fix(search): the revelance sorting was not done when having the llm r…

…esults

src/server/routers/initiative.ts

@@ -6,6 +6,7 @@ import { initiativeNotFoundError } from '@etabli/src/models/entities/errors';
 import { prisma } from '@etabli/src/prisma/client';
 import { initiativePrismaToModel } from '@etabli/src/server/routers/mappers';
 import { publicProcedure, router } from '@etabli/src/server/trpc';
+import { paginate } from '@etabli/src/utils/page';
 
 export const initiativeRouter = router({
   getInitiative: publicProcedure.input(GetInitiativeSchema).query(async ({ ctx, input }) => {
@@ -48,22 +49,35 @@ export const initiativeRouter = router({
     };
   }),
   listInitiatives: publicProcedure.input(ListInitiativesSchema).query(async ({ ctx, input }) => {
+    // TODO: for when implementing filters on associations
     const where: Prisma.InitiativeWhereInput = {};
 
+    let homemadePaginationInitiativeIds: string[] | null = null;
+    let homemadePaginationTotalCount: number | null = null;
+
     if (!!input.filterBy.query) {
       // Restrict the search, the pagination will work as expected
-      const initiativesIds = await llmManagerInstance.getInitiativesFromQuery(input.filterBy.query);
+      const matchingInitiativesIds = await llmManagerInstance.getInitiativesFromQuery(input.filterBy.query);
+      const currentPageInitiativesIds = paginate(matchingInitiativesIds, input.pageSize, input.page);
+
+      homemadePaginationInitiativeIds = currentPageInitiativesIds;
+      homemadePaginationTotalCount = matchingInitiativesIds.length;
 
       where.id = {
-        in: initiativesIds,
+        in: homemadePaginationInitiativeIds,
       };
     }
 
     // We do a transaction to get along the total count
     // Refs:
     // - https://github.com/prisma/prisma/issues/7550
     // - https://github.com/prisma/prisma/discussions/3087
-    const [initiatives, totalCount] = await prisma.$transaction([
+    //
+    // ---
+    // Prisma has a limitation to order by a given list (https://github.com/prisma/prisma/issues/11336#issuecomment-1986031261) and cannot only use a `whereRaw` to work around
+    // The first possibility would be to switch to a full raw query, but it's more complicated for typings and `include`... so we decided to do it in multiple steps to preverse the Prisma usage
+    // Note: in case of a full raw query we would just kept the original code and enable the logs debug mode to have 90% of the raw query written, and using a where with something like `ORDER BY array_position(ARRAY[1, 2, 3]::uuid[], table_name.id::uuid)`
+    let [initiatives, totalCount] = await prisma.$transaction([
       prisma.initiative.findMany({
         where: where,
         include: {
@@ -86,15 +100,32 @@ export const initiativeRouter = router({
             },
           },
         },
-        orderBy: {
-          name: 'asc',
-        },
-        skip: (input.page - 1) * input.pageSize,
-        take: input.pageSize,
+        ...(!!homemadePaginationInitiativeIds
+          ? {
+              // The pagination is done before this, and sorting will be done after
+            }
+          : {
+              orderBy: {
+                name: 'asc',
+              },
+              skip: (input.page - 1) * input.pageSize,
+              take: input.pageSize,
+            }),
       }),
-      prisma.initiative.count({ where: where }),
+      ...(homemadePaginationTotalCount !== null ? [] : [prisma.initiative.count({ where: where })]),
     ]);
 
+    if (totalCount === undefined && homemadePaginationTotalCount !== null) {
+      totalCount = homemadePaginationTotalCount;
+    }
+
+    if (!!homemadePaginationInitiativeIds) {
+      // As explained above we need to sort them since Prisma does not handle this, in the order returned by the LLM instance since IDs are initially sorted by relevance score
+      initiatives = initiatives.sort((a, b) => {
+        return (homemadePaginationInitiativeIds as string[]).indexOf(a.id) - (homemadePaginationInitiativeIds as string[]).indexOf(b.id);
+      });
+    }
+
     return {
       initiatives: initiatives.map((initiative) =>
         initiativePrismaToModel({

src/utils/page.ts

@@ -1,3 +1,8 @@
 export function formatPageTitle(pageSpecificTitle: string) {
   return `${pageSpecificTitle} - Établi`;
 }
+
+export function paginate<T>(items: T[], pageSize: number, pageNumber: number) {
+  // Human-readable page numbers in our application start with 1, so we reduce 1 in the first argument
+  return items.slice((pageNumber - 1) * pageSize, pageNumber * pageSize);
+}