From a34c37065c43a74039532a182e1aeb1636125421 Mon Sep 17 00:00:00 2001
From: Anthony Lukach <anthonylukach@gmail.com>
Date: Thu, 12 Dec 2024 20:31:35 -0800
Subject: [PATCH] Mv from dataclasses to higher order functions

---
 src/stac_auth_proxy/filters/template.py       | 77 ++++++++-----------
 src/stac_auth_proxy/handlers/reverse_proxy.py |  3 +-
 2 files changed, 33 insertions(+), 47 deletions(-)

diff --git a/src/stac_auth_proxy/filters/template.py b/src/stac_auth_proxy/filters/template.py
index 51e0fb5..45fa2ef 100644
--- a/src/stac_auth_proxy/filters/template.py
+++ b/src/stac_auth_proxy/filters/template.py
@@ -1,7 +1,6 @@
 """Generate CQL2 filter expressions via Jinja2 templating."""
 
-from dataclasses import dataclass, field
-from typing import Any, Callable
+from typing import Any, Annotated, Callable
 
 from cql2 import Expr
 from fastapi import Request, Security
@@ -10,48 +9,34 @@
 from ..utils import extract_variables
 
 
-@dataclass
-class Template:
+def Template(template_str: str, token_dependency: Callable[..., Any]):
     """Generate CQL2 filter expressions via Jinja2 templating."""
-
-    template_str: str
-    token_dependency: Callable[..., Any]
-
-    # Generated attributes
-    env: Environment = field(init=False)
-    dependency: Callable[[Request, Security], Expr] = field(init=False)
-
-    def __post_init__(self):
-        """Initialize the Jinja2 environment."""
-        self.env = Environment(loader=BaseLoader).from_string(self.template_str)
-        self.dependency = self.build()
-
-    def build(self):
-        """Generate a dependency for rendering a CQL2 filter expression."""
-
-        async def dependency(
-            request: Request, auth_token=Security(self.token_dependency)
-        ) -> Expr:
-            """Render a CQL2 filter expression with the request and auth token."""
-            # TODO: How to handle the case where auth_token is null?
-            context = {
-                "req": {
-                    "path": request.url.path,
-                    "method": request.method,
-                    "query_params": dict(request.query_params),
-                    "path_params": extract_variables(request.url.path),
-                    "headers": dict(request.headers),
-                    "body": (
-                        await request.json()
-                        if request.headers.get("content-type") == "application/json"
-                        else (await request.body()).decode()
-                    ),
-                },
-                "token": auth_token,
-            }
-            cql2_str = self.env.render(**context)
-            cql2_expr = Expr(cql2_str)
-            cql2_expr.validate()
-            return cql2_expr
-
-        return dependency
+    env = Environment(loader=BaseLoader).from_string(template_str)
+
+    async def dependency(
+        request: Request,
+        auth_token=Annotated[dict[str, Any], Security(token_dependency)],
+    ) -> Expr:
+        """Render a CQL2 filter expression with the request and auth token."""
+        # TODO: How to handle the case where auth_token is null?
+        context = {
+            "req": {
+                "path": request.url.path,
+                "method": request.method,
+                "query_params": dict(request.query_params),
+                "path_params": extract_variables(request.url.path),
+                "headers": dict(request.headers),
+                "body": (
+                    await request.json()
+                    if request.headers.get("content-type") == "application/json"
+                    else (await request.body()).decode()
+                ),
+            },
+            "token": auth_token,
+        }
+        cql2_str = env.render(**context)
+        cql2_expr = Expr(cql2_str)
+        cql2_expr.validate()
+        return cql2_expr
+
+    return dependency
diff --git a/src/stac_auth_proxy/handlers/reverse_proxy.py b/src/stac_auth_proxy/handlers/reverse_proxy.py
index c0d5943..841b83f 100644
--- a/src/stac_auth_proxy/handlers/reverse_proxy.py
+++ b/src/stac_auth_proxy/handlers/reverse_proxy.py
@@ -37,7 +37,7 @@ def __post_init__(self):
         for endpoint in [self.proxy_request, self.stream]:
             endpoint.__annotations__["collections_filter"] = Annotated[
                 Optional[Expr],
-                Depends(getattr(self.collections_filter, "dependency", lambda: None)),
+                Depends(self.collections_filter or (lambda: None)),
             ]
 
     async def proxy_request(
@@ -55,6 +55,7 @@ async def proxy_request(
         path = request.url.path
         query = request.url.query
 
+        # Appliy filters
         if utils.is_collection_endpoint(path) and collections_filter:
             if request.method == "GET" and path == "/collections":
                 query = utils.insert_filter(qs=query, filter=collections_filter)