# 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 _

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

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._ctx = ctx

        self._always = False

        if include:

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

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

        if exclude:

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

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

        if exact:

            if isinstance(patterns, list):

                self._files = patterns

            else:

                self._files = list(patterns)

        elif patterns:

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

            self._files = _roots(kindpats)

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

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

        else:

        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 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 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

    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

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, [])

        self._always = True

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

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

    '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

    """

    def __init__(self, path, matcher):

        self._root = matcher._root

        self._cwd = matcher._cwd

        self._path = path

        self._matcher = matcher

        self._always = matcher._always

        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 bad(self, f, msg):

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

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:

            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, pat, globsuffix):

    '''Convert a (normalized) pattern of any kind into a regular expression.

    globsuffix is appended to the regexp of globs.'''

    if not pat:

        return ''

    if kind == 're':

        return pat

    if kind == 'path':

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

    if kind == 'relglob':

        return '(?:|.*/)' + _globre(pat) + globsuffix

    if kind == 'relpath':

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

    if kind == 'relre':

        if pat.startswith('^'):

            return pat

        return '.*' + pat

    return _globre(pat) + globsuffix

def _buildmatch(ctx, kindpats, globsuffix):

    '''Return regexp string and a matcher function for kindpats.

    globsuffix is appended to the regexp of globs.'''

    fset, kindpats = _expandsets(kindpats, ctx)

    if not kindpats:

        return "", fset.__contains__

    regex, mf = _buildregexmatch(kindpats, globsuffix)

    if fset:

        return regex, lambda f: f in fset or mf(f)

    return regex, mf

def _buildregexmatch(kindpats, globsuffix):

    """Build a match function from a list of kinds and kindpats,

    return regexp string and a matcher function."""

    try:

        regex = '(?:%s)' % '|'.join([_regex(k, p, globsuffix)

                                     for (k, p) in kindpats])

        if len(regex) > 20000:

            raise OverflowError

        return regex, _rematcher(regex)

    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(kindpats)

        if l < 2:

            raise

        regexa, a = _buildregexmatch(kindpats[:l//2], globsuffix)

        regexb, b = _buildregexmatch(kindpats[l//2:], globsuffix)

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

    except re.error:

        for k, p in kindpats:

            try:

                _rematcher('(?:%s)' % _regex(k, p, globsuffix))

            except re.error:

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

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

def _normalize(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 += _normalize(files, default, root, cwd, auditor)

            continue

        # else: re or relre - which cannot be normalized

        kindpats.append((kind, pat))

    return kindpats