#!/usr/bin/env ruby

ENV["RAILS_ENV"] ||= "production"

APP_PATH = File.expand_path('../../config/application',  __FILE__)
require File.expand_path('../../config/boot',  __FILE__)
require APP_PATH
Rails.application.require_environment!

class String
  def force_to_ascii
    encode("us-ascii", :invalid => :replace, :undef => :replace,
      :replace => "?")
  end

  # like ActionView::Helpers::TextHelper but preserve > and indentation when
  # wrapping lines
  def word_wrap(len)
    split("\n").collect do |line|
      if line.length <= len
        line
      elsif m = line.match(/^(> ?|   +)(.*)/)
        ind = m[1]
        if len - ind.length < 0
          ind = "    "
        end
        m[2].gsub(/(.{1,#{len - ind.length}})(\s+|$)/, "#{ind}\\1\n").strip
      else
        line.gsub(/(.{1,#{len}})(\s+|$)/, "\\1\n").strip
      end
    end * "\n"
  end
end

EMAIL_WIDTH = 72
LAST_STORY_KEY = "mailing:last_story_id"
LAST_COMMENT_KEY = "mailing:last_comment_id"

mailing_list_users = User.where(:mailing_list_enabled => true)

last_story_id = (Keystore.value_for(LAST_STORY_KEY) || Story.last.id).to_i

Story.where("id > ?", last_story_id).order(:id).each do |s|
  s.fetch_story_cache!
  s.save
 
  mailing_list_users.each do |u|
    if (s.tags.map{|t| t.id } & u.tag_filters.map{|t| t.tag_id }).any?
      next
    end

    IO.popen([ {}, "/usr/sbin/sendmail", "-i", "-f", "nobody@lobste.rs",
    u.email ], "w") do |mail|
      mail.puts "From: #{s.user.username} <#{s.user.username}@lobste.rs>"
      mail.puts "Reply-To: lobsters-#{u.mailing_list_token}@lobste.rs"
      mail.puts "To: lobsters-#{u.mailing_list_token}@lobste.rs"
      mail.puts "X-BeenThere: lobsters-#{u.mailing_list_token}.lobste.rs"
      mail.puts "List-Id: Lobsters <lobsters-#{u.mailing_list_token}.lobste.rs>"
      mail.puts "List-Unsubscribe: <https://lobste.rs/settings>"
      mail.puts "Precedence: list"
      mail.puts "Content-Type: text/plain; charset=\"us-ascii\""
      mail.puts "Message-ID: <#{s.mailing_list_message_id}>"
      mail.puts "Date: " << s.created_at.strftime("%a, %d %b %Y %H:%M:%S %z")
      mail.puts "Subject: #{s.title.force_to_ascii}" <<
        s.tags.sort_by{|t| t.tag }.map{|t| " [#{t.tag}]" }.join

      mail.puts ""

      if s.description.present?
        mail.puts s.description.to_s.force_to_ascii.word_wrap(EMAIL_WIDTH)
      end

      if s.url.present?
        if s.description.present?
          mail.puts ""
        end

        mail.puts "Via: #{s.url}"

        if s.story_cache.present?
          mail.puts ""
          mail.puts s.story_cache.to_s.force_to_ascii.word_wrap(EMAIL_WIDTH)
        end
      end

      mail.puts ""
      mail.puts "-- "
      mail.puts "Vote: #{s.short_id_url}"
    end
  end

  last_story_id = s.id
end

Keystore.put(LAST_STORY_KEY, last_story_id)

# repeat for comments

last_comment_id = (Keystore.value_for(LAST_COMMENT_KEY) ||
  Comment.last.id).to_i

Comment.where("id > ?", last_comment_id).order(:id).each do |c|
  mailing_list_users.each do |u|
    if (c.story.tags.map{|t| t.id } & u.tag_filters.map{|t| t.tag_id }).any?
      next
    end

    IO.popen([ {}, "/usr/sbin/sendmail", "-i", "-f", "nobody@lobste.rs",
    u.email ], "w") do |mail|
      mail.puts "From: #{c.user.username} <#{c.user.username}@lobste.rs>"
      mail.puts "Reply-To: lobsters-#{u.mailing_list_token}@lobste.rs"
      mail.puts "To: lobsters-#{u.mailing_list_token}@lobste.rs"
      mail.puts "List-Id: Lobsters <lobsters-#{u.mailing_list_token}.lobste.rs>"
      mail.puts "List-Unsubscribe: <https://lobste.rs/settings>"
      mail.puts "Precedence: list"
      mail.puts "Content-Type: text/plain; charset=\"us-ascii\""
      mail.puts "Message-ID: <#{c.mailing_list_message_id}>"

      refs = [ "<#{c.story.mailing_list_message_id}>" ]

      if c.parent_comment_id
        mail.puts "In-Reply-To: <#{c.parent_comment.mailing_list_message_id}>"

        thread = []
        indent_level = 0
        Comment.ordered_for_story_or_thread_for_user(nil, c.thread_id,
        nil).reverse.each do |cc|
          if indent_level > 0 && cc.indent_level < indent_level
            thread.unshift cc
            indent_level = cc.indent_level
          elsif cc.id == c.id
            indent_level = cc.indent_level
          end
        end

        thread.each do |cc|
          refs.push "<#{cc.mailing_list_message_id}>"
        end
      else
        mail.puts "In-Reply-To: <#{c.story.mailing_list_message_id}>"
      end

      mail.print "References:"
      refs.each do |ref|
        mail.puts " #{ref}"
      end

      mail.puts "Date: " << c.created_at.strftime("%a, %d %b %Y %H:%M:%S %z")
      mail.puts "Subject: Re: #{c.story.title.force_to_ascii}" <<
        c.story.tags.sort_by{|t| t.tag }.map{|t| " [#{t.tag}]" }.join

      mail.puts ""

      mail.puts c.comment.to_s.force_to_ascii.word_wrap(EMAIL_WIDTH)

      mail.puts ""
      mail.puts "-- "
      mail.puts "Vote: #{c.short_id_url}"
    end
  end

  last_comment_id = c.id
end

Keystore.put(LAST_COMMENT_KEY, last_comment_id)