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# Copyright (C) 2009, Tutorius.org
# Copyright (C) 2009, Jean-Christophe Savard <savard.jean.christophe@gmail.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA


"""
This module contains all the data handling class of Tutorius  
"""

import logging
import os
import shutil
import tempfile
import uuid
import xml.dom.minidom
from xml.dom import NotFoundErr
import zipfile
from ConfigParser import SafeConfigParser

from . import addon
from .core import Tutorial, State, FiniteStateMachine

logger = logging.getLogger("tutorius")

# this is where user installed/generated tutorials will go
def _get_store_root():
    profile_name = os.getenv("SUGAR_PROFILE") or "default"
    return os.path.join(os.getenv("HOME"),
                        ".sugar",profile_name,"tutorius","data")
# this is where activity bundled tutorials should be, under the activity bundle
def _get_bundle_root():
    """
    Return the path of the bundled activity, or None if not applicable.
    """
    if os.getenv("SUGAR_BUNDLE_PATH") != None:
        return os.path.join(os.getenv("SUGAR_BUNDLE_PATH"),"data","tutorius","data")
    else:
        return None

INI_ACTIVITY_SECTION = "RELATED_ACTIVITIES"
INI_METADATA_SECTION = "GENERAL_METADATA"
INI_GUID_PROPERTY = "guid"
INI_NAME_PROPERTY = "name"
INI_XML_FSM_PROPERTY = "fsm_filename"
INI_VERSION_PROPERTY = 'version'
INI_FILENAME = "meta.ini"
TUTORIAL_FILENAME = "tutorial.xml"
NODE_COMPONENT = "Component"
NODE_SUBCOMPONENT = "property"
NODE_SUBCOMPONENTLIST = "listproperty"
NEXT_STATE_ATTR = "next_state"

class Vault(object):
    
    ## Vault internal functions :    
    @staticmethod
    def list_available_tutorials(activity_name = None, activity_vers = 0):
        """
        Generate the list of all tutorials present on disk for a
        given activity.

        @param activity_name the name of the activity associated with this tutorial. None means ALL activities
        @param activity_vers the version number of the activity to find tutorail for. 0 means find for ANY version. If activity_name is None, version number is not used
        @returns a map of tutorial {names : GUID}.
        """
        # check both under the activity data and user installed folders
        if _get_bundle_root() != None:
            paths = [_get_store_root(), _get_bundle_root()]
        else:
            paths = [_get_store_root()]

        tutoGuidName = {}

        for repository in paths:
            # (our) convention dictates that tutorial folders are named
            # with their GUID (for unicity)
            try:
                for tuto in os.listdir(repository):
                    parser = SafeConfigParser()
                    file = parser.read(os.path.join(repository, tuto, INI_FILENAME))
                    if file != []:
                        # If parser can read at least section
                        guid = parser.get(INI_METADATA_SECTION, INI_GUID_PROPERTY)
                        name = parser.get(INI_METADATA_SECTION, INI_NAME_PROPERTY)
                        activities = parser.options(INI_ACTIVITY_SECTION)
                        # enforce matching activity name AND version, as UI changes
                        # break tutorials. We may lower this requirement when the
                        # UAM gets less dependent on the widget order.
                        # Also note property names are always stored lowercase.
                        if (activity_name != None) and (activity_name.lower() in activities):
                            version = parser.get(INI_ACTIVITY_SECTION, activity_name)
                            if (activity_vers == version) or (activity_vers == 0):
                                tutoGuidName[guid] = name
                        elif (activity_name == None):
                            tutoGuidName[guid] = name
            except OSError:
                # the repository may not exist. Continue scanning
                pass

        return tutoGuidName
    
    ## Vault interface functions :
    @staticmethod
    def installTutorials(path, zip_file_name, forceinstall=False):
        """
        Extract the tutorial files in the ZIPPED tutorial archive at the
        specified path and add them inside the vault. This should remove any previous
        version of this tutorial, if there's any. On the opposite, if we are
        trying to install an earlier version, the function will return 1 if
        forceInstall is not set to true.
        
        @params path The path where the zipped tutorial archive is present
        @params forceinstall A flag that indicate if we need to force overwrite
        of a tutorial even if is version number is lower than the existing one.
        
        @returns 0 if it worked, 1 if the user needs to confirm the installation
        and 2 to mean an error happened
        """
        # TODO : Check with architecture team for exception vs error returns
        
        # test if the file is a valid pkzip file
        if zipfile.is_zipfile(os.path.join(path, zip_file_name)) != True:
            assert False, "Error : The given file is not a valid PKZip file"
                        
        # unpack the zip archive
        zfile = zipfile.ZipFile(os.path.join(path, zip_file_name), "r" )
        
        temp_path = tempfile.mkdtemp(dir=_get_store_root())
        zfile.extractall(temp_path)
            
        # get the tutorial file
        ini_file_path = os.path.join(temp_path, INI_FILENAME)
        ini_file = SafeConfigParser()
        ini_file.read(ini_file_path)
        
        # get the tutorial guid
        guid = ini_file.get(INI_METADATA_SECTION, INI_GUID_PROPERTY)
        
        # Check if tutorial already exist
        tutorial_path = os.path.join(_get_store_root(), guid)
        if os.path.isdir(tutorial_path) == False:
            # Copy the tutorial in the Vault
            shutil.copytree(temp_path, tutorial_path)
        
        else:
            # Check the version of the existing tutorial
            existing_version = ini_file.get(INI_METADATA_SECTION, INI_VERSION_PROPERTY)
            # Check the version of the new tutorial
            new_ini_file = SafeConfigParser()
            new_ini_file.read(os.path.join(tutorial_path, INI_FILENAME))
            new_version = new_ini_file.get(INI_METADATA_SECTION, INI_VERSION_PROPERTY)
            
            if new_version < existing_version and forceinstall == False:
                # Version of new tutorial is older and forceinstall is false, return exception
                return 1
            else :
                # New tutorial is newer or forceinstall flag is set, can overwrite the existing tutorial
                shutil.rmtree(tutorial_path)
                shutil.copytree(temp_path, tutorial_path)
                
        # Remove temp data
        shutil.rmtree(temp_path)
            
        return 0
        
    @staticmethod
    def query(keyword=[], relatedActivityNames=[], category=[]):
        """
        Returns the list of tutorials that corresponds to the specified parameters.
        
        @returns a list of Tutorial meta-data (TutorialID, Description,
        Rating, Category, PublishState, etc...)
        TODO : Search for tuto caracterised by the entry : OR between [], and between each
        
        The returned dictionnary is of this format : key = property name, value = property value
        The dictionnary also contain one dictionnary element whose key is the string 'activities'
        and whose value is another dictionnary of this form : key = related activity name,
        value = related activity version number
        """

        # Temp solution for returning all tutorials metadata

        tutorial_list = []
        tuto_guid_list = []
        ini_file = SafeConfigParser()
        if keyword == [] and relatedActivityNames == [] and category == []:
            # get all tutorials tuples (name:guid) for all activities and version
            tuto_dict = Vault.list_available_tutorials()
            for id in tuto_dict.keys():
                tuto_guid_list.append(id)

        # Find .ini metadata files with the guid list

        # Get the guid from the tuto tuples
        for guid in tuto_guid_list:
            # Create a dictionnary containing the metadata and also
            # another dictionnary containing the tutorial Related Acttivities,
            # and add it to a list
            
            # Create a TutorialBundler object from the guid
            bundler = TutorialBundler(guid)
            # Find the .ini file path for this guid
            ini_file_path = bundler.get_tutorial_path(guid)
            # Read the .ini file
            ini_file.read(os.path.join(ini_file_path, 'meta.ini'))

            metadata_dictionnary = {}
            related_act_dictionnary = {}
            metadata_list = ini_file.options(INI_METADATA_SECTION)
            for metadata_name in metadata_list:
                 # Create a dictionnary of tutorial metadata
                 metadata_dictionnary[metadata_name] = ini_file.get(INI_METADATA_SECTION, metadata_name)
            # Get Related Activities data from.ini files
            related_act_list = ini_file.options(INI_ACTIVITY_SECTION)
            for related_act in related_act_list:
                # For related activites, the format is : key = activity name, value = activity version
                related_act_dictionnary[related_act] = ini_file.get(INI_ACTIVITY_SECTION, related_act)
            
            # Add Related Activities dictionnary to metadata dictionnary
            metadata_dictionnary['activities'] = related_act_dictionnary
            
            # Add this dictionnary to tutorial list
            tutorial_list.append(metadata_dictionnary)
             
        # Return tutorial list
        return tutorial_list
            
    @staticmethod    
    def loadTutorial(Guid):
        """
        Creates an executable version of a tutorial from its saved representation.
        @returns an executable representation of a tutorial
        """
        
        bundle = TutorialBundler(Guid)
        bundle_path = bundle.get_tutorial_path(Guid)
        config = SafeConfigParser()
        config.read(os.path.join(bundle_path, INI_FILENAME))

        serializer = XMLSerializer()

        name = config.get(INI_METADATA_SECTION, INI_NAME_PROPERTY)
        fsm = serializer.load_fsm(Guid, bundle_path)

        tuto = Tutorial(name, fsm)
        return tuto
        
    @staticmethod    
    def saveTutorial(tutorial, metadata_dict):
        """
        Creates a persistent version of a tutorial in the Vault.
        @returns true if the tutorial was saved correctly
        """
        
        # Get the tutorial guid from metadata dictionnary
        guid = metadata_dict[INI_GUID_PROPERTY]
        
        # Check if tutorial already exist
        tutorial_path = os.path.join(_get_store_root(), guid)
        if os.path.isdir(tutorial_path) == False:
            
            # Serialize the tutorial and write it to disk
            xml_ser = XMLSerializer()
            os.makedirs(tutorial_path)
            xml_ser.save_fsm(tutorial.state_machine, TUTORIAL_FILENAME, tutorial_path)
            
            # Create the metadata file
            ini_file_path = os.path.join(tutorial_path, "meta.ini")
            parser = SafeConfigParser()
            parser.add_section(INI_METADATA_SECTION)
            for key, value in metadata_dict.items():
                if key != 'activities':
                    parser.set(INI_METADATA_SECTION, key, value)
                else:
                    related_activities_dict = value
                    parser.add_section(INI_ACTIVITY_SECTION)
                    for related_key, related_value in related_activities_dict.items():
                        parser.set(INI_ACTIVITY_SECTION, related_key, related_value)

            # Write the file to disk
            with open(ini_file_path, 'wb') as configfile:
                parser.write(configfile)

        else:
            # Error, tutorial already exist
            return False
        
    # TODO : wait for Ben input on how to unpublish tuto before coding this function
    # For now, no unpublishing will occur.
    
    
    @staticmethod
    def deleteTutorial(Tutorial):
        """
        Removes the tutorial from the Vault. It will unpublish the tutorial if need be,
        and it will also wipe it from the persistent storage.
        @returns true is the tutorial was deleted from the Vault
        """
        bundle = TutorialBundler(Guid)
        bundle_path = bundle.get_tutorial_path(Guid)
        
        # TODO : Need also to unpublish tutorial, need to interact with webservice module
        
        shutil.rmtree(bundle_path)
        if os.path.isdir(bundle_path) == False:
            return True
        else:
            return False
        

class Serializer(object):
    """
    Interface that provide serializing and deserializing of the FSM
    used in the tutorials to/from disk. Must be inherited.
    """
    
    def save_fsm(self,fsm):
        """
        Save fsm to disk. If a GUID parameter is provided, the existing GUID is
        located in the .ini files in the store root and bundle root and
        the corresponding FSM is/are overwritten. If the GUId is not found, an 
        exception occur. If no GUID is provided, FSM is written in a new file 
        in the store root.
        """
        raise NotImplementedError()
        
    def load_fsm(self):
        """
        Load fsm from disk.
        """
        raise NotImplementedError()
        
class XMLSerializer(Serializer):
    """
    Class that provide serializing and deserializing of the FSM
    used in the tutorials to/from a .xml file. Inherit from Serializer
    """
    
    def _create_state_dict_node(self, state_dict, doc):
        """
        Create and return a xml Node from a State dictionnary.
        """
        statesList = doc.createElement("States")
        for state_name, state in state_dict.items():
            stateNode = doc.createElement("State")
            statesList.appendChild(stateNode)
            stateNode.setAttribute("Name", state_name)
            actionsList = stateNode.appendChild(self._create_action_list_node(state.get_action_list(), doc))
            eventfiltersList = stateNode.appendChild(self._create_event_filters_node(state.get_event_filter_list(), doc))
        return statesList
    
    def _create_addon_component_node(self, parent_attr_name, comp, doc):
        """
        Takes a component that is embedded in another component (e.g. the content
        of a OnceWrapper) and encapsulate it in a node with the property name.

        e.g.
        <Component Class="OnceWrapper">
            <property name="addon">
                <Component Class="BubbleMessage" message="'Hi!'" position="[12,32]"/>
            </property>
        </Component>
        
        When reloading this node, we should look up the property name for the parent
        in the attribute of the node, then examine the subnode to create the addon
        object itself.

        @param parent_attr_name The name of the parent's attribute for this addon
                e.g. the OnceWrapper has the action attribute, which corresponds to a
                    sub-action it must execute once.
        @param comp The component node itself
        @param doc The XML document root (only used to create the nodes)
        @returns A NODE_SUBCOMPONENT node, with the property attribute and a sub node 
                that represents another component.
        """
        subCompNode = doc.createElement(NODE_SUBCOMPONENT)
        subCompNode.setAttribute("name", parent_attr_name)

        subNode = self._create_component_node(comp, doc)

        subCompNode.appendChild(subNode)

        return subCompNode

    def _create_addonlist_component_node(self, parent_attr_name, comp_list, doc):
        """
        Takes a list of components that are embedded in another component (ex. the
        content of a ChainAction) and encapsulate them in a node with the property
        name.
        
        e.g.
        <Component Class="ChainAction">
            <listproperty name="actions">
                <Component Class="BubbleMessage" message="'Hi!'" position="[15,35]"/> 
                <Component Class="DialogMessage" message="'Multi-action!'" position="[45,10]"/>
            </listproperty>
        </Component>

        When reloading this node, we should look up the property name for the parent
        in the the attribute of the node, then rebuild the list by appending the 
        content of all the subnodes.

        @param parent_attr_name The name of the parent component's property
        @param comp_list A list of components that comprise the property
        @param doc The XML document root (only for creating new nodes)
        @returns A NODE_SUBCOMPONENTLIST node with the property attribute
        """
        subCompListNode = doc.createElement(NODE_SUBCOMPONENTLIST)
        subCompListNode.setAttribute("name", parent_attr_name)

        for comp in comp_list:
            compNode = self._create_component_node(comp, doc)
            subCompListNode.appendChild(compNode)

        return subCompListNode

    def _create_component_node(self, comp, doc):
        """
        Takes a single component (action or eventfilter) and transforms it 
        into a xml node.
        
        @param comp A single component
        @param doc The XML document root (used to create nodes only
        @return A XML Node object with the component tag name
        """
        compNode = doc.createElement(NODE_COMPONENT)
        
        # Write down just the name of the Action class as the Class
        # property --
        compNode.setAttribute("Class",type(comp).__name__)

        # serialize all tutorius properties
        for propname in comp.get_properties():
            propval = getattr(comp, propname)
            if getattr(type(comp), propname).type == "addonlist":
                compNode.appendChild(self._create_addonlist_component_node(propname, propval, doc))
            elif getattr(type(comp), propname).type == "addon":
                #import rpdb2; rpdb2.start_embedded_debugger('pass')
                compNode.appendChild(self._create_addon_component_node(propname, propval, doc))
            else:
                # repr instead of str, as we want to be able to eval() it into a
                # valid object.
                compNode.setAttribute(propname, repr(propval))
        
        return compNode
        
    def _create_action_list_node(self, action_list, doc):
        """
        Create and return a xml Node from a Action list.
        
        @param action_list A list of actions
        @param doc The XML document root (used to create new nodes only)
        @return A XML Node object with the Actions tag name and a serie of 
        Action children
        """
        actionsList = doc.createElement("Actions")
        for action in action_list:
            # Create the action node
            actionNode = self._create_component_node(action, doc)
            # Append it to the list
            actionsList.appendChild(actionNode)
            
        return actionsList
    
    def _create_event_filters_node(self, event_filters, doc):
        """
        Create and return a xml Node from an event filters.
        """
        eventFiltersList = doc.createElement("EventFiltersList")
        for event, state in event_filters:
            eventFilterNode = self._create_component_node(event, doc)
            eventFilterNode.setAttribute(NEXT_STATE_ATTR, str(state))
            eventFiltersList.appendChild(eventFilterNode)

        return eventFiltersList

    def save_fsm(self, fsm, xml_filename, path):
        """
        Save fsm to disk, in the xml file specified by "xml_filename", in the 
        "path" folder. If the specified file doesn't exist, it will be created.
        """ 
        self.doc = doc = xml.dom.minidom.Document()
        fsm_element = doc.createElement("FSM")
        doc.appendChild(fsm_element)
        fsm_element.setAttribute("Name", fsm.name)
        fsm_element.setAttribute("StartStateName", fsm.start_state_name)
        statesDict = fsm_element.appendChild(self._create_state_dict_node(fsm._states, doc))
        
        fsm_actions_node = self._create_action_list_node(fsm.actions, doc)
        fsm_actions_node.tagName = "FSMActions"
        actionsList = fsm_element.appendChild(fsm_actions_node)
        
        file_object = open(os.path.join(path, xml_filename), "w")
        file_object.write(doc.toprettyxml())
        file_object.close()

    def _get_direct_descendants_by_tag_name(self, node, name):
        """
        Searches in the list of direct descendants of a node to find all the node
        that have the given name.
        
        This is used because the Document.getElementsByTagName() function returns the
        list of all the descendants (whatever their distance to the start node) that
        have that name. In the case of complex components, we absolutely need to inspect
        a single layer of the tree at the time.
        
        @param node The node from which we want the direct descendants with a particular
                    name
        @param name The name of the node
        @returns A list, possibly empty, of direct descendants of node that have this name 
        """
        return_list = []
        for childNode in node.childNodes:
            if childNode.nodeName == name:
                return_list.append(childNode)
        return return_list


##    def _load_xml_properties(self, properties_elem):
##        """
##        Changes a list of properties into fully instanciated properties.
##        
##        @param properties_elem An XML element reprensenting a list of 
##        properties
##        """
##        return []
    
    def _load_xml_event_filters(self, filters_elem):
        """
        Loads up a list of Event Filters.
        
        @param filters_elem An XML Element representing a list of event filters
        """
        transition_list = []
        event_filter_element_list = self._get_direct_descendants_by_tag_name(filters_elem, NODE_COMPONENT)
        new_event_filter = None
        
        for event_filter in event_filter_element_list:
            next_state = event_filter.getAttribute(NEXT_STATE_ATTR)
            try:
                event_filter.removeAttribute(NEXT_STATE_ATTR)
            except NotFoundErr:
                next_state = None
            new_event_filter = self._load_xml_component(event_filter)
            
            if new_event_filter is not None:
                transition_list.append((new_event_filter, next_state))
            
        return transition_list
    
    def _load_xml_subcomponents(self, node, properties):
        """
        Loads all the subcomponent node below the given node and inserts them with
        the right property name inside the properties dictionnary.

        @param node The parent node that contains one or many property nodes.
        @param properties A dictionnary where the subcomponent property names
                and the instantiated components will be stored
        @returns Nothing. The properties dict will contain the property->comp mapping.
        """
        subCompList = self._get_direct_descendants_by_tag_name(node, NODE_SUBCOMPONENT)

        for subComp in subCompList:
            property_name = subComp.getAttribute("name")
            internal_comp_node = self._get_direct_descendants_by_tag_name(subComp, NODE_COMPONENT)[0]
            internal_comp = self._load_xml_component(internal_comp_node)
            properties[str(property_name)] = internal_comp

    def _load_xml_subcomponent_lists(self, node, properties):
        """
        Loads all the subcomponent lists below the given node and stores them
        under the correct property name for that node.

        @param node The node from which we want to read the subComponent lists
        @param properties The dictionnary that will contain the mapping of prop->subCompList
        @returns Nothing. The values are returns inside the properties dict.
        """
        listOf_subCompListNode = self._get_direct_descendants_by_tag_name(node, NODE_SUBCOMPONENTLIST)
        for subCompListNode in listOf_subCompListNode:
            property_name = subCompListNode.getAttribute("name")
            subCompList = []
            for subCompNode in self._get_direct_descendants_by_tag_name(subCompListNode, NODE_COMPONENT):
                subComp = self._load_xml_component(subCompNode)
                subCompList.append(subComp)
            properties[str(property_name)] = subCompList

    def _load_xml_component(self, node):
        """
        Loads a single addon component instance from an Xml node.
        
        @param node The component XML Node to transform
        object
        @return The addon component object of the correct type according to the XML
        description
        """
        class_name = node.getAttribute("Class")
        
        properties = {}

        for prop in node.attributes.keys():
            if prop == "Class" : continue
            # security : keep sandboxed
            properties[str(prop)] = eval(node.getAttribute(prop))

        # Read the complex attributes
        self._load_xml_subcomponents(node, properties)
        self._load_xml_subcomponent_lists(node, properties)

        new_action = addon.create(class_name, **properties)

        if not new_action:
            return None

        return new_action
    
    def _load_xml_actions(self, actions_elem):
        """
        Transforms an Actions element into a list of instanciated Action.
        
        @param actions_elem An XML Element representing a list of Actions
        """
        reformed_actions_list = []
        actions_element_list = self._get_direct_descendants_by_tag_name(actions_elem, NODE_COMPONENT)
        
        for action in actions_element_list:
            new_action = self._load_xml_component(action)
            
            reformed_actions_list.append(new_action)
        
        return reformed_actions_list
    
    def _load_xml_states(self, states_elem):
        """
        Takes in a States element and fleshes out a complete list of State 
        objects.
        
        @param states_elem An XML Element that represents a list of States
        """
        reformed_state_list = []
        # item(0) because there is always only one <States> tag in the xml file
        # so states_elem should always contain only one element
        states_element_list = states_elem.item(0).getElementsByTagName("State")
        
        for state in states_element_list:
            stateName = state.getAttribute("Name")
            # Using item 0 in the list because there is always only one 
            # Actions and EventFilterList element per State node.
            actions_list = self._load_xml_actions(state.getElementsByTagName("Actions")[0])
            event_filters_list = self._load_xml_event_filters(state.getElementsByTagName("EventFiltersList")[0])
            reformed_state_list.append(State(stateName, actions_list, event_filters_list))
        
        return reformed_state_list

    def load_xml_fsm(self, fsm_elem):
        """
        Takes in an XML element representing an FSM and returns the fully 
        crafted FSM.
        
        @param fsm_elem The XML element that describes a FSM
        """
        # Load the FSM's name and start state's name
        fsm_name = fsm_elem.getAttribute("Name")
        
        fsm_start_state_name = None
        try:
            fsm_start_state_name = fsm_elem.getAttribute("StartStateName")
        except:
            pass
        
        fsm = FiniteStateMachine(fsm_name, start_state_name=fsm_start_state_name)
        
        # Load the states
        states = self._load_xml_states(fsm_elem.getElementsByTagName("States"))
        for state in states:
            fsm.add_state(state)
        
        # Load the actions on this FSM
        actions = self._load_xml_actions(fsm_elem.getElementsByTagName("FSMActions")[0])
        for action in actions:
            fsm.add_action(action)
            
        # Load the event filters
        events = self._load_xml_event_filters(fsm_elem.getElementsByTagName("EventFiltersList")[0])
        for event, next_state in events:
            fsm.add_event_filter(event, next_state)
            
        return fsm
        
    
    def load_fsm(self, guid, path=None):
        """
        Load fsm from xml file whose .ini file guid match argument guid.
        """
        # Fetch the directory (if any)
        bundler = TutorialBundler(guid)
        tutorial_dir = bundler.get_tutorial_path(guid)
        
        # Open the XML file
        tutorial_file = os.path.join(tutorial_dir, TUTORIAL_FILENAME)
        
        xml_dom = xml.dom.minidom.parse(tutorial_file)
        
        fsm_elem = xml_dom.getElementsByTagName("FSM")[0]
        
        return self.load_xml_fsm(fsm_elem)
        
    
class TutorialBundler(object):
    """
    This class provide the various data handling methods useable by the tutorial
    editor.
    """
    
    def __init__(self,generated_guid = None, bundle_path=None):
        """
        Tutorial_bundler constructor. If a GUID is given in the parameter, the
        Tutorial_bundler object will be associated with it. If no GUID is given,
        a new GUID will be generated,
        """
            
        self.Guid = generated_guid or str(uuid.uuid1())

        #FIXME: Look for the bundle in the activity first (more specific)
        #Look for the file in the path if a uid is supplied
        if generated_guid:
            #General store
            store_path = os.path.join(_get_store_root(), str(generated_guid), INI_FILENAME)
            if os.path.isfile(store_path):
                self.Path = os.path.dirname(store_path)
            elif _get_bundle_root() != None:
                #Bundle store
                bundle_path = os.path.join(_get_bundle_root(), str(generated_guid), INI_FILENAME)
                if os.path.isfile(bundle_path):
                    self.Path = os.path.dirname(bundle_path)
                else:
                    raise IOError(2,"Unable to locate metadata file for guid '%s'" % generated_guid)
            else:
                raise IOError(2,"Unable to locate metadata file for guid '%s'" % generated_guid)

        else:
                #Create the folder, any failure will go through to the caller for now
                store_path = os.path.join(_get_store_root(), self.Guid)
                os.makedirs(store_path)
                self.Path = store_path

    def write_metadata_file(self, tutorial):
        """
        Write metadata to the property file. 
        @param tutorial Tutorial for which to write metadata
        """
        #Create the Config Object and populate it
        cfg = SafeConfigParser()
        cfg.add_section(INI_METADATA_SECTION)
        cfg.set(INI_METADATA_SECTION, INI_GUID_PROPERTY, self.Guid)
        cfg.set(INI_METADATA_SECTION, INI_NAME_PROPERTY, tutorial.name)
        cfg.set(INI_METADATA_SECTION, INI_XML_FSM_PROPERTY, TUTORIAL_FILENAME)
        cfg.add_section(INI_ACTIVITY_SECTION)
        if os.environ['SUGAR_BUNDLE_NAME'] != None and os.environ['SUGAR_BUNDLE_VERSION'] != None:
            cfg.set(INI_ACTIVITY_SECTION, os.environ['SUGAR_BUNDLE_NAME'],
                os.environ['SUGAR_BUNDLE_VERSION'])
        else:
            cfg.set(INI_ACTIVITY_SECTION, 'not_an_activity', '0')

        #Write the ini file
        cfg.write( file( os.path.join(self.Path, INI_FILENAME), 'w' ) )


    @staticmethod
    def get_tutorial_path(guid):
        """
        Finds the tutorial with the associated GUID. If it is found, return
        the path to the tutorial's directory. If it doesn't exist, raise an
        IOError.
        
        A note : if there are two tutorials with this GUID in the folders,
        they will both be inspected and the one with the highest version
        number will be returned. If they have the same version number, the one
        from the global store will be returned.
        
        @param guid The GUID of the tutorial that is to be loaded.
        """
        # Attempt to find the tutorial's directory in the global directory
        global_dir = os.path.join(_get_store_root(),str(guid))
        # Then in the activty's bundle path
        if _get_bundle_root() != None:
            activity_dir = os.path.join(_get_bundle_root(), str(guid))
        else:
            activity_dir = ''
        
        # If they both exist
        if os.path.isdir(global_dir) and os.path.isdir(activity_dir):
            # Inspect both metadata files
            global_meta = os.path.join(global_dir, "meta.ini")
            activity_meta = os.path.join(activity_dir, "meta.ini")
            
            # Open both config files
            global_parser = SafeConfigParser()
            global_parser.read(global_meta)
            
            activity_parser = SafeConfigParser()
            activity_parser.read(activity_meta)
            
            # Get the version number for each tutorial
            global_version = global_parser.get(INI_METADATA_SECTION, "version")
            activity_version = activity_parser.get(INI_METADATA_SECTION, "version")
            
            # If the global version is higher or equal, we'll take it
            if global_version >= activity_version:
                return global_dir
            else:
                return activity_dir
        
        # Do we just have the global directory?
        if os.path.isdir(global_dir):
            return global_dir
        
        # Or just the activity's bundle directory?
        if os.path.isdir(activity_dir):
            return activity_dir
        
        # Error : none of these directories contain the tutorial
        raise IOError(2, "Neither the global nor the bundle directory contained the tutorial with GUID %s"%guid)
    
    
    def write_fsm(self, fsm):

        """
        Save fsm to disk. If a GUID parameter is provided, the existing GUID is
        located in the .ini files in the store root and bundle root and
        the corresponding FSM is/are created or overwritten. If the GUID is not 
        found, an exception occur.
        """

        config = SafeConfigParser()

        serializer = XMLSerializer()
        path = os.path.join(self.Path, "meta.ini")
        config.read(path)
        xml_filename = config.get(INI_METADATA_SECTION, INI_XML_FSM_PROPERTY)
        serializer.save_fsm(fsm, xml_filename, self.Path)

    @staticmethod
    def add_resources(typename, file):
        """
        Add ressources to metadata.
        """
        raise NotImplementedError("add_resources not implemented")