terom@29: 
terom@29: """
terom@29:     URL mapping for the irclogs.qmsk.net site
terom@29: """
terom@29: 
terom@36: import re
terom@36: 
terom@29: # our own handlers
terom@29: import handlers
terom@29: 
terom@36: # mapper
terom@36: from lib import map
terom@29: 
terom@36: class URLError (Exception) :
terom@29:     """
terom@36:         Error with an URL definition
terom@29:     """
terom@29: 
terom@36:     pass
terom@29: 
terom@36: class Label (object) :
terom@36:     """
terom@36:         Base class for URL labels (i.e. the segments of the URL between /s)
terom@36:     """
terom@36: 
terom@36:     @staticmethod
terom@36:     def parse (mask, defaults) :
terom@36:         """
terom@36:             Parse the given label-segment, and return a *Label instance
terom@36:         """
terom@36: 
terom@36:         # empty?
terom@36:         if not mask :
terom@36:             return EmptyLabel()
terom@36: 
terom@36:         # simple value?
terom@36:         match = SimpleValueLabel.EXPR.match(mask)
terom@36: 
terom@36:         if match :
terom@36:             # key
terom@36:             key = match.group('key')
terom@36: 
terom@36:             # default?
terom@36:             default = defaults.get(key)
terom@36: 
terom@36:             # build
terom@36:             return SimpleValueLabel(key, default)
terom@36:         
terom@36:         # static?
terom@36:         match = StaticLabel.EXPR.match(mask)
terom@36: 
terom@36:         if match :
terom@36:             return StaticLabel(match.group('name'))
terom@36: 
terom@36:         # invalid
terom@36:         raise URLError("Invalid label: %r" % (mask, ))
terom@36: 
terom@36: 
terom@36: class EmptyLabel (Label) :
terom@36:     """
terom@36:         An empty label, i.e. just a slash in the URL
terom@36:     """
terom@36:     
terom@36:     def __eq__ (self, other) :
terom@36:         """
terom@36:             Just compares type
terom@36:         """
terom@36: 
terom@36:         return isinstance(other, EmptyLabel)
terom@36:     
terom@36:     def __str__ (self) :
terom@36:         return ''
terom@36: 
terom@36: class StaticLabel (Label) :
terom@36:     """
terom@36:         A simple literal Label, used for fixed terms in the URL
terom@36:     """
terom@36: 
terom@36:     EXPR = re.compile(r'^(?P<name>[a-zA-Z_.-]+)$')
terom@36: 
terom@36:     def __init__ (self, name) :
terom@36:         """
terom@36:             The given name is the literal name of this label
terom@36:         """
terom@36: 
terom@36:         self.name = name
terom@36: 
terom@36:     def __eq__ (self, other) :
terom@36:         """
terom@36:             Compares names
terom@36:         """
terom@36: 
terom@36:         return isinstance(other, StaticLabel) and self.name == other.name
terom@36:     
terom@36:     def __str__ (self) :
terom@36:         return self.name
terom@36: 
terom@36: class ValueLabel (Label) :
terom@36:     """
terom@36:         A label with a key and a value
terom@36:     """
terom@36: 
terom@36:     def __init__ (self, key, default) :
terom@36:         """
terom@36:             Set the key and default value. Default value may be None if there is no default value defined
terom@36:         """
terom@36: 
terom@36:         self.key = key
terom@36:         self.default = default
terom@36: 
terom@36:     def __eq__ (self, other) :
terom@36:         """
terom@36:             Compares keys
terom@36:         """
terom@36: 
terom@36:         return isinstance(other, ValueLabel) and self.key == other.key
terom@36: 
terom@36: class SimpleValueLabel (ValueLabel) :
terom@36:     """
terom@36:         A label that has a name and a simple string value
terom@36:     """
terom@36: 
terom@36:     EXPR = re.compile(r'^\{(?P<key>[a-zA-Z_][a-zA-Z0-9_]*)\}$')
terom@36: 
terom@36:     def __init__ (self, key, default) :
terom@36:         """
terom@36:             The given key is the name of this label's value
terom@36:         """
terom@36: 
terom@36:         super(SimpleValueLabel, self).__init__(key, default)
terom@36:     
terom@36:     def __str__ (self) :
terom@36:         if self.default :
terom@36:             return '{%s=%s}' % (self.key, self.default)
terom@36:             
terom@36:         else :
terom@36:             return '{%s}' % (self.key, )
terom@36: 
terom@36: class URL (object) :
terom@36:     """
terom@36:         Represents a specific URL
terom@36:     """
terom@36: 
terom@36:     def __init__ (self, url_mask, handler, **defaults) :
terom@36:         """
terom@36:             Create an URL with the given url mask, handler, and default values
terom@36:         """
terom@36: 
terom@36:         # store
terom@36:         self.url_mask = url_mask
terom@36:         self.handler = handler
terom@36:         self.defaults = defaults
terom@36: 
terom@36:         # build our labels
terom@36:         self.label_path = [Label.parse(mask, defaults) for mask in url_mask.split('/')]
terom@36:         
terom@36:     def get_label_path (self) :
terom@36:         """
terom@36:             Returns a list containing the labels in this url
terom@36:         """
terom@36:         
terom@36:         # copy self.label_path
terom@36:         return list(self.label_path)
terom@36: 
terom@36:     def execute (self, request, xxx) :
terom@36:         """
terom@36:             Invoke the handler with the correct parameters
terom@36:         """
terom@36: 
terom@36:         xxx
terom@36:     
terom@36:     def __str__ (self) :
terom@36:         return '/'.join(str(label) for label in self.label_path)
terom@36:     
terom@36:     def __repr__ (self) :
terom@36:         return "URL(%r, %r)" % (str(self), self.handler)
terom@36: 
terom@36: class URLNode (object) :
terom@36:     """
terom@36:         Represents a node in the URLTree
terom@36:     """
terom@36: 
terom@36:     def __init__ (self, parent, label) :
terom@36:         """
terom@36:             Initialize with the given parent and label, empty children dict
terom@36:         """
terom@36:         
terom@36:         # the parent URLNode
terom@36:         self.parent = parent
terom@36: 
terom@36:         # this node's Label
terom@36:         self.label = label
terom@36: 
terom@36:         # list of child URLNodes
terom@36:         self.children = []
terom@36: 
terom@36:         # this node's URL, set by add_url for an empty label_path
terom@36:         self.url = None
terom@36: 
terom@36:     def _build_child (self, label) :
terom@36:         """
terom@36:             Build, insert and return a new child Node
terom@36:         """
terom@36:         
terom@36:         # build new child
terom@36:         child = URLNode(self, label)
terom@36:         
terom@36:         # add to children
terom@36:         self.children.append(child)
terom@36: 
terom@36:         # return
terom@36:         return child
terom@36: 
terom@36:     def add_url (self, url, label_path) :
terom@36:         """
terom@36:             Add a URL object to this node under the given path. Uses recursion to process the path.
terom@36: 
terom@36:             The label_path argument is a (partial) label path as returned by URL.get_label_path.
terom@36: 
terom@36:             If label_path is empty (len zero, or begins with EmptyLabel), then the given url is assigned to this node, if no
terom@36:             url was assigned before.
terom@36:         """
terom@36:         
terom@36:         # matches this node?
terom@36:         if not label_path or isinstance(label_path[0], EmptyLabel) :
terom@36:             if self.url :
terom@36:                 raise URLError(url, "node already defined")
terom@36: 
terom@36:             else :
terom@36:                 # set
terom@36:                 self.url = url
terom@36: 
terom@36:         else :
terom@36:             # pop child label from label_path
terom@36:             child_label = label_path.pop(0)
terom@36: 
terom@36:             # look for the child to recurse into
terom@36:             child = None
terom@36: 
terom@36:             # look for an existing child with that label
terom@36:             for child in self.children :
terom@36:                 if child.label == child_label :
terom@36:                     # found, use this
terom@36:                     break
terom@36: 
terom@36:             else :
terom@36:                 # build a new child
terom@36:                 child = self._build_child(child_label)
terom@36: 
terom@36:             # recurse to handle the rest of the label_path
terom@36:             child.add_url(url, label_path)
terom@36:     
terom@36:     def match_label (self, label) :
terom@36:         """
terom@36:             Match our label mask against the given label value.
terom@36: 
terom@36:             Returns either False (no match), True (matched, no value) or a (key, value) pair.
terom@36:         """
terom@36: 
terom@36:         # simple mask
terom@36:         if self.label.beginswith('{') and self.label.endswith('}') :
terom@36:             value_name = self.label.strip('{}')
terom@36: 
terom@36:             return (value_name, label)
terom@36:         
terom@36:         # literal mask
terom@36:         elif self.label == label :
terom@36:             return True
terom@36: 
terom@36:         else :  
terom@36:             return False
terom@36: 
terom@36:     def match (self, path, label_path) :
terom@36:         """
terom@36:             Locate the URL object corresponding to the given label_path value under this node, with the given path
terom@36:             containing the previously matched label values
terom@36:         """
terom@36: 
terom@36:         # empty label_path?
terom@36:         if not label_path or not label_path[0] :
terom@36:             # we wanted this node
terom@36:             if self.url :
terom@36:                 # this URL is the best match
terom@36:                 return [self]
terom@36:             
terom@36:             elif self.children :
terom@36:                 # continue testing our children
terom@36:                 label = None
terom@36:             
terom@36:             else :
terom@36:                 # incomplete URL
terom@36:                 raise URLError(url, "no URL handler defined for this Node")
terom@36:         
terom@36:         else :
terom@36:             # pop our child label from the label path
terom@36:             label = label_path.pop(0)
terom@36: 
terom@36:             # build a list of matching children
terom@36:             matches = []
terom@36: 
terom@36:             # recurse through our children
terom@36:             for child in self.children :
terom@36:                 matches.append(child.match(label_path))
terom@36: 
terom@36:             # return the list of matching children
terom@36:             return matches
terom@36:     
terom@36:     def dump (self, indent=0) :
terom@36:         """
terom@36:             Returns a multi-line string representation of this Node
terom@36:         """
terom@36: 
terom@36:         return '\n'.join([
terom@36:             "%-45s%s" % (
terom@36:                 ' '*indent + str(self.label) + ('/' if self.children else ''), 
terom@36:                 (' -> %r' % self.url) if self.url else ''
terom@36:             )
terom@36:         ] + [
terom@36:             child.dump(indent + 4) for child in self.children
terom@36:         ])
terom@36: 
terom@36:     def __str__ (self) :
terom@36:         return "%s/[%s]" % (self.label, ','.join(str(child) for child in self.children))
terom@36: 
terom@36: class URLTree (map.Mapper) :
terom@36:     """
terom@36:         Map requests to handlers, using a defined tree of URLs
terom@36:     """
terom@36: 
terom@36:     def __init__ (self, url_list) :
terom@36:         """
terom@36:             Initialize the tree using the given list of URLs
terom@36:         """
terom@36: 
terom@36:         # root node
terom@36:         self.root = URLNode(None, EmptyLabel())
terom@36:         
terom@36:         # just add each URL
terom@36:         for url in url_list :
terom@36:             self.add_url(url)
terom@36: 
terom@36:     def add_url (self, url) :
terom@36:         """
terom@36:             Adds the given URL to the tree. The URL must begin with a root slash.
terom@36:         """
terom@36:         # get url's label path
terom@36:         path = url.get_label_path()
terom@36: 
terom@36:         # should begin with root
terom@36:         root_label = path.pop(0)
terom@36:         assert root_label == self.root.label, "URL must begin with root"
terom@36: 
terom@36:         # add to root
terom@36:         self.root.add_url(url, path)
terom@36:         
terom@36:     def match (self, url) :
terom@36:         """
terom@36:             Returns the URL object best corresponding to the given url
terom@36:         """
terom@36: 
terom@36:         # normalize the URL
terom@36:         url = os.path.normpath(url)
terom@36: 
terom@36:         # split it into labels
terom@36:         label_path = url.split('/')
terom@36: 
terom@36:         # just match starting at root
terom@36:         return self.root.match(label_path)
terom@36: 
terom@36:     def handle_request (self, request) :
terom@36:         """
terom@36:             Looks up the request's URL, and invokes its handler
terom@36:         """
terom@36:         
terom@36:         # get the request's URL path
terom@36:         url = self.match(request.get_page_name())
terom@36: 
terom@36:         # XXX: figure out the argument values...
terom@36: 
terom@36:         # let the URL handle it
terom@36:         url.execute(request, xxx)
terom@36: 
terom@36: # urls
terom@36: index           = URL(  '/',                                            handlers.index                                          )
terom@36: channel_view    = URL(  '/channel/{channel}',                           handlers.channel_view                                   )
terom@36: channel_last    = URL(  '/channel/{channel}/last/{count}/{format}',     handlers.channel_last,      count=100, format="html"    )
terom@36: channel_search  = URL(  '/channel/{channel}/search',                    handlers.channel_search                                 )
terom@36: 
terom@36: # mapper
terom@36: mapper = URLTree([index, channel_view, channel_last, channel_search])
terom@36: