# This program is free software; you can redistribute it and/or modify
# it under the terms of the (LGPL) GNU Lesser General Public License as
# published by the Free Software Foundation; either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Library Lesser General Public License for more details at
# ( http://www.gnu.org/licenses/lgpl.html ).
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
# written by: Jeff Ortel ( jortel@redhat.com )

"""
Provides I{marshaller} core classes.
"""

from suds import *
from suds.mx import *
from suds.mx.appender import ContentAppender
from suds.sax.document import Document

from logging import getLogger
log = getLogger(__name__)


class Core:
    """
    An I{abstract} marshaller.  This class implement the core
    functionality of the marshaller.
    @ivar appender: A content appender.
    @type appender: L{ContentAppender}
    """

    def __init__(self):
        """
        """
        self.appender = ContentAppender(self)

    def process(self, content):
        """
        Process (marshal) the tag with the specified value using the
        optional type information.
        @param content: The content to process.
        @type content: L{Object}
        """
        log.debug('processing:\n%s', content)
        self.reset()
        if content.tag is None:
            content.tag = content.value.__class__.__name__
        document = Document()
        self.append(document, content)
        return document.root()

    def append(self, parent, content):
        """
        Append the specified L{content} to the I{parent}.
        @param parent: The parent node to append to.
        @type parent: L{Element}
        @param content: The content to append.
        @type content: L{Object}
        """
        log.debug('appending parent:\n%s\ncontent:\n%s', parent, content)
        if self.start(content):
            self.appender.append(parent, content)
            self.end(parent, content)

    def reset(self):
        """
        Reset the marshaller.
        """
        pass

    def node(self, content):
        """
        Create and return an XML node.
        @param content: Content information for the new node.
        @type content: L{Content}
        @return: An element.
        @rtype: L{Element}
        """
        raise NotImplementedError

    def start(self, content):
        """
        Appending this content has started.
        @param content: The content for which processing has started.
        @type content: L{Content}
        @return: True to continue appending
        @rtype: boolean
        """
        return True

    def suspend(self, content):
        """
        Appending this content has suspended.
        @param content: The content for which processing has been suspended.
        @type content: L{Content}
        """
        pass

    def resume(self, content):
        """
        Appending this content has resumed.
        @param content: The content for which processing has been resumed.
        @type content: L{Content}
        """
        pass

    def end(self, parent, content):
        """
        Appending this content has ended.
        @param parent: The parent node ending.
        @type parent: L{Element}
        @param content: The content for which processing has ended.
        @type content: L{Content}
        """
        pass

    def setnil(self, node, content):
        """
        Set the value of the I{node} to nill.
        @param node: A I{nil} node.
        @type node: L{Element}
        @param content: The content to set nil.
        @type content: L{Content}
        """
        pass

    def setdefault(self, node, content):
        """
        Set the value of the I{node} to a default value.
        @param node: A I{nil} node.
        @type node: L{Element}
        @param content: The content to set the default value.
        @type content: L{Content}
        @return: The default.
        """
        pass

    def optional(self, content):
        """
        Get whether the specified content is optional.
        @param content: The content which to check.
        @type content: L{Content}
        """
        return False