import kid
import os
from config import config, log
import mimeparse
import md5

extensions = {
    'html': ('text/html; charset=utf-8', 'html'),
    'xhtml': ('application/xhtml+xml; charset=utf-8', 'xhtml'),
    'atom': ('application/atom+xml; charset=utf-8', 'xml')
}

matching = {
    'text/html; charset=utf-8': 'html',
    'application/xhtml+xml; charset=utf-8': 'xhtml'
}

def render(environ, start_response, template_file, vars, headers={}, status="200 Ok", raw_etag=None):
    file=os.path.join("templates", template_file)
    if raw_etag:
        last_modified = str(os.stat(file).st_mtime)
        hash = md5.new(raw_etag)
        hash.update(last_modified)
        etag = '"%s"' % hash.hexdigest()
        headers['etag'] = etag    
        if etag == environ.get('HTTP_IF_NONE_MATCH', ''):
            return http304(environ, start_response)

    (contenttype, serialization) = ('text/html; charset=utf-8', 'html')
    ext = template_file.rsplit(".")
    if len(ext) > 1 and (ext[1] in extensions):
        (contenttype, serialization) = extensions[ext[1]]
    # Only serve XHTML to those clients that can understand it.
    if serialization in matching:
        best = mimeparse.best_match(matching.keys(), environ.get('HTTP_ACCEPT', 'application/xhtml+xml'))
        (contenttype, serialization) = (best, match[best])
    if serialization == 'xhtml' and environ.get('HTTP_USER_AGENT', '').find("MSIE") >= 0:
        (contenttype, serialization) = extensions['html']

    
    template = kid.Template(file, **vars)
    body = template.serialize(output=serialization, encoding='utf-8')
    headers['Content-Type'] = contenttype
    start_response(status, list(headers.iteritems()))
    return [body]

def render_json(start_response, struct):
    import simplejson
    body = simplejson.dumps(struct)
    start_response("200 OK", [('Content-Type', 'text/plain')])
    return [body]

def http404(environ, start_response):
    log.warning("404: %s" % environ.get('PATH_INFO', ''))
    start_response("404 Not Found", [('Content-Type', "text/html")])
    return ["<h1>File Not Found</h1>"]

def http304(environ, start_response):
    start_response("304 Not Modified", [])
    return []

def http405(environ, start_response):
    start_response("405 Method Not Allowed", [('Content-Type', "text/html")])
    return ["<h1>That action is not allowed on this resource.</h1>"]

def http403(environ, start_response):
    start_response("403 Forbidden", [('Content-Type', "text/html")])
    return ["<h1>You are unauthorized to modify that resource.</h1>"]