feat: update card on drop

src/server/api/root.ts

@@ -1,4 +1,5 @@
 import { boardRouter } from "~/server/api/routers/board";
+import { cardRouter } from "~/server/api/routers/card";
 import { createTRPCRouter } from "~/server/api/trpc";
 
 /**
@@ -8,6 +9,7 @@ import { createTRPCRouter } from "~/server/api/trpc";
  */
 export const appRouter = createTRPCRouter({
   board: boardRouter,
+  card: cardRouter
 });
 
 // export type definition of API

src/server/api/routers/card.ts

@@ -0,0 +1,43 @@
+import { z } from "zod";
+import { and, eq, gte, or} from "drizzle-orm";
+
+import { cards, lists } from "~/server/db/schema";
+
+import {
+  createTRPCRouter,
+  publicProcedure,
+} from "~/server/api/trpc";
+
+export const cardRouter = createTRPCRouter({
+  update: publicProcedure
+  .input(
+    z.object({ 
+      cardId: z.string().min(12),
+      currentListId: z.string().min(12),
+      newListId: z.string().min(12),
+      currentIndex: z.number(),
+      newIndex: z.number()
+    }))
+  .mutation(({ ctx, input }) => {
+    const userId = ctx.session?.user.id;
+
+    if (!userId) return;
+
+    return ctx.db.transaction(async (tx) => {
+      const [currentList, newList] = await tx.select({ id: lists.id }).from(lists).where(or(eq(lists.publicId, input.currentListId), eq(lists.publicId, input.newListId)))
+
+
+      if (!currentList?.id || !newList?.id) return;
+      
+      await tx
+        .update(cards)
+        .set({ index: input.newIndex + 1 })
+        .where(and(eq(cards.listId, newList.id), gte(cards.index, input.newIndex)))
+
+      await tx
+        .update(cards)
+        .set({ listId: newList.id, index: input.newIndex })
+        .where(eq(cards.publicId, input.cardId))
+    })
+  }),
+});