#!/usr/bin/ruby
#
# pdumpfs-clean: cleanup old backup directory for pdumpfs
#
# Usage:
#   pdumpfs-clean <pdumpfs backuped directories...>
#
# Copyright(C) 2003 Taku YASUI <tach@debian.or.jp>, All rights reserved.
# This is free software with ABSOLUTELY NO WARRANTY.
#
# You can redistribute it and/or modify it under the terms of 
# the GNU General Public License version 2.
#
# 2003-06-18:
# Modified by akira yamada <akira@arika.org>.

require 'getoptlong'
require 'date'
require 'find'

VERS = '$Id: pdumpfs-clean,v 1.2 2003/06/15 07:46:52 tach Exp $'.sub(/^.*,v ([\d\.]+) .*$/, "\\1") + ' + ay0'

def parse_options
  options = Hash.new
  parser = GetoptLong.new
  parser.set_options(['--help',          '-h', GetoptLong::NO_ARGUMENT],
		     ['--no-act',	 '-n', GetoptLong::NO_ARGUMENT],
		     ['--verbose',	 '-v', GetoptLong::NO_ARGUMENT],
		     ['--version',	 '-V', GetoptLong::NO_ARGUMENT],
		     ['--keep',		 '-k', GetoptLong::REQUIRED_ARGUMENT])
  parser.each_option {|name, arg|
    options[name.sub(/^--/, "")] = arg
  }
  show_version if options['version']
  show_usage if options['help'] or ARGV[0].nil?
  return options
end

def parse_keep(keep)
  return {'year' => 2,
	  'month' => 6,
	  'week' => 6,
	  'day' => 7} unless keep

  ch_tables = { 'year' => /(\d+)Y/i,
  		'month' => /(\d+)M/i,
		'week' => /(\d+)W/i,
		'day' => /(\d+)D/i }
  ret = {}
  ch_tables.each do |key, regex|
    if regex =~ keep
      ret[key] = $1.to_i
      ret[key] -= 1
    else
      ret[key] = 0
    end
  end
  ret
end

def create_keeprange(keep)
  from = Date.today
  to   = from.dup

  from = Date.new(from.year - keep['year'], from.month, from.day)
  from = from << keep['month']
  from = from -= keep['week']*7 + keep['day']

  from .. to
end 

def each_subdir(base, patt)
  Dir.foreach(base) do |x|
    next unless patt =~ x
    p = File.join(base, x)
    next unless FileTest.directory?(p)
    yield(p, x)
  end
end

def pdumpfs_dirs(dir)
  each_subdir(dir, /^\d{4}$/o) do |yp, yb|
    year = yb.to_i
    each_subdir(yp, /^\d{2}$/o) do |mp, mb|
      month = mb.to_i
      each_subdir(mp, /^\d{2}$/o) do |dp, db|
	day = db.to_i
	begin
	  date = Date.new(year, month, day)
	rescue ArgumentError
	  date = nil
	end
	yield(dp, mp, yp, date) if date
      end
    end
  end
end

def rm_rf(dir, verbose = false, no_act = true)
  print "Deleting #{dir} ... " if verbose
  unless no_act
    Find.find(dir) do |f|
      next if f == dir
      next if f == '.'
      next if f == '..'
      if !FileTest.symlink?(f) && FileTest.directory?(f)
	rm_rf(f, false, no_act)
	begin
	  Dir.rmdir(f)
	rescue => e
	  STDERR.puts e
	end
      else
	begin
	  File.delete(f)
	rescue => e
	  STDERR.puts e
	end
      end
    end
    begin
      Dir.rmdir(dir)
    rescue => e
      STDERR.puts e
    end
  end
  print "done.\n" if verbose
end

def rmdir(dir, verbose = false, no_act = true)
  print "Deleting #{dir} ..." if verbose
  begin
    Dir.rmdir(dir) unless no_act
  rescue => e
    $stderr.puts e
  end
  print " done.\n" if verbose
end

def show_usage
  print <<_EOT
Usage: pdumpfs-clean [OPTIONS] directories...
OPTIONS:
  --help,              -h: Show this help
  --keep KEEPARGS,     -k: use KEEPARGS to decide delete directories
  --no-act,            -n: run command but don't do it
  --verbose,           -v: Verbose output
  --version,           -V: Show software version
KEEPARGS: [digitY][digitM][digitW][digitD]
  ex: --keep 2Y6M6W7D (2years, 6months, 6weeks, 7days, default)
_EOT
  exit
end

def show_version
  print <<_EOT
pdumpfs-clean version #{VERS}
Copyright (C) 2003 Taku YASUI <tach@debian.or.jp>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at
your option) any later version.
_EOT
  exit
end

def main
  opts = parse_options
  keep_range = create_keeprange(parse_keep(opts['keep']))
  keeped = []

  ARGV.each do |basedir|
    pdumpfs_dirs(basedir) do |date_path, month_path, year_path, date|
      if keep_range === date
        keeped.push(date_path)
      else
	rm_rf(date_path, opts['verbose'], opts['no-act'])

	rmdir(month_path) if File.stat(month_path).nlink <= 2
	rmdir(year_path)  if File.stat(year_path).nlink  <= 2
      end
    end
    if opts['verbose']
      puts "Keep dirs:"
      keeped.each do |dir|
        puts dir
      end
    end
  end
end

main if __FILE__ == $0