"""automatically manage newlines in repository files

This extension allows you to manage the type of line endings (CRLF or

LF) that are used in the repository and in the local working

directory. That way you can get CRLF line endings on Windows and LF on

Unix/Mac, thereby letting everybody use their OS native line endings.

The extension reads its configuration from a versioned ``.hgeol``

configuration file found in the root of the working copy. The

``.hgeol`` file use the same syntax as all other Mercurial

configuration files. It uses two sections, ``[patterns]`` and

``[repository]``.

The ``[patterns]`` section specifies how line endings should be

converted between the working copy and the repository. The format is

specified by a file pattern. The first match is used, so put more

specific patterns first. The available line endings are ``LF``,

``CRLF``, and ``BIN``.

Files with the declared format of ``CRLF`` or ``LF`` are always

checked out and stored in the repository in that format and files

declared to be binary (``BIN``) are left unchanged. Additionally,

``native`` is an alias for checking out in the platform's default line

ending: ``LF`` on Unix (including Mac OS X) and ``CRLF`` on

Windows. Note that ``BIN`` (do nothing to line endings) is Mercurial's

default behaviour; it is only needed if you need to override a later,

more general pattern.

The optional ``[repository]`` section specifies the line endings to

use for files stored in the repository. It has a single setting,

``native``, which determines the storage line endings for files

declared as ``native`` in the ``[patterns]`` section. It can be set to

``LF`` or ``CRLF``. The default is ``LF``. For example, this means

that on Windows, files configured as ``native`` (``CRLF`` by default)

will be converted to ``LF`` when stored in the repository. Files

declared as ``LF``, ``CRLF``, or ``BIN`` in the ``[patterns]`` section

are always stored as-is in the repository.

Example versioned ``.hgeol`` file::

  [patterns]

  **.py = native

  **.vcproj = CRLF

  **.txt = native

  Makefile = LF

  **.jpg = BIN

  [repository]

  native = LF

.. note::

   The rules will first apply when files are touched in the working

   copy, e.g. by updating to null and back to tip to touch all files.

The extension uses an optional ``[eol]`` section in your hgrc file

(not the ``.hgeol`` file) for settings that control the overall

behavior. There are two settings:

- ``eol.native`` (default ``os.linesep``) can be set to ``LF`` or

  ``CRLF`` to override the default interpretation of ``native`` for

  checkout. This can be used with :hg:`archive` on Unix, say, to

  generate an archive where files have line endings for Windows.

- ``eol.only-consistent`` (default True) can be set to False to make

  the extension convert files with inconsistent EOLs. Inconsistent

  means that there is both ``CRLF`` and ``LF`` present in the file.

  Such files are normally not touched under the assumption that they

  have mixed EOLs on purpose.

The extension provides ``cleverencode:`` and ``cleverdecode:`` filters

like the deprecated win32text extension does. This means that you can

disable win32text and enable eol and your filters will still work. You

only need to these filters until you have prepared a ``.hgeol`` file.

The ``win32text.forbid*`` hooks provided by the win32text extension

have been unified into a single hook named ``eol.hook``. The hook will

lookup the expected line endings from the ``.hgeol`` file, which means

you must migrate to a ``.hgeol`` file first before using the hook.

See :hg:`help patterns` for more information about the glob patterns

used.

"""

from mercurial.i18n import _

from mercurial import util, config, extensions, match, error

import re, os

# Matches a lone LF, i.e., one that is not part of CRLF.

singlelf = re.compile('(^|[^\r])\n')

# Matches a single EOL which can either be a CRLF where repeated CR

# are removed or a LF. We do not care about old Machintosh files, so a

# stray CR is an error.

eolre = re.compile('\r*\n')

def inconsistenteol(data):

    return '\r\n' in data and singlelf.search(data)

def tolf(s, params, ui, **kwargs):

    """Filter to convert to LF EOLs."""

    if util.binary(s):

        return s

    if ui.configbool('eol', 'only-consistent', True) and inconsistenteol(s):

        return s

    return eolre.sub('\n', s)

def tocrlf(s, params, ui, **kwargs):

    """Filter to convert to CRLF EOLs."""

    if util.binary(s):

        return s

    if ui.configbool('eol', 'only-consistent', True) and inconsistenteol(s):

        return s

    return eolre.sub('\r\n', s)

def isbinary(s, params):

    """Filter to do nothing with the file."""

    return s

filters = {

    'to-lf': tolf,

    'to-crlf': tocrlf,

    'is-binary': isbinary,

    # The following provide backwards compatibility with win32text

    'cleverencode:': tolf,

    'cleverdecode:': tocrlf

}

class eolfile(object):

    def __init__(self, ui, root, data):

        self._decode = {'LF': 'to-lf', 'CRLF': 'to-crlf', 'BIN': 'is-binary'}

        self._encode = {'LF': 'to-lf', 'CRLF': 'to-crlf', 'BIN': 'is-binary'}

        self.cfg = config.config()

        # Our files should not be touched. The pattern must be

        # inserted first override a '** = native' pattern.

        self.cfg.set('patterns', '.hg*', 'BIN')

        # We can then parse the user's patterns.

        self.cfg.parse('.hgeol', data)

        isrepolf = self.cfg.get('repository', 'native') != 'CRLF'

        self._encode['NATIVE'] = isrepolf and 'to-lf' or 'to-crlf'

        iswdlf = ui.config('eol', 'native', os.linesep) in ('LF', '\n')

        self._decode['NATIVE'] = iswdlf and 'to-lf' or 'to-crlf'

        include = []

        exclude = []

        for pattern, style in self.cfg.items('patterns'):

            key = style.upper()

            if key == 'BIN':

                exclude.append(pattern)

            else:

                include.append(pattern)

        # This will match the files for which we need to care

        # about inconsistent newlines.

        self.match = match.match(root, '', [], include, exclude)

    def setfilters(self, ui):

        for pattern, style in self.cfg.items('patterns'):

            key = style.upper()

            try:

                ui.setconfig('decode', pattern, self._decode[key])

                ui.setconfig('encode', pattern, self._encode[key])

            except KeyError:

                ui.warn(_("ignoring unknown EOL style '%s' from %s\n")

                        % (style, self.cfg.source('patterns', pattern)))

def parseeol(ui, repo, nodes):

    try:

        for node in nodes:

            try:

                if node is None:

                    # Cannot use workingctx.data() since it would load

                    # and cache the filters before we configure them.

                    data = repo.wfile('.hgeol').read()

                else:

                    data = repo[node]['.hgeol'].data()

                return eolfile(ui, repo.root, data)

            except (IOError, LookupError):

                pass

    except error.ParseError, inst:

        ui.warn(_("warning: ignoring .hgeol file due to parse error "

                  "at %s: %s\n") % (inst.args[1], inst.args[0]))

    return None

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

    """verify that files have expected EOLs"""

    files = set()

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

        files.update(repo[rev].files())

    tip = repo['tip']

def preupdate(ui, repo, hooktype, parent1, parent2):

    #print "preupdate for %s: %s -> %s" % (repo.root, parent1, parent2)

    repo.loadeol([parent1])

    return False

def uisetup(ui):

    ui.setconfig('hooks', 'preupdate.eol', preupdate)

def extsetup(ui):

    try:

        extensions.find('win32text')

        raise util.Abort(_("the eol extension is incompatible with the "

                           "win32text extension"))

    except KeyError:

        pass

def reposetup(ui, repo):

    uisetup(repo.ui)

    #print "reposetup for", repo.root

    if not repo.local():

        return

    for name, fn in filters.iteritems():

        repo.adddatafilter(name, fn)

    ui.setconfig('patch', 'eol', 'auto')

    class eolrepo(repo.__class__):

        def loadeol(self, nodes):

            eol = parseeol(self.ui, self, nodes)

            if eol is None:

                return None

            eol.setfilters(self.ui)

            return eol.match

        def _hgcleardirstate(self):

            self._eolfile = self.loadeol([None, 'tip'])

            if not self._eolfile:

                self._eolfile = util.never

                return

            try:

                cachemtime = os.path.getmtime(self.join("eol.cache"))

            except OSError:

                cachemtime = 0

            try:

                eolmtime = os.path.getmtime(self.wjoin(".hgeol"))

            except OSError:

                eolmtime = 0

            if eolmtime > cachemtime:

                ui.debug("eol: detected change in .hgeol\n")

                wlock = None

                try:

                    wlock = self.wlock()

                    for f in self.dirstate:

                        if self.dirstate[f] == 'n':

                            # all normal files need to be looked at

                            # again since the new .hgeol file might no

                            # longer match a file it matched before

                            self.dirstate.normallookup(f)

                    # Touch the cache to update mtime.

                    self.opener("eol.cache", "w").close()

                    wlock.release()

                except error.LockUnavailable:

                    # If we cannot lock the repository and clear the

                    # dirstate, then a commit might not see all files

                    # as modified. But if we cannot lock the

                    # repository, then we can also not make a commit,

                    # so ignore the error.

                    pass

        def commitctx(self, ctx, error=False):

            for f in sorted(ctx.added() + ctx.modified()):

                if not self._eolfile(f):

                    continue

                data = ctx[f].data()

                if util.binary(data):

                    # We should not abort here, since the user should

                    # be able to say "** = native" to automatically

                    # have all non-binary files taken care of.

                    continue

                if inconsistenteol(data):

                    raise util.Abort(_("inconsistent newline style "

                                       "in %s\n" % f))

            return super(eolrepo, self).commitctx(ctx, error)

    repo.__class__ = eolrepo

    repo._hgcleardirstate()