#!/usr/bin/env ruby
# encoding: utf-8

$:.unshift File.join(File.dirname(__FILE__), *%w[.. lib])

require 'optimist'
require "sup"

opts = Optimist::options do
  version "sup-sync-back-maildir (sup #{Redwood::VERSION})"
  banner <<EOS
Export Xapian entries to Maildir sources on disk.

This script parses the Xapian entries for a given Maildir source and renames
(changes maildir flags) e-mail files on disk according to the labels stored in
the index. It will export all the changes you made in Sup to your
Maildirs so that they can be propagated to your IMAP server with e.g. offlineimap.

The script also merges some Maildir flags into Sup such
as R (replied) and P (passed, forwarded), for instance suppose you
have an e-mail file like this: foo_bar:2,FRS (flags are favorite,
replied, seen) and its Xapian entry has labels 'starred', the merge
operation will add the 'replied' label to the Xapian entry.

If you choose not to merge (-m) you will lose information ('replied'), and in
the previous example the file will be renamed to foo_bar:2,FS.

Running this script is *strongly* recommended when setting the
"sync_back_to_maildir" option from false to true in config.yaml or changing the
"sync_back" flag to true for a source in sources.yaml.

Usage:
  sup-sync-back-maildir [options] <source>*

where <source>* is source URIs. If no source is given, the default behavior is
to sync back all Maildir sources marked as usual and that have not disabled
sync back using the configuration parameter sync_back = false in sources.yaml.

Options include:
EOS
  opt :no_confirm, "Don't ask for confirmation before synchronizing", :default => false, :short => "n"
  opt :no_merge, "Don't merge new supported Maildir flags (R and P)", :default => false, :short => "m"
  opt :list_sources, "List your Maildir sources and exit", :default => false, :short => "l"
  opt :unusual_sources_too, "Sync unusual sources too if no specific source information is given", :default => false, :short => "u"
end

def die msg
  $stderr.puts "Error: #{msg}"
  exit(-1)
end

Redwood::start true
index = Redwood::Index.init
index.lock_interactively or exit
index.load

## Force sync_back_to_maildir option otherwise nothing will happen
$config[:sync_back_to_maildir] = true

begin
  sync_performed = []
  sync_performed = File.readlines(Redwood::SYNC_OK_FN).collect { |e| e.strip }.find_all { |e| not e.empty? } if File.exist? Redwood::SYNC_OK_FN
  sources = []

  ## Try to find out sources given in parameters
  sources = ARGV.map do |uri|
    s = Redwood::SourceManager.source_for(uri) or die "unknown source: #{uri}. Did you add it with sup-add first?"
    s.is_a?(Redwood::Maildir) or die "#{uri} is not a Maildir source."
    s.sync_back_enabled? or die "#{uri} has disabled sync back - check your configuration."
    s
  end unless opts[:list_sources]

  ## Otherwise, check all sources in sources.yaml
  if sources.empty? or opts[:list_sources] == true
    if opts[:unusual_sources_too]
      sources = Redwood::SourceManager.sources.select do |s|
        s.is_a? Redwood::Maildir and s.sync_back_enabled?
      end
    else
      sources = Redwood::SourceManager.usual_sources.select do |s|
        s.is_a? Redwood::Maildir and s.sync_back_enabled?
      end
    end
  end

  if opts[:list_sources] == true
    sources.each do |s|
      puts "id: #{s.id}, uri: #{s.uri}"
    end
  else
    sources.each do |s|
      if opts[:no_confirm] == false
        print "Are you sure you want to synchronize '#{s.uri}'? (Y/n) "
        next if STDIN.gets.chomp.downcase == 'n'
      end

      infos = index.enum_for(:each_source_info, s.id).to_a
      counter = 0
      infos.each do |info|
        print "\rSynchronizing '#{s.uri}'... #{((counter += 1)/infos.size.to_f*100).to_i}%"
        index.each_message({:location => [s.id, info]}, false) do |m|
          if opts[:no_merge] == false
            m.merge_labels_from_locations [:replied, :forwarded]
          end

          if Redwood::Index.message_joining_killed? m
            m.labels += [:killed]
          end

          index.save_message m
        end
      end
      print "\n"
      sync_performed << s.uri
    end
    ## Write a flag file to tell sup that the synchronization has been performed
    File.open(Redwood::SYNC_OK_FN, 'w') {|f| f.write(sync_performed.join("\n")) }
  end
rescue Exception => e
  File.open("sup-exception-log.txt", "w") { |f| f.puts e.backtrace }
  raise
ensure
  index.save_index
  Redwood::finish
  index.unlock
end