from mercurial.i18n import _
from mercurial import commands, cmdutil, context, filelog, revlog, util
import os.path, re, sys

# supported keywords for use in regexes
hgkeywords = 'Id|Header|Author|Date|Revision|RCSFile|Source'

def kwexpand(matchobj, repo, Revision, f, date, Author):
    '''Called by kwfilelog.read and pretxnkw.
    Sets supported keywords as local variables and evaluates them to
    their expansion if matchobj is equal to string representation.'''

    RCSFile = os.path.basename(f)+',v'
    Source = os.path.join(repo.root, f)+',v'
    Date = util.datestr(date=date)
    revdateauth = '%s %s %s' % (Revision,       # %Y-%m-%d %H:%M:%S
            util.datestr(date=date, format=util.defaultdateformats[0]),
            util.shortuser(Author))
    Header = '%s %s' % (Source, revdateauth)
    Id = '%s %s' % (RCSFile, revdateauth)

    return '$%s: %s $' % (matchobj.group(1), eval(matchobj.group(1)))


def reposetup(ui, repo):
    if not repo.local():
        return

    class kwrepo(repo.__class__):
        def file(self, f):
            if f[0] == '/':
                f = f[1:]
            return filelog.filelog(self.sopener, f, self, self.revlogversion)

    class kwfilelog(filelog.filelog):
        def __init__(self, opener, path, repo,
                     defversion=revlog.REVLOG_DEFAULT_VERSION):
            super(kwfilelog, self).__init__(opener, path, defversion)
            self._repo = repo
            self._path = path

        def read(self, node):
            data = super(kwfilelog, self).read(node)
            if util.binary(data):
                return data

            c = context.filectx(self._repo, self._path, fileid=node,
                                 filelog=self)
            f = c.path()
            if f.startswith('.hg'):
                return data

            for pat, opt in self._repo.ui.configitems('keyword'):
                if opt == 'expand':
                    mf = util.matcher(self._repo.root,
                            '', [pat], [], [])[1]
                    if mf(f):

                        def kwexpander(matchobj):
                            return kwexpand(matchobj,
                                    self._repo, c.changectx(), f,
                                    c.date(), c.user())

                        re_kw = re.compile(r'\$(%s)\$' % hgkeywords)
                        return re_kw.sub(kwexpander, data)
            return data

        def add(self, text, meta, tr, link, p1=None, p2=None):
            if (not util.binary(text) and
                   self._repo.ui.config('keyword', 'remove', True)):
                re_kw = re.compile(r'\$(%s): [^$]+? \$' % hgkeywords)
                text = re_kw.sub(r'$\1$', text)
            return super(kwfilelog, self).add(text, meta, tr, link, p1, p2)

    filelog.filelog = kwfilelog
    repo.__class__ = kwrepo


def pretxnkw(ui, repo, hooktype, **args):
    '''pretxncommit hook that collects candidates for keyword expansion
    on commit and expands keywords in working dir.'''

    if hooktype != 'pretxncommit': # bail out with error
        return True

    # reparse args, opts again as pretxncommit hook is silent about them
    cmd, sysargs, globalopts, cmdopts = commands.parse(ui, sys.argv[1:])[1:]
    # exclude tag and import
    if repr(cmd).split()[1] in ('tag', 'import_'):
        return False

    files, match, anypats = cmdutil.matchpats(repo, sysargs, cmdopts)
    # validity checks should have been done already
    modified, added = repo.status(files=files, match=match)[:2]
    candidates = [f for f in modified + added if not f.startswith('.hg')]

    if not candidates:
        return False

    # only check files that are configured in keyword section
    files = []
    # python2.4: files = set()
    for pat, opt in repo.ui.configitems('keyword'):
        if opt == 'expand':
            mf = util.matcher(repo.root, '', [pat], [], [])[1]
            for candidate in candidates:
                if mf(candidate) and candidate not in files:
                    files.append(candidate)
                # python2.4:
                # if mf(candidate): files.add(candidate)

    if not files:
        return False

    user, date = repo.changelog.read(repo.changelog.tip())[1:3]
    # expand both expanded and unexpanded keywords
    re_kw = re.compile(r'\$(%s)(: [^$]+? )?\$' % hgkeywords)

    for f in files:
        data = repo.wfile(f).read()
        if not util.binary(data):

            def kwexpander(matchobj):
                return kwexpand(matchobj,
                        repo, args['node'][:12], f, date, user)

            data, kwct = re_kw.subn(kwexpander, data)
            if kwct:
                ui.note(_('expanding keywords in %s\n' % f))
                # backup file?
                repo.wfile(f, 'w').write(data)