require 'email/html_cleaner' # # Handles an incoming message # module Email class Receiver include ActionView::Helpers::NumberHelper class ProcessingError < StandardError; end class EmailUnparsableError < ProcessingError; end class EmptyEmailError < ProcessingError; end class UserNotFoundError < ProcessingError; end class UserNotSufficientTrustLevelError < ProcessingError; end class BadDestinationAddress < ProcessingError; end class TopicNotFoundError < ProcessingError; end class TopicClosedError < ProcessingError; end class AutoGeneratedEmailError < ProcessingError; end class EmailLogNotFound < ProcessingError; end class InvalidPost < ProcessingError; end attr_reader :body, :email_log def initialize(raw) @raw = raw end def process raise EmptyEmailError if @raw.blank? message = Mail.new(@raw) body = parse_body message dest_info = {type: :invalid, obj: nil} message.to.each do |to_address| if dest_info[:type] == :invalid dest_info = check_address to_address end end raise BadDestinationAddress if dest_info[:type] == :invalid raise AutoGeneratedEmailError if message.header.to_s =~ /auto-generated/ || message.header.to_s =~ /auto-replied/ # TODO get to a state where we can remove this @message = message @body = body if dest_info[:type] == :category raise BadDestinationAddress unless SiteSetting.email_in category = dest_info[:obj] @category_id = category.id @allow_strangers = category.email_in_allow_strangers user_email = @message.from.first @user = User.find_by_email(user_email) if @user.blank? && @allow_strangers wrap_body_in_quote user_email # TODO This is WRONG it should register an account # and email the user details on how to log in / activate @user = Discourse.system_user end raise UserNotFoundError if @user.blank? raise UserNotSufficientTrustLevelError.new @user unless @allow_strangers || @user.has_trust_level?(TrustLevel[SiteSetting.email_in_min_trust.to_i]) create_new_topic else @email_log = dest_info[:obj] raise EmailLogNotFound if @email_log.blank? raise TopicNotFoundError if Topic.find_by_id(@email_log.topic_id).nil? raise TopicClosedError if Topic.find_by_id(@email_log.topic_id).closed? create_reply end rescue Encoding::UndefinedConversionError, Encoding::InvalidByteSequenceError => e raise EmailUnparsableError.new(e) end def check_address(address) category = Category.find_by_email(address) return {type: :category, obj: category} if category regex = Regexp.escape SiteSetting.reply_by_email_address regex = regex.gsub(Regexp.escape('%{reply_key}'), "(.*)") regex = Regexp.new regex match = regex.match address if match && match[1].present? reply_key = match[1] email_log = EmailLog.for(reply_key) return {type: :reply, obj: email_log} end {type: :invalid, obj: nil} end def parse_body(message) body = select_body message encoding = body.encoding raise EmptyEmailError if body.strip.blank? body = discourse_email_trimmer body raise EmptyEmailError if body.strip.blank? body = EmailReplyParser.parse_reply body raise EmptyEmailError if body.strip.blank? body.force_encoding(encoding).encode("UTF-8") end def select_body(message) html = nil # If the message is multipart, return that part (favor html) if message.multipart? html = fix_charset message.html_part text = fix_charset message.text_part # prefer plain text if text return text end elsif message.content_type =~ /text\/html/ html = fix_charset message end if html body = HtmlCleaner.new(html).output_html else body = fix_charset message end # Certain trigger phrases that means we didn't parse correctly if body =~ /Content\-Type\:/ || body =~ /multipart\/alternative/ || body =~ /text\/plain/ raise EmptyEmailError end body end # Force encoding to UTF-8 on a Mail::Message or Mail::Part def fix_charset(object) return nil if object.nil? if object.charset object.body.decoded.force_encoding(object.charset.gsub(/utf8/i, "UTF-8")).encode("UTF-8").to_s else object.body.to_s end end REPLYING_HEADER_LABELS = ['From', 'Sent', 'To', 'Subject', 'Reply To', 'Cc', 'Bcc', 'Date'] REPLYING_HEADER_REGEX = Regexp.union(REPLYING_HEADER_LABELS.map { |lbl| "#{lbl}:" }) def discourse_email_trimmer(body) lines = body.scrub.lines.to_a range_end = 0 lines.each_with_index do |l, idx| break if l =~ /\A\s*\-{3,80}\s*\z/ || l =~ Regexp.new("\\A\\s*" + I18n.t('user_notifications.previous_discussion') + "\\s*\\Z") || (l =~ /via #{SiteSetting.title}(.*)\:$/) || # This one might be controversial but so many reply lines have years, times and end with a colon. # Let's try it and see how well it works. (l =~ /\d{4}/ && l =~ /\d:\d\d/ && l =~ /\:$/) || (l =~ /On \w+ \d+,? \d+,?.*wrote:/) # Headers on subsequent lines break if (0..2).all? { |off| lines[idx+off] =~ REPLYING_HEADER_REGEX } # Headers on the same line break if REPLYING_HEADER_LABELS.count { |lbl| l.include? lbl } >= 3 range_end = idx end lines[0..range_end].join.strip end def wrap_body_in_quote(user_email) @body = "[quote=\"#{user_email}\"] #{@body} [/quote]" end private def create_reply create_post_with_attachments(@email_log.user, raw: @body, topic_id: @email_log.topic_id, reply_to_post_number: @email_log.post.post_number) end def create_new_topic post = create_post_with_attachments(@user, raw: @body, title: @message.subject, category: @category_id) EmailLog.create( email_type: "topic_via_incoming_email", to_address: @message.from.first, # pick from address because we want the user's email topic_id: post.topic.id, user_id: @user.id, ) post end def create_post_with_attachments(user, post_opts={}) options = { cooking_options: { traditional_markdown_linebreaks: true }, }.merge(post_opts) raw = options[:raw] # deal with attachments @message.attachments.each do |attachment| tmp = Tempfile.new("discourse-email-attachment") begin # read attachment File.open(tmp.path, "w+b") { |f| f.write attachment.body.decoded } # create the upload for the user upload = Upload.create_for(user.id, tmp, attachment.filename, tmp.size) if upload && upload.errors.empty? # TODO: should use the same code as the client to insert attachments raw << "\n#{attachment_markdown(upload)}\n" end ensure tmp.close! end end options[:raw] = raw create_post(user, options) end def attachment_markdown(upload) if FileHelper.is_image?(upload.original_filename) "" else "#{upload.original_filename} (#{number_to_human_size(upload.filesize)})" end end def create_post(user, options) # Mark the reply as incoming via email options[:via_email] = true options[:raw_email] = @raw creator = PostCreator.new(user, options) post = creator.create if creator.errors.present? raise InvalidPost, creator.errors.full_messages.join("\n") end post end end end