#

def rpairs(name):

    e = len(name)

    while e != -1:

        yield name[:e], name[e+1:]

        e = name.rfind('/', 0, e)

class filemapper(object):

    '''Map and filter filenames when importing.

    A name can be mapped to itself, a new name, or None (omit from new

    repository).'''

    def __init__(self, ui, path=None):

        self.ui = ui

        self.include = {}

        self.exclude = {}

        self.rename = {}

        if path:

            if self.parse(path):

                raise util.Abort(_('errors in filemap'))

    def parse(self, path):

        errs = 0

        def check(name, mapping, listname):

            if name in mapping:

                self.ui.warn(_('%s:%d: %r already in %s list\n') %

                             (lex.infile, lex.lineno, name, listname))

                return 1

            return 0

        lex = shlex.shlex(open(path), path, True)

        lex.wordchars += '!@#$%^&*()-=+[]{}|;:,./<>?'

        cmd = lex.get_token()

        while cmd:

            if cmd == 'include':

                name = lex.get_token()

                errs += check(name, self.exclude, 'exclude')

                self.include[name] = name

            elif cmd == 'exclude':

                name = lex.get_token()

                errs += check(name, self.include, 'include')

                errs += check(name, self.rename, 'rename')

                self.exclude[name] = name

            elif cmd == 'rename':

                src = lex.get_token()

                dest = lex.get_token()

                errs += check(src, self.exclude, 'exclude')

                self.rename[src] = dest

            elif cmd == 'source':

                errs += self.parse(lex.get_token())

            else:

                self.ui.warn(_('%s:%d: unknown directive %r\n') %

                             (lex.infile, lex.lineno, cmd))

                errs += 1

            cmd = lex.get_token()

        return errs

    def lookup(self, name, mapping):

        for pre, suf in rpairs(name):

            try:

                return mapping[pre], pre, suf

            except KeyError, err:

                pass

        return '', name, ''

    def __call__(self, name):

        if self.include:

            inc = self.lookup(name, self.include)[0]

        else:

            inc = name

        if self.exclude:

            exc = self.lookup(name, self.exclude)[0]

        else:

            exc = ''

        if not inc or exc:

            return None

        newpre, pre, suf = self.lookup(name, self.rename)

        if newpre:

            if newpre == '.':

                return suf

            if suf:

                return newpre + '/' + suf

            return newpre

        return name

    def active(self):

        return bool(self.include or self.exclude or self.rename)