# keyword.py - $Keyword$ expansion for Mercurial

#

# Copyright 2007 Christian Ebert <blacktrash@gmx.net>

#

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

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

#

# $Id$

#

# Keyword expansion hack against the grain of a DSCM

#

# There are many good reasons why this is not needed in a distributed

# SCM, still it may be useful in very small projects based on single

# files (like LaTeX packages), that are mostly addressed to an audience

# not running a version control system.

#

# For in-depth discussion refer to

# <http://www.selenic.com/mercurial/wiki/index.cgi/KeywordPlan>.

#

# Keyword expansion is based on Mercurial's changeset template mappings.

#

# Binary files are not touched.

#

# Setup in hgrc:

#

#   [extensions]

#   # enable extension

#   keyword = /full/path/to/hgkw/keyword.py

#   # or, if script in canonical hgext folder:

#   # hgext.keyword =

#

# Files to act upon/ignore are specified in the [keyword] section.

# Customized keyword template mappings in the [keywordmaps] section.

#

# Run "hg help keyword" and "hg kwdemo" to get info on configuration.

'''keyword expansion in local repositories

This extension expands RCS/CVS-like or self-customized $Keywords$

in tracked text files selected by your configuration.

Keywords are only expanded in local repositories and not stored in

the change history. The mechanism can be regarded as a convenience

for the current user or for archive distribution.

Configuration is done in the [keyword] and [keywordmaps] sections

of hgrc files.

Example:

    [keyword]

    # expand keywords in every python file except those matching "x*"

    **.py =

    x*    = ignore

Note: the more specific you are in your filename patterns

      the less you lose speed in huge repos.

For [keywordmaps] template mapping and expansion demonstration and

control run "hg kwdemo".

An additional date template filter {date|utcdate} is provided.

The default template mappings (view with "hg kwdemo -d") can be replaced

with customized keywords and templates.

Again, run "hg kwdemo" to control the results of your config changes.

Before changing/disabling active keywords, run "hg kwshrink" to avoid

the risk of inadvertedly storing expanded keywords in the change history.

To force expansion after enabling it, or a configuration change, run

"hg kwexpand".

Expansions spanning more than one line and incremental expansions,

like CVS' $Log$, are not supported. A keyword template map

"Log = {desc}" expands to the first line of the changeset description.

Caveat: "hg import" fails if the patch context contains an active

        keyword. In that case run "hg kwshrink", and then reimport.

        Or, better, use bundle/unbundle to share changes.

'''

from mercurial import commands, cmdutil, context, fancyopts

from mercurial import filelog, localrepo, templater, util, hg

from mercurial.i18n import gettext as _

import re, shutil, sys, tempfile, time

# findcmd, bail_if_changed were in commands until 0c61124ad877

try:

    findcmd = cmdutil.findcmd

    bail_if_changed = cmdutil.bail_if_changed

except AttributeError:

    findcmd = commands.findcmd

    bail_if_changed = commands.bail_if_changed

commands.optionalrepo += ' kwdemo'

def utcdate(date):

    '''Returns hgdate in cvs-like UTC format.'''

    return time.strftime('%Y/%m/%d %H:%M:%S', time.gmtime(date[0]))

class kwtemplater(object):

    '''

    Sets up keyword templates, corresponding keyword regex, and

    provides keyword substitution functions.

    '''

    deftemplates = {

        'Revision': '{node|short}',

        'Author': '{author|user}',

        'Date': '{date|utcdate}',

        'RCSFile': '{file|basename},v',

        'Source': '{root}/{file},v',

        'Id': '{file|basename},v {node|short} {date|utcdate} {author|user}',

        'Header': '{root}/{file},v {node|short} {date|utcdate} {author|user}',

    }

    def __init__(self, ui, repo, expand, path='', node=None):

        self.ui = ui

        self.repo = repo

        self.t = expand or None

        self.path = path

        self.node = node

        templates = dict(ui.configitems('keywordmaps'))

        if templates:

            for k in templates.keys():

                templates[k] = templater.parsestring(templates[k],

                                                     quoted=False)

        self.templates = templates or self.deftemplates

        escaped = [re.escape(k) for k in self.templates.keys()]

        rawkeyword = r'\$(%s)[^$\n\r]*?\$'

        self.re_kw = re.compile(rawkeyword % '|'.join(escaped))

        if self.t:

            templater.common_filters['utcdate'] = utcdate

            try:

                self.t = cmdutil.changeset_templater(self.ui, self.repo,

                                                     False, '', False)

            except TypeError:

                # depending on hg rev changeset_templater has extra "brinfo" arg

                self.t = cmdutil.changeset_templater(self.ui, self.repo,

                                                     False, None, '', False)

    def _ctxnode(self, node):

        '''Obtains missing node from file context.'''

        if not self.node:

            c = context.filectx(self.repo, self.path, fileid=node)

            self.node = c.node()

    def _kwsub(self, mobj):

        '''Substitutes keyword using corresponding template.'''

        kw = mobj.group(1)

        self.t.use_template(self.templates[kw])

        self.ui.pushbuffer()

        self.t.show(changenode=self.node, root=self.repo.root, file=self.path)

        keywordsub = templater.firstline(self.ui.popbuffer())

        return '$%s: %s $' % (kw, keywordsub)

    def expand(self, node, data):

        '''Returns data with keywords expanded.'''

        if util.binary(data):

            return data

        self._ctxnode(node)

        return self.re_kw.sub(self._kwsub, data)

    def process(self, node, data):

        '''Returns a tuple: data, count.

        Count is number of keywords/keyword substitutions.

        Keywords in data are expanded, if templater was initialized.'''

        if util.binary(data):

            return data, None

        if self.t:

            self._ctxnode(node)

            return self.re_kw.subn(self._kwsub, data)

        return data, self.re_kw.search(data)

    def shrink(self, text):

        '''Returns text with all keyword substitutions removed.'''

        if util.binary(text):

            return text

        return self.re_kw.sub(r'$\1$', text)

    def overwrite(self, candidates, man, commit):

        '''Overwrites files in working directory if keywords are detected.

        Keywords are expanded if keyword templater is initialized,

        otherwise their substitution is removed.'''

        expand = self.t is not None

        action = ('shrinking', 'expanding')[expand]

        notify = (self.ui.note, self.ui.debug)[commit]

        # backwards compatibility: older versions have dirstate.update

        nodirstateupdate = not hasattr(self.repo.dirstate, 'update')

        files = []

        for f in candidates:

            fp = self.repo.file(f, kwexp=expand, kwcnt=True)

            data, kwfound = fp.read(man[f])

            if kwfound:

                notify(_('overwriting %s %s keywords\n') % (f, action))

                try:

                    self.repo.wwrite(f, data, man.flags(f))

                except AttributeError:

                    # older versions want file descriptor as 3. optional arg

                    self.repo.wwrite(f, data)

                if nodirstateupdate:

                    self.repo.dirstate.normal(f)

                else:

                    files.append(f)

        if files:

            self.repo.dirstate.update(files, 'n')

class kwfilelog(filelog.filelog):

    '''

    Subclass of filelog to hook into its read, add, cmp methods.

    Keywords are "stored" unexpanded, and processed on reading.

    '''

    def __init__(self, opener, path, kwtemplater, kwcnt):

        super(kwfilelog, self).__init__(opener, path)

        self.kwtemplater = kwtemplater

        self.kwcnt = kwcnt

    def read(self, node):

        '''Passes data through kwemplater methods for

        either unconditional keyword expansion

        or counting of keywords and substitution method

        set by the calling overwrite function.'''

        data = super(kwfilelog, self).read(node)

        if not self.kwcnt:

            return self.kwtemplater.expand(node, data)

        return self.kwtemplater.process(node, data)

    def add(self, text, meta, tr, link, p1=None, p2=None):

        '''Removes keyword substitutions when adding to filelog.'''

        text = self.kwtemplater.shrink(text)

        return super(kwfilelog, self).add(text, meta, tr, link, p1=p1, p2=p2)

    def cmp(self, node, text):

        '''Removes keyword substitutions for comparison.'''

        text = self.kwtemplater.shrink(text)

        if self.renamed(node):

            t2 = super(kwfilelog, self).read(node)

            return t2 != text

        return super(kwfilelog, self).cmp(node, text)

def _keywordmatcher(ui, repo):

    '''Collects include/exclude filename patterns for expansion

    candidates of current configuration. Returns filename matching

    function if include patterns exist, None otherwise.'''

    inc, exc = [], ['.hg*']

    for pat, opt in ui.configitems('keyword'):

        if opt != 'ignore':

            inc.append(pat)

        else:

            exc.append(pat)

    if inc:

        return util.matcher(repo.root, inc=inc, exc=exc)[1]

    return None

def _weedcandidates(man, kwfmatcher, candidates):

    '''Weeds out files that do not match keyword file matcher,

    are not tracked, or are links.'''

    files = man.keys()

    if candidates:

        return [f for f in candidates if kwfmatcher(f)

                and f in files and not man.linkf(f)]

    # kwexpand w/o args on all files in manifest

    return [f for f in files if kwfmatcher(f) and not man.linkf(f)]

def _overwrite(ui, repo, files, expand):

    '''Expands/shrinks keywords in working directory.'''

    wlock = lock = None

    try:

        wlock = repo.wlock()

        lock = repo.lock()

        bail_if_changed(repo)

        ctx = repo.changectx()

        if not ctx:

            raise hg.RepoError(_('no revision checked out'))

        kwfmatcher = _keywordmatcher(ui, repo)

        if kwfmatcher is None:

            ui.warn(_('no files configured for keyword expansion\n'))

            return

        man = ctx.manifest()

        files = _weedcandidates(man, kwfmatcher, files)

        if not files:

            ui.warn(_('files not configured for expansion or untracked\n'))

            return

        commit = False

        kwt = kwtemplater(ui, repo, expand, node=ctx.node())

        kwt.overwrite(files, man, commit)

    finally:

        del wlock, lock

def shrink(ui, repo, *args):

    '''revert expanded keywords in working directory

    run before changing/disabling active keywords

    or if you experience problems with "hg import" or "hg merge"

    '''

    expand = False

    _overwrite(ui, repo, args, expand)

def expand(ui, repo, *args):

    '''expand keywords in working directory

    run after (re)enabling keyword expansion

    '''

    expand = True

    _overwrite(ui, repo, args, expand)

def demo(ui, repo, *args, **opts):

    '''print [keywordmaps] configuration and an expansion example

    show current, custom, or default keyword template maps and their expansion

    extend current configuration by specifying maps as arguments

    and optionally by reading from an additional hgrc file

    override current keyword template maps with "default" option

    '''

    def _demostatus(stat):

        ui.status(_('\n\t%s\n') % stat)

    def _showitems(section, items):

        ui.write('[%s]\n' % section)

        for k, v in items:

            ui.write('%s = %s\n' % (k, v))

    msg = 'hg keyword config and expansion example'

    kwstatus = 'current'

    fn = 'demo.txt'

    branchname = 'demobranch'

    tmpdir = tempfile.mkdtemp('', 'kwdemo.')

    ui.note(_('creating temporary repo at %s\n') % tmpdir)

    repo = localrepo.localrepository(ui, path=tmpdir, create=True)

    repo.ui = ui # backwards compatibility

    ui.setconfig('keyword', fn, '')

    if args or opts['rcfile']:

        kwstatus = 'custom'

    if opts['rcfile']:

        ui.readconfig(opts['rcfile'])

    if opts['default']:

        kwstatus = 'default'

        kwmaps = kwtemplater.deftemplates

        if ui.configitems('keywordmaps'):

            # override maps from optional rcfile

            for k, v in kwmaps.items():

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

    elif args:

        # simulate hgrc parsing

        rcmaps = ['[keywordmaps]\n'] + [a + '\n' for a in args]

        fp = repo.opener('hgrc', 'w')

        fp.writelines(rcmaps)

        fp.close()

        ui.readconfig(repo.join('hgrc'))

    if not opts['default']:

        kwmaps = (dict(ui.configitems('keywordmaps')) or

                  kwtemplater.deftemplates)

    reposetup(ui, repo)

    for k, v in ui.configitems('extensions'):

        if k.endswith('keyword'):

            extension = '%s = %s' % (k, v)

            break

    _demostatus('config using %s keyword template maps' % kwstatus)

    ui.write('[extensions]\n%s\n' % extension)

    _showitems('keyword', ui.configitems('keyword'))

    _showitems('keywordmaps', kwmaps.items())

    keywords = '$' + '$\n$'.join(kwmaps.keys()) + '$\n'

    repo.wopener(fn, 'w').write(keywords)

    repo.add([fn])

    path = repo.wjoin(fn)

    ui.note(_('\n%s keywords written to %s:\n') % (kwstatus, path))