#!/usr/bin/python
#
# Copyright 2005 Dean Gaudet, 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


import os, sys, re
import rdiff_backup.connection, rdiff_backup.regress
import rdiff_backup.rpath as rpath
import rdiff_backup.Globals as Globals
import rdiff_backup.restore as restore


tag = None # Set to an rdiff-backup session time

def check_args():
	global tag
	def error(msg):
		sys.stderr.write("Command line error: %s\n" % (msg,))
		sys.exit(2)
	if not (2 <= len(sys.argv) <= 3):
		error("usage: %s mirror-directory [date_tag]" % (sys.argv[0],))
	Globals.rbdir = rpath.RPath(Globals.local_connection,
								os.path.join(sys.argv[1], 'rdiff-backup-data'))
	if not Globals.rbdir.isdir():
		error("Directory %s not found" % (Globals.rbdir.path,))
	if len(sys.argv) == 3: tag = sys.argv[2]

def system(cmd):
	if os.system(cmd): sys.exit("Error running command '%s'\n" % (cmd,))

def get_rbdir_inc_rpath(prefix):
	"""Get rp in rdiff-backup-data given prefix (either newest or with tag)"""
	if tag:
		rp1 = Globals.rbdir.append('%s.%s.data' % (prefix, tag)) 
		if rp1.isreg(): return rp1
		rp2 = Globals.rbdir.append('%s.%s.data.gz' % (prefix, tag))
		if rp2.isreg(): return rp2
		sys.exit(rp.path + " is not a regular file.  Bad tag specified?")
	else:
		rp_base = Globals.rbdir.append(prefix)
		inclist = restore.get_inclist(rp_base)
		if not inclist: sys.exit("No data files in rdiff-backup-data dir "
								 "starting with %s were found!" % (prefix,))
		inclist.sort(key = lambda i: i.getinctime())
		return inclist[-1]

def print_statistics():
	print "\nSession statistics:"
	print get_rbdir_inc_rpath('session_statistics').get_data()
	print "\nAverage statistics:"
	system("rdiff-backup --calculate-average %s/session_statistics.*" %
		   (Globals.rbdir.path,))

def get_open_filestats():
	"""Return open file object based on file_statistics"""
	file_stats_rp = get_rbdir_inc_rpath('file_statistics')
	assert file_stats_rp.isincfile()
	fileobj = file_stats_rp.open('r', file_stats_rp.isinccompressed())
	fileobj.readline()
	if fileobj.readline() != ("# Filename Changed SourceSize "
							  "MirrorSize IncrementSize\n"):
		sys.stderr.write("Format of %s may be unfamiliar\n"
						 % (file_stats_rp.path))
	return fileobj

class FileStat:
	"""Hold the information in one line of file_statistics

	However, unlike file_statistics, a File can have subdirectories
	under it.  In that case, the information should be cumulative.

	"""
	def __init__(self, nametuple, changed, sourcesize, incsize):
		self.nametuple = nametuple
		self.changed = changed
		self.sourcesize, self.incsize = sourcesize, incsize
		self.children = []

	def add_child(self, child):
		self.children.append(child)
		self.changed += child.changed
		self.sourcesize += child.sourcesize
		self.incsize += child.incsize

	def __str__(self):
		return "%s %s %s %s" % (self.nametuple, self.changed,
								self.sourcesize, self.incsize)

def yield_fs_objs(filestatsobj):
	"""Iterate FileStats from open file_statistics fileobj"""
	r = re.compile("^(.*) ([0-9]+) ([0-9]+|NA) ([0-9]+|NA) ([0-9]+|NA)\n?$")
	while 1:
		line = filestatsobj.readline()
		if not line: break
		if line.startswith('#'): continue

		match = r.match(line)
		if not match:
			print "Error parsing line: ", line
			continue

		filename = match.group(1)
		if filename == '.': nametuple = ()
		else: nametuple = tuple(filename.split('/'))
		if match.group(3) == 'NA': sourcesize = 0
		else: sourcesize = int(match.group(3))
		if match.group(5) == 'NA': incsize = 0
		else: incsize = int(match.group(5))

		yield FileStat(nametuple, int(match.group(2)), sourcesize, incsize)

def make_tree(fs_iter, root_fs):
	"""Populate a tree of FileStat objects from fs_iter

	We require that the nametuple of every FileStat put into the tree
	starts with the same nametuple as root_fs.  Return value will be a
	tuple (root fs object, overflow), where overflow is the next
	FileStat object in the iterator, or None.

	"""
	try: fs = fs_iter.next()
	except StopIteration: return (root_fs, None)

	while 1:
		if fs.nametuple[:len(root_fs.nametuple)] != root_fs.nametuple:
			return (root_fs, fs)
		subtree, fs = make_tree(fs_iter, fs)
		root_fs.add_child(subtree)
		if not fs: return (root_fs, None)

def make_root_tree(fs_iter):
	"""Like make_tree, but assume fs_iter starts at the root"""
	try: root_fs = fs_iter.next()
	except StopIteration: sys.exit("No files in iterator")
	assert root_fs.nametuple == (), root_fs
	tree, overflow = make_tree(fs_iter, root_fs)
	assert overflow is None, overflow
	return tree

def get_top_fs(fs_tree, cutoff = .05, fs_func = lambda fs: fs.incsize):
	"""Process the FileStat tree and find everything above the cutoff

	cutoff is a fraction of the root.  Of course the root will be
	above the cutoff, but we try to find the most specific directories
	still above the cutoff.  The value of any directories that make
	the cutoff will be excluded from the value of parent directories.

	"""
	abs_cutoff = cutoff*fs_func(fs_tree)
	def helper(subtree):
		"""Returns ([list of (top fs, value)], total excluded amount)"""
		subtree_val = fs_func(subtree)
		if subtree_val <= abs_cutoff: return ([], 0)

		top_children, total_excluded = [], 0
		for child in subtree.children:
			top_sublist, excluded = helper(child)
			top_children.extend(top_sublist)
			total_excluded += excluded

		current_value = subtree_val - total_excluded
		if current_value >= abs_cutoff:
			return ([(subtree, current_value)] + top_children, subtree_val)
		else: return (top_children, total_excluded)
	return helper(fs_tree)[0]

def print_top_dirs(fs_tree, label, fs_func):
	"""Print the top directories in sorted order"""
	def print_line(fs, val):
		percentage = float(val)/fs_func(fs_tree) * 100
		path = fs.nametuple and '/'.join(fs.nametuple) or '.'
		print '%s (%02.1f%%)' % (path, percentage)

	s = "Top directories by %s (percent of total)" % (label,)
	print s + '\n' + ('-'*len(s))
	top_fs_pair_list = get_top_fs(fs_tree, .05, fs_func)
	top_fs_pair_list.sort(key = lambda pair: pair[1], reverse = 1)
	for fs, val in top_fs_pair_list: print_line(fs, val)
	
def Main():
	check_args()
	print_statistics()
	fs_tree = make_root_tree(yield_fs_objs(get_open_filestats()))
	print_top_dirs(fs_tree, "source size", lambda fs: fs.sourcesize)
	print
	print_top_dirs(fs_tree, "increment size", lambda fs: fs.incsize)
	print
	print_top_dirs(fs_tree, "number of files changed",
				   lambda fs: fs.changed)

if __name__ == '__main__': Main()