Merge remote-tracking branch 'origin/main'

Author: weblate

.github/copilot-instructions.md

@@ -13,10 +13,12 @@ SplitPro is a **Next.js PWA** expense-splitting app (Splitwise alternative). Cor
 
 ### 1. **BigInt for All Financial Values**
 - **All amounts are stored and computed as `BigInt`, never floats** to prevent rounding errors
-- When displaying: convert via `toUIString()` (divides by 100 for cents)
-- When receiving input: convert via `toSafeBigInt()` (multiplies by 100)
-- `BigMath` utility provides safe arithmetic operations
-- Read: `README.md` FAQ and `jest.config.ts` for BigInt JSON serialization
+- Use `getCurrencyHelpers({ currency, locale })` from `src/utils/numbers.ts` to get currency-aware helpers:
+  - `toUIString(value)` - Display BigInt as formatted currency (divides by 100 for cents)
+  - `toSafeBigInt(input)` - Parse user input to BigInt (multiplies by 100)
+  - Access these via `CurrencyHelpersContext` in React components
+- `BigMath` utility (`src/utils/numbers.ts`) provides safe arithmetic: `abs`, `sign`, `min`, `max`, `roundDiv`
+- **Jest setup**: `BigInt.prototype.toJSON` is defined in `jest.config.ts` for JSON serialization
 
 ### 2. **Double-Entry Balance Accounting**
 Every expense creates **two balance records** (bidirectional):
@@ -85,7 +87,22 @@ pnpm db:studio        # Open Prisma Studio GUI
 pnpm db:seed          # Seed database with dummy data
 ```
 
-**Pre-commit hooks** (Husky): prettier + oxlint auto-fixes. Override with `git commit --no-verify`.
+**Pre-commit hooks** (Husky):
+```bash
+pnpm lint-staged  # Runs prettier on staged files
+pnpm tsgo --noEmit  # TypeScript type checking without emit
+```
+Override with `git commit --no-verify` if needed.
+
+## Environment Setup
+
+Environment variables are validated via `@t3-oss/env-nextjs` in `src/env.ts`. Required variables:
+- **Database**: `DATABASE_URL` or separate `POSTGRES_*` vars
+- **Auth**: `NEXTAUTH_URL`, `NEXTAUTH_SECRET`, OAuth provider credentials (Google/Email SMTP)
+- **Storage**: R2/S3 credentials (`R2_*` or `AWS_S3_*` variables)
+- **Optional**: Bank integration (Plaid/GoCardless), currency rate API keys, push notification VAPID keys
+
+For local dev: run `pnpm d` to start PostgreSQL + MinIO in Docker. Access MinIO console at `http://localhost:9001` (user: `splitpro`, pass: `password`) to create access keys.
 
 ## Data Flow Specifics
 
@@ -113,6 +130,7 @@ GroupBalance(groupId, currency, userId, firendId)  // note: typo "firendId"
 - **Currency Rates**: Pluggable providers (Frankfurter, OXR, NBP) in `currencyRateService.ts`
 - **i18n**: next-i18next with Weblate; always add English keys first, let community translate
 - **Dates**: Use `date-fns` for formatting/parsing, store all dates in UTC
+- **PWA**: Serwist service worker (`worker/index.ts` → `public/sw.js`), disabled in dev mode
 
 
 ## Avoiding Common Pitfalls
@@ -240,3 +258,5 @@ The backend uses **tRPC** for type-safe API communication. Routers are in `src/s
 Always use context7 when I need code generation, setup or configuration steps, or
 library/API documentation. This means you should automatically use the Context7 MCP
 tools to resolve library id and get library docs without me having to explicitly ask.
+
+Do not generate documentation or tests if not explicitly requested.

README.md

@@ -149,6 +149,7 @@ We are grateful for the support of our sponsors.
 <a href="https://github.com/igorrrpawlowski"><img src="https:&#x2F;&#x2F;github.com&#x2F;igorrrpawlowski.png" width="60px" alt="User avatar: igorrrpawlowski" /></a>
 <a href="https://github.com/probeonstimpack"><img src="https:&#x2F;&#x2F;github.com&#x2F;probeonstimpack.png" width="60px" alt="User avatar: Marcel Szmeterowicz" /></a>
 <a href="https://github.com/mexicanhatman"><img src="https://avatars.githubusercontent.com/u/78694887?v=4" width="60px" alt="User avatar: mexicanhatman" /></a>
+<a href="https://github.com/felixdz"><img src="https://avatars.githubusercontent.com/u/11851415?v=4" width="60px" alt="User avatar: FelixDz" /></a>
 
 ## Star History
 

prisma/migrations/20251108122842_add_balance_view/migration.sql

@@ -0,0 +1,74 @@
+CREATE VIEW
+    "public"."BalanceView" AS
+    -- Use a Common Table Expression (CTE) to calculate the "one-way" balances.
+    -- This query is based on YOUR schema where `ep.amount < 0` is a debt.
+WITH
+    "BaseBalance" AS (
+        SELECT
+            CASE
+                WHEN ep."userId" < e."paidBy" THEN ep."userId"
+                ELSE e."paidBy"
+            END AS "user_id_A", -- The person who owes (debtor)
+            CASE
+                WHEN ep."userId" < e."paidBy" THEN e."paidBy"
+                ELSE ep."userId"
+            END AS "user_id_B", -- The person who is owed (creditor)
+            e."groupId",
+            e.currency,
+            SUM(
+                ep."amount" * (
+                    CASE
+                        WHEN ep."userId" < e."paidBy"
+                        -- A=participant, B=payer. A owes B. ep.amount is < 0. We need a NEGATIVE result.
+                        THEN 1
+                        -- B=participant, A=payer. B owes A. ep.amount is < 0. We need a POSITIVE result.
+                        ELSE -1
+                    END
+                )
+            ) AS "net_amount",
+            MIN(e."createdAt") AS "createdAt",
+            MAX(e."updatedAt") AS "updatedAt"
+        FROM
+            "public"."ExpenseParticipant" AS ep
+            JOIN "public"."Expense" AS e ON ep."expenseId" = e."id"
+        WHERE
+            -- A user can't owe themselves
+            ep."userId" != e."paidBy"
+            AND e."deletedAt" IS NULL
+        GROUP BY
+            -- Note: We group by the original columns
+            "user_id_A",
+            "user_id_B",
+            e."groupId",
+            e.currency
+    )
+    -- Query 1: The debtor's perspective (e.g., User 5, Friend 10, Amount -100)
+    -- This shows what "userId" owes to "friendId"
+SELECT
+    "user_id_A" AS "userId",
+    "user_id_B" AS "friendId",
+    "groupId",
+    currency,
+    "net_amount" AS amount,
+    "createdAt",
+    "updatedAt"
+FROM
+    "BaseBalance"
+UNION ALL
+-- Query 2: The creditor's perspective (e.g., User 10, Friend 5, Amount +100)
+-- This shows what "userId" (the creditor) is owed by "friendId" (the debtor)
+SELECT
+    "user_id_B" AS "userId", -- Swapped
+    "user_id_A" AS "friendId", -- Swapped
+    "groupId",
+    currency,
+    -- Invert the sign to show a positive balance (is owed)
+    - ("net_amount") AS amount,
+    "createdAt",
+    "updatedAt"
+FROM
+    "BaseBalance";
+
+-- We may want to migrate this to a materialized view in the future for performance reasons.
+-- CREATE UNIQUE INDEX ON "public"."BalanceView" ("userId", "friendId", "groupId", currency);
+-- CREATE INDEX ON "public"."BalanceView" ("userId");