class MailPresenter < SimpleDelegator
  attr_accessor :mail

  def initialize(mail, account = nil)
    super(mail)
    @mail = mail
    @account = account
  end

  def subject
    encode_to_unicode(@mail.subject || '')
  end

  def text_content
    @decoded_text_content ||= encode_to_unicode(text_part&.decoded || decoded_message || '')

    return {} if @decoded_text_content.blank?

    @text_content ||= {
      full: @decoded_text_content,
      reply: extract_reply(@decoded_text_content)[:reply],
      quoted: extract_reply(@decoded_text_content)[:quoted_text]
    }
  end

  def html_content
    @decoded_html_content ||= encode_to_unicode(html_part&.decoded)

    return {} if @decoded_html_content.blank?

    @html_content ||= {
      full: @decoded_html_content,
      reply: extract_reply(@decoded_html_content)[:reply],
      quoted: extract_reply(@decoded_html_content)[:quoted_text]
    }
  end

  def attachments
    # ref : https://github.com/gorails-screencasts/action-mailbox-action-text/blob/master/app/mailboxes/posts_mailbox.rb
    mail.attachments.map do |attachment|
      blob = ActiveStorage::Blob.create_and_upload!(
        io: StringIO.new(attachment.body.to_s),
        filename: attachment.filename,
        content_type: attachment.content_type
      )
      { original: attachment, blob: blob }
    end
  end

  def decoded_message
    if mail.multipart?
      return mail.text_part ? mail.text_part.decoded : nil
    end

    mail.decoded
  end

  def number_of_attachments
    mail.attachments.count
  end

  def serialized_data
    {
      bcc: bcc,
      cc: cc,
      content_type: content_type,
      date: date,
      from: from,
      html_content: html_content,
      in_reply_to: in_reply_to,
      message_id: message_id,
      multipart: multipart?,
      number_of_attachments: number_of_attachments,
      subject: subject,
      text_content: text_content,
      to: to
    }
  end

  def from
    # changing to downcase to avoid case mismatch while finding contact
    @mail.from.map(&:downcase)
  end

  def sender_name
    Mail::Address.new(@mail[:from].value).name
  end

  def original_sender
    @mail['X-Original-Sender'].try(:value) || from.first
  end

  def email_forwarded_for
    @mail['X-Forwarded-For'].try(:value)
  end

  def mail_receiver
    if @mail.to.blank?
      return [email_forwarded_for] if email_forwarded_for.present?

      []
    else
      @mail.to
    end
  end

  private

  # forcing the encoding of the content to UTF-8 so as to be compatible with database and serializers
  def encode_to_unicode(str)
    return '' if str.blank?

    current_encoding = str.encoding.name
    return str if current_encoding == 'UTF-8'

    str.encode(current_encoding, 'UTF-8', invalid: :replace, undef: :replace, replace: '?')
  end

  def extract_reply(content)
    # NOTE: implement the reply parser over here
    {
      reply: content.strip,
      quoted_text: content.strip
    }
  end
end