"""

"""

import os, sys

import py

class Checkers:

    _depend_on_existence = 'exists', 'link', 'dir', 'file'

    def __init__(self, path):

        self.path = path

    def dir(self):

        raise NotImplementedError

    def file(self):

        raise NotImplementedError

    def dotfile(self):

        return self.path.basename.startswith('.')

    def ext(self, arg):

        if not arg.startswith('.'):

            arg = '.' + arg

        return self.path.ext == arg

    def exists(self):

        raise NotImplementedError

    def basename(self, arg):

        return self.path.basename == arg

    def basestarts(self, arg):

        return self.path.basename.startswith(arg)

    def relto(self, arg):

        return self.path.relto(arg)

    def fnmatch(self, arg):

        return self.path.fnmatch(arg)

    def endswith(self, arg):

        return str(self.path).endswith(arg)

    def _evaluate(self, kw):

        for name, value in kw.items():

            invert = False

            meth = None

            try:

                meth = getattr(self, name)

            except AttributeError:

                if name[:3] == 'not':

                    invert = True

                    try:

                        meth = getattr(self, name[3:])

                    except AttributeError:

                        pass

            if meth is None:

                raise TypeError(

                    "no %r checker available for %r" % (name, self.path))

            try:

                if py.code.getrawcode(meth).co_argcount > 1:

                    if (not meth(value)) ^ invert:

                        return False

                else:

                    if bool(value) ^ bool(meth()) ^ invert:

                        return False

            except (py.error.ENOENT, py.error.ENOTDIR):

                for name in self._depend_on_existence:

                    if name in kw:

                        if kw.get(name):

                            return False

                    name = 'not' + name

                    if name in kw:

                        if not kw.get(name):

                            return False

        return True

class NeverRaised(Exception):

    pass

class PathBase(object):

    """ shared implementation for filesystem path objects."""

    Checkers = Checkers

    def __div__(self, other):

        return self.join(str(other))

    __truediv__ = __div__ # py3k

    def basename(self):

        """ basename part of path. """

        return self._getbyspec('basename')[0]

    basename = property(basename, None, None, basename.__doc__)

    def dirname(self):

        """ dirname part of path. """

        return self._getbyspec('dirname')[0]

    dirname = property(dirname, None, None, dirname.__doc__)

    def purebasename(self):

        """ pure base name of the path."""

        return self._getbyspec('purebasename')[0]

    purebasename = property(purebasename, None, None, purebasename.__doc__)

    def ext(self):

        """ extension of the path (including the '.')."""

        return self._getbyspec('ext')[0]

    ext = property(ext, None, None, ext.__doc__)

    def dirpath(self, *args, **kwargs):

        """ return the directory Path of the current Path joined

            with any given path arguments.

        """

        return self.new(basename='').join(*args, **kwargs)

    def read(self, mode='r'):

        """ read and return a bytestring from reading the path. """

        if sys.version_info < (2,3):

            for x in 'u', 'U':

                if x in mode:

                    mode = mode.replace(x, '')

        f = self.open(mode)

        try:

            return f.read()

        finally:

            f.close()

    def readlines(self, cr=1):

        """ read and return a list of lines from the path. if cr is False, the

newline will be removed from the end of each line. """

        if not cr:

            content = self.read('rU')

            return content.split('\n')

        else:

            f = self.open('rU')

            try:

                return f.readlines()

            finally:

                f.close()

    def load(self):

        """ (deprecated) return object unpickled from self.read() """

        f = self.open('rb')

        try:

            return py.error.checked_call(py.std.pickle.load, f)

        finally:

            f.close()

    def move(self, target):

        """ move this path to target. """

        if target.relto(self):

            raise py.error.EINVAL(target,

                "cannot move path into a subdirectory of itself")

        try:

            self.rename(target)

        except py.error.EXDEV:  # invalid cross-device link

            self.copy(target)

            self.remove()

    def __repr__(self):

        """ return a string representation of this path. """

        return repr(str(self))

    def check(self, **kw):

        """ check a path for existence and properties.

            Without arguments, return True if the path exists, otherwise False.

            valid checkers::

                file=1    # is a file

                file=0    # is not a file (may not even exist)

                dir=1     # is a dir

                link=1    # is a link

                exists=1  # exists

            You can specify multiple checker definitions, for example::

                path.check(file=1, link=1)  # a link pointing to a file

        """

        if not kw:

            kw = {'exists' : 1}

        return self.Checkers(self)._evaluate(kw)

    def fnmatch(self, pattern):

        """return true if the basename/fullname matches the glob-'pattern'.

        valid pattern characters::

            *       matches everything

            ?       matches any single character

            [seq]   matches any character in seq

            [!seq]  matches any char not in seq

        If the pattern contains a path-separator then the full path

        is used for pattern matching and a '*' is prepended to the

        pattern.

        if the pattern doesn't contain a path-separator the pattern

        is only matched against the basename.

        """

        return FNMatcher(pattern)(self)

    def relto(self, relpath):

        """ return a string which is the relative part of the path

        to the given 'relpath'.

        """

        if not isinstance(relpath, (str, PathBase)):

            raise TypeError("%r: not a string or path object" %(relpath,))

        strrelpath = str(relpath)

        if strrelpath and strrelpath[-1] != self.sep:

            strrelpath += self.sep

        #assert strrelpath[-1] == self.sep

        #assert strrelpath[-2] != self.sep

        strself = str(self)

        if sys.platform == "win32" or getattr(os, '_name', None) == 'nt':

            if os.path.normcase(strself).startswith(

               os.path.normcase(strrelpath)):

                return strself[len(strrelpath):]

        elif strself.startswith(strrelpath):

            return strself[len(strrelpath):]

        return ""

    def bestrelpath(self, dest):

        """ return a string which is a relative path from self

            (assumed to be a directory) to dest such that

            self.join(bestrelpath) == dest and if not such

            path can be determined return dest.

        """

        try:

            if self == dest:

                return os.curdir

            base = self.common(dest)

            if not base:  # can be the case on windows

                return str(dest)

            self2base = self.relto(base)

            reldest = dest.relto(base)

            if self2base:

                n = self2base.count(self.sep) + 1

            else:

                n = 0

            l = [os.pardir] * n

            if reldest:

                l.append(reldest)

            target = dest.sep.join(l)

            return target

        except AttributeError:

            return str(dest)

    def parts(self, reverse=False):

        """ return a root-first list of all ancestor directories

            plus the path itself.

        """

        current = self

        l = [self]

        while 1:

            last = current

            current = current.dirpath()

            if last == current:

                break

            l.insert(0, current)

        if reverse:

            l.reverse()

        return l

    def common(self, other):

        """ return the common part shared with the other path

            or None if there is no common part.

        """

        last = None

        for x, y in zip(self.parts(), other.parts()):

            if x != y:

                return last

            last = x

        return last

    def __add__(self, other):

        """ return new path object with 'other' added to the basename"""

        return self.new(basename=self.basename+str(other))

    def __cmp__(self, other):

        """ return sort value (-1, 0, +1). """

        try:

            return cmp(self.strpath, other.strpath)

        except AttributeError:

            return cmp(str(self), str(other)) # self.path, other.path)

    def __lt__(self, other):

        try:

            return self.strpath < other.strpath

        except AttributeError:

            return str(self) < str(other)

    def visit(self, fil=None, rec=None, ignore=NeverRaised, bf=False, sort=False):

        """ yields all paths below the current one

            fil is a filter (glob pattern or callable), if not matching the

            path will not be yielded, defaulting to None (everything is

            returned)

            rec is a filter (glob pattern or callable) that controls whether

            a node is descended, defaulting to None

            ignore is an Exception class that is ignoredwhen calling dirlist()

            on any of the paths (by default, all exceptions are reported)

            bf if True will cause a breadthfirst search instead of the

            default depthfirst. Default: False

            sort if True will sort entries within each directory level.

        """

        for x in Visitor(fil, rec, ignore, bf, sort).gen(self):

            yield x

    def _sortlist(self, res, sort):

        if sort:

            if hasattr(sort, '__call__'):

                res.sort(sort)

            else:

                res.sort()

    def samefile(self, other):

        """ return True if other refers to the same stat object as self. """

        return self.strpath == str(other)

class Visitor:

    def __init__(self, fil, rec, ignore, bf, sort):

        if isinstance(fil, str):

            fil = FNMatcher(fil)

        if isinstance(rec, str):

            self.rec = fnmatch(fil)

        elif not hasattr(rec, '__call__') and rec:

            self.rec = lambda path: True

        else:

            self.rec = rec

        self.fil = fil

        self.ignore = ignore

        self.breadthfirst = bf

        self.optsort = sort and sorted or (lambda x: x)

    def gen(self, path):

        try:

            entries = path.listdir()

        except self.ignore:

            return

        rec = self.rec

        dirs = self.optsort([p for p in entries

                    if p.check(dir=1) and (rec is None or rec(p))])

        if not self.breadthfirst:

            for subdir in dirs:

                for p in self.gen(subdir):

                    yield p

        for p in self.optsort(entries):

            if self.fil is None or self.fil(p):

                yield p

        if self.breadthfirst:

            for subdir in dirs:

                for p in self.gen(subdir):

                    yield p

class FNMatcher:

    def __init__(self, pattern):

        self.pattern = pattern

    def __call__(self, path):

        pattern = self.pattern

        if pattern.find(path.sep) == -1:

            name = path.basename

        else:

            name = str(path) # path.strpath # XXX svn?

            pattern = '*' + path.sep + pattern

        from fnmatch import fnmatch

        return fnmatch(name, pattern)