##   simplexml.py based on Mattew Allum's xmlstream.py

##

##   Copyright (C) 2003-2005 Alexey "Snake" Nezhdanov

##

##   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, 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.

# $Id: simplexml.py,v 1.30 2006/06/03 12:22:34 normanr Exp $

"""Simplexml module provides xmpppy library with all needed tools to handle XML nodes and XML streams.

I'm personally using it in many other separate projects. It is designed to be as standalone as possible."""

import xml.parsers.expat

def XMLescape(txt):

    """Returns provided string with symbols & < > " replaced by their respective XML entities."""

    return txt.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;").replace('"', "&quot;")

ENCODING='utf-8'

def ustr(what):

    """Converts object "what" to unicode string using it's own __str__ method if accessible or unicode method otherwise."""

    if type(what) == type(u''): return what

    try: r=what.__str__()

    except AttributeError: r=str(what)

    if type(r)<>type(u''): return unicode(r,ENCODING)

    return r

class Node:

    """ Node class describes syntax of separate XML Node. It have a constructor that permits node creation

        from set of "namespace name", attributes and payload of text strings and other nodes.

        It does not natively support building node from text string and uses NodeBuilder class for that purpose.

        After creation node can be mangled in many ways so it can be completely changed.

        Also node can be serialised into string in one of two modes: default (where the textual representation

        of node describes it exactly) and "fancy" - with whitespace added to make indentation and thus make

        result more readable by human.

        Node class have attribute FORCE_NODE_RECREATION that is defaults to False thus enabling fast node

        replication from the some other node. The drawback of the fast way is that new node shares some

        info with the "original" node that is changing the one node may influence the other. Though it is

        rarely needed (in xmpppy it is never needed at all since I'm usually never using original node after

        replication (and using replication only to move upwards on the classes tree).

    """

    FORCE_NODE_RECREATION=0

    def __init__(self, tag=None, attrs={}, payload=[], parent=None, node=None):

        """ Takes "tag" argument as the name of node (prepended by namespace, if needed and separated from it

            by a space), attrs dictionary as the set of arguments, payload list as the set of textual strings

            and child nodes that this node carries within itself and "parent" argument that is another node

            that this one will be the child of. Also the __init__ can be provided with "node" argument that is 

            either a text string containing exactly one node or another Node instance to begin with. If both

            "node" and other arguments is provided then the node initially created as replica of "node"

            provided and then modified to be compliant with other arguments."""

        if node:

            if self.FORCE_NODE_RECREATION and type(node)==type(self): node=str(node)

            if type(node)<>type(self): node=NodeBuilder(node,self)

            else:

                self.name,self.namespace,self.attrs,self.data,self.kids,self.parent = node.name,node.namespace,{},[],[],node.parent

                for key  in node.attrs.keys(): self.attrs[key]=node.attrs[key]

                for data in node.data: self.data.append(data)

                for kid  in node.kids: self.kids.append(kid)

        else: self.name,self.namespace,self.attrs,self.data,self.kids,self.parent = 'tag','',{},[],[],None

        if tag: self.namespace, self.name = ([self.namespace]+tag.split())[-2:]

        if parent: self.parent = parent

        if self.parent and not self.namespace: self.namespace=self.parent.namespace

        for attr in attrs.keys():

            self.attrs[attr]=attrs[attr]

        if type(payload) in (type(''),type(u'')): payload=[payload]

        for i in payload:

            if type(i)==type(self): self.addChild(node=i)

            else: self.data.append(ustr(i))

    def __str__(self,fancy=0):

        """ Method used to dump node into textual representation.

            if "fancy" argument is set to True produces indented output for readability."""

        s = (fancy-1) * 2 * ' ' + "<" + self.name

        if self.namespace:

            if not self.parent or self.parent.namespace!=self.namespace:

                s = s + ' xmlns="%s"'%self.namespace

        for key in self.attrs.keys():

            val = ustr(self.attrs[key])

            s = s + ' %s="%s"' % ( key, XMLescape(val) )

        s = s + ">"

        cnt = 0 

        if self.kids:

            if fancy: s = s + "\n"

            for a in self.kids:

                if not fancy and (len(self.data)-1)>=cnt: s=s+XMLescape(self.data[cnt])

                elif (len(self.data)-1)>=cnt: s=s+XMLescape(self.data[cnt].strip())

                s = s + a.__str__(fancy and fancy+1)

                cnt=cnt+1

        if not fancy and (len(self.data)-1) >= cnt: s = s + XMLescape(self.data[cnt])

        elif (len(self.data)-1) >= cnt: s = s + XMLescape(self.data[cnt].strip())

        if not self.kids and s[-1:]=='>':

            s=s[:-1]+' />'

            if fancy: s = s + "\n"

        else:

            if fancy and not self.data: s = s + (fancy-1) * 2 * ' '

            s = s + "</" + self.name + ">"

            if fancy: s = s + "\n"

        return s

    def getCDATA(self):

        """ Serialise node, dropping all tags and leaving CDATA intact.

            That is effectively kills all formatiing, leaving only text were contained in XML.

        """

        s =""

        cnt = 0

        if self.kids:

            for a in self.kids:

                s=s+self.data[cnt]

                s = s + mystr(a)

                cnt=cnt+1

        if (len(self.data)-1) >= cnt: s = s + self.data[cnt]

        return s

    def addChild(self, name=None, attrs={}, payload=[], namespace=None, node=None):

        """ If "node" argument is provided, adds it as child node. Else creates new node from

            the other arguments' values and adds it as well."""

        if attrs.has_key('xmlns'):

            raise AttributeError("Use namespace=x instead of attrs={'xmlns':x}")

        if namespace: name=namespace+' '+name

        if node:

            newnode=node

            node.parent = self

        else: newnode=Node(tag=name, parent=self, attrs=attrs, payload=payload)

        self.kids.append(newnode)

        return newnode

    def addData(self, data):

        """ Adds some CDATA to node. """

        self.data.append(ustr(data))

    def clearData(self):

        """ Removes all CDATA from the node. """

        self.data=[]

    def delAttr(self, key):

        """ Deletes an attribute "key" """

        del self.attrs[key]

    def delChild(self, node, attrs={}):

        """ Deletes the "node" from the node's childs list, if "node" is an instance.

            Else deletes the first node that have specified name and (optionally) attributes. """

        if type(node)<>type(self): node=self.getTag(node,attrs)

        self.kids.remove(node)

        return node

    def getAttrs(self):

        """ Returns all node's attributes as dictionary. """

        return self.attrs

    def getAttr(self, key):

        """ Returns value of specified attribute. """

        try: return self.attrs[key]

        except: return None

    def getChildren(self):

        """ Returns all node's child nodes as list. """

        return self.kids

    def getData(self):

        """ Returns all node CDATA as string (concatenated). """

        return ''.join(self.data)

    def getName(self):

        """ Returns the name of node """

        return self.name

    def getNamespace(self):

        """ Returns the namespace of node """

        return self.namespace

    def getParent(self):

        """ Returns the parent of node (if present). """

        return self.parent

    def getPayload(self):

        """ Return the payload of node i.e. list of child nodes and CDATA entries.

            F.e. for "<node>text1<nodea/><nodeb/> text2</node>" will be returned list:

            ['text1', <nodea instance>, <nodeb instance>, ' text2']. """

        ret=[]

        for i in range(len(self.kids)+len(self.data)+1):

            try:

                if self.data[i]: ret.append(self.data[i])

            except IndexError: pass

            try: ret.append(self.kids[i])

            except IndexError: pass

        return ret

    def getTag(self, name, attrs={}, namespace=None): 

        """ Filters all child nodes using specified arguments as filter.

            Returns the first found or None if not found. """

        return self.getTags(name, attrs, namespace, one=1)

    def getTagAttr(self,tag,attr):

        """ Returns attribute value of the child with specified name (or None if no such attribute)."""

        try: return self.getTag(tag).attrs[attr]

        except: return None

    def getTagData(self,tag):

        """ Returns cocatenated CDATA of the child with specified name."""

        try: return self.getTag(tag).getData()

        except: return None

    def getTags(self, name, attrs={}, namespace=None, one=0):

        """ Filters all child nodes using specified arguments as filter.

            Returns the list of nodes found. """

        nodes=[]

        for node in self.kids:

            if namespace and namespace<>node.getNamespace(): continue

            if node.getName() == name:

                for key in attrs.keys():

                   if not node.attrs.has_key(key) or node.attrs[key]<>attrs[key]: break

                else: nodes.append(node)

            if one and nodes: return nodes[0]

        if not one: return nodes

    def setAttr(self, key, val):

        """ Sets attribute "key" with the value "val". """

        self.attrs[key]=val

    def setData(self, data):

        """ Sets node's CDATA to provided string. Resets all previous CDATA!"""

        self.data=[ustr(data)]

    def setName(self,val):

        """ Changes the node name. """

        self.name = val

    def setNamespace(self, namespace):

        """ Changes the node namespace. """

        self.namespace=namespace

    def setParent(self, node): 

        """ Sets node's parent to "node". WARNING: do not checks if the parent already present 

            and not removes the node from the list of childs of previous parent. """

        self.parent = node

    def setPayload(self,payload,add=0):

        """ Sets node payload according to the list specified. WARNING: completely replaces all node's

            previous content. If you wish just to add child or CDATA - use addData or addChild methods. """

        if type(payload) in (type(''),type(u'')): payload=[payload]

        if add: self.kids+=payload

        else: self.kids=payload

    def setTag(self, name, attrs={}, namespace=None):

        """ Same as getTag but if the node with specified namespace/attributes not found, creates such

            node and returns it. """

        node=self.getTags(name, attrs, namespace=namespace, one=1)

        if node: return node

        else: return self.addChild(name, attrs, namespace=namespace)

    def setTagAttr(self,tag,attr,val):

        """ Creates new node (if not already present) with name "tag"

            and sets it's attribute "attr" to value "val". """

        try: self.getTag(tag).attrs[attr]=val

        except: self.addChild(tag,attrs={attr:val})

    def setTagData(self,tag,val,attrs={}):

        """ Creates new node (if not already present) with name "tag" and (optionally) attributes "attrs"

            and sets it's CDATA to string "val". """

        try: self.getTag(tag,attrs).setData(ustr(val))

        except: self.addChild(tag,attrs,payload=[ustr(val)])

    def has_attr(self,key):

        """ Checks if node have attribute "key"."""

        return self.attrs.has_key(key)

    def __getitem__(self,item):

        """ Returns node's attribute "item" value. """

        return self.getAttr(item)

    def __setitem__(self,item,val):

        """ Sets node's attribute "item" value. """

        return self.setAttr(item,val)

    def __delitem__(self,item):

        """ Deletes node's attribute "item". """

        return self.delAttr(item,val)

    def __getattr__(self,attr):

        """ Reduce memory usage caused by T/NT classes - use memory only when needed. """

        if attr=='T':

            self.T=T(self)

            return self.T

        if attr=='NT':

            self.NT=NT(self)

            return self.NT

        raise AttributeError

class T:

    """ Auxiliary class used to quick access to node's child nodes. """

    def __init__(self,node): self.__dict__['node']=node

    def __getattr__(self,attr): return self.node.getTag(attr)

    def __setattr__(self,attr,val):

        if isinstance(val,Node): Node.__init__(self.node.setTag(attr),node=val)

        else: return self.node.setTagData(attr,val)

    def __delattr__(self,attr): return self.node.delChild(attr)

class NT(T):

    """ Auxiliary class used to quick create node's child nodes. """

    def __getattr__(self,attr): return self.node.addChild(attr)

    def __setattr__(self,attr,val):

        if isinstance(val,Node): self.node.addChild(attr,node=val)

        else: return self.node.addChild(attr,payload=[val])

DBG_NODEBUILDER = 'nodebuilder'

class NodeBuilder:

    """ Builds a Node class minidom from data parsed to it. This class used for two purposes:

        1. Creation an XML Node from a textual representation. F.e. reading a config file. See an XML2Node method.

        2. Handling an incoming XML stream. This is done by mangling 

           the __dispatch_depth parameter and redefining the dispatch method.

        You do not need to use this class directly if you do not designing your own XML handler."""

    def __init__(self,data=None,initial_node=None):

        """ Takes two optional parameters: "data" and "initial_node".

            By default class initialised with empty Node class instance.

            Though, if "initial_node" is provided it used as "starting point".

            You can think about it as of "node upgrade".

            "data" (if provided) feeded to parser immidiatedly after instance init.

            """

        self.DEBUG(DBG_NODEBUILDER, "Preparing to handle incoming XML stream.", 'start')

        self._parser = xml.parsers.expat.ParserCreate(namespace_separator=' ')

        self._parser.StartElementHandler       = self.starttag

        self._parser.EndElementHandler         = self.endtag

        self._parser.CharacterDataHandler      = self.handle_data

        self._parser.StartNamespaceDeclHandler = self.handle_namespace_start

        self.Parse = self._parser.Parse

        self.__depth = 0

        self._dispatch_depth = 1

        self._document_attrs = None

        self._mini_dom=initial_node

        self.last_is_data = 1

        self._ptr=None

        self.namespaces={"http://www.w3.org/XML/1998/namespace":'xml:'}

        self.xmlns="http://www.w3.org/XML/1998/namespace"

        if data: self._parser.Parse(data,1)

    def destroy(self):

        """ Method used to allow class instance to be garbage-collected. """

        self._parser.StartElementHandler       = None

        self._parser.EndElementHandler         = None

        self._parser.CharacterDataHandler      = None

        self._parser.StartNamespaceDeclHandler = None

    def starttag(self, tag, attrs):

        """XML Parser callback. Used internally"""

        attlist=attrs.keys()       #

        for attr in attlist:       # FIXME: Crude hack. And it also slows down the whole library considerably.

            sp=attr.rfind(" ")     #

            if sp==-1: continue    #

            ns=attr[:sp]           #

            attrs[self.namespaces[ns]+attr[sp+1:]]=attrs[attr]

            del attrs[attr]        #

        self.__depth += 1

        self.DEBUG(DBG_NODEBUILDER, "DEPTH -> %i , tag -> %s, attrs -> %s" % (self.__depth, tag, `attrs`), 'down')

        if self.__depth == self._dispatch_depth:

            if not self._mini_dom : self._mini_dom = Node(tag=tag, attrs=attrs)

            else: Node.__init__(self._mini_dom,tag=tag, attrs=attrs)

            self._ptr = self._mini_dom

        elif self.__depth > self._dispatch_depth:

            self._ptr.kids.append(Node(tag=tag,parent=self._ptr,attrs=attrs))

            self._ptr = self._ptr.kids[-1]

        if self.__depth == 1:

            self._document_attrs = attrs

            ns, name = (['']+tag.split())[-2:]

            self.stream_header_received(ns, name, attrs)

        if not self.last_is_data and self._ptr.parent: self._ptr.parent.data.append('')

        self.last_is_data = 0

    def endtag(self, tag ):

        """XML Parser callback. Used internally"""

        self.DEBUG(DBG_NODEBUILDER, "DEPTH -> %i , tag -> %s" % (self.__depth, tag), 'up')

        if self.__depth == self._dispatch_depth:

            self.dispatch(self._mini_dom)

        elif self.__depth > self._dispatch_depth:

            self._ptr = self._ptr.parent

        else:

            self.DEBUG(DBG_NODEBUILDER, "Got higher than dispatch level. Stream terminated?", 'stop')

        self.__depth -= 1

        self.last_is_data = 0

        if self.__depth == 0: self.stream_footer_received()

    def handle_data(self, data):

        """XML Parser callback. Used internally"""

        self.DEBUG(DBG_NODEBUILDER, data, 'data')