Implement [[agora go links integration]].

app/agora.py

@@ -56,6 +56,35 @@ def today():
     today = datetime.datetime.now().date()
     return redirect("https://anagora.org/node/%s" % today.strftime("%Y-%m-%d"))
 
+@bp.route('/go/<node>')
+def go(node):
+    """Redirects to the URL in the given node in a block that starts with [[go]], if there is one."""
+    # TODO(flancian): all node-scoped stuff should move to actually use node objects.
+    try:
+        n = db.nodes_by_wikilink(node)
+    except KeyError:
+        return redirect("https://anagora.org/node/%s" % node)
+
+    if len(n) > 1:
+        current_app.logger.warning('nodes_by_wikilink returned more than one node, should not happen.')
+
+    if len(n) == 0:
+        # No nodes with this name -- redirect to node 404.
+        return redirect("https://anagora.org/node/%s" % node)
+
+    links = n[0].go()
+    if len(links) == 0:
+        # No go links detected in this node -- just redirect to the node.
+        # TODO(flancian): flash an explanation :)
+        return redirect("https://anagora.org/node/%s" % node)
+
+    if len(links) > 1:
+        # TODO(flancian): to be implemented.
+        # Likely default to one of the links, show all of them but redirect to default within n seconds.
+        current_app.logger.warning('Code to manage nodes with more than one go link is not Not implemented.')
+
+    return redirect(links[0])
+
 @bp.route('/u/<user>')
 @bp.route('/user/<user>')
 @bp.route('/@<user>')
@@ -76,7 +105,7 @@ def wikilink(node):
 def subnode(subnode):
     return render_template('subnode_rendered.html', subnode=db.subnode_by_uri(subnode), backlinks=db.subnodes_by_outlink(subnode))
 
-# Searching with GET: potentially useful but probably not a good idea.
+    # Searching with GET: potentially useful but probably not a good idea.
 # @bp.route('/search/<query>')
 # def search(query):
 #    return render_template('subnodes.html', subnodes=db.search_subnodes(query))

app/db.py

@@ -63,6 +63,14 @@ class Node:
     def size(self):
         return len(self.subnodes)
 
+    def go(self):
+        # There's surely a much better way to do this. Alas :)
+        go = []
+        for subnode in self.subnodes:
+            go.extend(subnode.go())
+        return go
+
+
 class Subnode:
     """A subnode is a note or media resource volunteered by a user of the Agora.
     It maps to a particular file in the Agora repository, stored (relative to 
@@ -98,6 +106,21 @@ class Subnode:
         # hack hack
         return 100-fuzz.ratio(self.wikilink, other.wikilink)
 
+    def go(self):
+        # returns a set of go links contained in this node
+        return subnode_to_actions(self, 'go')
+
+
+def subnode_to_actions(subnode, action):
+    # hack hack.
+    action_regex ='\[\[' + action + '\]\] (.*?)$'
+    content = subnode.content
+    actions = []
+    for line in content.splitlines():
+        m = re.search(action_regex, line)
+        if m:
+            actions.append(m.group(1))
+    return actions
 
 class User:
     def __init__(self, user):