# frozen_string_literal: true

class EmailImporter
  attr_accessor :email_class
  attr_accessor :html_to_text_class

  def initialize(
    email_class:            Email,
    html_to_text_class:     Rails.configuration.html_to_text_class)

    @email_class            = email_class
    @html_to_text_class     = html_to_text_class
  end

  def import(mail)
    email = email_class.new(
      message_id:   mail.message_id,
      subject:      mail.subject,
      date:         mail.date,
      to:           mail.to,
      delivered_to: delivered_to(mail),
      from:         mail.from,
      plain_body:   text_plain_body(mail),
      headers:      hashed_headers(mail)
    )
  rescue => ex
    binding.pry
  end

  def delivered_to(mail)
    values_from_header(header: mail.header["Delivered-To"], default: Array(mail.to))
  end

  def text_plain_body(mail)
    if mail.parts.present?
      if mail.text_part.present?
        mail.text_part.decoded
      elsif mail.html_part.present?
        html_to_text_class.new.convert(mail.html_part.decoded)
      else
        mail.parts[0].decoded
      end
    elsif mail.content_type && mail.content_type.match?(/\btext\/html\b/)
      plain_text = html_to_text_class.new.convert(mail.decoded)

      if mail.content_type.match?(/\butf-8\b/i) and !plain_text.valid_encoding?
        plain_text.encode('UTF-8', 'binary', invalid: :replace, undef: :replace)
      else
        plain_text
      end
    else
      mail.decoded
    end
  end

  def hashed_headers(mail)
    mail.header.map { |header|
      {
        "name" =>  header.name,
        "value" => header.value
      }
    }
  end

  def values_from_header(header:, default: [])
    if header.respond_to?(:map)
      header.map(&:value)
    elsif header.respond_to?(:value)
      Array(header.value)
    elsif block_given?
      yield(header)
    else
      default
    end
  end
end