SysJL

Daily sales and net profit tracker for a small distribution business in Bolivia selling Queso (cheese), Yogurt, Milk, and Mote.

Each seller takes Queso and Yogurt from the deposit, sells them with Milk and Mote, and records what was left over and their total sales. The app works out sales, unsold value, the daily winner and each seller's pay; admins also see net profit after Milk and grain costs. The full description of rules and calculations is in context/project-overview.md.

Tech Stack

• Next.js 16 (App Router, Turbopack, Partial Prerendering) + React 19 + TypeScript
• Prisma 6 on MongoDB (requires a replica set — see Database)
• Auth.js v5 (Credentials provider, JWT sessions, bcrypt password hashing)
• Tailwind CSS v4 (CSS-based @theme config — no tailwind.config.ts)
• Zod for input validation, Vitest for unit tests

Getting Started

1. Install dependencies

npm install

2. Configure environment variables

Copy .env.example to .env and fill in:

cp .env.example .env

• DATABASE_URL — a MongoDB connection string. Prisma's MongoDB connector requires a replica set; a standalone mongod will fail with "Transactions are not supported." A free-tier MongoDB Atlas cluster works out of the box.
• AUTH_SECRET — random secret for encrypting session JWTs. Generate one with:

  node -e "console.log(require('crypto').randomBytes(32).toString('base64'))"
  

3. Set up the database

This project uses prisma db push rather than prisma migrate (there is no prisma/migrations folder — MongoDB's Prisma connector doesn't support migrations the same way SQL databases do):

npx prisma generate
npx prisma db push

Then seed one admin and one seller:

npx prisma db seed

This creates:

Role	Email	Password
Admin	[email protected]	ChangeMe123!
Seller	[email protected]	ChangeMe123!

The seed is idempotent — re-running it won't duplicate users or overwrite an admin-set product price.

4. Run the dev server

npm run dev

Open http://localhost:3000.

Scripts

Command	Description
npm run dev	Start the dev server (Turbopack)
npm run build	Production build
npm start	Run the production build
npm run lint	ESLint
npm test	Run the Vitest suite once
npm run test:watch	Run Vitest in watch mode

Roles & Access

• Admin — manages users, Queso/Yogurt sale prices and purchase costs, grain purchases; sees and edits every sale record, costs and net profit.
• Seller (VEHICLE_USER) — records and edits their own daily sale records and sees every seller's pay. The acting user always comes from the server-side session, never from the client.
• Guest — sees the public landing page /, which presents the product to distribution companies (no real data).

src/proxy.ts requires sign-in everywhere except / and /login, and the admin role for /admin/*; every Server Action checks again.

Project Structure

src/
  app/
    page.tsx              # Public product landing page
    login/
    (panel)/              # Signed-in shell: sidebar, header, breadcrumbs
      dashboard/          # Sales charts, prices & costs (admin), sale records
      account/            # Change own password
      admin/users/        # Admin: user management
      admin/grains/       # Admin: grain purchases
  actions/                # Server Actions, one file per feature (+ tests)
  components/
    landing/              # Public landing page sections
    sale-records/         # Sale Records table, cells, record forms
    sales-charts/         # Charts, selected-day context
    admin/                # users/, grain-purchases/, stock-purchases/, product-pricing/
    layout/ ui/ auth/ account/ i18n/
  hooks/                  # Custom React hooks
  lib/
    daily-records.ts      # Builds sale record rows and the daily winner
    money/                # Prices, costs, revenue, net profit, seller pay
    auth/                 # Password hashing, session/admin guards
    i18n/                 # Translations (Spanish default, English)
  types/
prisma/
  schema.prisma
  seed.ts                 # Idempotent seed script
context/                  # Spec, coding standards, workflow, current feature, history

Data Model

• User — admin or seller role, active/inactive.
• DailyWorkRecord — one per user per day: Queso/Yogurt taken and left over, user-entered total sold (all four products), Milk liters and price per liter, and the sale prices snapshotted at creation so later price changes never rewrite past records.
• ProductPrice — current sale price and purchase cost for Queso and Yogurt; one row per product, updated in place.
• StockPurchase — a grain purchase (Maíz pelado, Maíz con cáscara, Haba): quantity and unit cost. Feeds net profit.

Internationalization

The app is bilingual — Spanish by default, English optional — via a cookie-backed language switcher; see src/lib/i18n/.

Testing

Vitest covers Server Actions (src/actions/) and business logic (src/lib/) only — React components are verified in the browser, not unit-tested (see context/coding-standards.md). Run npm test before committing.