Changes

Co-authored-by: renee-png <262607627+renee-png@users.noreply.github.com>

src/routes/settings.import.tsx

@@ -1271,6 +1271,89 @@ function ImportPage() {
     const chunkSize = 200;
     let inserted = 0;
     const inserted_rows: Row[] = [];
+
+    // INVOICES: special merge — match existing invoices by invoice_number
+    // (preferred) or external_id and UPDATE only header fields. Subtotal,
+    // total, tax, and amount_paid are left alone so totals stay = sum of
+    // line items already attached from the time/expense imports.
+    if (cfg.table === "invoices" && mapped.length > 0) {
+      const numbers = mapped.map((r) => String(r.invoice_number ?? "")).filter(Boolean);
+      const externalIds = mapped.map((r) => String(r.external_id ?? "")).filter(Boolean);
+      const byNumber = new Map<string, string>();
+      const byExt = new Map<string, string>();
+      for (let k = 0; k < numbers.length; k += 500) {
+        const slice = numbers.slice(k, k + 500);
+        const { data } = await supabase
+          .from("invoices")
+          .select("id, invoice_number")
+          .in("invoice_number", slice);
+        for (const row of (data ?? []) as { id: string; invoice_number: string }[]) {
+          byNumber.set(row.invoice_number, row.id);
+        }
+      }
+      for (let k = 0; k < externalIds.length; k += 500) {
+        const slice = externalIds.slice(k, k + 500);
+        const { data } = await supabase
+          .from("invoices")
+          .select("id, external_id")
+          .in("external_id", slice);
+        for (const row of (data ?? []) as { id: string; external_id: string }[]) {
+          byExt.set(row.external_id, row.id);
+        }
+      }
+
+      const HEADER_FIELDS = [
+        "status", "issue_date", "due_date", "notes",
+        "client_id", "case_id", "external_id", "invoice_number",
+      ] as const;
+      const toUpdateInv: Array<{ id: string; payload: Row }> = [];
+      const toInsertInv: Row[] = [];
+      for (const r of mapped) {
+        const num = r.invoice_number ? String(r.invoice_number) : "";
+        const ext = r.external_id ? String(r.external_id) : "";
+        const matchId = (num && byNumber.get(num)) || (ext && byExt.get(ext)) || null;
+        if (matchId) {
+          const payload: Row = {};
+          for (const f of HEADER_FIELDS) {
+            if (r[f] != null && r[f] !== "") payload[f] = r[f];
+          }
+          toUpdateInv.push({ id: matchId, payload });
+        } else {
+          toInsertInv.push(r);
+        }
+      }
+
+      for (let k = 0; k < toUpdateInv.length; k += 50) {
+        const slice = toUpdateInv.slice(k, k + 50);
+        const results = await Promise.all(
+          slice.map(({ id, payload }) =>
+            supabase.from("invoices").update(payload as any).eq("id", id).select("*").single(),
+          ),
+        );
+        for (const result of results) {
+          if (result.error) {
+            errors.push(`Invoice merge update: ${result.error.message}`);
+          } else if (result.data) {
+            inserted += 1;
+            inserted_rows.push(result.data as Row);
+          }
+        }
+      }
+
+      for (let k = 0; k < toInsertInv.length; k += chunkSize) {
+        const slice = toInsertInv.slice(k, k + chunkSize);
+        const { data, error } = await supabase.from("invoices").insert(slice as any).select("*");
+        if (error) errors.push(`Invoice merge insert: ${error.message}`);
+        else if (data) {
+          inserted += data.length;
+          inserted_rows.push(...(data as Row[]));
+        }
+      }
+
+      // Skip the generic chunk loop below for invoices.
+      mapped.length = 0;
+    }
+
     for (let i = 0; i < mapped.length; i += chunkSize) {
       const chunk = mapped.slice(i, i + chunkSize);
       // Filter out rows missing the conflict column for upsert; insert plain