fix: bulkCreate to stop imports with duplicate indices (#190)

* fix(db): normalize/compact indices to prevent import duplicates

- bulkCreate now assigns sequential indices per board (preserves order; ignores incoming indices).
- Auto-compact indices after create/insert if duplicates exist, keeping active lists unique and gap-free.
- Prevents reorder errors caused by duplicate indices from Trello imports.

* feat(db): normalize/compact indices with fail-safe duplicate recheck

packages/db/src/repository/list.repo.ts

@@ -59,9 +59,32 @@ export const create = async (
       .having(gt(countExpr, 1));
 
     if (duplicateIndices.length > 0) {
-      throw new Error(
-        `Duplicate indices found after reordering in board ${result.boardId}`,
-      );
+      // Compact indices to sequential values (0..n-1) to resolve duplicates while preserving order
+      await tx.execute(sql`
+        WITH ordered AS (
+          SELECT id, ROW_NUMBER() OVER (ORDER BY "index", id) - 1 AS new_index
+          FROM "list"
+          WHERE "boardId" = ${result.boardId} AND "deletedAt" IS NULL
+        )
+        UPDATE "list" l
+        SET "index" = o.new_index
+        FROM ordered o
+        WHERE l.id = o.id;
+      `);
+
+      // Last resort: verify fix; if duplicates persist (e.g., due to race conditions), rollback
+      const postFixDupes = await tx
+        .select({ index: lists.index, count: countExpr })
+        .from(lists)
+        .where(and(eq(lists.boardId, result.boardId), isNull(lists.deletedAt)))
+        .groupBy(lists.index)
+        .having(gt(countExpr, 1));
+
+      if (postFixDupes.length > 0) {
+        throw new Error(
+          `Invariant violation: duplicate indices remain after compaction in board ${result.boardId}`,
+        );
+      }
     }
 
     return result;
@@ -79,7 +102,98 @@ export const bulkCreate = async (
     importId?: number;
   }[],
 ) => {
-  return db.insert(lists).values(listInput).returning();
+  if (listInput.length === 0) return [];
+
+  return db.transaction(async (tx) => {
+    // Group incoming rows by board to compute safe, sequential indices per board
+    const byBoard = new Map<number, typeof listInput>();
+    for (const item of listInput) {
+      const arr = byBoard.get(item.boardId) ?? [];
+      arr.push(item);
+      byBoard.set(item.boardId, arr);
+    }
+
+    const allValuesToInsert: {
+      publicId: string;
+      name: string;
+      createdBy: string;
+      boardId: number;
+      index: number;
+      importId?: number;
+    }[] = [];
+
+    // For each board, append incoming lists after the current max index, preserving their relative order
+    for (const [boardId, items] of byBoard.entries()) {
+      // Find current max index for non-deleted lists in this board
+      const last = await tx.query.lists.findFirst({
+        columns: { index: true },
+        where: and(eq(lists.boardId, boardId), isNull(lists.deletedAt)),
+        orderBy: [desc(lists.index)],
+      });
+
+      let nextIndex = last ? last.index + 1 : 0;
+
+      // Sort incoming by their provided index to preserve Trello order, then reassign sequential indices
+      const sorted = [...items].sort((a, b) => a.index - b.index);
+      for (const it of sorted) {
+        allValuesToInsert.push({
+          publicId: it.publicId,
+          name: it.name,
+          createdBy: it.createdBy,
+          boardId: it.boardId,
+          index: nextIndex++,
+          importId: it.importId,
+        });
+      }
+    }
+
+    // Insert all rows in one go
+    const inserted = await tx
+      .insert(lists)
+      .values(allValuesToInsert)
+      .returning();
+
+    // Post-insert check: if duplicates exist, compact indices per board instead of failing
+    const countExpr = sql<number>`COUNT(*)`.mapWith(Number);
+    for (const boardId of byBoard.keys()) {
+      const duplicateIndices = await tx
+        .select({ index: lists.index, count: countExpr })
+        .from(lists)
+        .where(and(eq(lists.boardId, boardId), isNull(lists.deletedAt)))
+        .groupBy(lists.index)
+        .having(gt(countExpr, 1));
+
+      if (duplicateIndices.length > 0) {
+        await tx.execute(sql`
+          WITH ordered AS (
+            SELECT id, ROW_NUMBER() OVER (ORDER BY "index", id) - 1 AS new_index
+            FROM "list"
+            WHERE "boardId" = ${boardId} AND "deletedAt" IS NULL
+          )
+          UPDATE "list" l
+          SET "index" = o.new_index
+          FROM ordered o
+          WHERE l.id = o.id;
+        `);
+
+        // Last resort: verify fix; if duplicates persist (e.g., due to race conditions), rollback
+        const postFixDupes = await tx
+          .select({ index: lists.index, count: countExpr })
+          .from(lists)
+          .where(and(eq(lists.boardId, boardId), isNull(lists.deletedAt)))
+          .groupBy(lists.index)
+          .having(gt(countExpr, 1));
+
+        if (postFixDupes.length > 0) {
+          throw new Error(
+            `Invariant violation: duplicate indices remain after compaction in board ${boardId}`,
+          );
+        }
+      }
+    }
+
+    return inserted;
+  });
 };
 
 export const getByPublicId = async (db: dbClient, listPublicId: string) => {
@@ -180,9 +294,32 @@ export const reorder = async (
       .having(gt(countExpr, 1));
 
     if (duplicateIndices.length > 0) {
-      throw new Error(
-        `Duplicate indices found after reordering in board ${list.boardId}`,
-      );
+      // Attempt to auto-heal by compacting indices to sequential values (0..n-1) while preserving order
+      await tx.execute(sql`
+        WITH ordered AS (
+          SELECT id, ROW_NUMBER() OVER (ORDER BY "index", id) - 1 AS new_index
+          FROM "list"
+          WHERE "boardId" = ${list.boardId} AND "deletedAt" IS NULL
+        )
+        UPDATE "list" l
+        SET "index" = o.new_index
+        FROM ordered o
+        WHERE l.id = o.id;
+      `);
+
+      // Last resort verification: if duplicates persist, rollback
+      const postFixDupes = await tx
+        .select({ index: lists.index, count: countExpr })
+        .from(lists)
+        .where(and(eq(lists.boardId, list.boardId), isNull(lists.deletedAt)))
+        .groupBy(lists.index)
+        .having(gt(countExpr, 1));
+
+      if (postFixDupes.length > 0) {
+        throw new Error(
+          `Invariant violation: duplicate indices remain after compaction in board ${list.boardId}`,
+        );
+      }
     }
 
     const updatedList = await tx.query.lists.findFirst({