#!/usr/bin/python -tt

# Mostly-done port of Subversion's commit-mailer.pl to Python.
# Copyright (c) 2010, John Morrissey <jwm@horde.net>
#
# 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.
#
# This program 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 this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.

# I wanted to play a bit with pysvn, so I ported most of the easy parts of
# Subversion's commit-mailer.pl. There are still some things it doesn't do,
# such as property differences; all of these missing features should be
# covered by FIXMEs.
#
# Dunno how useful this is itself, but someone might stumble on it as a
# useful example of code that uses pysvn.

SENDMAIL = '/usr/sbin/sendmail'

# Whether to show the entire contents of deleted files in diff output.
# Set this to False if you want to save space in commit messages by
# not showing diffs for deleted files.
SHOW_DELETED_FILE_DIFFS = True

from email.Message import Message
from getopt import gnu_getopt, GetoptError
import os.path
from popen2 import Popen3
import re
import sre_constants
from subprocess import call
import sys
import tempfile
import time
from time import localtime, strftime
from urlparse import urlparse, urlunparse

import pysvn

PROGNAME = os.path.basename(sys.argv[0])

def usage():
	print \
"""%s [-f|--from fromaddr] [-h|--hostname mail_hostname]
      [-n|--diff-lines num] [-l|--log file] [-m|--match regex]
      [-r|--reply-to addr] [-s|--subject-prefix string]
      repo_path revnum mail_dest""" % PROGNAME

try:
	options = gnu_getopt(sys.argv[1:], 'f:h:n:l:m:r:s:', [
		'from=', 'hostname=', 'diff-lines=', 'log=', 'match=',
		'reply-to=', 'subject-prefix=',
	])
except GetoptError, e:
	print os.path.basename(sys.argv[0]) + ': ' + str(e)
	usage()
	sys.exit(1)

FROM = None
FROM_HOSTNAME = None
LOG = None
MATCH = None
DIFF_LINES = None
REPLY_TO = None
SUBJ_PREFIX = None

for option in options[0]:
	if option[0] == '-f' or option[0] == '--from':
		if FROM_HOSTNAME:
			print >>sys.stderr, \
				"%s: %s can't be used with -h/--hostname." % \
				(PROGNAME, option[0])
			usage()
			sys.exit(1)
		FROM = option[1]
	elif option[0] == '-h' or option[0] == '--hostname':
		if FROM:
			print >>sys.stderr, \
				"%s: %s can't be used with -f/--from." % \
				(PROGNAME, option[0])
			usage()
			sys.exit(1)
		FROM_HOSTNAME = option[1]
	elif option[0] == '-n' or option[0] == '--diff-lines':
		DIFF_LINES = int(option[1])
	elif option[0] == '-l' or option[0] == '--log':
		LOG = option[1]
	elif option[0] == '-m' or option[0] == '--match':
		# We match against relative paths, so be nice and remove any
		# leading slashes.
		try:
			MATCH = re.compile(re.sub(r'^/+', '', option[1]))
		except sre_constants.error, e:
			print >>sys.stderr, \
				'%s: %s: invalid regular expression.' % \
				(PROGNAME, option[0])
			usage()
			sys.exit(1)
	elif option[0] == '-r' or option[0] == '--reply-to':
		REPLY_TO = option[1]
	elif option[0] == '-s' or option[0] == '--subject-prefix':
		SUBJ_PREFIX = option[1]
	else:
		print '%s: unknown option: %s.' % (PROGNAME, option[0])
		usage()
		sys.exit(1)

if len(options[1]) != 3:
	print >>sys.stderr, '%s: not enough arguments.' % PROGNAME
	usage()
	sys.exit(1)

REPO_URL, REV, MAIL_DEST = options[1]
REV = int(REV)

parts = urlparse(REPO_URL)
if '@' in parts[1]:
	userpass = parts[1].split('@')[0]
	if ':' not in userpass:
		username = userpass
		password = None
	else:
		username, password = userpass.split(':')

	REPO_URL = urlunparse((parts[0], parts[1].split('@')[1],
		parts[2], parts[3], parts[4], parts[5]))

TEMPDIR = tempfile.mkdtemp(prefix='%s-' % PROGNAME)

SVN = pysvn.Client()
SVN.exception_style = 1
SVN.set_default_username(username)
SVN.set_default_password(password)

try:
	logs = SVN.log(
		url_or_path=REPO_URL,
		peg_revision=pysvn.Revision(pysvn.opt_revision_kind.number, REV),
		revision_start=pysvn.Revision(pysvn.opt_revision_kind.number, REV),
		revision_end=pysvn.Revision(pysvn.opt_revision_kind.number, REV),
		discover_changed_paths=True)
except pysvn.ClientError, e:
	if e.args[0] == 'callback_get_login required':
		print >>sys.stderr, '%s: authentication for user %s failed.' % \
			(PROGNAME, SVN_USER)
		sys.exit(1)

	# e.args[1] could contain multiple errors, but checking the first
	# one seems to be sane for the "no such revision" case.
	message, code = e.args[1][0]
	if code == 160006:
		print >>sys.stderr, '%s: revision %d not found.' % (PROGNAME, REV)
		sys.exit(1)
	else:
		print >>sys.stderr, "%s: couldn't retrieve revision %d: %s" % \
			(PROGNAME, REV, ' '.join(e.args[0]))
		sys.exit(1)

if len(logs) != 1:
	print >>sys.stderr, '%s: request for revision %d returned more than one log entry, exiting.' % \
		(PROGNAME, REV)
	sys.exit(1)

log = logs[0]

all_paths = []
dirs = []
copied = {}
added = []
removed = []
modified = []
unknown = []
for changed in log.changed_paths:
	path = changed.path
	if path[0] == '/':
		path = path[1:]

	rev = REV
	if changed.action in ['D']:
		rev = REV - 1

	# FIXME: SVN_DIRENT_TIME instead of .log() in get_diff()?
	diffs = SVN.list(
		url_or_path='%s/%s' % (REPO_URL, path),
		peg_revision=pysvn.Revision(pysvn.opt_revision_kind.number, rev),
		revision=pysvn.Revision(pysvn.opt_revision_kind.number, rev),
		dirent_fields=pysvn.SVN_DIRENT_KIND)

	if diffs[0][0].kind == pysvn.node_kind.dir:
		path += '/'
		dir = path
	else:
		dir = '/'.join(path.split('/')[:-1]) + '/'
	if dir not in dirs:
		dirs.append(dir)
		all_paths.append(dir)

	if changed.copyfrom_path and path not in copied:
		copyfrom_path = changed.copyfrom_path
		if copyfrom_path[0] == '/':
			copyfrom_path = copyfrom_path[1:]
		copied[path] = {
			'from_path': copyfrom_path,
			'from_rev': changed.copyfrom_revision.number,
		}

	if changed.action == 'A':
		added.append(path)
		all_paths.append(path)
	elif changed.action in ['R', 'D']:
		removed.append(path)
		all_paths.append(path)
		if changed.copyfrom_path:
			added.append(path)
	elif changed.action == 'M':
		modified.append(path)
		all_paths.append(path)
	else:
		unknown.append((changed.action, path))

dirs.sort()
added.sort()
removed.sort()
modified.sort()

# svnlook(1) sorts directories first in its diff output
# (slashes before dashes).
def diffsort(a, b):
	a_list = list(a)
	for i in range(len(a_list)):
		if a_list[i] == '/':
			a_list[i] = '-'
		elif a_list[i] == '-':
			a_list[i] = '/'

	b_list = list(b)
	for i in range(len(b_list)):
		if b_list[i] == '/':
			b_list[i] = '-'
		elif b_list[i] == '-':
			b_list[i] = '/'

	return cmp(a_list, b_list)
all_paths.sort(diffsort)

if MATCH:
	for path in all_paths:
		if MATCH.match(path):
			break
	else:
		sys.exit(0)

msg = Message()
msg['To'] = MAIL_DEST
if FROM:
	msg['From'] = FROM
elif FROM_HOSTNAME:
	msg['From'] = '%s@%s' % (log.author, FROM_HOSTNAME)
else:
	msg['From'] = log.author


common = dirs[0].split('/')
for dir in dirs[1:]:
	cur = dir.split('/')
	for i in range(len(common)):
		if i == len(cur) or common[i] != cur[i]:
			for j in range(i, len(common)):
				del common[i]
			break
common_path = '/'.join(common)

subject_dirs = [common_path]
for dir in dirs:
	if dir == common_path:
		continue

	parts = dir.replace(common_path + '/', '', 1).split('/')[:-1]
	for i in range(len(parts)):
		path = '/'.join(parts[:i + 1])
		if path not in subject_dirs:
			subject_dirs.append(path)
subject_dirs.sort()

def scrub_common_path(path):
	if path == common_path:
		return '.'
	return path.replace(common_path + '/', '', 1)
msg['Subject'] = 'commit: r%d - in %s: %s' % \
	(log.revision.number, common_path,
	 ' '.join(sorted(map(scrub_common_path, subject_dirs))))


if REPLY_TO:
	msg['Reply-To'] = REPLY_TO

# From: Greg Stein <gstein@lyra.org>
# Subject: Re: svn commit: rev 2599 - trunk/tools/cgi
# To: dev@subversion.tigris.org
# Date: Fri, 19 Jul 2002 23:42:32 -0700
# 
# Well... that isn't strictly true. The contents of the files
# might not be UTF-8, so the "diff" portion will be hosed.
# 
# If you want a truly "proper" commit message, then you'd use
# multipart MIME messages, with each file going into its own part,
# and labeled with an appropriate MIME type and charset. Of
# course, we haven't defined a charset property yet, but no biggy.
# 
# Going with multipart will surely throw out the notion of "cut
# out the patch from the email and apply." But then again: the
# commit emailer could see that all portions are in the same
# charset and skip the multipart thang. 
# 
# etc etc
# 
# Basically: adding/tweaking the content-type is nice, but don't
# think that is the proper solution.
msg['Content-Type'] = 'text/plain; charset=UTF-8'
msg['Content-Transfer-Encoding'] = '8bit'

if time.daylight:
	offset = time.altzone
else:
	offset = time.timezone
tz_hhmm = '%.2d%.2d' % (offset / 60 / 60, (offset / 60) % 60)
if offset >= 0:
	tz_hhmm = '+' + tz_hhmm
else:
	tz_hhmm = '-' + tz_hhmm

body = []
body.append("""Author: %s
Date: %s
New Revision: %d

""" % (log.author,
       strftime('%Y-%m-%d %H:%M:%S %%s (%a, %d %b %Y)', localtime(log.date)) % tz_hhmm,
       log.revision.number))

if added:
	body.append('Added:\n   ')
	body.append('\n   '.join(added))
	body.append('\n')
if removed:
	body.append('Removed:\n   ')
	body.append('\n   '.join(removed))
	body.append('\n')
if modified:
	body.append('Modified:\n   ')
	body.append('\n   '.join(modified))
	body.append('\n')
if unknown:
	body.append('Unknown Actions:\n   ')
	body.append('\n   '.join([
		'%s %s' % (action, path)
		for action, path
		 in unknown
	]))
	body.append('\n')

body.append('Log:\n%s\n\n' % log.message)

plus_re = re.compile(r'^\+\+\+ [^\t]+\t\(revision (\d+)\)$', re.MULTILINE)
minus_re = re.compile(r'^--- [^\t]+\t\(revision (\d+)\)$', re.MULTILINE)
index_re = re.compile(r'^Index: .*', re.MULTILINE)
def get_diff(path, rev1, rev2, index_replacement):
	global dirs

	# Don't emit diffs for directories, since pysvn.Client.diff()
	# will emit diffs for files in this directory, despite
	# recurse=False.
	if path in dirs:
		return ''

	try:
		# FIXME: need to manually add '\ No newline at end of file'
		# FIXME: need to generate property diffs, pysvn.Client.diff()
		# doesn't generate them for us.
		# SVN_DIRENT_HAS_PROPS to SVN.list() above?
		# SVN.prop{get,list}()
		diff = SVN.diff(
			tmp_path=os.path.join(TEMPDIR, PROGNAME),
			url_or_path='%s/%s' % (REPO_URL, path),
			recurse=False,
			revision1=pysvn.Revision(pysvn.opt_revision_kind.number, rev1),
			revision2=pysvn.Revision(pysvn.opt_revision_kind.number, rev2))
	except pysvn.ClientError, e:
		message, code = e.args[1][0]
		if code != 160013:
			raise

		global copied, removed

		if path in dirs:
			return ''

		diff = ''

		if path in removed and SHOW_DELETED_FILE_DIFFS:
			if path in copied:
				from_path = copied[path]['from_path']
				from_rev = copied[path]['from_rev']
			else:
				from_path = path
				from_rev = rev1

			diff += 'Deleted: %s\n%s\n' % (path, '=' * 67)

			# FIXME: how to determine a binary file
			if path.endswith('.gif') or path.endswith('.jpg') or path.endswith('.png'):
				diff += '(Binary files differ)\n'
			else:
				f = SVN.cat(url_or_path='%s/%s' % (REPO_URL, from_path),
					peg_revision=pysvn.Revision(pysvn.opt_revision_kind.number, from_rev),
					revision=pysvn.Revision(pysvn.opt_revision_kind.number, from_rev))
				f = f.split('\n')
				if f[-1] == '':
					del f[-1]
				f_diff = '\n'.join(['-%s' % line for line in f])

				logs = SVN.log(
					url_or_path=REPO_URL,
					peg_revision=pysvn.Revision(pysvn.opt_revision_kind.number, rev2),
					revision_start=pysvn.Revision(pysvn.opt_revision_kind.number, rev1),
					revision_end=pysvn.Revision(pysvn.opt_revision_kind.number, rev2))

				diff += '--- %s\t%s (rev %d)\n+++ %s\t%s (rev %d)\n@@ -%d,%d +%d,%d @@\n%s\n' % \
					(from_path, strftime('%Y-%m-%d %H:%M:%S %Z', localtime(logs[0].date)), from_rev,
					 path, strftime('%Y-%m-%d %H:%M:%S %Z', localtime(logs[1].date)),
					 rev2,
					 1, len(f), 0, 0, f_diff)
		if path in copied:
			if path in removed:
				diff += '\n'

			diff += 'Copied: %s (from rev %d, %s)\n%s\n' % \
				(path, copied[path]['from_rev'], copied[path]['from_path'],
				'=' * 67)

			# FIXME: how to determine a binary file
			if path.endswith('.gif') or path.endswith('.jpg') or path.endswith('.png'):
				diff += '(Binary files differ)\n'
			else:
				logs = SVN.log(
					url_or_path=REPO_URL,
					peg_revision=pysvn.Revision(pysvn.opt_revision_kind.number, rev2),
					revision_start=pysvn.Revision(pysvn.opt_revision_kind.number, rev2),
					revision_end=pysvn.Revision(pysvn.opt_revision_kind.number, rev2))

				f2 = SVN.cat(url_or_path='%s/%s' % (REPO_URL, path),
					peg_revision=pysvn.Revision(pysvn.opt_revision_kind.number, rev2),
					revision=pysvn.Revision(pysvn.opt_revision_kind.number, rev2))
				f2 = f2.split('\n')
				if f2[-1] == '':
					del f2[-1]
				f2_diff = '\n'.join(['+%s' % line for line in f2])

				diff += '--- %s\t%s (rev %d)\n+++ %s\t%s (rev %d)\n@@ -%d,%d +%d,%d @@\n%s\n' % \
					(path, ' ' * 23, 0,
					 path, strftime('%Y-%m-%d %H:%M:%S %Z', localtime(logs[0].date)), rev2,
					 0, 0, 1, len(f2), f2_diff)

		return diff

	logs = SVN.log(
		url_or_path=REPO_URL,
		peg_revision=pysvn.Revision(pysvn.opt_revision_kind.number, rev2),
		revision_start=pysvn.Revision(pysvn.opt_revision_kind.number, rev1),
		revision_end=pysvn.Revision(pysvn.opt_revision_kind.number, rev2))
	diff = minus_re.sub(
		r'--- %s\t%s (rev \1)' %
			(path, strftime('%Y-%m-%d %H:%M:%S %Z', localtime(logs[0].date))),
		diff)
	diff = plus_re.sub(
		r'+++ %s\t%s (rev \1)' %
			(path, strftime('%Y-%m-%d %H:%M:%S %Z', localtime(logs[1].date))),
		diff)

	diff = index_re.sub('%s: %s' % (index_replacement, path), diff, 2)
	return diff

diffs = []
for path in all_paths:
	if path in copied:
		diffs.append(get_diff(path, REV - 1, REV, None))
	elif path in removed:
		diffs.append(get_diff(path, REV - 1, REV, 'Removed'))
	elif path in modified:
		diffs.append(get_diff(path, REV - 1, REV, 'Modified'))
	elif path in added:
		diffs.append(get_diff(path, REV - 1, REV, 'Added'))

diffs = '\n'.join([diff for diff in diffs if diff != '']) + '\n\n'
if DIFF_LINES:
	diffs = diffs.split('\n')
	if len(diffs) > DIFF_LINES:
		diffs = diffs[:DIFF_LINES]
		truncated = 'Diffs truncated at %d lines.' % DIFF_LINES
		diffs.append('-' * len(truncated))
		diffs.append(truncated)
		diffs.append('-' * len(truncated))
	diffs = '\n'.join(diffs)
body.append(diffs)

msg.set_payload(''.join(body))

# no e-mail noise while debugging plz
#p = Popen3((SENDMAIL, '-f', '<>', '-ti'), 'w')
#p.tochild.write(str(msg))
#p.tochild.close()
#status = os.WEXITSTATUS(p.wait())
#if status:
#	print >>sys.stderr, \
#		'%s: error during sendmail execution, return code %d.' % \
#		(PROGNAME, status)
#	exit(1)

if LOG:
	try:
		fp = open(LOG, 'a')
		fp.write(str(msg))
		fp.close()
	except Exception, e:
		print >>sys.stderr, "%s: couldn't write message to log file: %s" % \
			(PROGNAME, str(e))

os.rmdir(TEMPDIR)