# win32text.py - LF <-> CRLF translation utilities for Windows users

#

# This software may be used and distributed according to the terms

# of the GNU General Public License, incorporated herein by reference.

#

# To perform automatic newline conversion, use:

#

# [extensions]

# hgext.win32text =

# [encode]

# ** = cleverencode:

# [decode]

# ** = cleverdecode:

#

# If not doing conversion, to make sure you do not commit CRLF by accident:

#

# [hooks]

# pretxncommit.crlf = python:hgext.win32text.forbidcrlf

#

# To do the same check on a server to prevent CRLF from being pushed or pulled:

#

# [hooks]

# pretxnchangegroup.crlf = python:hgext.win32text.forbidcrlf

from mercurial.i18n import gettext as _

from mercurial.node import bin, short

import re

# regexp for single LF without CR preceding.

re_single_lf = re.compile('(^|[^\r])\n', re.MULTILINE)

def dumbdecode(s, cmd, ui=None, repo=None, filename=None, **kwargs):

    # warn if already has CRLF in repository.

    # it might cause unexpected eol conversion.

    # see issue 302:

    #   http://www.selenic.com/mercurial/bts/issue302

    if '\r\n' in s and ui and filename and repo:

        ui.warn(_('WARNING: %s already has CRLF line endings\n'

                  'and does not need EOL conversion by the win32text plugin.\n'

                  'Before your next commit, please reconsider your '

                  'encode/decode settings in \nMercurial.ini or %s.\n') %

                (filename, repo.join('hgrc')))

    # replace single LF to CRLF

    return re_single_lf.sub('\\1\r\n', s)

def dumbencode(s, cmd):

    return s.replace('\r\n', '\n')

def clevertest(s, cmd):

    if '\0' in s: return False

    return True

def cleverdecode(s, cmd, **kwargs):

    if clevertest(s, cmd):

        return dumbdecode(s, cmd, **kwargs)

    return s

def cleverencode(s, cmd):

    if clevertest(s, cmd):

        return dumbencode(s, cmd)

    return s

_filters = {

    'dumbdecode:': dumbdecode,

    'dumbencode:': dumbencode,

    'cleverdecode:': cleverdecode,

    'cleverencode:': cleverencode,

    }

def forbidcrlf(ui, repo, hooktype, node, **kwargs):

    halt = False

    for rev in xrange(repo.changelog.rev(bin(node)), repo.changelog.count()):

        c = repo.changectx(rev)

        for f in c.files():

            if f not in c:

                continue

            data = c[f].data()

            if '\0' not in data and '\r\n' in data:

                if not halt:

                    ui.warn(_('Attempt to commit or push text file(s) '

                              'using CRLF line endings\n'))

                ui.warn(_('in %s: %s\n') % (short(c.node()), f))

                halt = True

    if halt and hooktype == 'pretxnchangegroup':

        ui.warn(_('\nTo prevent this mistake in your local repository,\n'

                  'add to Mercurial.ini or .hg/hgrc:\n'

                  '\n'

                  '[hooks]\n'

                  'pretxncommit.crlf = python:hgext.win32text.forbidcrlf\n'

                  '\n'

                  'and also consider adding:\n'

                  '\n'

                  '[extensions]\n'

                  'hgext.win32text =\n'

                  '[encode]\n'

                  '** = cleverencode:\n'

                  '[decode]\n'

                  '** = cleverdecode:\n'))

    return halt

def reposetup(ui, repo):

    if not repo.local():

        return

    for name, fn in _filters.iteritems():

        repo.adddatafilter(name, fn)