# 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.

Keywords expand to the changeset data pertaining to the latest change

relative to the working directory parent of each file.

Configuration is done in the [keyword], [keywordset] and [keywordmaps]

sections of hgrc files.

Example::

    [keyword]

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

    **.py =

    x*    = ignore

    [keywordset]

    # prefer svn- over cvs-like default keywordmaps

    svn = True

.. 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.

Three additional date template filters are provided::

    utcdate      "2006/09/18 15:13:13"

    svnutcdate   "2006-09-18 15:13:13Z"

    svnisodate   "2006-09-18 08:13:13 -700 (Mon, 18 Sep 2006)"

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`.

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, context, cmdutil, dispatch, filelog, extensions

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

from mercurial.hgweb import webcommands

from mercurial.i18n import _

import re, shutil, tempfile

commands.optionalrepo += ' kwdemo'

# hg commands that do not act on keywords

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

                ' outgoing push 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 kwexpand kwshrink record qrecord resolve transplant'

# names of extensions using dorecord

recordextensions = 'record'

# date like in cvs' $Date

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

# date like in svn's $Date

svnisodate = lambda x: util.datestr(x, '%Y-%m-%d %H:%M:%S %1%2 (%a, %d %b %Y)')

# date like in svn's $Id

svnutcdate = lambda x: util.datestr((x[0], 0), '%Y-%m-%d %H:%M:%SZ')

# make keyword tools accessible

kwtools = {'templater': None, 'hgcmd': ''}

def _defaultkwmaps(ui):

    '''Returns default keywordmaps according to keywordset configuration.'''

    templates = {

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

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

    }

    kwsets = ({

        '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}',

    }, {

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

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

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

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

        'LastChangedDate': '{date|svnisodate}',

    })

    templates.update(kwsets[ui.configbool('keywordset', 'svn')])

    return templates

def _shrinktext(text, subfunc):

    '''Helper for keyword expansion removal in text.

    Depending on subfunc also returns number of substitutions.'''

    return subfunc(r'$\1$', text)

def _preselect(wstatus, changed):

    '''Retrieves modfied and added files from a working directory state

    and returns the subset of each contained in given changed files

    retrieved from a change context.'''

    modified, added = wstatus[:2]

    modified = [f for f in modified if f in changed]

    added = [f for f in added if f in changed]

    return modified, added

class kwtemplater(object):

    '''

    Sets up keyword templates, corresponding keyword regex, and

    provides keyword substitution functions.

    '''

    def __init__(self, ui, repo, inc, exc):

        self.ui = ui

        self.repo = repo

        self.match = match.match(repo.root, '', [], inc, exc)

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

        self.record = False

        self.re_kw = None

        self.re_kwexp = None

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

        if kwmaps: # override default templates

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

                                  for k, v in kwmaps)

        else:

            self.templates = _defaultkwmaps(self.ui)

        templatefilters.filters.update({'utcdate': utcdate,

                                        'svnisodate': svnisodate,

                                        'svnutcdate': svnutcdate})

    def escape(self):

        '''Returns bar-separated list of keywords.'''

        return '|'.join(map(re.escape, self.templates.keys()))

    def rekw(self):

        '''Compiles regex for unexpanded keywords on demand.'''

        if self.re_kw is None:

            self.re_kw = re.compile(r'\$(%s)\$' % self.escape())

        return self.re_kw

    def rekwexp(self):

        '''Compiles regex for expanded keywords on demand.'''

        if self.re_kwexp is None:

            self.re_kwexp = re.compile(r'\$(%s): [^$\n\r]*? \$' % self.escape())

        return self.re_kwexp

    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 linkctx(self, path, fileid):

        '''Similar to filelog.linkrev, but returns a changectx.'''

        return self.repo.filectx(path, fileid=fileid).changectx()

    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.linkctx(path, node)

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

        return data

    def iskwfile(self, cand, ctx):

        '''Returns subset of candidates which are configured for keyword

        expansion are not symbolic links.'''

        return [f for f in cand if self.match(f) and not 'l' in ctx.flags(f)]

    def overwrite(self, ctx, candidates, lookup, expand, rekw=False):

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

        if self.restrict or lookup or self.record: # exclude kw_copy

            candidates = self.iskwfile(candidates, ctx)

        if not candidates:

            return

        kwcmd = self.restrict and lookup # kwexpand/kwshrink

        if self.restrict or expand and lookup:

            mf = ctx.manifest()

        lctx = ctx

        re_kw = (self.restrict or rekw) and self.rekw() or self.rekwexp()

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

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

        for f in candidates:

            if self.restrict:

                data = self.repo.file(f).read(mf[f])

            else:

                data = self.repo.wread(f)

            if util.binary(data):

                continue

            if expand:

                if lookup:

                    lctx = self.linkctx(f, mf[f])

                data, found = self.substitute(data, f, lctx, re_kw.subn)

            elif self.restrict:

                found = re_kw.search(data)

            else:

                data, found = _shrinktext(data, re_kw.subn)

            if found:

                self.ui.note(msg % f)

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

                if kwcmd:

                    self.repo.dirstate.normal(f)

                elif self.record:

                    self.repo.dirstate.normallookup(f)

    def shrink(self, fname, text):

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

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

            return _shrinktext(text, self.rekwexp().sub)

        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 _shrinktext(text, self.rekwexp().sub).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)

        if self.renamed(node):

            return data

        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)

        return super(kwfilelog, self).cmp(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.'''

    wctx = repo[None]

    if len(wctx.parents()) > 1:

        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(wctx, clean, True, expand)

    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]