# 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, revlog, templater, util

from mercurial.node import *

from mercurial.i18n import _

import re, shutil, sys, tempfile, time

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.

    '''

    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, expand, path='', node=None):

        self.ui = ui

        self.repo = repo

        self.t = expand or None

        self.path = path

        self.node = node

        self.debug = self.ui.debugflag

        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)

        if self.t:

            templater.common_filters['utcdate'] = utcdate

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

                                                 False, '', False)

    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 substitute(self, node, data, subfunc):

        '''Obtains node if missing.

        Ensures consistent templates regardless of ui.debugflag.

        Calls given substitution function.'''

        if not self.node:

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

            self.node = c.node()

        self.ui.debugflag = False

        result = subfunc(self.kwsub, data)

        self.ui.debugflag = self.debug

        return result

    def expand(self, node, data):

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

        if util.binary(data):

            return data

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

    def process(self, node, data):

        '''Returns a tuple: data, count.

        Count is number of keywords/keyword substitutions, indicates

        to caller whether to act on file containing data.

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

        if util.binary(data):

            return data, None

        if self.t:

            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)

    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]

        for f in candidates:

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

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

            if kwfound:

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

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

                self.repo.dirstate.normal(f)

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):

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

        self.kwtemplater = kwtemplater

    def kwctread(self, node):

        '''Reads expanding and counting keywords

        (only called from kwtemplater.overwrite).'''

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

        return self.kwtemplater.process(node, data)

    def read(self, node):

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

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

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

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

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

    Returns status of working directory.'''

    if hasattr(ui, 'kwfmatcher'):

        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 _iskwfile(ui, man, f):

    return not man.linkf(f) and ui.kwfmatcher(f)

def _overwrite(ui, repo, files, node, man, expand, commit):

    '''Passes given files to kwtemplater for overwriting.'''

    files.sort()

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

    kwt.overwrite(files, man, commit)

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()

        ctx = repo.changectx()

        man = ctx.manifest()

        candidates = [f for f in clean if _iskwfile(ui, man, f)]

        if candidates:

            # 7th argument sets commit to False

            _overwrite(ui, repo, candidates, ctx.node(), man, expand, False)

    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['rcfile']:

        kwstatus = 'custom'

    if opts['rcfile']:

        ui.readconfig(opts['rcfile'])

    if opts['default']:

        kwstatus = 'default'

        kwmaps = kwtemplater.templates

        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.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.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))

    ui.note(keywords)

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

    # silence branch command if not verbose

    quiet = ui.quiet

    verbose = ui.verbose

    ui.quiet = not 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)

    pathinfo = ('', ' in %s' % path)[ui.verbose]

    demostatus('%s keywords expanded%s' % (kwstatus, pathinfo))

    ui.write(repo.wread(fn))

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

    shutil.rmtree(tmpdir, ignore_errors=True)

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

    '''expand keywords in 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):

    '''print files currently configured for keyword expansion

    Crosscheck which files in working directory are potential targets for

    keyword expansion.

    That is, files matched by [keyword] config patterns but not symlinks.

    '''

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

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