# keyword.py - $Keyword$ expansion for Mercurial

#

# Copyright 2007, 2008 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".

Also, when committing with the record extension or using mq's qrecord, be aware

that keywords cannot be updated. Again, run "hg kwexpand" on the files in

question to update keyword expansions after all changes have been checked in.

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.

'''

from mercurial import commands, cmdutil, context, dispatch, filelog

from mercurial import patch, localrepo, revlog, templater, util

from mercurial.node import *

from mercurial.i18n import _

import re, shutil, sys, tempfile, time

commands.optionalrepo += ' kwdemo'

# handle for external callers

externalcall = None, None, {}

def externalcmdhook(hgcmd, *args, **opts):

    global externalcall

# hg commands that trigger expansion only when writing to working dir,

# not when reading filelog, and unexpand when reading from working dir

restricted = ('diff1', 'record',

              'qfold', 'qimport', 'qnew', 'qpush', 'qrefresh', 'qrecord')

def utcdate(date):

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

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

_kwtemplater = None

class kwtemplater(object):

    '''

    Sets up keyword templates, corresponding keyword regex, and

    provides keyword substitution functions.

    '''

    templates = {

        '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, inc, exc, hgcmd):

        self.ui = ui

        self.repo = repo

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

        self.hgcmd = hgcmd

        self.commitnode = None

        self.path = ''

        kwmaps = self.ui.configitems('keywordmaps')

        if kwmaps: # override default templates

            kwmaps = [(k, templater.parsestring(v, quoted=False))

                      for (k, v) in kwmaps]

            self.templates = dict(kwmaps)

        escaped = map(re.escape, self.templates.keys())

        kwpat = r'\$(%s)(: [^$\n\r]*? )??\$' % '|'.join(escaped)

        self.re_kw = re.compile(kwpat)

        templater.common_filters['utcdate'] = utcdate

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

                                              False, '', False)

    def substitute(self, node, data, subfunc):

        '''Obtains file's changenode if commit node not given,

        and calls given substitution function.'''

        if self.commitnode:

            fnode = self.commitnode

        else:

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

            fnode = c.node()

        def kwsub(mobj):

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

            kw = mobj.group(1)

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

            self.ui.pushbuffer()

            self.ct.show(changenode=fnode, root=self.repo.root, file=self.path)

            return '$%s: %s $' % (kw, templater.firstline(self.ui.popbuffer()))

        return subfunc(kwsub, data)

    def expand(self, node, data):

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

        if util.binary(data) or self.hgcmd in restricted:

            return data

        return self.substitute(node, data, self.re_kw.sub)

    def process(self, node, data, expand):

        '''Returns a tuple: data, count.

        Count is number of keywords/keyword substitutions,

        telling caller whether to act on file containing data.'''

        if util.binary(data):

            return data, None

        if expand:

            return self.substitute(node, data, self.re_kw.subn)

        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)

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):

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

        _kwtemplater.path = path

    def kwctread(self, node, expand):

        '''Reads expanding and counting keywords, called from _overwrite.'''

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

        return _kwtemplater.process(node, data, expand)

    def read(self, node):

        '''Expands keywords when reading filelog.'''

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

        return _kwtemplater.expand(node, data)

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

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

        text = _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 = _kwtemplater.shrink(text)

        if self.renamed(node):

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

            return t2 != text

        return revlog.revlog.cmp(self, node, text)

# store original patch.patchfile.__init__

_patchfile_init = patch.patchfile.__init__

def _kwpatchfile_init(self, ui, fname, missing=False):

    '''Monkeypatch/wrap patch.patchfile.__init__ to avoid

    rejects or conflicts due to expanded keywords in working dir.'''

    _patchfile_init(self, ui, fname, missing=missing)

    if _kwtemplater.matcher(self.fname):

        # shrink keywords read from working dir

        kwshrunk = _kwtemplater.shrink(''.join(self.lines))

        self.lines = kwshrunk.splitlines(True)

def _iskwfile(f, link):

    return not link(f) and _kwtemplater.matcher(f)

def _status(ui, repo, *pats, **opts):

    '''Bails out if [keyword] configuration is not active.

    Returns status of working directory.'''

    if _kwtemplater:

        files, match, anypats = cmdutil.matchpats(repo, pats, opts)

        return repo.status(files=files, match=match, list_clean=True)

    if ui.configitems('keyword'):

        raise util.Abort(_('[keyword] patterns cannot match'))

    raise util.Abort(_('no [keyword] patterns configured'))

def _overwrite(ui, repo, node=None, expand=True, files=None):

    '''Overwrites selected files expanding/shrinking keywords.'''

    ctx = repo.changectx(node)

    mf = ctx.manifest()

    if node is not None:   # commit

        _kwtemplater.commitnode = node

        files = [f for f in ctx.files() if f in mf]

        notify = ui.debug

    else:                  # kwexpand/kwshrink

        notify = ui.note

    candidates = [f for f in files if _iskwfile(f, mf.linkf)]

    if candidates:

        candidates.sort()

        action = expand and 'expanding' or 'shrinking'

        for f in candidates:

            fp = repo.file(f, kwmatch=True)

            data, kwfound = fp.kwctread(mf[f], expand)

            if kwfound:

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

                repo.wwrite(f, data, mf.flags(f))

                repo.dirstate.normal(f)

def _kwfwrite(ui, repo, expand, *pats, **opts):

    '''Selects files and passes them to _overwrite.'''

    status = _status(ui, repo, *pats, **opts)

    modified, added, removed, deleted, unknown, ignored, clean = status

    if modified or added or removed or deleted:

        raise util.Abort(_('outstanding uncommitted changes in given files'))

    wlock = lock = None

    try:

        wlock = repo.wlock()

        lock = repo.lock()

        _overwrite(ui, repo, expand=expand, files=clean)

    finally:

        del wlock, lock

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 demoitems(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)

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

    if args or opts.get('rcfile'):

        kwstatus = 'custom'

    if opts.get('rcfile'):

        ui.readconfig(opts.get('rcfile'))

    if opts.get('default'):

        kwstatus = 'default'

        kwmaps = kwtemplater.templates

        if ui.configitems('keywordmaps'):

            # override maps from optional rcfile

            for k, v in kwmaps.iteritems():

                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.get('default'):

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

    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)

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

    demoitems('keywordmaps', kwmaps.iteritems())

    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))

    ui.note(keywords)

    ui.note('\nhg -R "%s" branch "%s"\n' % (tmpdir, branchname))

    # silence branch command if not verbose

    quiet = ui.quiet

    ui.quiet = not ui.verbose

    commands.branch(ui, repo, branchname)

    ui.quiet = quiet

    for name, cmd in ui.configitems('hooks'):

        if name.split('.', 1)[0].find('commit') > -1:

            repo.ui.setconfig('hooks', name, '')

    ui.note(_('unhooked all commit hooks\n'))