside a method where you will be sending an email,
    #   set SanitizeEmail.force_sanitize = true just prior to delivering it.  Also useful in the console.
    # 2. Mail.register_interceptor(SanitizeEmail::Bleach.new(:engage => true)) # by default it is nil
    #   If SanitizeEmail seems to not be sanitizing you have probably not registered the interceptor.  SanitizeEmail tries to do this for you.
    #   Note: If you are working in an environment that has a Mail or Mailer class that uses the register_interceptor API, the interceptor will already have been registered by SanitizeEmail (however, note lack of :engage => true):
    #     Mail.register_interceptor(SanitizeEmail::Bleach.new
    #   Without :engage => true the interceptor is inactive, and will require engaging via one of the other methods.
    #   As an example you could do the following to engage SanitizeEmail:
    #     SanitizeEmail::Config.configure {|config| config[:engage] = true }
    # 3. SanitizeEmail::Config.configure {|config| config[:activation_proc] = Proc.new { true } } # by default it is false
    #   If you don't need to compute anything, then don't use the Proc, go with the next option.
    # 4. SanitizeEmail::Config.configure {|config| config[:engage] = true } # by default it is nil
    #
    # Note: Number 1 is the method used by the SanitizeEmail.sanitary block
    # Note: Number 2 See note accompanying 2: you may need to setup your own register_interceptor
    #
    # If installed but not configured, sanitize_email DOES NOTHING.  Until configured the defaults leave it turned off.
    def sanitize_engaged?(message)

      # Don't sanitize the message if it will not be delivered
      return false unless message.perform_deliveries

      # Has it been forced via the force_sanitize mattr?
      forced = SanitizeEmail.force_sanitize
      return forced unless forced.nil?

      # Is this particular instance of Bleach engaged
      engaged = self.engage
      return engaged unless engaged.nil?

      # Should we sanitize due to the activation_proc?
      return SanitizeEmail.activate?(message)

    end

  end # end Class Bleach
end # end Module SanitizeEmail