#!/usr/bin/env ruby

require 'uri'
require 'rubygems'
require 'trollop'
require "sup"

class Float
  def to_s; sprintf '%.2f', self; end
   def to_time_s
     infinite? ? "unknown" : super
   end
end

class Numeric
  def to_time_s
    i = to_i
    sprintf "%d:%02d:%02d", i / 3600, (i / 60) % 60, i % 60
  end
end

def time
  startt = Time.now
  yield
  Time.now - startt
end

opts = Trollop::options do
  version "sup-sync (sup #{Redwood::VERSION})"
  banner <<EOS
Synchronizes the Sup index with one or more message sources by adding
messages, deleting messages, or changing message state in the index as
appropriate.

"Message state" means read/unread, archived/inbox, starred/unstarred,
and all user-defined labels on each message.

"Default source state" refers to any state that a source itself has
keeps about a message. Sup-sync uses this information when adding a
new message to the index. The source state is typically limited to
read/unread, archived/inbox status and a single label based on the
source name. Messages using the default source state are placed in
the inbox (i.e. not archived) and unstarred.

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

where <source>* is zero or more source URIs. If no sources are given,
sync from all usual sources. Supported source URI schemes can be seen
by running "sup-add --help".

Options controlling WHICH messages sup-sync operates on:
EOS
  opt :new, "Operate on new messages only. Don't scan over the entire source. (Default.)", :short => :none
  opt :changed, "Scan over the entire source for messages that have been deleted, altered, or moved from another source. (In the case of mbox sources, this includes all messages AFTER an altered message.)"
  opt :restored, "Operate only on those messages included in a dump file as specified by --restore which have changed state."
  opt :all, "Operate on all messages in the source, regardless of newness or changedness."
  opt :start_at, "For --changed and --all, start at a particular offset.", :type => :int

text <<EOS

Options controlling HOW message state is altered:
EOS
  opt :asis, "If the message is already in the index, preserve its state. Otherwise, use default source state. (Default.)", :short => :none
  opt :restore, "Restore message state from a dump file created with sup-dump. If a message is not in this dumpfile, act as --asis.", :type => String, :short => :none
  opt :discard, "Discard any message state in the index and use the default source state. Dangerous!", :short => :none
  opt :archive, "When using the default source state, mark messages as archived.", :short => "-x"
  opt :read, "When using the default source state, mark messages as read."
  opt :extra_labels, "When using the default source state, also apply these user-defined labels. Should be a comma-separated list.", :type => String, :short => :none

text <<EOS

Other options:
EOS
  opt :verbose, "Print message ids as they're processed."
  opt :optimize, "As the final operation, optimize the index."
  opt :all_sources, "Scan over all sources.", :short => :none
  opt :dry_run, "Don't actually modify the index. Probably only useful with --verbose.", :short => "-n"
  opt :version, "Show version information", :short => :none

  conflicts :changed, :all, :new, :restored
  conflicts :asis, :restore, :discard
end
Trollop::die :restored, "requires --restore" if opts[:restored] unless opts[:restore]
if opts[:start_at]
  Trollop::die :start_at, "must be non-negative" if opts[:start_at] < 0
  Trollop::die :start_at, "requires either --changed or --all" unless opts[:changed] || opts[:all]
end

target = [:new, :changed, :all, :restored].find { |x| opts[x] } || :new
op = [:asis, :restore, :discard].find { |x| opts[x] } || :asis

Redwood::start
index = Redwood::Index.new

restored_state =
  if opts[:restore]
    dump = {}
    $stderr.puts "Loading state dump from #{opts[:restore]}..."
    IO.foreach opts[:restore] do |l|
      l =~ /^(\S+) \((.*?)\)$/ or raise "Can't read dump line: #{l.inspect}"
      mid, labels = $1, $2
      dump[mid] = labels.split(" ").map { |x| x.intern }
    end
    $stderr.puts "Read #{dump.size} entries from dump file."
    dump
  else
    {}
  end

seen = {}
index.lock_or_die
begin
  index.load

  sources = ARGV.map do |uri|
    index.source_for uri or Trollop::die "Unknown source: #{uri}. Did you add it with sup-add first?"
  end
  
  sources = index.usual_sources if sources.empty?
  sources = index.sources if opts[:all_sources]

  unless target == :new
    if opts[:start_at]
      sources.each { |s| s.seek_to! opts[:start_at] }
    else
      sources.each { |s| s.reset! }
    end
  end
  
  sources.each do |source|
    $stderr.puts "Scanning #{source}..."
    num_added = num_updated = num_scanned = num_restored = 0
    last_info_time = start_time = Time.now

    Redwood::PollManager.add_messages_from source do |m, offset, entry|
      num_scanned += 1
      seen[m.id] = true

      ## skip if we're operating only on changed messages, the message
      ## is in the index, and it's unchanged from what the source is
      ## reporting.
      next if target == :changed && entry && entry[:source_id].to_i == source.id && entry[:source_info].to_i == offset

      ## get the state currently in the index
      index_state =
        if entry
          entry[:label].split(/\s+/).map { |x| x.intern }
        else
          nil
        end

      ## skip if we're operating on restored messages, and this one
      ## ain't.
      next if target == :restored && (!restored_state[m.id] || (index_state && restored_state[m.id].sort_by { |s| s.to_s } == index_state.sort_by { |s| s.to_s }))

      ## m.labels is the default source labels. tweak these according
      ## to default source state modification flags.
      m.labels -= [:inbox] if opts[:archive]
      m.labels -= [:unread] if opts[:read]
      m.labels += opts[:extra_labels].split(/\s*,\s*/).map { |x| x.intern } if opts[:extra_labels]

      ## assign message labels based on the operation we're performing
      case op
      when :asis
        m.labels = index_state if index_state
      when :restore
        ## if the entry exists on disk
        if restored_state[m.id]
          m.labels = restored_state[m.id]
          num_restored += 1
        elsif index_state
          m.labels = index_state
        end
      when :discard
        ## nothin! use default source labels
      end

      if Time.now - last_info_time > 60
        last_info_time = Time.now
        elapsed = last_info_time - start_time
        pctdone = source.respond_to?(:pct_done) ? source.pct_done : 100.0 * (source.cur_offset.to_f - source.start_offset).to_f / (source.end_offset - source.start_offset).to_f
        remaining = (100.0 - pctdone) * (elapsed.to_f / pctdone)
        $stderr.puts "## #{num_scanned} (#{pctdone}%) read; #{elapsed.to_time_s} elapsed; #{remaining.to_time_s} remaining"
      end

      if index_state.nil?
        puts "Adding message #{source}##{offset} with state {#{m.labels * ', '}}" if opts[:verbose]
        num_added += 1
      else
        puts "Updating message #{source}##{offset}, source #{entry[:source_id]} => #{source.id}, offset #{entry[:source_info]} => #{offset}, state {#{index_state * ', '}} => {#{m.labels * ', '}}" if opts[:verbose]
        num_updated += 1
      end

      opts[:dry_run] ? nil : m
    end
    $stderr.puts "Scanned #{num_scanned}, added #{num_added}, updated #{num_updated} messages from #{source}."
    $stderr.puts "Restored state on #{num_restored} (#{100.0 * num_restored / num_scanned}%) messages." if num_restored > 0
  end

  ## delete any messages in the index that claim they're from one of
  ## these sources, but that we didn't see.
  ##
  ## kinda crappy code here, because we delve directly into the Ferret
  ## API.
  ##
  ## TODO: move this to Index, i suppose.


  if target == :all || target == :changed
    $stderr.puts "Deleting missing messages from the index..."
    num_del, num_scanned = 0, 0
    sources.each do |source|
      raise "no source id for #{source}" unless source.id
      q = "+source_id:#{source.id}"
      q += " +source_info: >= #{opts[:start_at]}" if opts[:start_at]
      index.index.search_each(q, :limit => :all) do |docid, score|
        num_scanned += 1
        mid = index.index[docid][:message_id]
        unless seen[mid]
          puts "Deleting #{mid}" if opts[:verbose]
          index.index.delete docid unless opts[:dry_run]
          num_del += 1
        end
      end
    end
    $stderr.puts "Deleted #{num_del} / #{num_scanned} messages"
  end

  index.save

  if opts[:optimize]
    $stderr.puts "Optimizing index..."
    optt = time { index.index.optimize unless opts[:dry_run] }
    $stderr.puts "Optimized index of size #{index.size} in #{optt}s."
  end
rescue Redwood::FatalSourceError => e
  $stderr.puts "Sorry, I couldn't communicate with a source: #{e.message}"
rescue Exception => e
  File.open("sup-exception-log.txt", "w") { |f| f.puts e.backtrace }
  raise
ensure
  Redwood::finish
  index.unlock
end