# 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, pathutil

from i18n import _

propertycache = util.propertycache

def _rematcher(regex):

    '''compile the regexp with the best available regexp engine and return a

    matcher function'''

    m = util.re.compile(regex)

    try:

        # slightly faster, provided by facebook's re2 bindings

        return m.test_match

    except AttributeError:

        return m.match

def _expandsets(kindpats, ctx):

    '''Returns the kindpats list with the 'set' patterns expanded.'''

    fset = set()

    other = []

    for kind, pat in kindpats:

        if kind == 'set':

            if not ctx:

                raise util.Abort("fileset expression with no context")

            s = ctx.getfileset(pat)

            fset.update(s)

            continue

        other.append((kind, pat))

    return fset, other

def _kindpatsalwaysmatch(kindpats):

    """"Checks whether the kindspats match everything, as e.g.

    'relpath:.' does.

    """

    for kind, pat in kindpats:

        if pat != '' or kind not in ['relpath', 'glob']:

            return False

    return True

class match(object):

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

                 default='glob', exact=False, auditor=None, ctx=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 (unless they are excluded)

        exclude - patterns to exclude (even if they are included)

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

        exact - patterns are actually filenames (include/exclude still apply)

        a pattern is one of:

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

        're:<regexp>' - a regular expression

        'path:<path>' - a path relative to repository root

        '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

        'set:<fileset>' - a fileset expression

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

        """

        self._root = root

        self._cwd = cwd

        self._files = [] # exact files and roots of patterns

        self._anypats = bool(include or exclude)

        self._always = False

        self._pathrestricted = bool(include or exclude or patterns)

        matchfns = []

        if include:

            kindpats = self._normalize(include, 'glob', root, cwd, auditor)

            self.includepat, im = _buildmatch(ctx, kindpats, '(?:/|$)')

            matchfns.append(im)

        if exclude:

            kindpats = self._normalize(exclude, 'glob', root, cwd, auditor)

            self.excludepat, em = _buildmatch(ctx, kindpats, '(?:/|$)')

            matchfns.append(lambda f: not em(f))

        if exact:

            if isinstance(patterns, list):

                self._files = patterns

            else:

                self._files = list(patterns)

            matchfns.append(self.exact)

        elif patterns:

            kindpats = self._normalize(patterns, default, root, cwd, auditor)

            if not _kindpatsalwaysmatch(kindpats):

                self._files = _roots(kindpats)

                self._anypats = self._anypats or _anypats(kindpats)

                self.patternspat, pm = _buildmatch(ctx, kindpats, '$')

                matchfns.append(pm)

        if not matchfns:

            m = util.always

            self._always = True

        elif len(matchfns) == 1:

            m = matchfns[0]

        else:

            def m(f):

                for matchfn in matchfns:

                    if not matchfn(f):

                        return False

                return 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

    # Callbacks related to how the matcher is used by dirstate.walk.

    # Subscribers to these events must monkeypatch the matcher object.

    def bad(self, f, msg):

        '''Callback from dirstate.walk for each explicit file that can't be

        found/accessed, with an error message.'''

        pass

    # If an explicitdir is set, it will be called when an explicitly listed

    # directory is visited.

    explicitdir = None

    # If an traversedir is set, it will be called when a directory discovered

    # by recursive traversal is visited.

    traversedir = None

    def abs(self, f):

        '''Convert a repo path back to path that is relative to the root of the

        matcher.'''

        return f

    def rel(self, f):

        '''Convert repo path back to path that is relative to cwd of matcher.'''

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

    def uipath(self, f):

        '''Convert repo path to a display path.  If patterns or -I/-X were used

        to create this matcher, the display path will be relative to cwd.

        Otherwise it is relative to the root of the repo.'''

        return (self._pathrestricted and self.rel(f)) or self.abs(f)

    def files(self):

        '''Explicitly listed files or patterns or roots:

        if no patterns or .always(): empty list,

        if exact: list exact files,

        if not .anypats(): list all files and dirs,

        else: optimal roots'''

        return self._files

    @propertycache

    def _dirs(self):

        return set(util.dirs(self._fmap)) | set(['.'])

    def visitdir(self, dir):

        '''Helps while traversing a directory tree. Returns the string 'all' if

        the given directory and all subdirectories should be visited. Otherwise

        returns True or False indicating whether the given directory should be

        visited. If 'all' is returned, calling this method on a subdirectory

        gives an undefined result.'''

        if not self._fmap or self.exact(dir):

            return 'all'

        return dir in self._dirs

    def exact(self, f):

        '''Returns True if f is in .files().'''

        return f in self._fmap

    def anypats(self):

        '''Matcher uses patterns or include/exclude.'''

        return self._anypats

    def always(self):

        '''Matcher will match everything and .files() will be empty

        - optimization might be possible and necessary.'''

        return self._always

    def isexact(self):

        return self.matchfn == self.exact

    def _normalize(self, patterns, default, root, cwd, auditor):

        '''Convert 'kind:pat' from the patterns list to tuples with kind and

        normalized and rooted patterns and with listfiles expanded.'''

        kindpats = []

        for kind, pat in [_patsplit(p, default) for p in patterns]:

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

                pat = pathutil.canonpath(root, cwd, pat, auditor)

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

                pat = util.normpath(pat)

            elif kind in ('listfile', 'listfile0'):

                try:

                    files = util.readfile(pat)

                    if kind == 'listfile0':

                        files = files.split('\0')

                    else:

                        files = files.splitlines()

                    files = [f for f in files if f]

                except EnvironmentError:

                    raise util.Abort(_("unable to read file list (%s)") % pat)

                kindpats += self._normalize(files, default, root, cwd, auditor)

                continue

            # else: re or relre - which cannot be normalized

            kindpats.append((kind, pat))

        return kindpats

def exact(root, cwd, files):

    return match(root, cwd, files, exact=True)

def always(root, cwd):

    return match(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

    >>> util.pconvert(m2.rel('b.txt'))

    'sub/b.txt'

    >>> def bad(f, msg):

    ...     print "%s: %s" % (f, msg)

    >>> m1.bad = bad

    >>> m2.bad('x.txt', 'No such file')

    sub/x.txt: No such file

    >>> m2.abs('c.txt')

    'sub/c.txt'

    """

    def __init__(self, path, matcher):

        self._root = matcher._root

        self._cwd = matcher._cwd

        self._path = path

        self._matcher = matcher

        self._always = matcher._always

        self._pathrestricted = matcher._pathrestricted

        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 abs(self, f):

        return self._matcher.abs(self._path + "/" + f)

    def bad(self, f, msg):

        self._matcher.bad(self._path + "/" + f, msg)

    def rel(self, f):

        return self._matcher.rel(self._path + "/" + f)

def patkind(pattern, default=None):

    '''If pattern is 'kind:pat' with a known kind, return kind.'''

    return _patsplit(pattern, default)[0]

def _patsplit(pattern, default):

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

    pattern."""

    if ':' in pattern:

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

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

                    'listfile', 'listfile0', 'set'):

            return kind, pat

    return default, pattern

def _globre(pat):

    r'''Convert an extended glob string to a regexp string.

    >>> print _globre(r'?')

    .

    >>> print _globre(r'*')

    [^/]*

    >>> print _globre(r'**')

    .*

    >>> print _globre(r'**/a')

    (?:.*/)?a

    >>> print _globre(r'a/**/b')

    a\/(?:.*/)?b

    >>> print _globre(r'[a*?!^][^b][!c]')

    [a*?!^][\^b][^c]

    >>> print _globre(r'{a,b}')

    (?:a|b)

    >>> print _globre(r'.\*\?')

    \.\*\?

    '''

    i, n = 0, len(pat)

    res = ''

    group = 0

    escape = util.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

                if peek() == '/':

                    i += 1

                    res += '(?:.*/)?'

                else:

                    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: