discourse/lib/email/receiver.rb
2015-12-07 17:01:08 +01:00

312 lines
9.5 KiB
Ruby

require_dependency 'new_post_manager'
require_dependency 'email/html_cleaner'
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, opts=nil)
@raw = raw
@opts = opts || {}
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|
dest_info = check_address(to_address)
break if dest_info[:type] != :invalid
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
user_email = @message.from.first
@user = User.find_by_email(user_email)
case dest_info[:type]
when :group
raise BadDestinationAddress unless SiteSetting.email_in
group = dest_info[:obj]
if @user.blank?
if SiteSetting.allow_staged_accounts
@user = create_staged_account(user_email)
else
wrap_body_in_quote(user_email)
@user = Discourse.system_user
end
end
raise UserNotFoundError if @user.blank?
raise UserNotSufficientTrustLevelError.new(@user) unless @user.has_trust_level?(TrustLevel[SiteSetting.email_in_min_trust.to_i])
create_new_topic(archetype: Archetype.private_message, target_group_names: [group.name])
when :category
raise BadDestinationAddress unless SiteSetting.email_in
category = dest_info[:obj]
if @user.blank? && category.email_in_allow_strangers
if SiteSetting.allow_staged_accounts
@user = create_staged_account(user_email)
else
wrap_body_in_quote(user_email)
@user = Discourse.system_user
end
end
raise UserNotFoundError if @user.blank?
raise UserNotSufficientTrustLevelError.new(@user) unless category.email_in_allow_strangers || @user.has_trust_level?(TrustLevel[SiteSetting.email_in_min_trust.to_i])
create_new_topic(category: category.id)
when :reply
@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 create_staged_account(email)
User.create(
email: email,
username: UserNameSuggester.suggest(email),
name: User.suggest_name(email),
staged: true
)
end
def check_address(address)
group = Group.find_by_email(address)
return { type: :group, obj: group } if group
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 message.multipart?
text = fix_charset message.text_part
# prefer text over html
return text if text
html = fix_charset message.html_part
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
return body if @opts[:skip_sanity_check]
# 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
rescue
nil
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 line_is_quote?(l)
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+.*wrote:/)
end
def discourse_email_trimmer(body)
lines = body.scrub.lines.to_a
range_start = 0
range_end = 0
# If we started with a quote, skip it
lines.each_with_index do |l, idx|
break unless line_is_quote?(l) or l =~ /^>/ or l.blank?
range_start = idx + 1
end
lines[range_start..-1].each_with_index do |l, idx|
break if line_is_quote?(l)
# 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 = range_start + idx
end
lines[range_start..range_end].join.strip
end
private
def wrap_body_in_quote(user_email)
@body = "[quote=\"#{user_email}\"]\n#{@body}\n[/quote]"
end
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(topic_options={})
topic_options[:raw] = @body
topic_options[:title] = @message.subject
result = create_post_with_attachments(@user, topic_options)
topic_id = result.post.present? ? result.post.topic_id : nil
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: topic_id,
user_id: @user.id,
)
result
end
def create_post_with_attachments(user, post_options={})
options = {
cooking_options: { traditional_markdown_linebreaks: true },
}.merge(post_options)
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?
# try to inline images
if attachment.content_type.start_with?("image/")
if raw =~ /\[image: Inline image \d+\]/
raw.sub!(/\[image: Inline image \d+\]/, attachment_markdown(upload))
next
end
end
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)
"<img src='#{upload.url}' width='#{upload.width}' height='#{upload.height}'>"
else
"<a class='attachment' href='#{upload.url}'>#{upload.original_filename}</a> (#{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
manager = NewPostManager.new(user, options)
result = manager.perform
if result.errors.present?
raise InvalidPost, result.errors.full_messages.join("\n")
end
result
end
end
end