"""CSSMediaRule implements DOM Level 2 CSS CSSMediaRule."""
__all__ = ['CSSMediaRule']
__docformat__ = 'restructuredtext'
__version__ = '$Id$'

from . import cssrule
import cssutils
import xml.dom

class CSSMediaRule(cssrule.CSSRuleRules):
    """
    Objects implementing the CSSMediaRule interface can be identified by the
    MEDIA_RULE constant. On these objects the type attribute must return the
    value of that constant.

    Format::

      : MEDIA_SYM S* medium [ COMMA S* medium ]* 
      
          STRING? # the name
      
      LBRACE S* ruleset* '}' S*;
      
    ``cssRules``
        All Rules in this media rule, a :class:`~cssutils.css.CSSRuleList`.
    """
    def __init__(self, mediaText='all', name=None,
                 parentRule=None, parentStyleSheet=None, readonly=False):
        """constructor"""
        super(CSSMediaRule, self).__init__(parentRule=parentRule, 
                                           parentStyleSheet=parentStyleSheet)
        self._atkeyword = '@media'
        
        # 1. media 
        if mediaText:
            self.media = mediaText
        else:
            self.media = cssutils.stylesheets.MediaList()

        self.name = name
        self._readonly = readonly

    def __repr__(self):
        return "cssutils.css.%s(mediaText=%r)" % (
                self.__class__.__name__,
                self.media.mediaText)
        
    def __str__(self):
        return "<cssutils.css.%s object mediaText=%r at 0x%x>" % (
                self.__class__.__name__,
                self.media.mediaText,
                id(self))

    def _getCssText(self):
        """Return serialized property cssText."""
        return cssutils.ser.do_CSSMediaRule(self)

    def _setCssText(self, cssText):
        """
        :param cssText:
            a parseable string or a tuple of (cssText, dict-of-namespaces)
        :Exceptions:
            - :exc:`~xml.dom.NamespaceErr`:
              Raised if a specified selector uses an unknown namespace
              prefix.
            - :exc:`~xml.dom.SyntaxErr`:
              Raised if the specified CSS string value has a syntax error and
              is unparsable.
            - :exc:`~xml.dom.InvalidModificationErr`:
              Raised if the specified CSS string value represents a different
              type of rule than the current one.
            - :exc:`~xml.dom.HierarchyRequestErr`:
              Raised if the rule cannot be inserted at this point in the
              style sheet.
            - :exc:`~xml.dom.NoModificationAllowedErr`:
              Raised if the rule is readonly.
        """
        # media "name"? { cssRules }
        super(CSSMediaRule, self)._setCssText(cssText)
        
        # might be (cssText, namespaces)
        cssText, namespaces = self._splitNamespacesOff(cssText)
        
        try:
            # use parent style sheet ones if available
            namespaces = self.parentStyleSheet.namespaces
        except AttributeError:
            pass
        
        tokenizer = self._tokenize2(cssText)
        attoken = self._nexttoken(tokenizer, None)
        if self._type(attoken) != self._prods.MEDIA_SYM:
            self._log.error('CSSMediaRule: No CSSMediaRule found: %s' %
                self._valuestr(cssText),
                error=xml.dom.InvalidModificationErr)
        
        else:            
            # save if parse goes wrong
            oldMedia = self._media
            oldName = self._name
            oldCssRules = self._cssRules
            
            ok = True

            # media
            mediatokens, end = self._tokensupto2(tokenizer, 
                                                 mediaqueryendonly=True,
                                                 separateEnd=True)        
            if '{' == self._tokenvalue(end)\
               or self._prods.STRING == self._type(end):
                self.media = cssutils.stylesheets.MediaList(parentRule=self)
                # TODO: remove special case
                self.media.mediaText = mediatokens
                ok = ok and self.media.wellformed
            else:
                ok = False
            
            # name (optional)
            name = None
            nameseq = self._tempSeq()
            if self._prods.STRING == self._type(end):
                name = self._stringtokenvalue(end)
                # TODO: for now comments are lost after name
                nametokens, end = self._tokensupto2(tokenizer, 
                                                    blockstartonly=True,
                                                    separateEnd=True)
                wellformed, expected = self._parse(None, 
                                                   nameseq, 
                                                   nametokens, 
                                                   {})
                if not wellformed:
                    ok = False
                    self._log.error('CSSMediaRule: Syntax Error: %s' % 
                                    self._valuestr(cssText))
                    

            # check for {
            if '{' != self._tokenvalue(end):
                self._log.error('CSSMediaRule: No "{" found: %s' % 
                                self._valuestr(cssText))
                return
            
            # cssRules
            cssrulestokens, braceOrEOF = self._tokensupto2(tokenizer, 
                                               mediaendonly=True,
                                               separateEnd=True)
            nonetoken = self._nexttoken(tokenizer, None)
            if 'EOF' == self._type(braceOrEOF):
                # HACK!!!
                # TODO: Not complete, add EOF to rule and } to @media
                cssrulestokens.append(braceOrEOF)
                braceOrEOF = ('CHAR', '}', 0, 0)
                self._log.debug('CSSMediaRule: Incomplete, adding "}".', 
                                token=braceOrEOF, neverraise=True)

            if '}' != self._tokenvalue(braceOrEOF):
                self._log.error('CSSMediaRule: No "}" found.', 
                                token=braceOrEOF)
            elif nonetoken:
                self._log.error('CSSMediaRule: Trailing content found.',
                                token=nonetoken)
            else:                
                # for closures: must be a mutable
                new = {'wellformed': True }
                                   
                def COMMENT(expected, seq, token, tokenizer=None):
                    self.insertRule(cssutils.css.CSSComment([token],
                                                            parentRule=self,
                                                            parentStyleSheet=self.parentStyleSheet))
                    return expected

                def ruleset(expected, seq, token, tokenizer):
                    rule = cssutils.css.CSSStyleRule(parentRule=self,
                                                     parentStyleSheet=self.parentStyleSheet)
                    rule.cssText = self._tokensupto2(tokenizer, token)
                    if rule.wellformed:
                        self.insertRule(rule)
                    return expected
        
                def atrule(expected, seq, token, tokenizer):
                    # TODO: get complete rule!
                    tokens = self._tokensupto2(tokenizer, token)
                    atval = self._tokenvalue(token)
                    factories = {
                        '@page': cssutils.css.CSSPageRule,
                        '@media': CSSMediaRule,
                    }
                    if atval in ('@charset ', '@font-face', '@import', 
                                 '@namespace', '@variables'):
                        self._log.error('CSSMediaRule: This rule is not '
                                        'allowed in CSSMediaRule - ignored: '
                                        '%s.' % self._valuestr(tokens),
                                        token = token, 
                                        error=xml.dom.HierarchyRequestErr)
                    elif atval in factories:
                        rule = factories[atval](
                            parentRule=self,
                            parentStyleSheet=self.parentStyleSheet)
                        rule.cssText = tokens
                        if rule.wellformed:
                            self.insertRule(rule)
                    else:
                        rule = cssutils.css.CSSUnknownRule(tokens,
                                                           parentRule=self, 
                                        parentStyleSheet=self.parentStyleSheet)
                        if rule.wellformed:
                            self.insertRule(rule)
                    return expected
                
                # save for possible reset
                oldCssRules = self.cssRules
                
                self.cssRules = cssutils.css.CSSRuleList()
                seq = [] # not used really

                tokenizer = iter(cssrulestokens)
                wellformed, expected = self._parse(braceOrEOF,
                                                   seq,
                                                   tokenizer, {
                                                     'COMMENT': COMMENT,
                                                     'CHARSET_SYM': atrule,
                                                     'FONT_FACE_SYM': atrule,
                                                     'IMPORT_SYM': atrule,
                                                     'NAMESPACE_SYM': atrule,
                                                     'PAGE_SYM': atrule,
                                                     'MEDIA_SYM': atrule,
                                                     'ATKEYWORD': atrule
                                                   }, 
                                                   default=ruleset,
                                                   new=new)
                ok = ok and wellformed
                
            if ok:
                self.name = name
                self._setSeq(nameseq)
            else:
                self._media = oldMedia
                self._cssRules = oldCssRules
                                            
    cssText = property(_getCssText, _setCssText,
                       doc="(DOM) The parsable textual representation of this "
                           "rule.")

    def _setName(self, name):
        if isinstance(name, str) or name is None:
            # "" or ''
            if not name:
                name = None

            self._name = name
        else:
            self._log.error('CSSImportRule: Not a valid name: %s' % name)

    name = property(lambda self: self._name, _setName,
                    doc="An optional name for this media rule.")

    def _setMedia(self, media):
        """
        :param media:
            a :class:`~cssutils.stylesheets.MediaList` or string
        """
        self._checkReadonly()
        if isinstance(media, str):
            self._media = cssutils.stylesheets.MediaList(mediaText=media, 
                                                         parentRule=self)
        else:
            media._parentRule = self
            self._media = media
        
        # NOT IN @media seq at all?!
#        # update seq
#        for i, item in enumerate(self.seq):
#            if item.type == 'media':
#                self._seq[i] = (self._media, 'media', None, None)
#                break
#        else:
#            # insert after @media if not in seq at all
#            self.seq.insert(0, 
#                             self._media, 'media', None, None)
            
    media = property(lambda self: self._media, _setMedia,
                     doc="(DOM) A list of media types for this rule "
                         "of type :class:`~cssutils.stylesheets.MediaList`.")
    
            
    def insertRule(self, rule, index=None):
        """Implements base ``insertRule``."""
        rule, index = self._prepareInsertRule(rule, index)
        
        if rule is False or rule is True:
            # done or error
            return
        
        # check hierarchy
        if isinstance(rule, cssutils.css.CSSCharsetRule) or \
           isinstance(rule, cssutils.css.CSSFontFaceRule) or \
           isinstance(rule, cssutils.css.CSSImportRule) or \
           isinstance(rule, cssutils.css.CSSNamespaceRule) or \
           isinstance(rule, cssutils.css.MarginRule):
            self._log.error('%s: This type of rule is not allowed here: %s' 
                            % (self.__class__.__name__, rule.cssText),
                            error=xml.dom.HierarchyRequestErr)
            return

        return self._finishInsertRule(rule, index)

    type = property(lambda self: self.MEDIA_RULE, 
                    doc="The type of this rule, as defined by a CSSRule "
                        "type constant.")

    wellformed = property(lambda self: self.media.wellformed)
