terom@53: """
terom@53:     Handling user preferences
terom@53: """
terom@53: 
terom@53: import functools
terom@53: import Cookie
terom@53: 
terom@53: from qmsk.web import urltree
terom@53: 
terom@53: class Preference (urltree.URLType) :
terom@53:     """
terom@53:         A specific preference
terom@53:     """
terom@53: 
terom@53:     # the name to use
terom@53:     name = None
terom@53: 
terom@53:     # the default value
terom@53:     default = None
terom@53:     
terom@53:     def process (self, preferences, value) :
terom@53:         """
terom@53:             Post-process this preference value. This can access the values of other preferences or the request via
terom@53:             the given RequestPreferences. Note that the other items will not be post-processed here.
terom@53: 
terom@53:             Defaults to just return value.
terom@53:         """
terom@53: 
terom@53:         return value
terom@53: 
terom@53: class RequestPreferences (object) :
terom@53:     """
terom@53:         Represents the specific preferences for some request
terom@53:     """
terom@53: 
terom@53:     def __init__ (self, preferences, request, value_map=None) :
terom@53:         """
terom@53:             Initialize with the given Preferences object, http Request, and list of mapping of raw preference values
terom@53:         """
terom@53:         
terom@53:         # store
terom@53:         self.preferences = preferences
terom@53:         self.request = request
terom@53: 
terom@53:         # initialize
terom@53:         self.values = {}
terom@53:         self.set_cookies = {}
terom@53: 
terom@53:         # load preferences
terom@53:         for pref in preferences.pref_list :
terom@53:             # got a value for it?
terom@53:             if value_map and pref.name in value_map :
terom@53:                 # get value
terom@53:                 value = value_map[pref.name]
terom@53: 
terom@53:                 # parse it
terom@53:                 value = pref.parse(value)
terom@53: 
terom@53:             else :
terom@53:                 # use default value
terom@53:                 value = pref.default
terom@53:             
terom@53:             # add
terom@53:             self.values[pref.name] = value
terom@53:         
terom@53:         # then post-process using the Preferences
terom@53:         self.values = dict(
terom@53:             (name, self.preferences.pref_map[name].process(self, value)) for name, value in self.values.iteritems()
terom@53:         )
terom@53: 
terom@53:     def get (self, pref) :
terom@53:         """
terom@53:             Return the value for the given Preference
terom@53:         """
terom@53:         
terom@53:         return self.values[pref.name]
terom@53:     
terom@53:     def set (self, name, value_obj) :
terom@53:         """
terom@53:             Set a new value for the given preference
terom@53:         """
terom@53: 
terom@53:         # sanity-check to make sure we're not setting it twice...
terom@53:         assert name not in self.set_cookies
terom@53: 
terom@53:         # encode using the Preference object
terom@53:         value_str = self.preferences.pref_map[name].build(value_obj)
terom@53: 
terom@53:         # update in our dict
terom@53:         self.values[name] = value_obj
terom@53: 
terom@53:         # add to set_cookies
terom@53:         self.set_cookies[name] = value_str
terom@53: 
terom@53: class Preferences (object) :
terom@53:     """
terom@53:         Handle user preferences using cookies
terom@53:     """
terom@53: 
terom@53:     def __init__ (self, pref_list) :
terom@53:         """
terom@53:             Use the given list of Preference objects
terom@53:         """
terom@53: 
terom@53:         # store
terom@53:         self.pref_list = pref_list
terom@53: 
terom@53:         # translate to mapping as well
terom@53:         self.pref_map = dict((pref.name, pref) for pref in pref_list)
terom@53: 
terom@53:     def load (self, request, ) :
terom@53:         """
terom@53:             Load the set of preferences for the given request, and return as a { name -> value } dict
terom@53:         """
terom@53: 
terom@53:         # the dict of values
terom@53:         values = {}
terom@53: 
terom@53:         # load the cookies
terom@53:         cookie_data = request.env.get('HTTP_COOKIE')
terom@53: 
terom@53:         # got any?
terom@53:         if cookie_data :
terom@53:             # parse into a SimpleCookie
terom@53:             cookies = Cookie.SimpleCookie(cookie_data)
terom@53: 
terom@53:             # update the the values
terom@53:             values.update((morsel.key, morsel.value) for morsel in cookies.itervalues())
terom@53:         
terom@53:         else :
terom@53:             cookies = None
terom@53: 
terom@53:         # apply any query parameters
terom@53:         for pref in self.pref_list :
terom@53:             # look for a query param
terom@53:             value = request.get_arg(pref.name)
terom@53: 
terom@53:             if value :
terom@53:                 # override
terom@53:                 values[pref.name] = value
terom@53: 
terom@53:         # build the RequestPreferences object
terom@53:         return cookies, RequestPreferences(self, request, values)
terom@53: 
terom@53:     def handler (self, *pref_list) :
terom@53:         """
terom@53:             Intended to be used as a decorator for a request handler, this will load the give Preferences and pass
terom@53:             them to the wrapped handler as keyword arguments, in addition to any others given.
terom@53:         """
terom@53: 
terom@53:         def _decorator (func) :
terom@53:             @functools.wraps(func)
terom@53:             def _handler (request, **args) :
terom@53:                 # load preferences
terom@53:                 cookies, prefs = self.load(request)
terom@53: 
terom@53:                 # update args with new ones
terom@53:                 args.update(((pref.name, prefs.get(pref)) for pref in pref_list))
terom@53: 
terom@53:                 # handle to get response
terom@53:                 response = func(request, **args)
terom@53: 
terom@53:                 # set cookies?
terom@53:                 if prefs.set_cookies :
terom@53:                     # update cookies
terom@53:                     for key, value in prefs.set_cookies.iteritems() :
terom@53:                         cookies[key] = value
terom@53: 
terom@53:                     # add headers
terom@53:                     for morsel in cookies.itervalues() :
terom@53:                         response.add_header('Set-cookie', morsel.OutputString())
terom@53: 
terom@53:                 return response
terom@53:             
terom@53:             # return wrapped handler
terom@53:             return _handler
terom@53:         
terom@53:         # return decorator...
terom@53:         return _decorator
terom@53: 
terom@53: # now for our defined preferences....
terom@53: import pytz
terom@53: 
terom@53: class TimeFormat (urltree.URLStringType, Preference) :
terom@53:     """
terom@53:         Time format
terom@53:     """
terom@53: 
terom@53:     # set name
terom@53:     name = 'time_format'
terom@53: 
terom@53:     # default value
terom@53:     default = "%H:%M:%S"
terom@53: 
terom@53: class DateFormat (urltree.URLStringType, Preference) :
terom@53:     """
terom@53:         Date format
terom@53:     """
terom@53: 
terom@53:     # set name
terom@53:     name = 'date_format'
terom@53: 
terom@53:     # default value
terom@53:     default = "%Y-%m%d"
terom@53: 
terom@53: class Timezone (Preference) :
terom@53:     """
terom@53:         Timezone
terom@53:     """
terom@53:     
terom@53:     # set name
terom@53:     name = 'timezone'
terom@53: 
terom@53:     # default value is UTC...
terom@53:     default = pytz.utc
terom@53: 
terom@53:     def parse (self, name) :
terom@53:         """
terom@53:             tz_name -> pytz.timezone
terom@53:         """
terom@53: 
terom@53:         return pytz.timezone(name)
terom@53: 
terom@53:     def build (self, tz) :
terom@53:         """
terom@53:             pytz.timezone -> tz_name
terom@53:         """
terom@53: 
terom@53:         return tz.zone
terom@53: 
terom@53: class Formatter (Preference) :
terom@53:     """
terom@53:         LogFormatter to use
terom@53:     """
terom@53: 
terom@53:     # set name
terom@53:     name = 'formatter'
terom@53: 
terom@53:     def __init__ (self, formatters, default) :
terom@53:         """
terom@53:             Use the given { name -> class LogFormatter } dict and default (a LogFormatter class)
terom@53:         """
terom@53: 
terom@53:         self.formatters = formatters
terom@53:         self.default = default
terom@53:     
terom@53:     def parse (self, fmt_name) :
terom@53:         """
terom@53:             fmt_name -> class LogFormatter
terom@53:         """
terom@53: 
terom@53:         return self.formatters[fmt_name]
terom@53:     
terom@53:     def build (self, fmt_cls) :
terom@53:         """
terom@53:             class LogFormatter -> fmt_name
terom@53:         """
terom@53: 
terom@53:         return fmt.name
terom@53:     
terom@53:     def process (self, prefs, fmt_cls) :
terom@53:         """
terom@53:             class LogFormatter -> LogFormatter(tz, time_fmt)
terom@53:         """
terom@53: 
terom@53:         return fmt_cls(prefs.get(Timezone), prefs.get(TimeFormat))
terom@53: 
terom@53: # and then build the Preferences object
terom@53: import log_formatter
terom@53: 
terom@53: preferences = Preferences([
terom@53:     TimeFormat(),
terom@53:     DateFormat(),
terom@53:     Timezone(),
terom@53:     Formatter(log_formatter.FORMATTERS, log_formatter.IrssiFormatter),
terom@53: ])
terom@53: