From 3a9b01632017da51a05cc14c53578942b8e38b83 Mon Sep 17 00:00:00 2001
From: Tim Van Baak <tim.vanbaak@gmail.com>
Date: Thu, 2 Sep 2021 18:43:04 -0700
Subject: [PATCH] Add uuid werkzeug route converter for character routes

---
 amanuensis/server/__init__.py                 |  4 ++++
 amanuensis/server/helpers.py                  | 20 ++++++++++++++++++-
 .../server/lexicon/characters/__init__.py     | 11 +++-------
 3 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/amanuensis/server/__init__.py b/amanuensis/server/__init__.py
index 8f5c842..f0f4d2f 100644
--- a/amanuensis/server/__init__.py
+++ b/amanuensis/server/__init__.py
@@ -9,6 +9,7 @@ from amanuensis.config import AmanuensisConfig, CommandLineConfig
 from amanuensis.db import DbContext
 from amanuensis.parser import filesafe_title
 import amanuensis.server.auth as auth
+from amanuensis.server.helpers import UuidConverter
 import amanuensis.server.home as home
 import amanuensis.server.lexicon as lexicon
 
@@ -75,6 +76,9 @@ def get_app(
     app.template_filter("articlelink")(article_link)
     app.context_processor(include_backend)
 
+    # Set up uuid route converter
+    app.url_map.converters["uuid"] = UuidConverter
+
     # Set up Flask-Login
     auth.get_login_manager().init_app(app)
 
diff --git a/amanuensis/server/helpers.py b/amanuensis/server/helpers.py
index 434dcb3..06dc06c 100644
--- a/amanuensis/server/helpers.py
+++ b/amanuensis/server/helpers.py
@@ -1,13 +1,31 @@
 from functools import wraps
-from typing import Optional
+from typing import Optional, Any
+from uuid import UUID
 
 from flask import g, flash, redirect, url_for
 from flask_login import current_user
+from werkzeug.routing import BaseConverter, ValidationError
 
 from amanuensis.backend import lexiq, memq
 from amanuensis.db import DbContext, Lexicon, User, Membership
 
 
+class UuidConverter(BaseConverter):
+    """Converter that matches version 4 UUIDs"""
+    regex = r"[0-9A-Fa-f]{8}-[0-9A-Fa-f]{4}-4[0-9A-Fa-f]{3}-[89aAbB][0-9A-Fa-f]{3}-[0-9A-Fa-f]{12}"
+
+    def to_python(self, value: str) -> Any:
+        try:
+            return UUID(value)
+        except:
+            return ValidationError(f"Invalid UUID: {value}")
+
+    def to_url(self, value: Any) -> str:
+        if not isinstance(value, UUID):
+            raise ValueError(f"Expected UUID, got {type(value)}: {value}")
+        return str(value)
+
+
 def lexicon_param(route):
     """
     Wrapper for loading a route's lexicon to `g`.
diff --git a/amanuensis/server/lexicon/characters/__init__.py b/amanuensis/server/lexicon/characters/__init__.py
index c2b5c86..000aa68 100644
--- a/amanuensis/server/lexicon/characters/__init__.py
+++ b/amanuensis/server/lexicon/characters/__init__.py
@@ -22,16 +22,11 @@ def list(name):
     return render_template("characters.jinja", name=name)
 
 
-@bp.route("/edit/<character_id>", methods=["GET", "POST"])
+@bp.route("/edit/<uuid:character_id>", methods=["GET", "POST"])
 @lexicon_param
 @player_required
-def edit(name, character_id):
-    try:
-        char_uuid = uuid.UUID(character_id)
-    except:
-        flash("Character not found")
-        return redirect(url_for("lexicon.characters.list", name=name))
-    character: Optional[Character] = charq.try_from_public_id(g.db, char_uuid)
+def edit(name, character_id: uuid.UUID):
+    character: Optional[Character] = charq.try_from_public_id(g.db, character_id)
     if not character:
         flash("Character not found")
         return redirect(url_for("lexicon.characters.list", name=name))