# 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, revlog

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

from mercurial.hgweb import webcommands

from mercurial.node import *

from mercurial.i18n import _

import re, shutil, tempfile, time

commands.optionalrepo += ' kwdemo'

# hg commands that do not act on keywords

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

                ' log outgoing push remove rename rollback tip'

                ' 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 = '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]))

# make keyword tools accessible

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

# store originals of monkeypatches

_patchfile_init = patch.patchfile.__init__

_patch_diff = patch.diff

_dispatch_parse = dispatch._parse

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)

    # shrink keywords read from working dir

    kwt = kwx['templater']

    self.lines = kwt.shrinklines(self.fname, self.lines)

def _kw_diff(repo, node1=None, node2=None, files=None, match=util.always,

             fp=None, changes=None, opts=None):

    # only expand if comparing against working dir

    if node2 is not None:

        kwx['templater'].matcher = util.never

        kwx['templater'].restrict = True

    _patch_diff(repo, node1=node1, node2=node2, files=files, match=match,

                fp=fp, changes=changes, opts=opts)

def _kwweb_changeset(web, req, tmpl):

    '''Wraps webcommands.changeset turning off keyword expansion.'''

    kwx['templater'].matcher = util.never

    return web.changeset(tmpl, web.changectx(req))

def _kwweb_filediff(web, req, tmpl):

    '''Wraps webcommands.filediff turning off keyword expansion.'''

    kwx['templater'].matcher = util.never

    return web.filediff(tmpl, web.filectx(req))

def _kwdispatch_parse(ui, args):

    '''Monkeypatch dispatch._parse to obtain running hg command.'''

    cmd, func, args, options, cmdoptions = _dispatch_parse(ui, args)

    kwx['hgcmd'] = cmd

    return cmd, func, args, options, cmdoptions

# dispatch._parse is run before reposetup, so wrap it here

dispatch._parse = _kwdispatch_parse

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):

        self.ui = ui

        self.repo = repo

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

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

        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)

        templatefilters.filters['utcdate'] = utcdate

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

                                              False, '', False)

    def getnode(self, path, fnode):

        '''Derives changenode from file context.'''

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

        return c.node()

    def substitute(self, data, path, node, 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(changenode=node, 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.matcher(path) and not util.binary(data):

            changenode = self.getnode(path, node)

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

        return data

    def iskwfile(self, path, islink):

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

        and is not a symbolic link.

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

        return self.matcher(path) and not islink(path)

    def overwrite(self, node=None, expand=True, files=None):

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

        ctx = self.repo.changectx(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, mf.linkf)]

        if candidates:

            self.restrict = True # do not expand when reading

            candidates.sort()

            action = expand and 'expanding' or 'shrinking'

            for f in candidates:

                fp = self.repo.file(f)

                data = fp.read(mf[f])

                if util.binary(data):

                    continue

                if expand:

                    changenode = node or self.getnode(f, mf[f])

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

                                                  self.re_kw.subn)

                else:

                    found = self.re_kw.search(data)

                if found:

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

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

                    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.matcher(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.matcher(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, path):

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

        self.kwt = kwx['templater']

        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=p1, p2=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:

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

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

    kwt = kwx['templater']

    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 in given files'))

    wlock = lock = None

    try:

        wlock = repo.wlock()

        lock = repo.lock()

        kwt.overwrite(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')