feat(rules): apply_split rules with run history and revert

- POST /api/rules/apply — run all enabled rules against unmatched transactions
- POST /api/rules/apply/:id — apply a single rule by id
- DELETE /api/rules/apply/:id — revert a rule run (remove applied splits)
- Rules page: show run history with revert button, apply individual rules

src/app/api/rules/apply/[id]/revert/route.ts

@@ -0,0 +1,102 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getCurrentUser } from "@/lib/auth";
+import { queryRaw } from "@/lib/db";
+
+interface SnapshotEntry {
+  transaction_id: number;
+  had_override: boolean;
+  prev_category_override: string | null;
+  prev_merchant_normalized: string | null;
+  prev_tag_ids: number[];
+  prev_splits: { participant_id: number; share_percent: number; settled: boolean }[];
+}
+
+export async function POST(req: NextRequest, { params }: { params: Promise<{ id: string }> }) {
+  const user = await getCurrentUser(req);
+  if (!user) return NextResponse.json({ error: "Unauthorized" }, { status: 403 });
+
+  const { id } = await params;
+  const runId = Number(id);
+
+  const rows = await queryRaw<{
+    id: number;
+    owner_id: number;
+    reverted_at: string | null;
+    snapshot: unknown;
+  }>(
+    `SELECT id, owner_id, reverted_at, snapshot FROM rule_apply_runs WHERE id = $1`,
+    [runId]
+  );
+
+  if (!rows.length) return NextResponse.json({ error: "Run not found" }, { status: 404 });
+  const run = rows[0];
+  if (run.owner_id !== user.id) return NextResponse.json({ error: "Unauthorized" }, { status: 403 });
+  if (run.reverted_at) return NextResponse.json({ error: "Already reverted" }, { status: 409 });
+
+  const snapshot = (typeof run.snapshot === "string"
+    ? JSON.parse(run.snapshot)
+    : run.snapshot) as SnapshotEntry[];
+
+  for (const entry of snapshot) {
+    const txId = entry.transaction_id;
+
+    // Restore overrides
+    if (entry.had_override) {
+      await queryRaw(
+        `INSERT INTO transaction_overrides (transaction_id, category_override, merchant_normalized)
+         VALUES ($1, $2, $3)
+         ON CONFLICT (transaction_id) DO UPDATE SET
+           category_override = $2,
+           merchant_normalized = $3,
+           updated_at = NOW()`,
+        [txId, entry.prev_category_override, entry.prev_merchant_normalized]
+      );
+    } else {
+      // No override existed before — remove any that were created
+      await queryRaw(
+        `DELETE FROM transaction_overrides WHERE transaction_id = $1
+           AND category_override IS NULL AND merchant_normalized IS NULL`,
+        [txId]
+      );
+      // If override row exists but was only partially set by this run, clear those fields
+      await queryRaw(
+        `UPDATE transaction_overrides SET
+           category_override = NULL,
+           merchant_normalized = NULL,
+           updated_at = NOW()
+         WHERE transaction_id = $1`,
+        [txId]
+      );
+    }
+
+    // Restore tags: remove any that weren't there before, don't touch pre-existing ones
+    const prevTagIds = entry.prev_tag_ids;
+    if (prevTagIds.length > 0) {
+      await queryRaw(
+        `DELETE FROM transaction_tags WHERE transaction_id = $1 AND tag_id != ALL($2::int[])`,
+        [txId, prevTagIds]
+      );
+    } else {
+      // No tags existed before — remove all tags (they were all added by this run)
+      // Note: this only removes tags on transactions that matched this run
+      await queryRaw(`DELETE FROM transaction_tags WHERE transaction_id = $1`, [txId]);
+    }
+
+    // Restore splits
+    await queryRaw(`DELETE FROM transaction_splits WHERE transaction_id = $1`, [txId]);
+    for (const s of entry.prev_splits) {
+      await queryRaw(
+        `INSERT INTO transaction_splits (transaction_id, participant_id, share_percent, settled)
+         VALUES ($1, $2, $3, $4) ON CONFLICT DO NOTHING`,
+        [txId, s.participant_id, s.share_percent, s.settled]
+      );
+    }
+  }
+
+  await queryRaw(
+    `UPDATE rule_apply_runs SET reverted_at = NOW() WHERE id = $1`,
+    [runId]
+  );
+
+  return NextResponse.json({ reverted: snapshot.length });
+}

src/app/api/rules/apply/route.ts

@@ -4,7 +4,7 @@ import { queryRaw } from "@/lib/db";
 import { getTransactions } from "@/lib/queries";
 
 interface Condition {
-  field: "merchant_normalized" | "description" | "category" | "bank_name" | "amount";
+  field: "merchant_normalized" | "description" | "category" | "bank_name" | "amount" | "transaction_type";
   operator: "contains" | "equals" | "starts_with" | "gt" | "lt" | "not_equals";
   value: string;
 }
@@ -21,12 +21,22 @@ interface Actions {
   apply_split?: SplitEntry[];
 }
 
+interface SnapshotEntry {
+  transaction_id: number;
+  had_override: boolean;
+  prev_category_override: string | null;
+  prev_merchant_normalized: string | null;
+  prev_tag_ids: number[];
+  prev_splits: { participant_id: number; share_percent: number; settled: boolean }[];
+}
+
 interface TxFields {
   effective_category: string;
   effective_merchant: string;
   description: string;
   bank_name: string;
   amount: number;
+  transaction_type: string;
 }
 
 function evaluateCondition(cond: Condition, tx: TxFields): boolean {
@@ -48,6 +58,7 @@ function evaluateCondition(cond: Condition, tx: TxFields): boolean {
     case "description": fieldVal = tx.description || ""; break;
     case "category": fieldVal = tx.effective_category || ""; break;
     case "bank_name": fieldVal = tx.bank_name || ""; break;
+    case "transaction_type": fieldVal = tx.transaction_type || ""; break;
     default: return false;
   }
 
@@ -62,6 +73,26 @@ function evaluateCondition(cond: Condition, tx: TxFields): boolean {
   }
 }
 
+export async function GET(req: NextRequest) {
+  const user = await getCurrentUser(req);
+  if (!user) return NextResponse.json({ error: "Unauthorized" }, { status: 403 });
+
+  const runs = await queryRaw<{
+    id: number;
+    applied_at: string;
+    split_from: string | null;
+    matched: number;
+    transactions_affected: number;
+    reverted_at: string | null;
+  }>(
+    `SELECT id, applied_at, split_from, matched, transactions_affected, reverted_at
+     FROM rule_apply_runs WHERE owner_id = $1 ORDER BY applied_at DESC LIMIT 20`,
+    [user.id]
+  );
+
+  return NextResponse.json(runs);
+}
+
 export async function POST(req: NextRequest) {
   const user = await getCurrentUser(req);
   if (!user) return NextResponse.json({ error: "Unauthorized" }, { status: 403 });
@@ -73,22 +104,81 @@ export async function POST(req: NextRequest) {
 
   if (!rules.length) return NextResponse.json({ matched: 0, transactions_affected: 0 });
 
+  const body = await req.json().catch(() => ({})) as { splitFrom?: string | null };
+  const splitFrom = body.splitFrom || null;
+
   const { data: transactions } = await getTransactions(user.id, { limit: 100000, offset: 0 });
 
+  // --- Pre-pass: find all transactions that will match any rule ---
+  const parsedRules = rules.map((r) => ({
+    conditions: (typeof r.conditions === "string" ? JSON.parse(r.conditions) : r.conditions) as Condition[],
+    actions: (typeof r.actions === "string" ? JSON.parse(r.actions) : r.actions) as Actions,
+  }));
+
+  const matchedIds = new Set<number>();
+  for (const tx of transactions) {
+    for (const { conditions } of parsedRules) {
+      if (conditions.length === 0 || conditions.every((c) => evaluateCondition(c, tx))) {
+        matchedIds.add(tx.id);
+        break;
+      }
+    }
+  }
+
+  // --- Capture before-state for all matched transactions (batched) ---
+  const snapshot: SnapshotEntry[] = [];
+  if (matchedIds.size > 0) {
+    const ids = Array.from(matchedIds);
+    const idList = ids.join(",");
+
+    const overrides = await queryRaw<{ transaction_id: number; category_override: string | null; merchant_normalized: string | null }>(
+      `SELECT transaction_id, category_override, merchant_normalized FROM transaction_overrides WHERE transaction_id = ANY($1::int[])`,
+      [ids]
+    );
+    const overrideMap = new Map(overrides.map((o) => [o.transaction_id, o]));
+
+    const tagRows = await queryRaw<{ transaction_id: number; tag_id: number }>(
+      `SELECT transaction_id, tag_id FROM transaction_tags WHERE transaction_id = ANY($1::int[])`,
+      [ids]
+    );
+    const tagMap = new Map<number, number[]>();
+    for (const row of tagRows) {
+      if (!tagMap.has(row.transaction_id)) tagMap.set(row.transaction_id, []);
+      tagMap.get(row.transaction_id)!.push(row.tag_id);
+    }
+
+    const splitRows = await queryRaw<{ transaction_id: number; participant_id: number; share_percent: number; settled: boolean }>(
+      `SELECT transaction_id, participant_id, share_percent, settled FROM transaction_splits WHERE transaction_id = ANY($1::int[])`,
+      [ids]
+    );
+    const splitMap = new Map<number, { participant_id: number; share_percent: number; settled: boolean }[]>();
+    for (const row of splitRows) {
+      if (!splitMap.has(row.transaction_id)) splitMap.set(row.transaction_id, []);
+      splitMap.get(row.transaction_id)!.push({ participant_id: row.participant_id, share_percent: row.share_percent, settled: row.settled });
+    }
+
+    for (const id of ids) {
+      const ov = overrideMap.get(id);
+      snapshot.push({
+        transaction_id: id,
+        had_override: !!ov,
+        prev_category_override: ov?.category_override ?? null,
+        prev_merchant_normalized: ov?.merchant_normalized ?? null,
+        prev_tag_ids: tagMap.get(id) ?? [],
+        prev_splits: splitMap.get(id) ?? [],
+      });
+    }
+
+    void idList; // suppress unused warning
+  }
+
+  // --- Apply rules ---
   let matched = 0;
   const affectedIds = new Set<number>();
 
-  for (const rule of rules) {
-    const conditions = (typeof rule.conditions === "string"
-      ? JSON.parse(rule.conditions)
-      : rule.conditions) as Condition[];
-    const actions = (typeof rule.actions === "string"
-      ? JSON.parse(rule.actions)
-      : rule.actions) as Actions;
-
+  for (const { conditions, actions } of parsedRules) {
     for (const tx of transactions) {
-      const allMatch =
-        conditions.length === 0 || conditions.every((c) => evaluateCondition(c, tx));
+      const allMatch = conditions.length === 0 || conditions.every((c) => evaluateCondition(c, tx));
       if (!allMatch) continue;
 
       matched++;
@@ -116,7 +206,7 @@ export async function POST(req: NextRequest) {
       }
 
       if (actions.apply_split?.length) {
-        // Delete existing splits then insert new ones
+        if (splitFrom && tx.transaction_date < splitFrom) continue;
         await queryRaw(`DELETE FROM transaction_splits WHERE transaction_id = $1`, [tx.id]);
         for (const s of actions.apply_split) {
           await queryRaw(
@@ -129,5 +219,12 @@ export async function POST(req: NextRequest) {
     }
   }
 
-  return NextResponse.json({ matched, transactions_affected: affectedIds.size });
+  // --- Save run record ---
+  const run = await queryRaw<{ id: number }>(
+    `INSERT INTO rule_apply_runs (owner_id, split_from, matched, transactions_affected, snapshot)
+     VALUES ($1, $2, $3, $4, $5) RETURNING id`,
+    [user.id, splitFrom, matched, affectedIds.size, JSON.stringify(snapshot)]
+  );
+
+  return NextResponse.json({ id: run[0].id, matched, transactions_affected: affectedIds.size });
 }