#   Copyright 2000-2004 Michael Hudson-Doyle <micahel@gmail.com>
#
#                        All Rights Reserved
#
#
# Permission to use, copy, modify, and distribute this software and
# its documentation for any purpose is hereby granted without fee,
# provided that the above copyright notice appear in all copies and
# that both that copyright notice and this permission notice appear in
# supporting documentation.
#
# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

try:
    import __builtin__ as builtins
except ImportError:
    import builtins

class Completer:
    def __init__(self, ns):
        self.ns = ns

    def complete(self, text):
        if "." in text:
            return self.attr_matches(text)
        else:
            return self.global_matches(text)

    def global_matches(self, text):
        """Compute matches when text is a simple name.

        Return a list of all keywords, built-in functions and names
        currently defines in __main__ that match.

        """
        import keyword
        matches = []
        for list in [keyword.kwlist,
                     builtins.__dict__.keys(),
                     self.ns.keys()]:
            for word in list:
                if word.startswith(text) and word != "__builtins__":
                    matches.append(word)
        return matches

    def attr_matches(self, text):
        """Compute matches when text contains a dot.

        Assuming the text is of the form NAME.NAME....[NAME], and is
        evaluatable in the globals of __main__, it will be evaluated
        and its attributes (as revealed by dir()) are used as possible
        completions.  (For class instances, class members are are also
        considered.)

        WARNING: this can still invoke arbitrary C code, if an object
        with a __getattr__ hook is evaluated.

        """
        import re
        m = re.match(r"(\w+(\.\w+)*)\.(\w*)", text)
        if not m:
            return []
        expr, attr = m.group(1, 3)
        object = eval(expr, self.ns)
        words = dir(object)
        if hasattr(object, '__class__'):
            words.append('__class__')
            words = words + get_class_members(object.__class__)
        matches = []
        n = len(attr)
        for word in words:
            if word[:n] == attr and word != "__builtins__":
                matches.append("%s.%s" % (expr, word))
        return matches

def get_class_members(klass):
    ret = dir(klass)
    if hasattr(klass, '__bases__'):
        for base in klass.__bases__:
            ret = ret + get_class_members(base)
    return ret


