# ERP System — Inventory & Supply Chain (Phase 1)

A modular ERP built in phases. **Phase 1** delivers Inventory & Supply Chain: master data, procurement, goods receipt, and stock management with **FIFO** costing, **multi-warehouse**, single-tenant.

Monorepo: a .NET 10 REST API backend and a Next.js frontend, with all documentation under `docs/`.

## Repository layout
```
erp-monorepo/
├── Backend/      # ASP.NET Core Web API (.NET 10, PostgreSQL) + PROGRESS.md
├── Frontend/     # Next.js (App Router, TypeScript) + PROGRESS.md
└── docs/         # all documentation — START AT docs/00-CORE.md
```

## Start here
**All work begins at [`docs/00-CORE.md`](docs/00-CORE.md)** — the hub. It defines structure, tech stack, backend setup, and routes you to the right doc.

| Doc | Purpose |
|---|---|
| `docs/00-CORE.md` | Hub: structure, stack, backend init, routing |
| `docs/01-DOC-GUIDE.md` | Doc map, reading order, tracking conventions |
| `docs/10-BACKEND-PHASE1.md` | Backend spec: SRS + ER model + architecture |
| `docs/11-BACKEND-PHASE1.md` | Backend API reference (complete req/res) |
| `docs/20-FRONTEND.md` | Frontend user-flows + rules + validation posture |
| `Backend/PROGRESS.md`, `Frontend/PROGRESS.md` | Change checklists (git-shared) |

## Prerequisites
- .NET 10 SDK (`dotnet --version` → `10.0.x`)
- PostgreSQL running on localhost
- `dotnet-ef` tool (`dotnet tool install --global dotnet-ef`)
- Node.js (for the frontend)

## Run the backend
```bash
# create the database in your local Postgres first, e.g.:
#   createdb -U postgres ERPCore   (or: CREATE DATABASE "ERPCore"; in psql)
cd Backend/ERPCore
# set Username/Password in appsettings.Development.json to your local Postgres login
dotnet ef database update
dotnet run
```
- Swagger UI: `https://localhost:<port>/swagger`
- Health: `https://localhost:<port>/health` → `Healthy`

Full setup (packages, folder scaffold, Program.cs wiring) is in `docs/00-CORE.md §5`.

## Run the frontend
```bash
cd Frontend
cp .env.local.example .env.local      # set NEXT_PUBLIC_API_BASE_URL=https://localhost:<port>
npm install
npm run dev
```

## Configuration & secrets
- Three appsettings files: base (`appsettings.json`, placeholders only), `Development` (localhost), `Production` (env vars).
- **Local dev only** currently. Before any shared/staging/production use, move secrets to User Secrets (dev) and environment variables (prod), keep `appsettings.Development.json` / `appsettings.Production.json` out of git, and rotate any credential ever committed.

## Tech stack
**Backend:** .NET 10, ASP.NET Core Web API, EF Core 10, PostgreSQL (Npgsql), JWT bearer auth, Serilog, Swashbuckle/Swagger, HealthChecks. Layering: Controller → Service → Repository → UnitOfWork, DTOs at the controller boundary, FIFO in a domain service.
**Frontend:** Next.js (App Router) + TypeScript, plain React hooks, dependency-free validation (client for UX; **server is authoritative**).

## Conventions
- Documentation: one source of truth per topic; edit in place; navigate from `docs/00-CORE.md`.
- Progress: update the relevant `PROGRESS.md` in the same commit as the code (`docs/01-DOC-GUIDE.md §6`).

## Roadmap (future phases)
Sales & CRM · Manufacturing & Production · QC/QA · Accounting · HRM. Phase 1 reserves the integration seams (GL-ready journal entries, reservation status, goods-issue movement, inspection hold, user identity) so later phases integrate without a schema migration.
