Added the 'i2pconv' template filter to convert I2P urls to clearnet as required

i2p2www/__init__.py

@@ -69,15 +69,6 @@ def detect_theme():
         return resp
 
 
-############################
-# Hooks - request processing
-
-@app.template_filter('restructuredtext')
-def restructuredtext(value):
-    parts = publish_parts(source=value, writer_name="html")
-    return parts['html_body']
-
-
 #######################
 # Hooks - after request
 
@@ -88,7 +79,38 @@ def call_after_request_callbacks(response):
     return response
 
 
-###############
+##################
+# Template filters
+
+@app.template_filter('restructuredtext')
+def restructuredtext(value):
+    parts = publish_parts(source=value, writer_name="html")
+    return parts['html_body']
+
+# Convert an I2P url to an equivalent clearnet one
+i2ptoclear = {
+    'www.i2p2.i2p': 'www.i2p2.de',
+    'forum.i2p': 'forum.i2p2.de',
+    'trac.i2p2.i2p': 'trac.i2p2.de',
+    }
+@app.template_filter('i2pconv')
+def convert_url_to_clearnet(value):
+    if not value.endswith('.i2p'):
+        # The url being passed in isn't an I2P url, so just return it
+        return value
+    if request.headers.get('X-I2P-Desthash') and not request.headers.get('X-Forwarded-Server'):
+        # The request is from within I2P, so use I2P url
+        return value
+    # The request is either directly from clearnet or through an inproxy
+    try:
+        # Return the known clearnet url corresponding to the I2P url
+        return i2ptoclear[value]
+    except KeyError:
+        # The I2P site has no known clearnet address, so use an inproxy
+        return value + '.to'
+
+
+################
 # Error handlers
 
 @app.errorhandler(404)