"""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 directory. 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 directory 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 behavior; 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

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

The extension uses an optional ``[eol]`` section read from both the

normal Mercurial configuration files and the ``.hgeol`` file, with the

latter overriding the former. You can use that section to control the

overall behavior. There are three 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.

- ``eol.fix-trailing-newline`` (default False) can be set to True to

  ensure that converted files end with a EOL character (either ``\\n``

  or ``\\r\\n`` as per the configured patterns).

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.checkheadshook``. 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. ``eol.checkheadshook`` only checks heads, intermediate

invalid revisions will be pushed. To forbid them completely, use the

``eol.checkallhook`` hook. These hooks are best used as

``pretxnchangegroup`` hooks.

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

used.

"""

from __future__ import absolute_import

import os

import re

from mercurial.i18n import _

from mercurial import (

    config,

    error,

    extensions,

    match,

    util,

)

# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for

# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should

# be specifying the version(s) of Mercurial they are tested with, or

# leave the attribute unspecified.

testedwith = 'ships-with-hg-core'

# 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 Macintosh 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

    if (ui.configbool('eol', 'fix-trailing-newline', False)

        and s and s[-1] != '\n'):

        s = s + '\n'

    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

    if (ui.configbool('eol', 'fix-trailing-newline', False)

        and s and s[-1] != '\n'):

        s = s + '\n'

    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', 'eol')

        # 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 = []

        self.patterns = []

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

            key = style.upper()

            if key == 'BIN':

                exclude.append(pattern)

            else:

                include.append(pattern)

            m = match.match(root, '', [pattern])

            self.patterns.append((pattern, key, m))

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

        # about inconsistent newlines.

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

    def copytoui(self, ui):

        for pattern, key, m in self.patterns:

            try:

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

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

            except KeyError:

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

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

        # eol.only-consistent can be specified in ~/.hgrc or .hgeol

        for k, v in self.cfg.items('eol'):

            ui.setconfig('eol', k, v, 'eol')

    def checkrev(self, repo, ctx, files):

        failed = []

        for f in (files or ctx.files()):

            if f not in ctx:

                continue

            for pattern, key, m in self.patterns:

                if not m(f):

                    continue

                target = self._encode[key]

                data = ctx[f].data()

                if (target == "to-lf" and "\r\n" in data

                    or target == "to-crlf" and singlelf.search(data)):

                    failed.append((f, target, str(ctx)))

                break

        return failed

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.

                else:

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

                return eolfile(ui, repo.root, data)

            except (IOError, LookupError):

                pass

    except error.ParseError as inst:

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

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

    return None

def _checkhook(ui, repo, node, headsonly):

    # Get revisions to check and touched files at the same time

    files = set()

    revs = set()

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

        revs.add(rev)

        if headsonly:

            ctx = repo[rev]

            files.update(ctx.files())

            for pctx in ctx.parents():

                revs.discard(pctx.rev())

    failed = []

    for rev in revs:

        ctx = repo[rev]

        eol = parseeol(ui, repo, [ctx.node()])

        if eol:

            failed.extend(eol.checkrev(repo, ctx, files))

    if failed:

        eols = {'to-lf': 'CRLF', 'to-crlf': 'LF'}

        msgs = []

        for f, target, node in sorted(failed):

            msgs.append(_("  %s in %s should not have %s line endings") %

                        (f, node, eols[target]))

        raise error.Abort(_("end-of-line check failed:\n") + "\n".join(msgs))

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

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

    _checkhook(ui, repo, node, False)

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

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

    _checkhook(ui, repo, node, True)

# "checkheadshook" used to be called "hook"

hook = checkheadshook

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

    repo.loadeol([parent1])

    return False

def uisetup(ui):

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

def extsetup(ui):

    try:

        extensions.find('win32text')

        ui.warn(_("the eol extension is incompatible with the "

                  "win32text extension\n"))

    except KeyError:

        pass

def reposetup(ui, repo):

    uisetup(repo.ui)

    if not repo.local():

        return

    for name, fn in filters.iteritems():

        repo.adddatafilter(name, fn)

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

    class eolrepo(repo.__class__):

        def loadeol(self, nodes):

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

            if eol is None:

                return None

            eol.copytoui(self.ui)

            return eol.match

        def _hgcleardirstate(self):

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

            if not self._eolmatch:

                self._eolmatch = util.never

                return

            oldeol = None

            try:

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

            except OSError:

                cachemtime = 0

            else:

                olddata = self.vfs.read("eol.cache")

                if olddata:

                    oldeol = eolfile(self.ui, self.root, olddata)

            try:

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

            except OSError:

                eolmtime = 0

            if eolmtime > cachemtime:

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

                hgeoldata = self.wvfs.read('.hgeol')

                neweol = eolfile(self.ui, self.root, hgeoldata)

                wlock = None

                try:

                    wlock = self.wlock()

                    for f in self.dirstate:

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

                            continue

                        if oldeol is not None:

                            if not oldeol.match(f) and not neweol.match(f):

                                continue

                            oldkey = None

                            for pattern, key, m in oldeol.patterns:

                                if m(f):

                                    oldkey = key

                                    break

                            newkey = None

                            for pattern, key, m in neweol.patterns:

                                if m(f):

                                    newkey = key

                                    break

                            if oldkey == newkey:

                                continue

                        # all normal files need to be looked at again since

                        # the new .hgeol file specify a different filter

                        self.dirstate.normallookup(f)

                    # Write the cache to update mtime and cache .hgeol

                    with self.vfs("eol.cache", "w") as f:

                        f.write(hgeoldata)

                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

                finally:

                    if wlock is not None:

                        wlock.release()

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

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

                if not self._eolmatch(f):

                    continue

                fctx = ctx[f]

                if fctx is None:

                    continue

                data = fctx.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 error.Abort(_("inconsistent newline style "

                                       "in %s\n") % f)