"""

Represents the response header list as a dictionary-like object.

"""

from webob.multidict import MultiDict

try:

    reversed

except NameError:

    from webob.util.reversed import reversed

class HeaderDict(MultiDict):

    """

    Like a MultiDict, this wraps a list.  Keys are normalized

    for case and whitespace.

    """

    def normalize(self, key):

        return str(key).lower().strip()

    def __getitem__(self, key):

        normalize = self.normalize

        key = normalize(key)

        for k, v in reversed(self._items):

            if normalize(k) == key:

                return v

        raise KeyError(key)

    def getall(self, key):

        normalize = self.normalize

        key = normalize(key)

        result = []

        for k, v in self._items:

            if normalize(k) == key:

                result.append(v)

        return result

    def mixed(self):

        result = {}

        multi = {}

        normalize = self.normalize

        for key, value in self.iteritems():

            key = normalize(key)

            if key in result:

                if key in multi:

                    result[key].append(value)

                else:

                    result[key] = [result[key], value]

                    multi[key] = None

            else:

                result[key] = value

        return result

    def dict_of_lists(self):

        result = {}

        normalize = self.normalize

        for key, value in self.iteritems():

            key = normalize(key)

            if key in result:

                result[key].append(value)

            else:

                result[key] = [value]

        return result

    def __delitem__(self, key):

        normalize = self.normalize

        key = normalize(key)

        items = self._items

        found = False

        for i in range(len(items)-1, -1, -1):

            if normalize(items[i][0]) == key:

                del items[i]

                found = True

        if not found:

            raise KeyError(key)

    def __contains__(self, key):

        normalize = self.normalize

        key = normalize(key)

        for k, v in self._items:

            if normalize(k) == key:

                return True

        return False

    has_key = __contains__

    def setdefault(self, key, default=None):

        normalize = self.normalize

        c_key = normalize(key)

        for k, v in self._items:

            if normalize(k) == c_key:

                return v

        self._items.append((key, default))

        return default

    def pop(self, key, *args):

        if len(args) > 1:

            raise TypeError, "pop expected at most 2 arguments, got "\

                              + repr(1 + len(args))

        key = self.normalize(key)

        for i in range(len(self._items)):

            if self.normalize(self._items[i][0]) == key:

                v = self._items[i][1]

                del self._items[i]

                return v

        if args:

            return args[0]

        else:

            raise KeyError(key)