=begin

This is the abstract class that other mailers will inherit from in order to send mail

You can set the default delivery settings through:

  SinatraMore::MailerBase.smtp_settings = {
    :host   => 'smtp.yourserver.com',
    :port   => '25',
    :user   => 'user',
    :pass   => 'pass',
    :auth   => :plain # :plain, :login, :cram_md5, no auth by default
    :domain => "localhost.localdomain" # the HELO domain provided by the client to the server
  }

and then all delivered mail will use these settings unless otherwise specified.

=end

module SinatraMore
  class MailerBase
    # Returns the available mail fields when composing a message
    def self.mail_fields
      [:to, :from, :subject, :type, :charset, :via, :attachments]
    end

    attr_accessor :mail_attributes

    def initialize(mail_name=nil)
      @mail_name = mail_name
      @mail_attributes = {}
    end

    # Defines a method allowing mail attributes to be set into a hash for use when delivering
    self.mail_fields.each do |field|
      define_method(field) { |value| @mail_attributes[field] = value }
    end

    # Assigns the body key to the mail attributes either with the rendered body from a template or the given string value
    def body(body_value)
      @mail_attributes[:body] = Tilt.new(template_path).render(self, body_value.symbolize_keys) if body_value.is_a?(Hash)
      @mail_attributes[:body] = body_value if body_value.is_a?(String)
    end

    # Returns the path to the email template searched for using glob pattern
    def template_path
      Dir[File.join(self.views_path, self.class.name.underscore.split("/").last, "#{@mail_name}.*")].first
    end

    cattr_accessor :smtp_settings
    cattr_accessor :views_path

    # Delivers the specified message for mail_name to the intended recipients
    # mail_name corresponds to the name of a defined method within the mailer class
    # SampleMailer.deliver(:birthday_message)
    def self.deliver(mail_name, *args)
      mail_object = self.new(mail_name)
      mail_object.method(mail_name).call(*args)
      MailObject.new(mail_object.mail_attributes, self.smtp_settings).deliver
    end

    # Returns true if a mail exists with the name being delivered
    def self.respond_to?(method_sym, include_private = false)
      method_sym.to_s =~ /deliver_(.*)/ ? self.method_defined?($1) : super
    end

    # Handles method missing for a mailer class. Delivers a message based on the method
    # being called i.e #deliver_birthday_message(22) invokes #birthday_message(22) to setup mail object
    def self.method_missing(method_sym, *arguments, &block)
      method_sym.to_s =~ /deliver_(.*)/ ? self.deliver($1, *arguments) : super
    end
  end
end