# NTech [πŸ‡·πŸ‡Έ Srpska verzija](Readme_sr.md) ![Go Version](https://img.shields.io/badge/go-1.26-blue) ![License](https://img.shields.io/badge/license-MIT-green) image A business application for computer repair shop management, parts inventory tracking, and sales. Built with Go, it runs in the browser and requires no internet connection or external services. > ⚠️ The project is under active development. It is not ready for production use. **Live demo:** [https://demo.vm-net.in.rs](https://demo.vm-net.in.rs) β€” log in with `Demo` / `Demo1234` (admin role; password and 2FA changes are disabled in demo mode). --- ## About the Project NTech is an internal application built for a specific user β€” a computer repair shop that, in addition to repairs, manages a parts inventory, sales of components and pre-built configurations, as well as client and supplier records. The goal is simple: everything the repair shop needs to track is located in one place, without relying on Excel spreadsheets or paper records. --- ## Features ### Implemented - Initial setup on first run (setup wizard) - Database migration system - User interface β€” sidebar navigation, theme system (dark/light), dashboard with statistics - User login β€” server-side sessions, account locking - Two-factor authentication (TOTP) β€” activation with a QR code; secret encrypted at rest (AES-256-GCM, key kept outside the database) - Backup (one-time) codes for 2FA β€” generated on activation, stored as bcrypt hashes; a fallback to TOTP at login - Brute-force protection β€” IP locking after 5 failed attempts within 15 minutes - CSRF protection β€” double-submit cookie pattern, automatic token injection into all forms - Security HTTP headers (CSP, X-Frame-Options, Referrer-Policy, nosniff...) - Login attempt logging β€” history by user, IP, reason, date - Users and roles β€” admin panel, user management - Inventory β€” items, categories, filtering, critical stock levels, per-item stock card, supplier links, item transfers - Service orders: - Intake form, status bar, archive - Diagnostic workflow β€” fault description, technician notes, work done, diagnostic fee - Parts and services β€” used items deducted from stock; suggested items (proposal to client) - Client proposal approval β€” client receives a public link (QR code) to accept or reject a parts/service proposal with a comment - Public status page β€” client can check order status and receive notifications via a unique link - Documents β€” work order, pre-invoice (estimate), dispatch note, return slip, device label (QR + Code128 barcode) - Pickup with payment β€” tracks payment method and advance amount - Guarantee period, expected completion date, technician assignment, client notes - Sales orders β€” items, calculation, receipt with company and client details - Services catalog β€” service price list used for billing in service orders - Expenses β€” expense records with category and amount - Procurement β€” records of purchases from suppliers - Sales price calculation on procurement β€” markup (global, per category, per item), landed costs (customs, shipping...) allocated across items, two-way markup↔price computation; respects VAT-payer status - Price revaluation (nivelacija) β€” sales price changes with an audit trail (oldβ†’new, reason, source, user) - Company profile and modules β€” features toggle based on company type and VAT-payer status - VAT records (KIR/KPR) β€” books of issued and received invoices, auto-filled from sales and procurement - VAT calculation per period + mapping to the PP-PDV form; imports (customs declaration) tracked in fields 006/106 - VAT rate code list - Clients and suppliers β€” contact database - Reminders β€” records with deadlines - Reports β€” revenue overview, inventory status, inventory value report, stock movement list, stocktake (physical count) - Settings β€” company name, address, Tax ID (PIB), logo; theme toggle - Background images β€” login page and app, with blur, transparency and glass effect - Personal theme and background β€” each user can set their own theme and background image - Permission matrix (RBAC) β€” admin panel for permissions by role; enforced at the route level (both mutations and views) and in handlers - Flash messages β€” one-time feedback after an action - Automatic SQLite backup β€” with configurable number of retained copies; restore from a copy (safe, with no downtime) - Charts β€” monthly revenue on reports (Chart.js) - Structured logging β€” `log/slog` (JSON in production, text in development); separate auth log in fail2ban format - Automated tests β€” unit and integration over a SQLite database (crypto, RBAC, login flows, form validators, reports) - **Demo mode** (`NTECH_ENV=demo`) β€” auto-created demo user, pre-filled login form, restricted backup count, blocked password/2FA changes ### In Progress - **Fiscalization (ESIR/PFR)** β€” Teron L-PFR mock server included in `Fisk/`; Go client integration planned ### Planned - KPO book and double-entry bookkeeping (optional, later phase) - PostgreSQL support (for multi-user environments) - WebAuthn / Passkey login (database schema is already prepared) - Notifications (email / WhatsApp) β€” deferred to a later phase - Barcode scanning via camera β€” deferred to a later phase --- ## Technologies | Technology | Role | | ------------------------------------------------------------------------------------ | ------------------------------- | | [Go](https://go.dev) | backend language | | [chi](https://github.com/go-chi/chi) | HTTP router | | [html/template](https://pkg.go.dev/html/template) | server-side templates | | [HTMX](https://htmx.org) | dynamic HTML over HTTP | | [Alpine.js](https://alpinejs.dev) | client-side UI logic | | [SQLite](https://sqlite.org) + [modernc.org/sqlite](https://gitlab.com/cznic/sqlite) | main database (pure Go, no CGO) | | [PostgreSQL](https://www.postgresql.org) + [pgx/v5](https://github.com/jackc/pgx) | optional production database | --- ## Running the Application ### Requirements - Go 1.24 or newer - Git ### Steps ```bash # 1. Clone the repository git clone cd GoNtech # 2. Run in development mode (reads files from disk, no HTTPS required) go run ./cmd/ntech ``` The application opens at `http://localhost:8080`. On first run the setup wizard starts automatically. ### Production Build Use the interactive build script: ```bash ./start.sh ``` It asks for the version, environment (production/development), platform (Linux/Windows/both), optional UPX compression, and whether to push a Docker image to Gitea and GitHub Container Registry. Or build manually: ```bash CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build \ -ldflags "-X main.Verzija=1.0.0 -s -w" \ -trimpath \ -o ntech ./cmd/ntech ``` The result is a single static binary with no external dependencies. --- ## Environment Variables The application reads environment variables on startup. In development, place them in `ntech.env` alongside the SQLite database file. In production/demo the program creates `ntech.env` automatically in the same directory as the database. `ntech.env` is **never committed** to Git. | Variable | Default | Description | | ---------------- | ------------- | ----------------------------------------------------------------- | | `NTECH_ENV` | `development` | Mode: `development`, `production`, or `demo` | | `NTECH_PORT` | `8080` | HTTP port | | `NTECH_DB` | `sqlite` | Database type: `sqlite` or `postgres` | | `NTECH_SQLITE` | `ntech.db` | Path to the SQLite file | | `NTECH_DSN` | β€” | PostgreSQL connection string | | `NTECH_SECRET` | β€” | Session signing key (min. 32 bytes); auto-generated if missing | | `NTECH_TOTP_KEY` | β€” | AES-256 key for TOTP secret encryption; auto-generated if missing | `NTECH_SECRET` and `NTECH_TOTP_KEY` are generated automatically on the first run and saved to `ntech.env`. **Back this file up** β€” losing `NTECH_TOTP_KEY` invalidates all 2FA secrets stored in the database. --- ## Docker Deployment Docker images are published to: - `ghcr.io/dalibor31/ntech:latest` - `git.vm-net.in.rs/dasko/ntech:latest` ### Production ```yaml # docker-compose.yml services: ntech: image: ghcr.io/dalibor31/ntech:latest restart: unless-stopped environment: NTECH_ENV: production NTECH_PORT: "8000" NTECH_SQLITE: /app/data/ntech.db volumes: - ./data:/app/data # database + ntech.env (secrets) - ./uploads:/app/uploads # uploaded images - ./logs:/app/logs # structured + auth logs - ./backups:/app/backups # automatic database backups ports: - "8000:8000" ``` On the **first start** the setup wizard runs and creates the first admin user. After that, `./data/ntech.env` contains the auto-generated secrets β€” **back it up**. Place the app behind a reverse proxy (Caddy, nginx) that terminates HTTPS. Secure cookies require HTTPS. Example Caddy config: ``` your.domain.com { reverse_proxy ntech:8000 } ``` ### With Teron L-PFR Mock (Fiscalization Testing) The `Fisk/` directory contains a Python mock server that simulates a [Teron](https://teron.rs) L-PFR fiscal device (port 4566). It implements the Teron HTTP API β€” invoice signing, PDV calculation, QR code generation, and per-type counters β€” without requiring real hardware or a certificate. Use it alongside NTech for fiscalization development and testing: ```yaml # docker-compose.yml services: ntech: image: ghcr.io/dalibor31/ntech:latest container_name: ntech restart: unless-stopped ports: - "8000:8000" environment: NTECH_ENV: production NTECH_PORT: "8000" NTECH_SQLITE: /app/data/ntech.db volumes: - ./data:/app/data - ./uploads:/app/web/static/uploads - ./logs:/var/log/ntech - ./backups:/app/backups networks: - ntech-net teron-mock: image: ghcr.io/dalibor31/ntech-fisk:latest container_name: teron_mock restart: unless-stopped volumes: - teron-data:/app/data networks: - ntech-net volumes: teron-data: networks: ntech-net: ``` The `teron-mock` service is reachable from `ntech` at `http://teron-mock:4566` over the internal Docker network β€” the port is not exposed to the host. To run the mock server locally (without Docker): ```bash cd Fisk pip install -r requirements.txt python server.py # or: ./start.sh ``` #### Teron Mock Endpoints | Method | Path | Description | |--------|------|-------------| | GET | `/api/status` | Device status and last invoice number | | GET | `/api/attention` | Active alerts | | POST | `/api/pin` | PIN verification (BE unlock) | | GET | `/api/settings` | Device settings | | POST | `/api/invoices` | Issue a fiscal invoice | | POST | `/api/invoices/final` | Finalize an advance invoice | | GET | `/api/invoices/last` | Last issued invoice | | GET | `/api/invoices/:invoiceNumber` | Invoice by number | | POST | `/api/invoices/search` | Search invoices | Counters, signed receipts, QR codes, and JSON invoice data are persisted in `Fisk/data/`. --- ### Demo Mode Demo mode runs a fully functional copy with a pre-created `Demo` / `Demo1234` admin account. Password and 2FA changes are blocked. Backup is limited to 2 copies. ```yaml # docker-compose.yml (demo) services: ntech-demo: image: ghcr.io/dalibor31/ntech:latest restart: unless-stopped environment: NTECH_ENV: demo NTECH_PORT: "8000" NTECH_SQLITE: /app/data/ntech.db volumes: - ./data:/app/data - ./uploads:/app/uploads - ./logs:/app/logs - ./backups:/app/backups ports: - "8000:8000" ``` Demo also requires HTTPS (Caddy or similar) because Secure cookies are enabled. --- ## Project Structure ``` ntech/ β”œβ”€β”€ cmd/ β”‚ └── ntech/ # entry point β”œβ”€β”€ internal/ β”‚ β”œβ”€β”€ auth/ # login, sessions, fail2ban log β”‚ β”œβ”€β”€ config/ # settings, setup wizard β”‚ β”œβ”€β”€ db/ # database layer β”‚ β”‚ └── sqlite/ # SQLite implementation β”‚ β”œβ”€β”€ handler/ # HTTP handlers β”‚ β”œβ”€β”€ middleware/ # CSRF, security headers, authentication β”‚ └── model/ # shared data types β”œβ”€β”€ web/ β”‚ β”œβ”€β”€ static/ # CSS, JavaScript, images, logos β”‚ └── templates/ # HTML templates β”œβ”€β”€ migrations/ # SQL migrations (001_desc.sql, 002_desc.sql, ...) β”œβ”€β”€ logs/ # auth.log and other logs β”œβ”€β”€ backups/ # database backups β”œβ”€β”€ start.sh # interactive build and Docker push script β”œβ”€β”€ Dockerfile β”œβ”€β”€ go.mod └── go.sum ```