# keyword.py - $Keyword$ expansion for Mercurial

#

# Copyright 2007-2010 Christian Ebert <blacktrash@gmx.net>

#

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

# GNU General Public License version 2 or any later version.

#

# $Id$

#

# 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://mercurial.selenic.com/wiki/KeywordPlan>.

#

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

#

# Binary files are not touched.

#

# 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.

'''expand keywords in tracked files

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 repositories.

For [keywordmaps] template mapping and expansion demonstration and

control run :hg:`kwdemo`. See :hg:`help templates` for a list of

available templates and filters.

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

returns a date like "2006/09/18 15:13:13".

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 inadvertently 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, dispatch, filelog, revlog, extensions

from mercurial import patch, localrepo, templater, templatefilters, util, match

from mercurial.hgweb import webcommands

from mercurial.node import nullid

from mercurial.i18n import _

import re, shutil, tempfile

commands.optionalrepo += ' kwdemo'

# hg commands that do not act on keywords

nokwcommands = ('add addremove annotate bundle copy export grep incoming init'

                ' log outgoing push rename rollback tip verify'

                ' convert email glog')

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

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

# provide cvs-like UTC date filter

utcdate = lambda x: util.datestr((x[0], 0), '%Y/%m/%d %H:%M:%S')

# make keyword tools accessible

kwtools = {'templater': None, 'hgcmd': '', 'inc': [], 'exc': ['.hg*']}

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',

        'RCSFile': '{file|basename},v', # kept for backwards compatibility

                                        # with hg-keyword

        '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):

        self.ui = ui

        self.repo = repo

        self.match = match.match(repo.root, '', [],

                                 kwtools['inc'], kwtools['exc'])

        self.restrict = kwtools['hgcmd'] in restricted.split()

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

        if kwmaps: # override default templates

            self.templates = dict((k, templater.parsestring(v, False))

                                  for k, v in kwmaps)

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

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

        self.re_kw = re.compile(kwpat)

        templatefilters.filters['utcdate'] = utcdate

    def substitute(self, data, path, ctx, subfunc):

        '''Replaces keywords in data with expanded template.'''

        def kwsub(mobj):

            kw = mobj.group(1)

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

                                             False, None, '', False)

            ct.use_template(self.templates[kw])

            self.ui.pushbuffer()

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

            ekw = templatefilters.firstline(self.ui.popbuffer())

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

        return subfunc(kwsub, data)

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

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

        if not self.restrict and self.match(path) and not util.binary(data):

            ctx = self.repo.filectx(path, fileid=node).changectx()

            return self.substitute(data, path, ctx, self.re_kw.sub)

        return data

    def iskwfile(self, path, flagfunc):

        '''Returns true if path matches [keyword] pattern

        and is not a symbolic link.

        Caveat: localrepository._link fails on Windows.'''

        return self.match(path) and not 'l' in flagfunc(path)

    def overwrite(self, node, expand, candidates):

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

        ctx = self.repo[node]

        mf = ctx.manifest()

        if node is not None:     # commit

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

        candidates = [f for f in candidates if self.iskwfile(f, ctx.flags)]

        if candidates:

            self.restrict = True # do not expand when reading

            msg = (expand and _('overwriting %s expanding keywords\n')

                   or _('overwriting %s shrinking keywords\n'))

            for f in candidates:

                fp = self.repo.file(f)

                data = fp.read(mf[f])

                if util.binary(data):

                    continue

                if expand:

                    if node is None:

                        ctx = self.repo.filectx(f, fileid=mf[f]).changectx()

                    data, found = self.substitute(data, f, ctx,

                                                  self.re_kw.subn)

                else:

                    found = self.re_kw.search(data)

                if found:

                    self.ui.note(msg % f)

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

                    if node is None:

                        self.repo.dirstate.normal(f)

            self.restrict = False

    def shrinktext(self, text):

        '''Unconditionally removes all keyword substitutions from text.'''

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

    def shrink(self, fname, text):

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

        if self.match(fname) and not util.binary(text):

            return self.shrinktext(text)

        return text

    def shrinklines(self, fname, lines):

        '''Returns lines with keyword substitutions removed.'''

        if self.match(fname):

            text = ''.join(lines)

            if not util.binary(text):

                return self.shrinktext(text).splitlines(True)

        return lines

    def wread(self, fname, data):

        '''If in restricted mode returns data read from wdir with

        keyword substitutions removed.'''

        return self.restrict and self.shrink(fname, data) or data

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, kwt, path):

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

        self.kwt = kwt

        self.path = path

    def read(self, node):

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

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

        return self.kwt.expand(self.path, node, data)

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

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

        text = self.kwt.shrink(self.path, text)

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

    def cmp(self, node, text):

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

        text = self.kwt.shrink(self.path, text)

        if self.renamed(node):

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

            return t2 != text

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

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

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

    Returns status of working directory.'''

    if kwt:

        return repo.status(match=cmdutil.match(repo, pats, opts), clean=True,

                           unknown=opts.get('unknown') or opts.get('all'))

    if ui.configitems('keyword'):

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

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

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

    '''Selects files and passes them to kwtemplater.overwrite.'''

    if repo.dirstate.parents()[1] != nullid:

        raise util.Abort(_('outstanding uncommitted merge'))

    kwt = kwtools['templater']

    wlock = repo.wlock()

    try:

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

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

        if modified or added or removed or deleted:

            raise util.Abort(_('outstanding uncommitted changes'))

        kwt.overwrite(None, expand, clean)

    finally:

        wlock.release()

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

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

    Show current, custom, or default keyword template maps and their

    expansions.

    Extend the current configuration by specifying maps as arguments

    and using -f/--rcfile to source an external hgrc file.

    Use -d/--default to disable current configuration.

    See "hg help templates" for information on templates and filters.

    '''

    def demoitems(section, items):

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

        for k, v in sorted(items):

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

    fn = 'demo.txt'

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

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

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

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

    uikwmaps = ui.configitems('keywordmaps')

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

        ui.status(_('\n\tconfiguration using custom keyword template maps\n'))

        if uikwmaps:

            ui.status(_('\textending current template maps\n'))

        if opts.get('default') or not uikwmaps:

            ui.status(_('\toverriding default template maps\n'))

        if opts.get('rcfile'):

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

        if 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'))

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

    elif opts.get('default'):

        ui.status(_('\n\tconfiguration using default keyword template maps\n'))

        kwmaps = kwtemplater.templates

        if uikwmaps:

            ui.status(_('\tdisabling current template maps\n'))

            for k, v in kwmaps.iteritems():

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

    else:

        ui.status(_('\n\tconfiguration using current keyword template maps\n'))

        kwmaps = dict(uikwmaps) or kwtemplater.templates

    uisetup(ui)

    reposetup(ui, repo)

    ui.write('[extensions]\nkeyword =\n')

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

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

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

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

    repo.add([fn])

    ui.note(_('\nkeywords written to %s:\n') % fn)

    ui.note(keywords)

    repo.dirstate.setbranch('demobranch')

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

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

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

    msg = _('hg keyword configuration and expansion example')

    ui.note("hg ci -m '%s'\n" % msg)

    repo.commit(text=msg)

    ui.status(_('\n\tkeywords expanded\n'))

    ui.write(repo.wread(fn))

    shutil.rmtree(tmpdir, ignore_errors=True)

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

    '''expand keywords in the working directory

    Run after (re)enabling keyword expansion.

    kwexpand refuses to run if given files contain local changes.

    '''

    # 3rd argument sets expansion to True

    _kwfwrite(ui, repo, True, *pats, **opts)

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

    '''show files configured for keyword expansion

    List which files in the working directory are matched by the

    [keyword] configuration patterns.

    Useful to prevent inadvertent keyword expansion and to speed up

    execution by including only files that are actual candidates for

    expansion.

    See :hg:`help keyword` on how to construct patterns both for

    inclusion and exclusion of files.

    With -A/--all and -v/--verbose the codes used to show the status

    of files are::

      K = keyword expansion candidate

      k = keyword expansion candidate (not tracked)

      I = ignored