Add support to re-write depot URLs

This will enable support to use https://assets.algobowl.org URLs in
algobowl-mines-prod.

algobowl/controllers/file_redirector.py

@@ -1,12 +1,13 @@
 import datetime
 import re
+from typing import Union
 
 import tg
 
 import algobowl.model as model
 
 
-def input_redirector(group_id):
+def input_redirector(group_id: str) -> model.Input:
     group_id = int(group_id)
     group = model.DBSession.query(model.Group).get(group_id)
     if not group:
@@ -24,12 +25,12 @@ def input_redirector(group_id):
     if file_is_public or is_group_member or is_admin:
         if not group.input:
             tg.abort(404, "An input file has not been uploaded yet.")
-        return group.input.data
+        return group.input
 
     tg.abort(403, "You do not have access to this file at this time.")
 
 
-def output_redirector(from_group_id, to_group_id):
+def output_redirector(from_group_id: str, to_group_id: str) -> model.Output:
     from_group_id = int(from_group_id)
     to_group_id = int(to_group_id)
     output = (
@@ -57,7 +58,7 @@ def output_redirector(from_group_id, to_group_id):
         or is_admin
         or (is_verifier and visible_to_verifier)
     ):
-        return output.data
+        return output
 
     tg.abort(403, "You do not have access to this file at this time.")
 
@@ -68,7 +69,7 @@ def output_redirector(from_group_id, to_group_id):
 ]
 
 
-def get_file(filename):
+def get_file(filename: str) -> Union[model.Input, model.Output]:
     for pattern, func in file_pattern_handlers:
         m = pattern.fullmatch(filename)
         if m:

algobowl/controllers/root.py

@@ -51,11 +51,13 @@ def tos(self):
 
     @expose()
     def files(self, filename, redirect=False):
-        file = file_redirector.get_file(filename)
+        db_obj = file_redirector.get_file(filename)
+        if "://" in db_obj.url:
+            tg.redirect(db_obj.url)
         if redirect:
-            tg.redirect(file.url)
+            tg.redirect(db_obj.data.url)
         tg.response.content_type = "application/octet-stream"
-        return file.file.read()
+        return db_obj.data.file.read()
 
     @expose()
     def login(self):

algobowl/model.py

@@ -1,5 +1,6 @@
 import datetime
 import enum
+from typing import Optional
 
 import sqlalchemy as sa
 import tg
@@ -287,6 +288,14 @@ def __repr__(self):
 )
 
 
+def _get_depot_url(filename: str, file_id: Optional[str]) -> str:
+    """Helper to implement .url property of Input/Output objects."""
+    rewrite_rule = tg.config.get("algobowl.depot_url_rewrite")
+    if rewrite_rule and file_id:
+        return rewrite_rule.format(filename=filename, file_id=file_id)
+    return tg.url(f"/files/{filename}")
+
+
 class Input(DeclarativeBase):
     __tablename__ = "input"
     db_icon = "far fa-file"
@@ -308,7 +317,7 @@ def filename(self):
 
     @property
     def url(self):
-        return tg.url(f"/files/{self.filename}")
+        return _get_depot_url(self.filename, self.data and self.data.file_id)
 
     def __repr__(self):
         return "Input from [{!r}]".format(self.group)
@@ -350,7 +359,7 @@ def filename(self):
 
     @property
     def url(self):
-        return tg.url(f"/files/{self.filename}")
+        return _get_depot_url(self.filename, self.data and self.data.file_id)
 
     def __repr__(self):
         return "Output from [{!r}] for {!r}".format(self.group, self.input)