import kid
import os
from config import config
import logging
import mimeparse
import md5

HTML_SER = kid.HTMLSerializer(doctype=("HTML",), encoding='utf-8', inject_type=False)

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

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

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

    file=os.path.join(config.get("templates", "dir"), template_file)
    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 expand_uri_template(uri, params):
    # Add braces around each of the keys and %-expand all the values
    quoted_params = dict([("{%s}" % key, urllib.quote(value.encode('utf-8'))) 
        for key, value in params.iteritems()])

    # define a function that we will later use to do the
    # regular expression substitution. Replace matches
    # only if they have valus in quoted_uri_parameters.
    def replace(match):
        return quoted_params.get(match.group(0), match.group(0))

    return re.sub(r"{.*?}", replace, uri)

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):
    logging.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):
    logging.info("304: %s" % environ.get('PATH_INFO', ''))
    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>"]

def http415(environ, start_response, message="The server is refusing to service the request because the entity of the request is in a format not supported by the requested resource for the requested method."):
    start_response("415 Unsupported Media Type", [('Content-Type', "text/html")])
    return [message]