feat : fix a lot of stuff

routes/(apps)/students/api/promotions/[idPromo].ts

@@ -1,15 +1,25 @@
 import { FreshContext, Handlers } from "$fresh/server.ts";
 import { db } from "$root/databases/db.ts";
-import { promotions } from "$root/databases/schema.ts";
+import {
+  ajustements,
+  enseignements,
+  modules,
+  notes,
+  promotions,
+  students,
+  ueModules,
+  ues,
+} from "$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: "Ressource introuvable" }),
-  { status: 404, headers: { "content-type": "application/json" } },
-);
+const NOT_FOUND = () =>
+  new Response(
+    JSON.stringify({ error: "Ressource introuvable" }),
+    { status: 404, headers: { "content-type": "application/json" } },
+  );
 
-const FORBIDDEN = new Response(null, { status: 403 });
+const FORBIDDEN = () => new Response(null, { status: 403 });
 
 export const handler: Handlers<null, AuthenticatedState> = {
   // #15 GET /promotions/{idPromo}
@@ -18,7 +28,7 @@ export const handler: Handlers<null, AuthenticatedState> = {
     context: FreshContext<AuthenticatedState>,
   ): Promise<Response> {
     if (context.state.session.eduPersonPrimaryAffiliation !== "employee") {
-      return FORBIDDEN;
+      return FORBIDDEN();
     }
 
     const promo = await db
@@ -27,7 +37,7 @@ export const handler: Handlers<null, AuthenticatedState> = {
       .where(eq(promotions.id, context.params.idPromo))
       .then((rows) => rows[0] ?? null);
 
-    if (!promo) return NOT_FOUND;
+    if (!promo) return NOT_FOUND();
 
     return new Response(JSON.stringify(promo), {
       headers: { "content-type": "application/json" },
@@ -40,7 +50,7 @@ export const handler: Handlers<null, AuthenticatedState> = {
     context: FreshContext<AuthenticatedState>,
   ): Promise<Response> {
     if (context.state.session.eduPersonPrimaryAffiliation !== "employee") {
-      return FORBIDDEN;
+      return FORBIDDEN();
     }
 
     const body: { annee: string } = await request.json();
@@ -51,7 +61,7 @@ export const handler: Handlers<null, AuthenticatedState> = {
       .where(eq(promotions.id, context.params.idPromo))
       .returning();
 
-    if (!updated) return NOT_FOUND;
+    if (!updated) return NOT_FOUND();
 
     return new Response(JSON.stringify(updated), {
       headers: { "content-type": "application/json" },
@@ -59,20 +69,104 @@ export const handler: Handlers<null, AuthenticatedState> = {
   },
 
   // #17 DELETE /promotions/{idPromo}
+  // Blocked if students are still assigned (409).
+  // Cascade: deletes linked ue_modules, enseignements, and orphaned
+  // modules (+ their notes) & UEs (+ their ajustements).
   async DELETE(
     _request: Request,
     context: FreshContext<AuthenticatedState>,
   ): Promise<Response> {
     if (context.state.session.eduPersonPrimaryAffiliation !== "employee") {
-      return FORBIDDEN;
+      return FORBIDDEN();
     }
 
-    const [deleted] = await db
-      .delete(promotions)
-      .where(eq(promotions.id, context.params.idPromo))
-      .returning();
+    const idPromo = context.params.idPromo;
 
-    if (!deleted) return NOT_FOUND;
+    const promo = await db
+      .select()
+      .from(promotions)
+      .where(eq(promotions.id, idPromo))
+      .then((r) => r[0] ?? null);
+
+    if (!promo) return NOT_FOUND();
+
+    // Block deletion if students are still assigned
+    const assignedStudents = await db
+      .select()
+      .from(students)
+      .where(eq(students.idPromo, idPromo))
+      .then((r) => r.length);
+
+    if (assignedStudents > 0) {
+      return new Response(
+        JSON.stringify({
+          error:
+            `Impossible de supprimer : ${assignedStudents} étudiant(s) encore assigné(s) à cette promotion`,
+        }),
+        { status: 409, headers: { "content-type": "application/json" } },
+      );
+    }
+
+    await db.transaction(async (tx) => {
+      // Collect linked module IDs and UE IDs before deleting junction rows
+      const linkedUeModules = await tx
+        .select({ idModule: ueModules.idModule, idUE: ueModules.idUE })
+        .from(ueModules)
+        .where(eq(ueModules.idPromo, idPromo));
+
+      const linkedEns = await tx
+        .select({ idModule: enseignements.idModule })
+        .from(enseignements)
+        .where(eq(enseignements.idPromo, idPromo));
+
+      const moduleIds = [
+        ...new Set([
+          ...linkedUeModules.map((um) => um.idModule),
+          ...linkedEns.map((e) => e.idModule),
+        ]),
+      ];
+      const ueIds = [...new Set(linkedUeModules.map((um) => um.idUE))];
+
+      // Delete junction rows that directly reference this promo
+      await tx.delete(ueModules).where(eq(ueModules.idPromo, idPromo));
+      await tx.delete(enseignements).where(eq(enseignements.idPromo, idPromo));
+
+      // Delete orphaned modules (not used by another promo) and their notes
+      for (const modId of moduleIds) {
+        const stillInUeModules = await tx
+          .select()
+          .from(ueModules)
+          .where(eq(ueModules.idModule, modId))
+          .then((r) => r.length > 0);
+        const stillInEns = await tx
+          .select()
+          .from(enseignements)
+          .where(eq(enseignements.idModule, modId))
+          .then((r) => r.length > 0);
+
+        if (!stillInUeModules && !stillInEns) {
+          await tx.delete(notes).where(eq(notes.idModule, modId));
+          await tx.delete(modules).where(eq(modules.id, modId));
+        }
+      }
+
+      // Delete orphaned UEs (not used by another promo) and their ajustements
+      for (const ueId of ueIds) {
+        const stillUsed = await tx
+          .select()
+          .from(ueModules)
+          .where(eq(ueModules.idUE, ueId))
+          .then((r) => r.length > 0);
+
+        if (!stillUsed) {
+          await tx.delete(ajustements).where(eq(ajustements.idUE, ueId));
+          await tx.delete(ues).where(eq(ues.id, ueId));
+        }
+      }
+
+      // Delete the promotion
+      await tx.delete(promotions).where(eq(promotions.id, idPromo));
+    });
 
     return new Response(null, { status: 204 });
   },