# 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 version 2, 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://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".

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 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.lock import release

from mercurial.node import nullid, hex

from mercurial.i18n import _

import re, shutil, tempfile, time

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

restricted = 'merge record resolve 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]))

# 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',

        '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

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

        templatefilters.filters['utcdate'] = utcdate

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

                                              False, None, '', False)

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

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

        def kwsub(mobj):

            kw = mobj.group(1)

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

            self.ui.pushbuffer()

            self.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, files):

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

        ctx = self.repo[node]

        mf = ctx.manifest()

        if node is not None:     # commit

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

            notify = self.ui.debug

        else:                    # kwexpand/kwshrink

            notify = self.ui.note

        candidates = [f for f in files 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:

                    notify(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, unknown, *pats, **opts):

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

    Returns status of working directory.'''

    if kwt:

        match = cmdutil.match(repo, pats, opts)

        return repo.status(match=match, unknown=unknown, clean=True)

    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']

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

    modified, added, removed, deleted = status[:4]

    if modified or added or removed or deleted:

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

    wlock = lock = None

    try:

        wlock = repo.wlock()

        lock = repo.lock()

        kwt.overwrite(None, expand, status[6])

    finally:

        release(lock, wlock)

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 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 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 repository at %s\n') % tmpdir)

    repo = localrepo.localrepository(ui, tmpdir, 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

    uisetup(ui)

    reposetup(ui, repo)

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

        if k.endswith('keyword'):

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

            break

    ui.status(_('\n\tconfig using %s keyword template maps\n') % 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'))

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

    repo.commit(text=msg)

    fmt = ui.verbose and ' in %s' % path or ''

    ui.status(_('\n\t%s keywords expanded%s\n') % (kwstatus, fmt))

    ui.write(repo.wread(fn))

    ui.debug(_('\nremoving temporary repository %s\n') % tmpdir)

    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.