import htmlentitydefs
from xml.sax.saxutils import escape

def valueOrExec(value):
    if hasattr(value, 'im_func'):
        return value()
    return value

def convert_to_ents(txt):
    buf = ''
    for c in txt:
        mat = ''
        for x in htmlentitydefs.entitydefs:
            a = htmlentitydefs.entitydefs[x].decode('iso-8859-1')
            if c == a:
                mat = x
                continue
        if mat: buf += '&%s;' % mat
        else: buf += c
    return escape(buf)

def RSS(entries, conf={}):
    """ package results as RSS """
    formatted = """<?xml version="1.0" encoding="utf-8"?>
<rss version="2.0"
    xmlns:content="http://purl.org/rss/1.0/modules/content/"
    xmlns:wfw="http://wellformedweb.org/CommentAPI/"
    xmlns:dc="http://purl.org/dc/elements/1.1/"
    >
<channel>
\t<title>%s</title>
\t<link>%s</link>
\t<description>%s</description>
\t<generator>%s</generator>
\t<language>%s</language>\n""" % ( conf.get('channel_title', 'Aggregated feed'),
        conf.get('channel_link', ''),
        conf.get('channel_desc', ''),
        conf.get('channel_generator', 'Feedmoot'),
        conf.get('channel_lang', '')
        )
    for x in entries:
        title = x.get('title').encode('utf-8')
        link = x.get('link').encode('utf-8')
        updated = x.get('updated').encode('utf-8')
        comments = ''
        
        guid = ''
        if   x.has_key('guid'): guid = x.get('guid')
        elif x.has_key('id'):   guid = x.get('id')
        elif x.has_key('link'): guid = x.get('link')
        guid.encode('utf-8')

        summary = ''
        if x.has_key('summary'):
            summary = x.get('summary')
        content = ''
        if x.has_key('content'):
            content = x.get('content')[0].get('value').encode('utf-8')

        author = ''
        if x.has_key('author'):
            author = x.get('author').encode('utf-8')

        cat = ''
        if x.has_key('category'):
            cat = x.get('category')
        
        formatted += '\t<item>\n'
        formatted += '\t\t<title>%s</title>\n' % convert_to_ents(title)
        formatted += '\t\t<link>%s</link>\n' % link
        formatted += '\t\t<comments>%s</comments>\n' % comments
        formatted += '\t\t<pubDate>%s</pubDate>\n' % updated
        if author:
            formatted += '\t\t<dc:creator>%s</dc:creator>' % author
        if cat:
            formatted += '\t\t<category>%s</category>\n' % cat
        formatted += '\t\t<guid>%s</guid>\n' % convert_to_ents(guid)

        formatted += '\t\t<description><![CDATA[%s]]></description>\n' % summary
        if content:
            formatted += '\t\t<content:encoded><![CDATA[<p>%s</p>]]></content:encoded>\n' % content
        formatted += '\t</item>\n'
    formatted += '</channel>\n</rss>'
    return formatted