discourse/lib/email/sender.rb

178 lines
5.8 KiB
Ruby

#
# A helper class to send an email. It will also handle a nil message, which it considers
# to be "do nothing". This is because some Mailers will decide not to do work for some
# reason. For example, emailing a user too frequently. A nil to address is also considered
# "do nothing"
#
# It also adds an HTML part for the plain text body
#
require_dependency 'email/renderer'
require 'uri'
require 'net/smtp'
SMTP_CLIENT_ERRORS = [Net::SMTPFatalError, Net::SMTPSyntaxError]
module Email
class Sender
def initialize(message, email_type, user=nil)
@message = message
@email_type = email_type
@user = user
end
def send
return if SiteSetting.disable_emails
return skip(I18n.t('email_log.message_blank')) if @message.blank?
return skip(I18n.t('email_log.message_to_blank')) if @message.to.blank?
if @message.text_part
return skip(I18n.t('email_log.text_part_body_blank')) if @message.text_part.body.to_s.blank?
else
return skip(I18n.t('email_log.body_blank')) if @message.body.to_s.blank?
end
@message.charset = 'UTF-8'
opts = {}
renderer = Email::Renderer.new(@message, opts)
if @message.html_part
@message.html_part.body = renderer.html
else
@message.html_part = Mail::Part.new do
content_type 'text/html; charset=UTF-8'
body renderer.html
end
end
@message.parts[0].body = @message.parts[0].body.to_s.gsub(/\[\/?email-indent\]/, '')
# Fix relative (ie upload) HTML links in markdown which do not work well in plain text emails.
# These are the links we add when a user uploads a file or image.
# Ideally we would parse general markdown into plain text, but that is almost an intractable problem.
url_prefix = Discourse.base_url
@message.parts[0].body = @message.parts[0].body.to_s.gsub(/<a class="attachment" href="(\/uploads\/default\/[^"]+)">([^<]*)<\/a>/, '[\2]('+url_prefix+'\1)')
@message.parts[0].body = @message.parts[0].body.to_s.gsub(/<img src="(\/uploads\/default\/[^"]+)"([^>]*)>/, '![]('+url_prefix+'\1)')
@message.text_part.content_type = 'text/plain; charset=UTF-8'
# Set up the email log
email_log = EmailLog.new(email_type: @email_type,
to_address: to_address,
user_id: @user.try(:id))
host = Email::Sender.host_for(Discourse.base_url)
topic_id = header_value('X-Discourse-Topic-Id')
post_id = header_value('X-Discourse-Post-Id')
reply_key = header_value('X-Discourse-Reply-Key')
# always set a default Message ID from the host
uuid = SecureRandom.uuid
@message.header['Message-ID'] = "<#{uuid}@#{host}>"
if topic_id.present?
email_log.topic_id = topic_id
topic_identifier = "<topic/#{topic_id}@#{host}>"
post_identifier = "<topic/#{topic_id}/#{post_id}@#{host}>"
@message.header['Message-ID'] = post_identifier
@message.header['In-Reply-To'] = topic_identifier
@message.header['References'] = topic_identifier
topic = Topic.where(id: topic_id).first
# http://www.ietf.org/rfc/rfc2919.txt
if topic && topic.category && !topic.category.uncategorized?
list_id = "<#{topic.category.name.downcase.gsub(' ', '-')}.#{host}>"
# subcategory case
if !topic.category.parent_category_id.nil?
parent_category_name = Category.find_by(id: topic.category.parent_category_id).name
list_id = "<#{topic.category.name.downcase.gsub(' ', '-')}.#{parent_category_name.downcase.gsub(' ', '-')}.#{host}>"
end
else
list_id = "<#{host}>"
end
@message.header['List-ID'] = list_id
@message.header['List-Archive'] = topic.url if topic
# http://www.ietf.org/rfc/rfc3834.txt
@message.header['Precedence'] = 'list'
end
if reply_key.present?
if @message.header['Reply-To'] =~ /\<([^\>]+)\>/
email = Regexp.last_match[1]
@message.header['List-Post'] = "<mailto:#{email}>"
end
end
email_log.post_id = post_id if post_id.present?
email_log.reply_key = reply_key if reply_key.present?
# Remove headers we don't need anymore
@message.header['X-Discourse-Topic-Id'] = nil if topic_id.present?
@message.header['X-Discourse-Post-Id'] = nil if post_id.present?
@message.header['X-Discourse-Reply-Key'] = nil if reply_key.present?
# Suppress images from short emails
if SiteSetting.strip_images_from_short_emails && @message.html_part.body.to_s.bytesize <= SiteSetting.short_email_length && @message.html_part.body =~ /<img[^>]+>/
style = Email::Styles.new(@message.html_part.body.to_s)
@message.html_part.body = style.strip_avatars_and_emojis
end
begin
@message.deliver_now
rescue *SMTP_CLIENT_ERRORS => e
return skip(e.message)
end
# Save and return the email log
email_log.save!
email_log
end
def to_address
@to_address ||= begin
to = @message ? @message.to : nil
to.is_a?(Array) ? to.first : to
end
end
def self.host_for(base_url)
host = "localhost"
if base_url.present?
begin
uri = URI.parse(base_url)
host = uri.host.downcase if uri.host.present?
rescue URI::InvalidURIError
end
end
host
end
private
def header_value(name)
header = @message.header[name]
return nil unless header
header.value
end
def skip(reason)
EmailLog.create(email_type: @email_type,
to_address: to_address,
user_id: @user.try(:id),
skipped: true,
skipped_reason: reason)
end
end
end