feat(api): implement UE-Module association get endpoint

- GET /ue-modules/{idModule}/{idUE}/{idPromo}: recover the detail of an
  ue-module association by its composite key
- requires employee role

routes/(apps)/notes/api/ue-modules/[idModule]/[idUE]/[idPromo].ts

@@ -0,0 +1,53 @@
+import { FreshContext, Handlers } from "$fresh/server.ts";
+import { db } from "$root/databases/db.ts";
+import { ueModules } from "$root/databases/schema.ts";
+import { AuthenticatedState } from "$root/defaults/interfaces.ts";
+import { eq } from "npm:drizzle-orm@0.45.2";
+
+const NOT_FOUND = new Response(
+  JSON.stringify({ error: "Association UE-Module introuvable" }),
+  { status: 404, headers: { "content-type": "application/json" } },
+);
+
+const FORBIDDEN = new Response(null, { status: 403 });
+
+const BAD_REQUEST = new Response(
+  JSON.stringify({ error: "Paramètres invalides" }),
+  { status: 400, headers: { "content-type": "application/json" } },
+);
+
+export const handler: Handlers<null, AuthenticatedState> = {
+  // #39 GET /ue-modules/{idModule}/{idUE}/{idPromo}
+  async GET(
+    _request: Request,
+    context: FreshContext<AuthenticatedState>,
+  ): Promise<Response> {
+    if (context.state.session.eduPersonPrimaryAffiliation !== "employee") {
+      return FORBIDDEN;
+    }
+
+    const idModule = context.params.idModule;
+    const idUE = Number(context.params.idUE);
+    const idPromo = context.params.idPromo;
+
+    if (isNaN(idUE)) {
+      return BAD_REQUEST;
+    }
+
+    const ueModuleAssociation = await db
+      .select()
+      .from(ueModules)
+      .where(
+        eq(ueModules.idModule, idModule),
+        eq(ueModules.idUE, idUE),
+        eq(ueModules.idPromo, idPromo),
+      )
+      .then((rows) => rows[0] ?? null);
+
+    if (!ueModuleAssociation) return NOT_FOUND;
+
+    return new Response(JSON.stringify(ueModuleAssociation), {
+      headers: { "content-type": "application/json" },
+    });
+  },
+};