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@129: import utils
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@129:     # the default value, as from parse()
terom@53:     default = None
terom@53:     
terom@129:     def is_default (self, value) :
terom@129:         """
terom@129:             Returns True if the given post-value is the default value for this preference.
terom@129: 
terom@129:             Defaults to just compare against self.default
terom@129:         """
terom@129: 
terom@129:         return (value == self.default)
terom@129:         
terom@53:     def process (self, preferences, value) :
terom@53:         """
terom@129:             Post-process this preference value. This can access the post-processed values of all other preferences that
terom@129:             were defined before this one in the list given to Preferences. 
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@129:             Initialize with the given Preferences object, http Request, and { key: value } mapping of raw preference values.
terom@129: 
terom@129:             This will build a mapping of { name: pre-value } using Preference.parse/Preference.default, and then
terom@129:             post-process them into the final { name: value } mapping using Preference.process, in strict pref_list
terom@129:             order. Note that the process() method will only have access to those preferences processed before it was.
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@129:         # initial value map
terom@129:         pre_values = {}
terom@129: 
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@129:                 
terom@53:             # add
terom@129:             pre_values[pref.name] = value
terom@53:         
terom@129:         # then post-process using Preferences.process(), in strict pref_list order
terom@129:         for pref in preferences.pref_list :
terom@129:             # store into self.values, so that pref.get(...) will be able to access the still-incomplete self.values
terom@129:             # dict
terom@129:             self.values[pref.name] = pref.process(self, pre_values[pref.name])
terom@59:     
terom@129:     def _get_name (self, pref) :
terom@129:         """
terom@129:             Look up a Preference's name, either by class, object or name.
terom@129:         """
terom@129: 
terom@129:         # Preference -> name
terom@129:         if isinstance(pref, Preference) :
terom@129:             pref = pref.name
terom@129: 
terom@129:         return pref
terom@129:     
terom@129:     def pref (self, name) :
terom@129:         """
terom@129:             Look up a Preference by object, name
terom@129:         """
terom@129: 
terom@129:         # Preference
terom@129:         if isinstance(name, Preference) :
terom@129:             return name
terom@129:         
terom@129:         # Preference.name
terom@129:         elif isinstance(name, basestring) :
terom@129:             return self.preferences.pref_map[name]
terom@129:         
terom@129:         # XXX: class?
terom@129:         else :
terom@129:             assert False
terom@129: 
terom@53:     def get (self, pref) :
terom@53:         """
terom@62:             Return the value for the given Preference, or preference name
terom@53:         """
terom@53:         
terom@62:         # look up
terom@129:         return self.values[self._get_name(pref)]
terom@59: 
terom@59:     # support dict-access
terom@59:     __getitem__ = get
terom@129:     
terom@129:     def is_default (self, pref) :
terom@129:         """
terom@129:             Returns True if the given preference is at its default value
terom@129:         """
terom@129:         
terom@129:         # determine using Preference.is_default
terom@129:         return self.pref(pref).is_default(self.get(pref))
terom@59: 
terom@129:     def build (self, pref) :
terom@53:         """
terom@129:             Like 'get', but return the raw cookie value
terom@129:         """
terom@129:         
terom@129:         # the Preference
terom@129:         pref = self.pref(pref)
terom@129:         
terom@129:         # build
terom@129:         return pref.build(self.get(pref))
terom@129:     
terom@129:     def parse (self, pref, value=None) :
terom@129:         """
terom@129:             Parse+process the raw value for some pref into a value object.
terom@129: 
terom@129:             Is the given raw value is None, this uses Preference.default
terom@129:         """
terom@129: 
terom@129:         # lookup pref
terom@129:         pref = self.pref(pref)
terom@129:         
terom@129:         # build value
terom@129:         if value is not None :
terom@129:             # parse
terom@129:             value = pref.parse(value)
terom@129:         
terom@129:         else :
terom@129:             # default
terom@129:             value = pref.default
terom@129:         
terom@129:         # post-process
terom@129:         value = pref.process(self, value)
terom@129: 
terom@129:         # return
terom@129:         return value
terom@129: 
terom@129:     def set (self, name, value_obj=None) :
terom@129:         """
terom@129:             Set a new value for the given preference (by str name).
terom@129: 
terom@129:             If value_obj is None, then the preference cookie is unset
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@129:         
terom@129:         # None?
terom@129:         if value_obj is not None :
terom@129:             # encode using the Preference object
terom@129:             value_str = self.preferences.pref_map[name].build(value_obj)
terom@129:         
terom@129:         else :
terom@129:             # unset as None
terom@129:             value_str = None
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@129:             Use the given list of Preference objects.
terom@129: 
terom@129:             The ordering of the given pref_list is significant for the process() implementation, as the
terom@129:             Preferences are process()'d in order.
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@59:                 # bind to request.prefs
terom@59:                 # XXX: better way to do this? :/
terom@59:                 request.prefs = prefs
terom@59: 
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@129:                     # default, empty, cookiejar
terom@59:                     if not cookies :
terom@59:                         cookies = Cookie.SimpleCookie('')
terom@59: 
terom@53:                     # update cookies
terom@53:                     for key, value in prefs.set_cookies.iteritems() :
terom@129:                         if value is None :
terom@129:                             assert False, "Not implemented yet..."
terom@129: 
terom@129:                         else :
terom@129:                             # set
terom@129:                             cookies[key] = value
terom@131:                             cookies[key]["path"] = config.PREF_COOKIE_PATH
terom@131:                             cookies[key]["expires"] = config.PREF_COOKIE_EXPIRE_SECONDS
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@73: import config
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@73:     default = config.PREF_TIME_FMT_DEFAULT
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@73:     default = config.PREF_DATE_FMT_DEFAULT
terom@53: 
terom@129: class TimezoneOffset (Preference) :
terom@129:     """
terom@129:         If the DST-aware 'timezone' is missing, we can fallback to a fixed-offset timezone as detected by
terom@129:         Javascript.
terom@129: 
terom@129:         This is read-only, and None by default
terom@129:     """
terom@129: 
terom@129:     name = 'timezone_offset'
terom@129:     default = None
terom@129: 
terom@129:     def parse (self, offset) :
terom@129:         """
terom@129:             Offset in minutes -> said minutes
terom@129:         """
terom@129: 
terom@129:         return int(offset)
terom@129: 
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@129:     # default is handled via process()
terom@129:     default = 'auto'
terom@129: 
terom@129:     # the list of available (value, name) options for use with helpers.select_options
terom@129:     OPTIONS = [('auto', "Autodetect")] + [(None, tz_name) for tz_name in pytz.common_timezones]
terom@53: 
terom@53:     def parse (self, name) :
terom@53:         """
terom@129:             default -> default
terom@53:             tz_name -> pytz.timezone
terom@53:         """
terom@129:         
terom@129:         # special-case for 'auto'
terom@129:         if name == self.default :
terom@129:             return self.default
terom@53: 
terom@129:         else :
terom@129:             return pytz.timezone(name)
terom@129: 
terom@129:     def is_default (self, tz) :
terom@129:         """
terom@131:             True if it's a FixedOffsetTimezone or PREF_TIMEZONE_FALLBACK
terom@129:         """
terom@129: 
terom@131:         return (isinstance(tz, utils.FixedOffsetTimezone) or tz == config.PREF_TIMEZONE_FALLBACK)
terom@53: 
terom@53:     def build (self, tz) :
terom@53:         """
terom@129:             FixedOffsetTimezone -> None
terom@53:             pytz.timezone -> tz_name
terom@53:         """
terom@129:         
terom@129:         # special-case for auto/no explicit timezone
terom@129:         if self.is_default(tz) :
terom@129:             return self.default
terom@53: 
terom@129:         else :
terom@129:             # pytz.timezone zone name
terom@129:             return tz.zone
terom@129:     
terom@129:     def process (self, prefs, tz) :
terom@129:         """
terom@129:             If this timezone is given, simply build that. Otherwise, try and use TimezoneOffset, and if that fails,
terom@129:             just return the default.
terom@129: 
terom@131:             None -> FixedOffsetTimezone/PREF_TIMEZONE_FALLBACK
terom@129:             pytz.timezone -> pytz.timezone
terom@129:         """
terom@129:         
terom@129:         # specific timezone set?
terom@129:         if tz != self.default :
terom@129:             return tz
terom@129:         
terom@129:         # fixed offset?
terom@129:         elif prefs[timezone_offset] is not None :
terom@129:             return utils.FixedOffsetTimezone(prefs[timezone_offset])
terom@129:         
terom@129:         # default
terom@129:         else :
terom@131:             return config.PREF_TIMEZONE_FALLBACK
terom@53: 
terom@79: class ImageFont (Preference) :
terom@79:     """
terom@79:         Font for ImageFormatter
terom@79:     """
terom@79: 
terom@79:     # set name
terom@79:     name = 'image_font'
terom@79:     
terom@79:     def __init__ (self, font_dict, default_name) :
terom@79:         """
terom@79:             Use the given { name: (path, title) } dict and default the given name
terom@79:         """
terom@79: 
terom@79:         self.font_dict = font_dict
terom@79:         self.default = self.parse(default_name)
terom@79:     
terom@79:     def parse (self, name) :
terom@79:         """
terom@79:             name -> (name, path, title)
terom@79:         """
terom@79: 
terom@79:         path, title = self.font_dict[name]
terom@79: 
terom@79:         return name, path, title
terom@79:     
terom@79:     def build (self, font_info) :
terom@79:         """
terom@79:             (name, path, title) -> name
terom@79:         """
terom@79: 
terom@79:         name, path, title = font_info
terom@79: 
terom@79:         return name
terom@79: 
terom@79: class ImageFontSize (urltree.URLIntegerType, Preference) :
terom@79:     # set name, default
terom@79:     name = 'image_font_size'
terom@79:     default = config.PREF_IMAGE_FONT_SIZE_DEFAULT
terom@79:     
terom@129:     # XXX: constraints for valid values
terom@79: 
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@59:         return fmt_cls.name
terom@53:     
terom@53:     def process (self, prefs, fmt_cls) :
terom@53:         """
terom@79:             class LogFormatter -> LogFormatter(tz, time_fmt, image_font.path)
terom@53:         """
terom@53: 
terom@129:         # time stuff
terom@129:         tz = prefs[timezone]
terom@129:         time_fmt = prefs[time_format]
terom@129:         
terom@129:         # font stuff
terom@79:         font_name, font_path, font_title = prefs[image_font]
terom@79:         font_size = prefs[image_font_size]
terom@79: 
terom@129:         return fmt_cls(tz, time_fmt, font_path, font_size)
terom@53: 
terom@73: class Count (urltree.URLIntegerType, Preference) :
terom@73:     """
terom@73:         Number of lines of log data to display per page
terom@73:     """
terom@53: 
terom@73:     # set name
terom@73:     name = "count"
terom@73:     
terom@73:     # default
terom@73:     default = config.PREF_COUNT_DEFAULT
terom@73:     
terom@73:     def __init__ (self) :
terom@73:         super(Count, self).__init__(allow_negative=False, allow_zero=False, max=config.PREF_COUNT_MAX)
terom@73: 
terom@73: # and then build the Preferences object
terom@73: time_format     = TimeFormat()
terom@73: date_format     = DateFormat()
terom@129: timezone_offset = TimezoneOffset()
terom@73: timezone        = Timezone()
terom@79: image_font      = ImageFont(config.FORMATTER_IMAGE_FONTS, config.PREF_IMAGE_FONT_DEFAULT)
terom@79: image_font_size = ImageFontSize()
terom@73: formatter       = Formatter(config.LOG_FORMATTERS, config.PREF_FORMATTER_DEFAULT)
terom@73: count           = Count()
terom@59: 
terom@53: preferences = Preferences([
terom@59:     time_format,
terom@59:     date_format,
terom@129:     timezone_offset,
terom@59:     timezone,
terom@79:     image_font,
terom@79:     image_font_size,
terom@59:     formatter,
terom@73:     count,
terom@53: ])
terom@53: