# win32text.py - LF <-> CRLF/CR translation utilities for Windows/Mac 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:

# # or ** = macencode:

# [decode]

# ** = cleverdecode:

# # or ** = macdecode:

#

# If not doing conversion, to make sure you do not commit CRLF/CR by

# accident:

#

# [hooks]

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

# # or pretxncommit.cr = python:hgext.win32text.forbidcr

#

# To do the same check on a server to prevent CRLF/CR from being

# pushed or pulled:

#

# [hooks]

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

# # or pretxnchangegroup.cr = python:hgext.win32text.forbidcr

from mercurial.i18n import _

from mercurial.node import short

from mercurial import util

import re

# regexp for single LF without CR preceding.

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

newlinestr = {'\r\n': 'CRLF', '\r': 'CR'}

filterstr = {'\r\n': 'clever', '\r': 'mac'}

def checknewline(s, newline, ui=None, repo=None, filename=None):

    # warn if already has 'newline' in repository.

    # it might cause unexpected eol conversion.

    # see issue 302:

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

    if newline in s and ui and filename and repo:

        ui.warn(_('WARNING: %s already has %s 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, newlinestr[newline], repo.join('hgrc')))

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

    checknewline(s, '\r\n', **kwargs)

    # 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 macdumbdecode(s, cmd, **kwargs):

    checknewline(s, '\r', **kwargs)

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

def macdumbencode(s, cmd):

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

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

    if not util.binary(s):

        return dumbdecode(s, cmd, **kwargs)

    return s

def cleverencode(s, cmd):

    if not util.binary(s):

        return dumbencode(s, cmd)

    return s

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

    if not util.binary(s):

        return macdumbdecode(s, cmd, **kwargs)

    return s

def macencode(s, cmd):

    if not util.binary(s):

        return macdumbencode(s, cmd)

    return s

_filters = {

    'dumbdecode:': dumbdecode,

    'dumbencode:': dumbencode,

    'cleverdecode:': cleverdecode,

    'cleverencode:': cleverencode,

    'macdumbdecode:': macdumbdecode,

    'macdumbencode:': macdumbencode,

    'macdecode:': macdecode,

    'macencode:': macencode,

    }

def forbidnewline(ui, repo, hooktype, node, newline, **kwargs):

    halt = False

    seen = set()

    # we try to walk changesets in reverse order from newest to

    # oldest, so that if we see a file multiple times, we take the

    # newest version as canonical. this prevents us from blocking a

    # changegroup that contains an unacceptable commit followed later

    # by a commit that fixes the problem.

    tip = repo['tip']

    for rev in xrange(len(repo)-1, repo[node].rev()-1, -1):

        c = repo[rev]

        for f in c.files():

            if f in seen or f not in tip or f not in c:

                continue

            seen.add(f)

            data = c[f].data()

            if not util.binary(data) and newline in data:

                if not halt:

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

                              'using %s line endings\n') %

                              newlinestr[newline])

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

                halt = True

    if halt and hooktype == 'pretxnchangegroup':

        crlf = newlinestr[newline].lower()

        filter = filterstr[newline]

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

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

                  '\n'

                  '[hooks]\n'

                  'pretxncommit.%s = python:hgext.win32text.forbid%s\n'

                  '\n'

                  'and also consider adding:\n'

                  '\n'

                  '[extensions]\n'

                  'hgext.win32text =\n'

                  '[encode]\n'

                  '** = %sencode:\n'

                  '[decode]\n'

                  '** = %sdecode:\n') % (crlf, crlf, filter, filter))

    return halt

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

    return forbidnewline(ui, repo, hooktype, node, '\r\n', **kwargs)

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

    return forbidnewline(ui, repo, hooktype, node, '\r', **kwargs)

def reposetup(ui, repo):

    if not repo.local():

        return

    for name, fn in _filters.iteritems():

        repo.adddatafilter(name, fn)