import sys, traceback
import urllib2
import yaml
import re
from django.core.exceptions import MiddlewareNotUsed
from django.views.debug import get_safe_settings
from django.conf import settings

def _parse_environment(request):
    env = dict( (str(k), str(v)) for (k, v) in get_safe_settings().items() )
    env.update( dict( (str(k), str(v)) for (k, v) in request.META.items() ) )
    
    env['REQUEST_URI'] = request.build_absolute_uri()
    
    return env

def _parse_traceback(trace):
    p_traceback = [ "%s:%d:in `%s'" % (filename, lineno, funcname) 
                    for filename, lineno, funcname, _
                    in traceback.extract_tb(trace) ]
    p_traceback.reverse()
    
    return p_traceback

def _parse_message(exc):
    return '%s: %s' % (exc.__class__.__name__, str(exc))

def _parse_request(request):
    request_get = dict( (str(k), str(v)) for (k, v) in request.GET.items() )
    request_post = dict( (str(k), str(v)) for (k, v) in request.POST.items() )
    return request_post if request_post else request_get

def _parse_session(session):
    return dict( (str(k), str(v)) for (k, v) in session.items() )


def _generate_payload(request, exc=None, trace=None, message=None, error_class=None):
    """Generate a YAML payload for a Hoptoad notification.
    
    Parameters:
    request -- A Django HTTPRequest.  This is required.
    
    Keyword parameters:
    exc -- A Python Exception object.  If this is not given the 
           mess parameter must be.
    trace -- A Python Traceback object.  This is not required.
    message -- A string representing the error message.  If this is not
               given, the exc parameter must be.
    error_class -- A string representing the error class.  If this is not
                   given the excc parameter must be.
    """
    p_message = message if message else _parse_message(exc)
    p_error_class = error_class if error_class else exc.__class__.__name__
    p_traceback = _parse_traceback(trace) if trace else []
    p_environment = _parse_environment(request)
    p_request = _parse_request(request)
    p_session = _parse_session(request.session)
    
    return yaml.dump({ 'notice': {
        'api_key':       settings.HOPTOAD_API_KEY,
        'error_class':   p_error_class,
        'error_message': p_message,
        'backtrace':     p_traceback,
        'request':       { 'url': request.build_absolute_uri(),
                           'params': p_request },
        'session':       { 'key': '', 'data': p_session },
        'environment':   p_environment,
    }}, default_flow_style=False)

def _ride_the_toad(payload, timeout):
    """Send a notification (an HTTP POST request) to Hoptoad.
    
    Parameters:
    payload -- the YAML payload for the request from _generate_payload()
    timeout -- the maximum timeout, in seconds, or None to use the default
    """
    headers = { 'Content-Type': 'application/x-yaml', 
                'Accept': 'text/xml, application/xml', }
    r = urllib2.Request('http://hoptoadapp.com/notices', payload, headers)
    try:
        if timeout:
            urllib2.urlopen(r, timeout=timeout)
        else:
            urllib2.urlopen(r)
    except urllib2.URLError:
        pass


class HoptoadNotifierMiddleware(object):
    def __init__(self):
        """Initialize the middleware."""
        all_settings = settings.get_all_members()
        
        if 'HOPTOAD_API_KEY' not in all_settings:
            raise MiddlewareNotUsed
        
        if settings.DEBUG and \
           (not 'HOPTOAD_NOTIFY_WHILE_DEBUG' in all_settings
            or not settings.HOPTOAD_NOTIFY_WHILE_DEBUG ):
            raise MiddlewareNotUsed
        
        self.timeout = ( settings.HOPTOAD_TIMEOUT 
                         if 'HOPTOAD_TIMEOUT' in all_settings else None )
        
        self.notify_404 = ( settings.HOPTOAD_NOTIFY_404 
                            if 'HOPTOAD_NOTIFY_404' in all_settings else False )
        self.notify_403 = ( settings.HOPTOAD_NOTIFY_403 
                            if 'HOPTOAD_NOTIFY_403' in all_settings else False )
        self.ignore_agents = ( map(re.compile, settings.HOPTOAD_IGNORE_AGENTS)
                            if 'HOPTOAD_IGNORE_AGENTS' in all_settings else [] )
    
    def _ignore(self, request):
        """Return True if the given request should be ignored, False otherwise."""
        user_agent = request.META['HTTP_USER_AGENT']
        return any(i.search(user_agent) for i in self.ignore_agents)
    
    def process_response(self, request, response):
        """Process a reponse object.
        
        Hoptoad will be notified of a 404 error if the response is a 404
        and 404 tracking is enabled in the settings.
        
        Hoptoad will be notified of a 403 error if the response is a 403
        and 403 tracking is enabled in the settings.
        
        Regardless of whether Hoptoad is notified, the reponse object will
        be returned unchanged.
        """
        if self._ignore(request):
            return response
        
        if self.notify_404 and response.status_code == 404:
            error_class = 'Http404'
            
            message = 'Http404: Page not found at %s' % request.build_absolute_uri()
            payload = _generate_payload(request, error_class=error_class, message=message)
            
            _ride_the_toad(payload, self.timeout)
        
        if self.notify_403 and response.status_code == 403:
            error_class = 'Http403'
            
            message = 'Http403: Forbidden at %s' % request.build_absolute_uri()
            payload = _generate_payload(request, error_class=error_class, message=message)
            
            _ride_the_toad(payload, self.timeout)
        
        return response
    
    def process_exception(self, request, exc):
        """Process an exception.
        
        Hoptoad will be notified of the exception and None will be
        returned so that Django's normal exception handling will then
        be used.
        """
        if self._ignore(request):
            return None
        
        excc, _, tb = sys.exc_info()
        
        payload = _generate_payload(request, exc, tb)
        _ride_the_toad(payload, self.timeout)
        
        return None
    


@@ -3434,16 +3434,48 @@
 settings
+ or not settings.HOPTOAD_API_KEY
 :%0A      

Check for a blank API key.