"""
Inserts appropriate link tags into the HTML header, including handling
home, up, first, last, next, previous, author, contents, index, glossary,
appendices, chapters, subchapters, bookmarks, icons, and style sheets.
"""
# Copyright © 2004 Saugus.net, Inc.
# All Rights Reserved.

# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.


request=container.REQUEST
response=request.RESPONSE
linkTag=None

def getFullLinkTag(obj,relName,url,titleAtt,typeAtt,mediaAtt,langAtt):
    """
    Assemble the link tag based upon its component parts.
    """
    if url:
        # only bother if there's a url to work with...
        if titleAtt:
            if titleAtt==1:
                if obj:
                    # title wanted, get it from existing object
                    if obj.title_or_id()!=obj.getId():
                        titleAttText=' title="'+obj.title_or_id()+'"'
                    else:
                        # this odd case handles persistent (nameless) style sheets
                        titleAttText=""
                else:
                    # default; pretty lame
                    titleAttText=' title="'+relName+'"'
            else:
                # title wanted and provided; use it
                titleAttText=' title="'+titleAtt+'"'
        else:
            # title not wanted
            titleAttText=""
        if typeAtt:
            typeAttText=""
            if typeAtt==1:
                if obj:
                    # type wanted, get it from existing object
                    typeAttText=' type="'+obj.getContentType()+'"'
                else:
                    # default
                    typeAttText=' type="image/png"'
            else:
                # type wanted and provided; use it
                typeAttText=' type="'+typeAtt+'"'
        else:
            # type not wanted
            typeAttText=""
        if mediaAtt:
            if mediaAtt==1:
                if obj:
                    # media type wanted, get it from existing object
                    mediaAttText=' media="'+obj.getitem('target_media')+'"'
                else:
                    # default
                    mediaAttText=' media="all"'
            else:
                # media wanted and provided; use it
                mediaAttText=' media="'+mediaAtt+'"'
        else:
            # media not wanted
            mediaAttText=""
        if langAtt:
            if langAtt==1:
                if obj:
                    # lang type wanted, get it from existing object
                    langAttText=' lang="'+obj.getitem('target_language')+'"'
                else:
                    # default
                    langAttText=' lang="en"'
            else:
                # language wanted and provided; use it
                langAttText=' lang="'+langAtt+'"'
        else:
            # language not wanted
            langAttText=""
        return '<link rel="'+relName+'" href="'+url+'"'+titleAttText+typeAttText+mediaAttText+langAttText+' />'
    else:
        return ''


def getLinkTags(attrPair,**kw):
    """
    """
    titleAtt=None
    typeAtt=None
    mediaAtt=None
    langAtt=None
    for eachKW in kw.keys():
        if eachKW=='titleAtt':
            titleAtt=kw[eachKW]
        elif eachKW=='typeAtt':
            typeAtt=kw[eachKW]
        elif eachKW=='mediaAtt':
            mediaAtt=kw[eachKW]
        elif eachKW=='langAtt':
            langAtt=kw[eachKW]
    linkTag=""
    obj=None
    if _.has_key(attrPair[0]):
        obj=_.getitem(attrPair[0])
        if obj:
            if same_type(obj,[]) or same_type(obj,()):
                for eachObj in obj:
                    if _.has_key(eachObj):
                        eachObj=_.getitem(eachObj)
                        url=eachObj.absolute_url()
                        if url!=request.URL1:
                            if len(linkTag)>0:
                                linkTag+='\n'
                            linkTag+=getFullLinkTag(eachObj,attrPair[1],url,titleAtt,typeAtt,mediaAtt,langAtt)
                    else:
                        url=eachObj
                        eachObj=None
                        if len(linkTag)>0:
                            linkTag+='\n'
                        linkTag+=getFullLinkTag(eachObj,attrPair[1],url,titleAtt,typeAtt,mediaAtt,langAtt)
            elif _.has_key(obj):
                obj=_.getitem(obj)
                url=obj.absolute_url()
                if url!=request.URL1:
                    linkTag=getFullLinkTag(obj,attrPair[1],url,titleAtt,typeAtt,mediaAtt,langAtt)
            else:
                url=obj
                obj=None
                linkTag=getFullLinkTag(obj,attrPair[1],url,titleAtt,typeAtt,mediaAtt,langAtt)
        else:
            url=obj
            obj=None
            linkTag=getFullLinkTag(obj,attrPair[1],url,titleAtt,typeAtt,mediaAtt,langAtt)
    return linkTag


# Author/Made links have fixed title
for attrPair in [('link_contact','Author'),
                 ('link_contact','Made')]:
    if _.has_key(attrPair[0]):
        address=_.getitem(attrPair[0])
        linkTag=context.eMailTag(address,attrPair[1],'E-mail webmaster','HTML link')
    if linkTag:
        print linkTag

# if there's a level above, it's always okay to include Home & Up
if context.notAtRoot():
    print '<link rel="Home" title="Home" href="/" />'
    print '<link rel="Up" title="Up" href="../" />'

# handle link_first, link_last, link_next, and link_prev specially as they require scripts
for attrPair in [('link_first','First'),
                 ('link_first','Start'),
                 ('link_next','Next'),
                 ('link_prev','Previous'),
                 ('link_prev','Prev'),
                 ('link_last','Last'),
                 ('link_last','End')]:
    if _.has_key(attrPair[0]):
        url=_.getitem(attrPair[0],1)
        obj=None
        if url!=request.URL1:
            linkTag=getFullLinkTag(obj,attrPair[1],url,1,0,0,0)
            if linkTag:
                print linkTag

# position and context rel links want a title but not really anything else
for attrPair in [('link_copyright','Copyright'),
                 ('link_bookmarks','Bookmarks'),
                 ('link_search','Search'),
                 ('link_search','Find'),
                 ('link_help','Help'),
                 ('link_toc','Contents'),
                 ('link_toc','ToC'),
                 ('link_chapters','Chapter'),
                 ('link_sections','Section'),
                 ('link_subsections','Subsection'),
                 ('link_glossary','Glossary'),
                 ('link_appendices','Appendix'),
                 ('link_index','Index'),
                 ('link_subdocuments','Subdocument'),
                 ('link_prefetch','prefetch')]:
    linkTag=getLinkTags(attrPair,titleAtt=1)
    if linkTag:
        print linkTag

#icons (proper and MS-specific) want a MIME type
linkTag=getLinkTags(('link_favicon','Shortcut Icon'),typeAtt="application/octet-stream")
if linkTag:
    print linkTag
else:
    print '<link rel="Shortcut Icon" href="http://microsoft.com/favicon.ico/requests/are/flooding/my/error/log" />'
linkTag=getLinkTags(('link_icon','Icon'),typeAtt=1)
if linkTag:
    print linkTag

#MSIE compliance
print """<!--[if lt IE 7]>
<script src="/IE7/ie7-standard-p.js" type="text/javascript"
        charset="ISO-8859-1"></script>
<![endif]-->"""

#RDF
print """<link rel="meta" type="application/rdf+xml" href="metadata.rdf" />"""

#stylesheets; primary and alternates -- each can have multiples; type is important
for attrPair in [('link_stylesheets','Stylesheet'),
                 ('link_alternate_stylesheets','Alternate Stylesheet')]:
     
    linkTag=getLinkTags(attrPair,typeAtt="text/css",titleAtt=1)
    if linkTag:
        print linkTag

#alternates; often multiple
for attrPair in [('link_alternates','Alternate'),
                 ('link_alternate_copyright','Alternate Copyright'),
                 ('link_alternate_search','Alternate Search'),
                 ('link_alternate_search','Alternate Find'),
                 ('link_alternate_help','Alternate Help'),
                 ('link_alternate_toc','Alternate Contents'),
                 ('link_alternate_chapters','Alternate Chapter'),
                 ('link_alternate_sections','Alternate Section'),
                 ('link_alternate_subsections','Alternate Subsection'),
                 ('link_alternate_glossary','Alternate Glossary'),
                 ('link_alternate_appendices','Alternate Appendix'),
                 ('link_alternate_index','Alternate Index'),
                 ('link_alternate_next','Alternate Next'),
                 ('link_alternate_prev','Alternate Prev'),
                 ('link_alternate_first','Alternate First'),
                 ('link_alternate_last','Alternate Last'),
                 ('link_alternate_first','Alternate Start'),
                 ('link_alternate_last','Alternate End')]:
    linkTag=getLinkTags(attrPair,titleAtt=1,mediaAtt=1,langAtt=1)
    if linkTag:
        print linkTag

#anything raw to be inserted
if _.has_key('raw_html_headers'):
  rawHeaders=_.getitem('raw_html_headers')
  for eachHeader in rawHeaders:
    print eachHeader

latestTime=DateTime().latestTime().timeTime()
expirationTime=DateTime().timeTime()+_.getitem('cacheDefaultExpire')
if latestTime<expirationTime and (not _.has_key('noCalendar') or not _.getitem('noCalendar')):
  expirationTime=latestTime
response.setHeader('Expires',DateTime(expirationTime).toZone('GMT').rfc822())
#response.setHeader('Last-Modified',context.bobobase_modification_time().toZone('GMT').rfc822())
response.setHeader('Last-Modified',DateTime().toZone('GMT').rfc822())
#response.setHeader('Vary','user-Agent; accept-language')

return printed