"""Beautiful Soup

Elixir and Tonic

"The Screen-Scraper's Friend"

http://www.crummy.com/software/BeautifulSoup/

Beautiful Soup parses a (possibly invalid) XML or HTML document into a

tree representation. It provides methods and Pythonic idioms that make

it easy to navigate, search, and modify the tree.

A well-formed XML/HTML document yields a well-formed data

structure. An ill-formed XML/HTML document yields a correspondingly

ill-formed data structure. If your document is only locally

well-formed, you can use this library to find and process the

well-formed part of it.

Beautiful Soup works with Python 2.2 and up. It has no external

dependencies, but you'll have more success at converting data to UTF-8

if you also install these three packages:

* chardet, for auto-detecting character encodings

  http://chardet.feedparser.org/

* cjkcodecs and iconv_codec, which add more encodings to the ones supported

  by stock Python.

  http://cjkpython.i18n.org/

Beautiful Soup defines classes for two main parsing strategies:

 * BeautifulStoneSoup, for parsing XML, SGML, or your domain-specific

   language that kind of looks like XML.

 * BeautifulSoup, for parsing run-of-the-mill HTML code, be it valid

   or invalid. This class has web browser-like heuristics for

   obtaining a sensible parse tree in the face of common HTML errors.

Beautiful Soup also defines a class (UnicodeDammit) for autodetecting

the encoding of an HTML or XML document, and converting it to

Unicode. Much of this code is taken from Mark Pilgrim's Universal Feed Parser.

For more than you ever wanted to know about Beautiful Soup, see the

documentation:

http://www.crummy.com/software/BeautifulSoup/documentation.html

Here, have some legalese:

Copyright (c) 2004-2009, Leonard Richardson

All rights reserved.

Redistribution and use in source and binary forms, with or without

modification, are permitted provided that the following conditions are

met:

  * Redistributions of source code must retain the above copyright

    notice, this list of conditions and the following disclaimer.

  * Redistributions in binary form must reproduce the above

    copyright notice, this list of conditions and the following

    disclaimer in the documentation and/or other materials provided

    with the distribution.

  * Neither the name of the the Beautiful Soup Consortium and All

    Night Kosher Bakery nor the names of its contributors may be

    used to endorse or promote products derived from this software

    without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR

CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE, DAMMIT.

"""

from __future__ import generators

__author__ = "Leonard Richardson (leonardr@segfault.org)"

__version__ = "3.1.0.1"

__copyright__ = "Copyright (c) 2004-2009 Leonard Richardson"

__license__ = "New-style BSD"

import codecs

import markupbase

import types

import re

from HTMLParser import HTMLParser, HTMLParseError

try:

    from htmlentitydefs import name2codepoint

except ImportError:

    name2codepoint = {}

try:

    set

except NameError:

    from sets import Set as set

#These hacks make Beautiful Soup able to parse XML with namespaces

markupbase._declname_match = re.compile(r'[a-zA-Z][-_.:a-zA-Z0-9]*\s*').match

DEFAULT_OUTPUT_ENCODING = "utf-8"

# First, the classes that represent markup elements.

def sob(unicode, encoding):

    """Returns either the given Unicode string or its encoding."""

    if encoding is None:

        return unicode

    else:

        return unicode.encode(encoding)

class PageElement:

    """Contains the navigational information for some part of the page

    (either a tag or a piece of text)"""

    def setup(self, parent=None, previous=None):

        """Sets up the initial relations between this element and

        other elements."""

        self.parent = parent

        self.previous = previous

        self.next = None

        self.previousSibling = None

        self.nextSibling = None

        if self.parent and self.parent.contents:

            self.previousSibling = self.parent.contents[-1]

            self.previousSibling.nextSibling = self

    def replaceWith(self, replaceWith):

        oldParent = self.parent

        myIndex = self.parent.contents.index(self)

        if hasattr(replaceWith, 'parent') and replaceWith.parent == self.parent:

            # We're replacing this element with one of its siblings.

            index = self.parent.contents.index(replaceWith)

            if index and index < myIndex:

                # Furthermore, it comes before this element. That

                # means that when we extract it, the index of this

                # element will change.

                myIndex = myIndex - 1

        self.extract()

        oldParent.insert(myIndex, replaceWith)

    def extract(self):

        """Destructively rips this element out of the tree."""

        if self.parent:

            try:

                self.parent.contents.remove(self)

            except ValueError:

                pass

        #Find the two elements that would be next to each other if

        #this element (and any children) hadn't been parsed. Connect

        #the two.

        lastChild = self._lastRecursiveChild()

        nextElement = lastChild.next

        if self.previous:

            self.previous.next = nextElement

        if nextElement:

            nextElement.previous = self.previous

        self.previous = None

        lastChild.next = None

        self.parent = None

        if self.previousSibling:

            self.previousSibling.nextSibling = self.nextSibling

        if self.nextSibling:

            self.nextSibling.previousSibling = self.previousSibling

        self.previousSibling = self.nextSibling = None

        return self

    def _lastRecursiveChild(self):

        "Finds the last element beneath this object to be parsed."

        lastChild = self

        while hasattr(lastChild, 'contents') and lastChild.contents:

            lastChild = lastChild.contents[-1]

        return lastChild

    def insert(self, position, newChild):

        if (isinstance(newChild, basestring)

            or isinstance(newChild, unicode)) \

            and not isinstance(newChild, NavigableString):

            newChild = NavigableString(newChild)

        position =  min(position, len(self.contents))

        if hasattr(newChild, 'parent') and newChild.parent != None:

            # We're 'inserting' an element that's already one

            # of this object's children.

            if newChild.parent == self:

                index = self.find(newChild)

                if index and index < position:

                    # Furthermore we're moving it further down the

                    # list of this object's children. That means that

                    # when we extract this element, our target index

                    # will jump down one.

                    position = position - 1

            newChild.extract()

        newChild.parent = self

        previousChild = None

        if position == 0:

            newChild.previousSibling = None

            newChild.previous = self

        else:

            previousChild = self.contents[position-1]

            newChild.previousSibling = previousChild

            newChild.previousSibling.nextSibling = newChild

            newChild.previous = previousChild._lastRecursiveChild()

        if newChild.previous:

            newChild.previous.next = newChild

        newChildsLastElement = newChild._lastRecursiveChild()

        if position >= len(self.contents):

            newChild.nextSibling = None

            parent = self

            parentsNextSibling = None

            while not parentsNextSibling:

                parentsNextSibling = parent.nextSibling

                parent = parent.parent

                if not parent: # This is the last element in the document.

                    break

            if parentsNextSibling:

                newChildsLastElement.next = parentsNextSibling

            else:

                newChildsLastElement.next = None

        else:

            nextChild = self.contents[position]

            newChild.nextSibling = nextChild

            if newChild.nextSibling:

                newChild.nextSibling.previousSibling = newChild

            newChildsLastElement.next = nextChild

        if newChildsLastElement.next:

            newChildsLastElement.next.previous = newChildsLastElement

        self.contents.insert(position, newChild)

    def append(self, tag):

        """Appends the given tag to the contents of this tag."""

        self.insert(len(self.contents), tag)

    def findNext(self, name=None, attrs={}, text=None, **kwargs):

        """Returns the first item that matches the given criteria and

        appears after this Tag in the document."""

        return self._findOne(self.findAllNext, name, attrs, text, **kwargs)

    def findAllNext(self, name=None, attrs={}, text=None, limit=None,

                    **kwargs):

        """Returns all items that match the given criteria and appear

        after this Tag in the document."""

        return self._findAll(name, attrs, text, limit, self.nextGenerator,

                             **kwargs)

    def findNextSibling(self, name=None, attrs={}, text=None, **kwargs):

        """Returns the closest sibling to this Tag that matches the

        given criteria and appears after this Tag in the document."""

        return self._findOne(self.findNextSiblings, name, attrs, text,

                             **kwargs)

    def findNextSiblings(self, name=None, attrs={}, text=None, limit=None,

                         **kwargs):

        """Returns the siblings of this Tag that match the given

        criteria and appear after this Tag in the document."""

        return self._findAll(name, attrs, text, limit,

                             self.nextSiblingGenerator, **kwargs)

    fetchNextSiblings = findNextSiblings # Compatibility with pre-3.x

    def findPrevious(self, name=None, attrs={}, text=None, **kwargs):

        """Returns the first item that matches the given criteria and

        appears before this Tag in the document."""

        return self._findOne(self.findAllPrevious, name, attrs, text, **kwargs)

    def findAllPrevious(self, name=None, attrs={}, text=None, limit=None,

                        **kwargs):

        """Returns all items that match the given criteria and appear

        before this Tag in the document."""

        return self._findAll(name, attrs, text, limit, self.previousGenerator,

                           **kwargs)

    fetchPrevious = findAllPrevious # Compatibility with pre-3.x

    def findPreviousSibling(self, name=None, attrs={}, text=None, **kwargs):

        """Returns the closest sibling to this Tag that matches the

        given criteria and appears before this Tag in the document."""

        return self._findOne(self.findPreviousSiblings, name, attrs, text,

                             **kwargs)

    def findPreviousSiblings(self, name=None, attrs={}, text=None,

                             limit=None, **kwargs):

        """Returns the siblings of this Tag that match the given

        criteria and appear before this Tag in the document."""

        return self._findAll(name, attrs, text, limit,

                             self.previousSiblingGenerator, **kwargs)

    fetchPreviousSiblings = findPreviousSiblings # Compatibility with pre-3.x

    def findParent(self, name=None, attrs={}, **kwargs):

        """Returns the closest parent of this Tag that matches the given

        criteria."""

        # NOTE: We can't use _findOne because findParents takes a different

        # set of arguments.

        r = None

        l = self.findParents(name, attrs, 1)

        if l:

            r = l[0]

        return r

    def findParents(self, name=None, attrs={}, limit=None, **kwargs):

        """Returns the parents of this Tag that match the given

        criteria."""

        return self._findAll(name, attrs, None, limit, self.parentGenerator,

                             **kwargs)

    fetchParents = findParents # Compatibility with pre-3.x

    #These methods do the real heavy lifting.

    def _findOne(self, method, name, attrs, text, **kwargs):

        r = None

        l = method(name, attrs, text, 1, **kwargs)

        if l:

            r = l[0]

        return r

    def _findAll(self, name, attrs, text, limit, generator, **kwargs):

        "Iterates over a generator looking for things that match."

        if isinstance(name, SoupStrainer):

            strainer = name

        else:

            # Build a SoupStrainer

            strainer = SoupStrainer(name, attrs, text, **kwargs)

        results = ResultSet(strainer)

        g = generator()

        while True:

            try:

                i = g.next()

            except StopIteration:

                break

            if i:

                found = strainer.search(i)

                if found:

                    results.append(found)

                    if limit and len(results) >= limit:

                        break

        return results

    #These Generators can be used to navigate starting from both

    #NavigableStrings and Tags.

    def nextGenerator(self):

        i = self

        while i:

            i = i.next

            yield i

    def nextSiblingGenerator(self):

        i = self

        while i:

            i = i.nextSibling

            yield i

    def previousGenerator(self):

        i = self

        while i:

            i = i.previous

            yield i

    def previousSiblingGenerator(self):

        i = self

        while i:

            i = i.previousSibling

            yield i

    def parentGenerator(self):

        i = self

        while i:

            i = i.parent

            yield i

    # Utility methods

    def substituteEncoding(self, str, encoding=None):

        encoding = encoding or "utf-8"

        return str.replace("%SOUP-ENCODING%", encoding)

    def toEncoding(self, s, encoding=None):

        """Encodes an object to a string in some encoding, or to Unicode.

        ."""

        if isinstance(s, unicode):

            if encoding:

                s = s.encode(encoding)

        elif isinstance(s, str):

            if encoding:

                s = s.encode(encoding)

            else:

                s = unicode(s)

        else:

            if encoding:

                s  = self.toEncoding(str(s), encoding)

            else:

                s = unicode(s)

        return s

class NavigableString(unicode, PageElement):

    def __new__(cls, value):

        """Create a new NavigableString.

        When unpickling a NavigableString, this method is called with

        the string in DEFAULT_OUTPUT_ENCODING. That encoding needs to be

        passed in to the superclass's __new__ or the superclass won't know

        how to handle non-ASCII characters.

        """

        if isinstance(value, unicode):

            return unicode.__new__(cls, value)

        return unicode.__new__(cls, value, DEFAULT_OUTPUT_ENCODING)

    def __getnewargs__(self):

        return (unicode(self),)

    def __getattr__(self, attr):

        """text.string gives you text. This is for backwards

        compatibility for Navigable*String, but for CData* it lets you

        get the string without the CData wrapper."""

        if attr == 'string':

            return self

        else:

            raise AttributeError, "'%s' object has no attribute '%s'" % (self.__class__.__name__, attr)

    def encode(self, encoding=DEFAULT_OUTPUT_ENCODING):

        return self.decode().encode(encoding)

    def decodeGivenEventualEncoding(self, eventualEncoding):

        return self

class CData(NavigableString):

    def decodeGivenEventualEncoding(self, eventualEncoding):

        return u'<![CDATA[' + self + u']]>'

class ProcessingInstruction(NavigableString):

    def decodeGivenEventualEncoding(self, eventualEncoding):

        output = self

        if u'%SOUP-ENCODING%' in output:

            output = self.substituteEncoding(output, eventualEncoding)

        return u'<?' + output + u'?>'

class Comment(NavigableString):

    def decodeGivenEventualEncoding(self, eventualEncoding):

        return u'<!--' + self + u'-->'

class Declaration(NavigableString):

    def decodeGivenEventualEncoding(self, eventualEncoding):

        return u'<!' + self + u'>'

class Tag(PageElement):

    """Represents a found HTML tag with its attributes and contents."""

    def _invert(h):

        "Cheap function to invert a hash."

        i = {}

        for k,v in h.items():

            i[v] = k

        return i

    XML_ENTITIES_TO_SPECIAL_CHARS = { "apos" : "'",

                                      "quot" : '"',

                                      "amp" : "&",

                                      "lt" : "<",

                                      "gt" : ">" }

    XML_SPECIAL_CHARS_TO_ENTITIES = _invert(XML_ENTITIES_TO_SPECIAL_CHARS)

    def _convertEntities(self, match):

        """Used in a call to re.sub to replace HTML, XML, and numeric

        entities with the appropriate Unicode characters. If HTML

        entities are being converted, any unrecognized entities are

        escaped."""

        x = match.group(1)

        if self.convertHTMLEntities and x in name2codepoint:

            return unichr(name2codepoint[x])

        elif x in self.XML_ENTITIES_TO_SPECIAL_CHARS:

            if self.convertXMLEntities:

                return self.XML_ENTITIES_TO_SPECIAL_CHARS[x]

            else:

                return u'&%s;' % x

        elif len(x) > 0 and x[0] == '#':

            # Handle numeric entities

            if len(x) > 1 and x[1] == 'x':

                return unichr(int(x[2:], 16))

            else:

                return unichr(int(x[1:]))

        elif self.escapeUnrecognizedEntities:

            return u'&%s;' % x

        else:

            return u'&%s;' % x

    def __init__(self, parser, name, attrs=None, parent=None,

                 previous=None):

        "Basic constructor."

        # We don't actually store the parser object: that lets extracted

        # chunks be garbage-collected

        self.parserClass = parser.__class__

        self.isSelfClosing = parser.isSelfClosingTag(name)

        self.name = name

        if attrs == None:

            attrs = []

        self.attrs = attrs

        self.contents = []

        self.setup(parent, previous)

        self.hidden = False

        self.containsSubstitutions = False

        self.convertHTMLEntities = parser.convertHTMLEntities

        self.convertXMLEntities = parser.convertXMLEntities

        self.escapeUnrecognizedEntities = parser.escapeUnrecognizedEntities

        def convert(kval):

            "Converts HTML, XML and numeric entities in the attribute value."

            k, val = kval

            if val is None:

                return kval

            return (k, re.sub("&(#\d+|#x[0-9a-fA-F]+|\w+);",

                              self._convertEntities, val))

        self.attrs = map(convert, self.attrs)