# match.py - filename matching

#

#  Copyright 2008, 2009 Matt Mackall <mpm@selenic.com> and others

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2 or any later version.

import re

import util

from i18n import _

class match(object):

    def __init__(self, root, cwd, patterns, include=[], exclude=[],

                 default='glob', exact=False, auditor=None):

        """build an object to match a set of file patterns

        arguments:

        root - the canonical root of the tree you're matching against

        cwd - the current working directory, if relevant

        patterns - patterns to find

        include - patterns to include

        exclude - patterns to exclude

        default - if a pattern in names has no explicit type, assume this one

        exact - patterns are actually literals

        a pattern is one of:

        'glob:<glob>' - a glob relative to cwd

        're:<regexp>' - a regular expression

        'path:<path>' - a path relative to canonroot

        'relglob:<glob>' - an unrooted glob (*.c matches C files in all dirs)

        'relpath:<path>' - a path relative to cwd

        'relre:<regexp>' - a regexp that needn't match the start of a name

        '<something>' - a pattern of the specified default type

        """

        self._root = root

        self._cwd = cwd

        self._files = []

        self._anypats = bool(include or exclude)

        if include:

            im = _buildmatch(_normalize(include, 'glob', root, cwd, auditor),

                             '(?:/|$)')

        if exclude:

            em = _buildmatch(_normalize(exclude, 'glob', root, cwd, auditor),

                             '(?:/|$)')

        if exact:

            self._files = patterns

            pm = self.exact

        elif patterns:

            pats = _normalize(patterns, default, root, cwd, auditor)

            self._files = _roots(pats)

            self._anypats = self._anypats or _anypats(pats)

            pm = _buildmatch(pats, '$')

        if patterns or exact:

            if include:

                if exclude:

                    m = lambda f: im(f) and not em(f) and pm(f)

                else:

                    m = lambda f: im(f) and pm(f)

            else:

                if exclude:

                    m = lambda f: not em(f) and pm(f)

                else:

                    m = pm

        else:

            if include:

                if exclude:

                    m = lambda f: im(f) and not em(f)

                else:

                    m = im

            else:

                if exclude:

                    m = lambda f: not em(f)

                else:

                    m = lambda f: True

        self.matchfn = m

        self._fmap = set(self._files)

    def __call__(self, fn):

        return self.matchfn(fn)

    def __iter__(self):

        for f in self._files:

            yield f

    def bad(self, f, msg):

        '''callback for each explicit file that can't be

        found/accessed, with an error message

        '''

        pass

    def dir(self, f):

        pass

    def missing(self, f):

        pass

    def exact(self, f):

        return f in self._fmap

    def rel(self, f):

        return util.pathto(self._root, self._cwd, f)

    def files(self):

        return self._files

    def anypats(self):

        return self._anypats

class exact(match):

    def __init__(self, root, cwd, files):

        match.__init__(self, root, cwd, files, exact = True)

class always(match):

    def __init__(self, root, cwd):

        match.__init__(self, root, cwd, [])

class narrowmatcher(match):

    """Adapt a matcher to work on a subdirectory only.

    The paths are remapped to remove/insert the path as needed:

    >>> m1 = match('root', '', ['a.txt', 'sub/b.txt'])

    >>> m2 = narrowmatcher('sub', m1)

    >>> bool(m2('a.txt'))

    False

    >>> bool(m2('b.txt'))

    True

    >>> bool(m2.matchfn('a.txt'))

    False

    >>> bool(m2.matchfn('b.txt'))

    True

    >>> m2.files()

    ['b.txt']

    >>> m2.exact('b.txt')

    True

    """

    def __init__(self, path, matcher):

        self._path = path

        self._matcher = matcher

        self._files = [f[len(path) + 1:] for f in matcher._files

                       if f.startswith(path + "/")]

        self._anypats = matcher._anypats

        self.matchfn = lambda fn: matcher.matchfn(self._path + "/" + fn)

        self._fmap = set(self._files)

def patkind(pat):

    return _patsplit(pat, None)[0]

def _patsplit(pat, default):

    """Split a string into an optional pattern kind prefix and the

    actual pattern."""

    if ':' in pat:

        kind, val = pat.split(':', 1)

        if kind in ('re', 'glob', 'path', 'relglob', 'relpath', 'relre'):

            return kind, val

    return default, pat

def _globre(pat):

    "convert a glob pattern into a regexp"

    i, n = 0, len(pat)

    res = ''

    group = 0

    escape = re.escape

    def peek():

        return i < n and pat[i]

    while i < n:

        c = pat[i]

        i += 1

        if c not in '*?[{},\\':

            res += escape(c)

        elif c == '*':

            if peek() == '*':

                i += 1

                res += '.*'

            else:

                res += '[^/]*'

        elif c == '?':

            res += '.'

        elif c == '[':

            j = i

            if j < n and pat[j] in '!]':

                j += 1

            while j < n and pat[j] != ']':

                j += 1

            if j >= n:

                res += '\\['

            else:

                stuff = pat[i:j].replace('\\','\\\\')

                i = j + 1

                if stuff[0] == '!':

                    stuff = '^' + stuff[1:]

                elif stuff[0] == '^':

                    stuff = '\\' + stuff

                res = '%s[%s]' % (res, stuff)

        elif c == '{':

            group += 1

            res += '(?:'

        elif c == '}' and group:

            res += ')'

            group -= 1

        elif c == ',' and group:

            res += '|'

        elif c == '\\':

            p = peek()

            if p:

                i += 1

                res += escape(p)

            else:

                res += escape(c)

        else:

            res += escape(c)

    return res

def _regex(kind, name, tail):

    '''convert a pattern into a regular expression'''

    if not name:

        return ''

    if kind == 're':

        return name

    elif kind == 'path':

        return '^' + re.escape(name) + '(?:/|$)'

    elif kind == 'relglob':

        return '(?:|.*/)' + _globre(name) + tail

    elif kind == 'relpath':

        return re.escape(name) + '(?:/|$)'

    elif kind == 'relre':

        if name.startswith('^'):

            return name

        return '.*' + name

    return _globre(name) + tail

def _buildmatch(pats, tail):

    """build a matching function from a set of patterns"""

    try:

        pat = '(?:%s)' % '|'.join([_regex(k, p, tail) for (k, p) in pats])

        if len(pat) > 20000:

            raise OverflowError()

        return re.compile(pat).match

    except OverflowError:

        # We're using a Python with a tiny regex engine and we

        # made it explode, so we'll divide the pattern list in two

        # until it works

        l = len(pats)

        if l < 2:

            raise

        a, b = _buildmatch(pats[:l//2], tail), _buildmatch(pats[l//2:], tail)

        return lambda s: a(s) or b(s)

    except re.error:

        for k, p in pats:

            try:

                re.compile('(?:%s)' % _regex(k, p, tail))

            except re.error:

                raise util.Abort(_("invalid pattern (%s): %s") % (k, p))

        raise util.Abort(_("invalid pattern"))

def _normalize(names, default, root, cwd, auditor):

    pats = []

    for kind, name in [_patsplit(p, default) for p in names]:

        if kind in ('glob', 'relpath'):

            name = util.canonpath(root, cwd, name, auditor)

        elif kind in ('relglob', 'path'):

            name = util.normpath(name)

        pats.append((kind, name))

    return pats

def _roots(patterns):

    r = []

    for kind, name in patterns:

        if kind == 'glob': # find the non-glob prefix

            root = []

            for p in name.split('/'):

                if '[' in p or '{' in p or '*' in p or '?' in p:

                    break

                root.append(p)

            r.append('/'.join(root) or '.')

        elif kind in ('relpath', 'path'):

            r.append(name or '.')

        elif kind == 'relglob':

            r.append('.')

    return r

def _anypats(patterns):

    for kind, name in patterns:

        if kind in ('glob', 're', 'relglob', 'relre'):

            return True