# Copyright 2002, 2003, 2004, 2005 Ben Escoto
#
# This file is part of rdiff-backup.
#
# rdiff-backup is free software; you can redistribute it and/or modify
# 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.
#
# rdiff-backup is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with rdiff-backup; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
# USA

"""Start (and end) here - read arguments, set global settings, etc."""

from __future__ import generators
import getopt, sys, re, os, cStringIO
from log import Log, LoggerError, ErrorLog
import Globals, Time, SetConnections, selection, robust, rpath, \
	   manage, backup, connection, restore, FilenameMapping, \
	   Security, Hardlink, regress, C, fs_abilities, statistics, compare


action = None
create_full_path = None
remote_cmd, remote_schema = None, None
force = None
select_opts = []
select_files = []
user_mapping_filename, group_mapping_filename, preserve_numerical_ids = \
					   None, None, None

# These are global because they are set while we are trying to figure
# whether to restore or to backup
restore_root, restore_index, restore_root_set = None, None, 0
return_val = None # Set to cause exit code to be specified value

def parse_cmdlineoptions(arglist):
	"""Parse argument list and set global preferences"""
	global args, action, create_full_path, force, restore_timestr, remote_cmd
	global remote_schema, remove_older_than_string
	global user_mapping_filename, group_mapping_filename, \
		   preserve_numerical_ids

	def sel_fl(filename):
		"""Helper function for including/excluding filelists below"""
		try: return open(filename, "r")
		except IOError: Log.FatalError("Error opening file %s" % filename)

	def normalize_path(path):
		"""Used below to normalize the security paths before setting"""
		return rpath.RPath(Globals.local_connection, path).normalize().path

	try: optlist, args = getopt.getopt(arglist, "blr:sv:V",
		 ["backup-mode", "calculate-average", "carbonfile",
		  "check-destination-dir",
		  "compare", "compare-at-time=", "compare-hash",
		  "compare-hash-at-time=", "compare-full", "compare-full-at-time=",
		  "create-full-path", "current-time=", "exclude=",
		  "exclude-device-files", "exclude-fifos", "exclude-filelist=",
		  "exclude-symbolic-links", "exclude-sockets",
		  "exclude-filelist-stdin", "exclude-globbing-filelist=",
		  "exclude-globbing-filelist-stdin", "exclude-mirror=",
		  "exclude-other-filesystems", "exclude-regexp=",
		  "exclude-special-files", "force", "group-mapping-file=",
		  "include=", "include-filelist=", "include-filelist-stdin",
		  "include-globbing-filelist=",
		  "include-globbing-filelist-stdin", "include-regexp=",
		  "include-special-files", "include-symbolic-links",
		  "list-at-time=", "list-changed-since=", "list-increments",
		  "list-increment-sizes", "never-drop-acls",
		  "max-file-size=", "min-file-size=",
		  "no-acls", "no-carbonfile",
		  "no-compare-inode", "no-compression", "no-compression-regexp=",
		  "no-eas", "no-file-statistics", "no-hard-links", "null-separator",
		  "override-chars-to-quote=", "parsable-output",
		  "preserve-numerical-ids", "print-statistics",
		  "remote-cmd=", "remote-schema=",
		  "remove-older-than=", "restore-as-of=", "restrict=",
		  "restrict-read-only=", "restrict-update-only=", "server",
		  "ssh-no-compression", "terminal-verbosity=", "test-server",
		  "user-mapping-file=", "verbosity=", "verify",
		  "verify-at-time=", "version"])
	except getopt.error, e:
		commandline_error("Bad commandline options: " + str(e))

	for opt, arg in optlist:
		if opt == "-b" or opt == "--backup-mode": action = "backup"
		elif opt == "--calculate-average": action = "calculate-average"
		elif opt == "--carbonfile": Globals.set("carbonfile_active", 1)
		elif opt == "--check-destination-dir": action = "check-destination-dir"
		elif opt in ("--compare", "--compare-at-time",
					 "--compare-hash", "--compare-hash-at-time",
					 "--compare-full", "--compare-full-at-time"):
			if opt[-8:] == "-at-time": restore_timestr, opt = arg, opt[:-8]
			else: restore_timestr = "now"
			action = opt[2:]
		elif opt == "--create-full-path": create_full_path = 1
		elif opt == "--current-time":
			Globals.set_integer('current_time', arg)
		elif (opt == "--exclude" or
			  opt == "--exclude-device-files" or
			  opt == "--exclude-fifos" or
			  opt == "--exclude-other-filesystems" or
			  opt == "--exclude-regexp" or
			  opt == "--exclude-special-files" or
			  opt == "--exclude-sockets" or
			  opt == "--exclude-symbolic-links"):
			select_opts.append((opt, arg))
		elif opt == "--exclude-filelist":
			select_opts.append((opt, arg))
			select_files.append(sel_fl(arg))
		elif opt == "--exclude-filelist-stdin":
			select_opts.append(("--exclude-filelist", "standard input"))
			select_files.append(sys.stdin)
		elif opt == "--exclude-globbing-filelist":
			select_opts.append((opt, arg))
			select_files.append(sel_fl(arg))
		elif opt == "--exclude-globbing-filelist-stdin":
			select_opts.append(("--exclude-globbing-filelist",
								"standard input"))
			select_files.append(sys.stdin)
		elif opt == "--force": force = 1
		elif opt == "--group-mapping-file": group_mapping_filename = arg
		elif (opt == "--include" or
			  opt == "--include-special-files" or
			  opt == "--include-symbolic-links"):
			select_opts.append((opt, arg))
		elif opt == "--include-filelist":
			select_opts.append((opt, arg))
			select_files.append(sel_fl(arg))
		elif opt == "--include-filelist-stdin":
			select_opts.append(("--include-filelist", "standard input"))
			select_files.append(sys.stdin)
		elif opt == "--include-globbing-filelist":
			select_opts.append((opt, arg))
			select_files.append(sel_fl(arg))
		elif opt == "--include-globbing-filelist-stdin":
			select_opts.append(("--include-globbing-filelist",
								"standard input"))
			select_files.append(sys.stdin)
		elif opt == "--include-regexp": select_opts.append((opt, arg))
		elif opt == "--list-at-time":
			restore_timestr, action = arg, "list-at-time"
		elif opt == "--list-changed-since":
			restore_timestr, action = arg, "list-changed-since"
		elif opt == "-l" or opt == "--list-increments":
			action = "list-increments"
		elif opt == '--list-increment-sizes': action = 'list-increment-sizes'
		elif opt == "--max-file-size": select_opts.append((opt, arg))
		elif opt == "--min-file-size": select_opts.append((opt, arg))
		elif opt == "--never-drop-acls": Globals.set("never_drop_acls", 1)
		elif opt == "--no-acls": Globals.set("acls_active", 0)
		elif opt == "--no-carbonfile": Globals.set("carbonfile_active", 0)
		elif opt == "--no-compare-inode": Globals.set("compare_inode", 0)
		elif opt == "--no-compression": Globals.set("compression", None)
		elif opt == "--no-compression-regexp":
			Globals.set("no_compression_regexp_string", arg)
		elif opt == "--no-eas": Globals.set("eas_active", 0)
		elif opt == "--no-file-statistics": Globals.set('file_statistics', 0)
		elif opt == "--no-hard-links": Globals.set('preserve_hardlinks', 0)
		elif opt == "--null-separator": Globals.set("null_separator", 1)
		elif opt == "--override-chars-to-quote":
			Globals.set('chars_to_quote', arg)
		elif opt == "--parsable-output": Globals.set('parsable_output', 1)
		elif opt == "--preserve-numerical-ids": preserve_numerical_ids = 1
		elif opt == "--print-statistics": Globals.set('print_statistics', 1)
		elif opt == "-r" or opt == "--restore-as-of":
			restore_timestr, action = arg, "restore-as-of"
		elif opt == "--remote-cmd": remote_cmd = arg
		elif opt == "--remote-schema": remote_schema = arg
		elif opt == "--remove-older-than":
			remove_older_than_string = arg
			action = "remove-older-than"
		elif opt == "--no-resource-forks":
			Globals.set('resource_forks_active', 0)
		elif opt == "--restrict": Globals.restrict_path = normalize_path(arg)
		elif opt == "--restrict-read-only":
			Globals.security_level = "read-only"
			Globals.restrict_path = normalize_path(arg)
		elif opt == "--restrict-update-only":
			Globals.security_level = "update-only"
			Globals.restrict_path = normalize_path(arg)
		elif opt == "-s" or opt == "--server":
			action = "server"
			Globals.server = 1
		elif opt == "--ssh-no-compression":
			Globals.set('ssh_compression', None)
		elif opt == "--terminal-verbosity": Log.setterm_verbosity(arg)
		elif opt == "--test-server": action = "test-server"
		elif opt == "--user-mapping-file": user_mapping_filename = arg
		elif opt == "-v" or opt == "--verbosity": Log.setverbosity(arg)
		elif opt == "--verify": action, restore_timestr = "verify", "now"
		elif opt == "--verify-at-time": action, restore_timestr = "verify", arg
		elif opt == "-V" or opt == "--version":
			print "rdiff-backup " + Globals.version
			sys.exit(0)
		else: Log.FatalError("Unknown option %s" % opt)

def check_action():
	"""Check to make sure action is compatible with args"""
	global action
	arg_action_dict = {0: ['server'],
					   1: ['list-increments', 'list-increment-sizes',
						   'remove-older-than', 'list-at-time',
						   'list-changed-since', 'check-destination-dir',
						   'verify'],
					   2: ['backup', 'restore', 'restore-as-of',
						   'compare', 'compare-hash', 'compare-full']}
	l = len(args)
	if l == 0 and action not in arg_action_dict[l]:
		commandline_error("No arguments given")
	elif not action:
		if l == 2: pass # Will determine restore or backup later
		else:
			commandline_error("Switches missing or wrong number of arguments")
	elif action == 'test-server' or action == 'calculate-average':
		pass # these two take any number of args
	elif l > 2 or action not in arg_action_dict[l]:
		commandline_error("Wrong number of arguments given.")

def final_set_action(rps):
	"""If no action set, decide between backup and restore at this point"""
	global action
	if action: return
	assert len(rps) == 2, rps
	if restore_set_root(rps[0]): action = "restore"
	else: action = "backup"

def commandline_error(message):
	Log.FatalError(message + "\nSee the rdiff-backup manual page for "
				   "more information.")

def misc_setup(rps):
	"""Set default change ownership flag, umask, relay regexps"""
	os.umask(077)
	Time.setcurtime(Globals.current_time)
	SetConnections.UpdateGlobal("client_conn", Globals.local_connection)
	Globals.postset_regexp('no_compression_regexp',
						   Globals.no_compression_regexp_string)
	for conn in Globals.connections:
		conn.robust.install_signal_handlers()
		conn.Hardlink.initialize_dictionaries()

def init_user_group_mapping(destination_conn):
	"""Initialize user and group mapping on destination connection"""
	global user_mapping_filename, group_mapping_filename, \
		   preserve_numerical_ids
	def get_string_from_file(filename):
		if not filename: return None
		rp = rpath.RPath(Globals.local_connection, filename)
		try: return rp.get_data()
		except OSError, e:
			Log.FatalError("Error '%s' reading mapping file '%s'" %
						   (str(e), filename))
	user_mapping_string = get_string_from_file(user_mapping_filename)
	destination_conn.user_group.init_user_mapping(user_mapping_string,
												  preserve_numerical_ids)
	group_mapping_string = get_string_from_file(group_mapping_filename)
	destination_conn.user_group.init_group_mapping(group_mapping_string,
												   preserve_numerical_ids)

def take_action(rps):
	"""Do whatever action says"""
	if action == "server":
		connection.PipeConnection(sys.stdin, sys.stdout).Server()
		sys.exit(0)
	elif action == "backup": Backup(rps[0], rps[1])
	elif action == "calculate-average": CalculateAverage(rps)
	elif action == "check-destination-dir": CheckDest(rps[0])
	elif action.startswith("compare"): Compare(action, rps[0], rps[1])
	elif action == "list-at-time": ListAtTime(rps[0])
	elif action == "list-changed-since": ListChangedSince(rps[0])
	elif action == "list-increments": ListIncrements(rps[0])
	elif action == 'list-increment-sizes': ListIncrementSizes(rps[0])
	elif action == "remove-older-than": RemoveOlderThan(rps[0])
	elif action == "restore": Restore(*rps)
	elif action == "restore-as-of": Restore(rps[0], rps[1], 1)
	elif action == "test-server": SetConnections.TestConnections()
	elif action == "verify": Verify(rps[0])
	else: raise AssertionError("Unknown action " + action)

def cleanup():
	"""Do any last minute cleaning before exiting"""
	Log("Cleaning up", 6)
	if ErrorLog.isopen(): ErrorLog.close()
	Log.close_logfile()
	if not Globals.server: SetConnections.CloseConnections()

def error_check_Main(arglist):
	"""Run Main on arglist, suppressing stack trace for routine errors"""
	try: Main(arglist)
	except SystemExit: raise
	except Exception, exc:
		errmsg = robust.is_routine_fatal(exc)
		if errmsg:
			Log.exception(2, 6)
			Log.FatalError(errmsg)
		else:
			Log.exception(2, 2)
			raise

def Main(arglist):
	"""Start everything up!"""
	parse_cmdlineoptions(arglist)
	check_action()
	cmdpairs = SetConnections.get_cmd_pairs(args, remote_schema, remote_cmd)
	Security.initialize(action or "mirror", cmdpairs)
	rps = map(SetConnections.cmdpair2rp, cmdpairs)
	final_set_action(rps)
	misc_setup(rps)
	take_action(rps)
	cleanup()
	if return_val is not None: sys.exit(return_val)

def Backup(rpin, rpout):
	"""Backup, possibly incrementally, src_path to dest_path."""
	global incdir
	SetConnections.BackupInitConnections(rpin.conn, rpout.conn)
	backup_check_dirs(rpin, rpout)
	backup_set_rbdir(rpin, rpout)
	rpout.conn.fs_abilities.backup_set_globals(rpin)
	if Globals.chars_to_quote: rpout = backup_quoted_rpaths(rpout)
	init_user_group_mapping(rpout.conn)
	backup_final_init(rpout)
	backup_set_select(rpin)
	backup_warn_if_infinite_regress(rpin, rpout)
	if prevtime:
		Time.setprevtime(prevtime)
		rpout.conn.Main.backup_touch_curmirror_local(rpin, rpout)
		backup.Mirror_and_increment(rpin, rpout, incdir)
		rpout.conn.Main.backup_remove_curmirror_local()
	else:
		backup.Mirror(rpin, rpout)
		rpout.conn.Main.backup_touch_curmirror_local(rpin, rpout)

def backup_quoted_rpaths(rpout):
	"""Get QuotedRPath versions of important RPaths.  Return rpout"""
	global incdir
	SetConnections.UpdateGlobal(
		'rbdir', FilenameMapping.get_quotedrpath(Globals.rbdir))
	incdir = FilenameMapping.get_quotedrpath(incdir)
	return FilenameMapping.get_quotedrpath(rpout)

def backup_set_select(rpin):
	"""Create Select objects on source connection"""
	rpin.conn.backup.SourceStruct.set_source_select(rpin, select_opts,
													*select_files)

def backup_check_dirs(rpin, rpout):
	"""Make sure in and out dirs exist and are directories"""
	if rpout.lstat() and not rpout.isdir():
		if not force: Log.FatalError("Destination %s exists and is not a "
									 "directory" % rpout.path)
		else:
			Log("Deleting %s" % rpout.path, 3)
			rpout.delete()
	if not rpout.lstat():
		try: 
			if create_full_path: rpout.makedirs()
			else: rpout.mkdir()
		except os.error:
			Log.FatalError("Unable to create directory %s" % rpout.path)

	if not rpin.lstat():
		Log.FatalError("Source directory %s does not exist" % rpin.path)
	elif not rpin.isdir():
		Log.FatalError("Source %s is not a directory" % rpin.path)
	Globals.rbdir = rpout.append_path("rdiff-backup-data")

def backup_set_rbdir(rpin, rpout):
	"""Initialize data dir and logging"""
	global incdir
	incdir = Globals.rbdir.append_path("increments")

	assert rpout.lstat(), (rpout.path, rpout.lstat())
	if rpout.isdir() and not rpout.listdir(): # rpout is empty dir
		try:
			rpout.chmod(0700) # just make sure permissions aren't too lax
		except OSError:
			log.Log("Cannot change permissions on target directory.", 2)
	elif not Globals.rbdir.lstat() and not force: Log.FatalError(
"""Destination directory

%s

exists, but does not look like a rdiff-backup directory.  Running
rdiff-backup like this could mess up what is currently in it.  If you
want to update or overwrite it, run rdiff-backup with the --force
option.""" % rpout.path)

	if not Globals.rbdir.lstat(): Globals.rbdir.mkdir()
	SetConnections.UpdateGlobal('rbdir', Globals.rbdir)

def backup_warn_if_infinite_regress(rpin, rpout):
	"""Warn user if destination area contained in source area"""
	# Just a few heuristics, we don't have to get every case
	if rpout.conn is not rpin.conn: return
	if len(rpout.path) <= len(rpin.path)+1: return
	if rpout.path[:len(rpin.path)+1] != rpin.path + '/': return

	relative_rpout_comps = tuple(rpout.path[len(rpin.path)+1:].split('/'))
	relative_rpout = rpin.new_index(relative_rpout_comps)
	if not Globals.select_mirror.Select(relative_rpout): return

	Log(
"""Warning: The destination directory '%s' may be contained in the
source directory '%s'.  This could cause an infinite regress.  You
may need to use the --exclude option.""" % (rpout.path, rpin.path), 2)

def backup_get_mirrortime():
	"""Return time in seconds of previous mirror, or None if cannot"""
	incbase = Globals.rbdir.append_path("current_mirror")
	mirror_rps = restore.get_inclist(incbase)
	assert len(mirror_rps) <= 1, \
		   "Found %s current_mirror rps, expected <=1" % (len(mirror_rps),)
	if mirror_rps: return mirror_rps[0].getinctime()
	else: return None

def backup_final_init(rpout):
	"""Open the backup log and the error log, create increments dir"""
	global prevtime
	if Log.verbosity > 0:
		Log.open_logfile(Globals.rbdir.append("backup.log"))
	checkdest_if_necessary(rpout)
	prevtime = backup_get_mirrortime()
	if prevtime >= Time.curtime: Log.FatalError(
"""Time of Last backup is not in the past.  This is probably caused
by running two backups in less than a second.  Wait a second a try again.""")
	ErrorLog.open(Time.curtimestr, compress = Globals.compression)
	inc_base = Globals.rbdir.append_path("increments")
	if not inc_base.lstat(): inc_base.mkdir()

def backup_touch_curmirror_local(rpin, rpout):
	"""Make a file like current_mirror.time.data to record time

	When doing an incremental backup, this should happen before any
	other writes, and the file should be removed after all writes.
	That way we can tell whether the previous session aborted if there
	are two current_mirror files.

	When doing the initial full backup, the file can be created after
	everything else is in place.

	"""
	mirrorrp = Globals.rbdir.append("current_mirror.%s.%s" % (Time.curtimestr,
															  "data"))
	Log("Writing mirror marker %s" % mirrorrp.path, 6)
	try: pid = os.getpid()
	except: pid = "NA"
	mirrorrp.write_string("PID %s\n" % (pid,))
	mirrorrp.fsync_with_dir()

def backup_remove_curmirror_local():
	"""Remove the older of the current_mirror files.  Use at end of session"""
	assert Globals.rbdir.conn is Globals.local_connection
	curmir_incs = restore.get_inclist(Globals.rbdir.append("current_mirror"))
	assert len(curmir_incs) == 2
	if curmir_incs[0].getinctime() < curmir_incs[1].getinctime():
		older_inc = curmir_incs[0]
	else: older_inc = curmir_incs[1]

	C.sync() # Make sure everything is written before curmirror is removed
	older_inc.delete()


def Restore(src_rp, dest_rp, restore_as_of = None):
	"""Main restoring function

	Here src_rp should be the source file (either an increment or
	mirror file), dest_rp should be the target rp to be written.

	"""
	if not restore_root_set and not restore_set_root(src_rp):
		Log.FatalError("Could not find rdiff-backup repository at "
					   + src_rp.path)
	restore_check_paths(src_rp, dest_rp, restore_as_of)
	dest_rp.conn.fs_abilities.restore_set_globals(dest_rp)
	init_user_group_mapping(dest_rp.conn)
	src_rp = restore_init_quoting(src_rp)
	restore_check_backup_dir(restore_root, src_rp, restore_as_of)
	inc_rpath = Globals.rbdir.append_path('increments', restore_index)
	if restore_as_of:
		try: time = Time.genstrtotime(restore_timestr, rp = inc_rpath)
		except Time.TimeException, exc: Log.FatalError(str(exc))
	else: time = src_rp.getinctime()
	restore_set_select(restore_root, dest_rp)
	restore_start_log(src_rp, dest_rp, time)
	restore.Restore(restore_root.new_index(restore_index),
					inc_rpath, dest_rp, time)
	Log("Restore finished", 4)

def restore_init_quoting(src_rp):
	"""Change rpaths into quoted versions of themselves if necessary"""
	global restore_root
	if not Globals.chars_to_quote: return src_rp
	for conn in Globals.connections: conn.FilenameMapping.set_init_quote_vals()
	restore_root = FilenameMapping.get_quotedrpath(restore_root)
	SetConnections.UpdateGlobal(
		'rbdir', FilenameMapping.get_quotedrpath(Globals.rbdir))
	return FilenameMapping.get_quotedrpath(src_rp)

def restore_set_select(mirror_rp, target):
	"""Set the selection iterator on both side from command line args

	We must set both sides because restore filtering is different from
	select filtering.  For instance, if a file is excluded it should
	not be deleted from the target directory.

	The StringIO stuff is because filelists need to be read and then
	duplicated, because we need two copies of them now.

	"""
	def fp2string(fp):
		buf = fp.read()
		assert not fp.close()
		return buf
	select_data = map(fp2string, select_files)
	if select_opts: 
		mirror_rp.conn.restore.MirrorStruct.set_mirror_select(
			target, select_opts, *map(cStringIO.StringIO, select_data))
		target.conn.restore.TargetStruct.set_target_select(
			target, select_opts, *map(cStringIO.StringIO, select_data))

def restore_start_log(rpin, target, time):
	"""Open restore log file, log initial message"""
	try: Log.open_logfile(Globals.rbdir.append("restore.log"))
	except (LoggerError, Security.Violation), e:
		Log("Warning - Unable to open logfile: " + str(e), 2)

	# Log following message at file verbosity 3, but term verbosity 4
	log_message = ("Starting restore of %s to %s as it was as of %s." %
				   (rpin.path, target.path, Time.timetopretty(time)))
	if Log.term_verbosity >= 4: Log.log_to_term(log_message, 4)
	if Log.verbosity >= 3: Log.log_to_file(log_message)

def restore_check_paths(rpin, rpout, restoreasof = None):
	"""Make sure source and destination exist, and have appropriate type"""
	if not restoreasof:
		if not rpin.lstat():
			Log.FatalError("Source file %s does not exist" % rpin.path)
	if not force and rpout.lstat() and (not rpout.isdir() or rpout.listdir()):
		Log.FatalError("Restore target %s already exists, "
					   "specify --force to overwrite." % rpout.path)
	if force and rpout.lstat() and not rpout.isdir(): rpout.delete()

def restore_check_backup_dir(mirror_root, src_rp = None, restore_as_of = 1):
	"""Make sure backup dir root rpin is in consistent state"""
	if not restore_as_of and not src_rp.isincfile():
		Log.FatalError("""File %s does not look like an increment file.

Try restoring from an increment file (the filenames look like
"foobar.2001-09-01T04:49:04-07:00.diff").""" % src_rp.path)

	result = checkdest_need_check(mirror_root)
	if result is None:
		Log.FatalError("%s does not appear to be an rdiff-backup directory."
					   % (Globals.rbdir.path,))
	elif result == 1: Log.FatalError(
		"Previous backup to %s seems to have failed.\nRerun rdiff-backup "
		"with --check-destination-dir option to revert directory "
		"to state before unsuccessful session." % (mirror_root.path,))

def restore_set_root(rpin):
	"""Set data dir, restore_root and index, or return None if fail

	The idea here is to keep backing up on the path until we find
	a directory that contains "rdiff-backup-data".  That is the
	mirror root.  If the path from there starts
	"rdiff-backup-data/increments*", then the index is the
	remainder minus that.  Otherwise the index is just the path
	minus the root.

	All this could fail if the increment file is pointed to in a
	funny way, using symlinks or somesuch.

	"""
	global restore_root, restore_index, restore_root_set
	if rpin.isincfile(): relpath = rpin.getincbase().path
	else: relpath = rpin.path
	if rpin.conn is not Globals.local_connection:
		# For security checking consistency, don't get absolute path
		pathcomps = relpath.split('/')
	else: pathcomps = os.path.join(os.getcwd(), relpath).split("/")
	if not pathcomps[0]: min_len_pathcomps = 2 # treat abs paths differently
	else: min_len_pathcomps = 1

	i = len(pathcomps)
	while i >= min_len_pathcomps:
		parent_dir = rpath.RPath(rpin.conn, "/".join(pathcomps[:i]))
		if (parent_dir.isdir() and
			"rdiff-backup-data" in parent_dir.listdir()): break
		if parent_dir.path == rpin.conn.Globals.get('restrict_path'):
			return None
		i = i-1
	else: return None

	restore_root = parent_dir
	Log("Using mirror root directory %s" % restore_root.path, 6)
	if restore_root.conn is Globals.local_connection:
		Security.reset_restrict_path(restore_root)
	SetConnections.UpdateGlobal('rbdir',
								restore_root.append_path("rdiff-backup-data"))
	if not Globals.rbdir.isdir():
		Log.FatalError("Unable to read rdiff-backup-data directory %s" %
					   Globals.rbdir.path)

	from_datadir = tuple(pathcomps[i:])
	if not from_datadir or from_datadir[0] != "rdiff-backup-data":
		restore_index = from_datadir # in mirror, not increments
	else:
		assert (from_datadir[1] == "increments" or
				(len(from_datadir) == 2 and
				 from_datadir[1].startswith('increments'))), from_datadir
		restore_index = from_datadir[2:]
	restore_root_set = 1
	return 1


def ListIncrements(rp):
	"""Print out a summary of the increments and their times"""
	rp = require_root_set(rp, 1)
	restore_check_backup_dir(restore_root)
	mirror_rp = restore_root.new_index(restore_index)
	inc_rpath = Globals.rbdir.append_path('increments', restore_index)
	incs = restore.get_inclist(inc_rpath)
	mirror_time = restore.MirrorStruct.get_mirror_time()
	if Globals.parsable_output:
		print manage.describe_incs_parsable(incs, mirror_time, mirror_rp)
	else: print manage.describe_incs_human(incs, mirror_time, mirror_rp)

def require_root_set(rp, read_only):
	"""Make sure rp is or is in a valid rdiff-backup dest directory.

	Also initializes fs_abilities (read or read/write) and quoting and
	return quoted rp if necessary.

	"""
	if not restore_set_root(rp):
		Log.FatalError(("Bad directory %s.\n" % (rp.path,)) +
		  "It doesn't appear to be an rdiff-backup destination dir")
	Globals.rbdir.conn.fs_abilities.single_set_globals(Globals.rbdir,
													   read_only)
	if Globals.chars_to_quote: return restore_init_quoting(rp)
	else: return rp
	

def ListIncrementSizes(rp):
	"""Print out a summary of the increments """
	rp = require_root_set(rp, 1)
	print manage.ListIncrementSizes(restore_root, restore_index)


def CalculateAverage(rps):
	"""Print out the average of the given statistics files"""
	statobjs = map(lambda rp: statistics.StatsObj().read_stats_from_rp(rp),
				   rps)
	average_stats = statistics.StatsObj().set_to_average(statobjs)
	print average_stats.get_stats_logstring(
		"Average of %d stat files" % len(rps))


def RemoveOlderThan(rootrp):
	"""Remove all increment files older than a certain time"""
	rootrp = require_root_set(rootrp, 0)
	rot_require_rbdir_base(rootrp)

	time = rot_check_time(remove_older_than_string)
	if time is None: return
	Log("Actual remove older than time: %s" % (time,), 6)
	manage.delete_earlier_than(Globals.rbdir, time)

def rot_check_time(time_string):
	"""Check remove older than time_string, return time in seconds"""
	try: time = Time.genstrtotime(time_string)
	except Time.TimeException, exc: Log.FatalError(str(exc))

	times_in_secs = [inc.getinctime() for inc in 
		  restore.get_inclist(Globals.rbdir.append_path("increments"))]
	times_in_secs = filter(lambda t: t < time, times_in_secs)
	if not times_in_secs:
		Log("No increments older than %s found, exiting." %
			(Time.timetopretty(time),), 3)
		return None

	times_in_secs.sort()
	inc_pretty_time = "\n".join(map(Time.timetopretty, times_in_secs))
	if len(times_in_secs) > 1 and not force:
		Log.FatalError("Found %d relevant increments, dated:\n%s"
			"\nIf you want to delete multiple increments in this way, "
			"use the --force." % (len(times_in_secs), inc_pretty_time))
	if len(times_in_secs) == 1:
		Log("Deleting increment at time:\n" + inc_pretty_time, 3)
	else: Log("Deleting increments at times:\n" + inc_pretty_time, 3)
	return times_in_secs[-1]+1 # make sure we don't delete current increment

def rot_require_rbdir_base(rootrp):
	"""Make sure pointing to base of rdiff-backup dir"""
	if restore_index != ():
		Log.FatalError("Increments for directory %s cannot be removed "
					   "separately.\nInstead run on entire directory %s." %
					   (rootrp.path, restore_root.path))


def ListChangedSince(rp):
	"""List all the files under rp that have changed since restoretime"""
	rp = require_root_set(rp, 1)
	try: rest_time = Time.genstrtotime(restore_timestr)
	except Time.TimeException, exc: Log.FatalError(str(exc))
	mirror_rp = restore_root.new_index(restore_index)
	inc_rp = mirror_rp.append_path("increments", restore_index)
	for rorp in rp.conn.restore.ListChangedSince(mirror_rp, inc_rp, rest_time):
		# This is a hack, see restore.ListChangedSince for rationale
		print rorp.index[0]


def ListAtTime(rp):
	"""List files in archive under rp that are present at restoretime"""
	rp = require_root_set(rp, 1)
	try: rest_time = Time.genstrtotime(restore_timestr)
	except Time.TimeException, exc: Log.FatalError(str(exc))
	mirror_rp = restore_root.new_index(restore_index)
	inc_rp = mirror_rp.append_path("increments", restore_index)
	for rorp in rp.conn.restore.ListAtTime(mirror_rp, inc_rp, rest_time):
		print rorp.get_indexpath()
	

def Compare(compare_type, src_rp, dest_rp, compare_time = None):
	"""Compare metadata in src_rp with metadata of backup session

	Prints to stdout whenever a file in the src_rp directory has
	different metadata than what is recorded in the metadata for the
	appropriate session.

	Session time is read from restore_timestr if compare_time is None.

	"""
	global return_val
	dest_rp = require_root_set(dest_rp, 1)
	if not compare_time:
		try: compare_time = Time.genstrtotime(restore_timestr)
		except Time.TimeException, exc: Log.FatalError(str(exc))

	mirror_rp = restore_root.new_index(restore_index)
	inc_rp = Globals.rbdir.append_path("increments", restore_index)
	backup_set_select(src_rp) # Sets source rorp iterator
	if compare_type == "compare": compare_func = compare.Compare
	elif compare_type == "compare-hash": compare_func = compare.Compare_hash
	else:
		assert compare_type == "compare-full", compare_type
		compare_func = compare.Compare_full
	return_val = compare_func(src_rp, mirror_rp, inc_rp, compare_time)

def Verify(dest_rp, verify_time = None):
	"""Check the hashes of the regular files against mirror_metadata"""
	global return_val
	dest_rp = require_root_set(dest_rp, 1)
	if not verify_time:
		try: verify_time = Time.genstrtotime(restore_timestr)
		except Time.TimeException, exc: Log.FatalError(str(exc))

	mirror_rp = restore_root.new_index(restore_index)
	inc_rp = Globals.rbdir.append_path("increments", restore_index)
	return_val = dest_rp.conn.compare.Verify(mirror_rp, inc_rp, verify_time)


def CheckDest(dest_rp):
	"""Check the destination directory, """
	if Globals.chars_to_quote:
		dest_rp = FilenameMapping.get_quotedrpath(dest_rp)
	if Globals.rbdir is None:
		SetConnections.UpdateGlobal('rbdir',
									dest_rp.append_path("rdiff-backup-data"))
	need_check = checkdest_need_check(dest_rp)
	if need_check is None:
		Log.FatalError("No destination dir found at %s" % (dest_rp.path,))
	elif need_check == 0:
		Log.FatalError("Destination dir %s does not need checking" %
					   (dest_rp.path,), errlevel = 0)
	init_user_group_mapping(dest_rp.conn)
	dest_rp.conn.regress.Regress(dest_rp)

def checkdest_need_check(dest_rp):
	"""Return None if no dest dir found, 1 if dest dir needs check, 0 o/w"""
	if not dest_rp.isdir() or not Globals.rbdir.isdir(): return None
	for filename in Globals.rbdir.listdir():
		if filename not in ['chars_to_quote', 'backup.log']: break
	else: # This may happen the first backup just after we test for quoting
		return None
	curmirroot = Globals.rbdir.append("current_mirror")
	curmir_incs = restore.get_inclist(curmirroot)
	if not curmir_incs:
		Log.FatalError(
"""Bad rdiff-backup-data dir on destination side

The rdiff-backup data directory
%s
exists, but we cannot find a valid current_mirror marker.  You can
avoid this message by removing the rdiff-backup-data directory;
however any data in it will be lost.

Probably this error was caused because the first rdiff-backup session
into a new directory failed.  If this is the case it is safe to delete
the rdiff-backup-data directory because there is no important
information in it.

""" % (Globals.rbdir.path,))
	elif len(curmir_incs) == 1: return 0
	else:
		if not force: curmir_incs[0].conn.regress.check_pids(curmir_incs)
		assert len(curmir_incs) == 2, "Found too many current_mirror incs!"
		return 1

def checkdest_if_necessary(dest_rp):
	"""Check the destination dir if necessary.

	This can/should be run before an incremental backup.

	"""
	need_check = checkdest_need_check(dest_rp)
	if need_check == 1:
		Log("Previous backup seems to have failed, regressing "
			"destination now.", 2)
		dest_rp.conn.regress.Regress(dest_rp)