readme

README.md

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+# HS Codes API
+
+![CI](https://github.com/DigitalTouchCode/Hs_codes_api/actions/workflows/ci.yml/badge.svg)
+![Python](https://img.shields.io/badge/python-3.12-blue.svg)
+![Django](https://img.shields.io/badge/django-6.0-092E20?logo=django)
+![PostgreSQL](https://img.shields.io/badge/postgresql-16-336791?logo=postgresql)
+![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)
+![License: MIT](https://img.shields.io/badge/license-MIT-green.svg)
+
+A public REST API for searching ZIMRA Harmonised System (HS) codes using trigram similarity. The search endpoint is open — uploading HS code data is internal and not part of the public API.
+
+**Live:** https://tools.digitaltouch.co.zw
+
+## Features
+
+- Fuzzy search across HS code and description using PostgreSQL trigram similarity
+- Configurable similarity threshold
+- Throttling on all endpoints
+- Health check endpoint
+
+## Requirements
+
+- Python 3.12
+- PostgreSQL 16
+- Docker & Docker Compose (for containerised setup)
+
+## Local Setup
+
+**1. Clone and create a virtual environment**
+```bash
+git clone git@github.com:DigitalTouchCode/Hs_codes_api.git
+cd Hs_codes_api
+python -m venv venv
+source venv/bin/activate
+pip install -r requirements.txt
+```
+
+**2. Configure environment**
+```bash
+cp .env.example .env
+```
+
+Edit `.env`:
+```env
+SECRET_KEY=your-secret-key
+DEBUG=True
+ALLOWED_HOSTS=localhost,127.0.0.1
+DATABASE_URL=postgres://hsuser:hspass@localhost:5432/hsdb
+HS_CODE_SEARCH_THRESHOLD=0.1
+```
+
+**3. Run migrations**
+```bash
+python manage.py migrate
+```
+
+**4. Run the development server**
+```bash
+DJANGO_SETTINGS_MODULE=core.settings.development python manage.py runserver
+```
+
+## Docker Setup
+
+```bash
+cp .env.example .env  # fill in values
+docker compose up -d --build
+```
+
+The API will be available at `http://localhost:8001`.
+
+## Environment Variables
+
+| Variable | Required | Default | Description |
+|---|---|---|---|
+| `SECRET_KEY` | Yes | — | Django secret key |
+| `DEBUG` | Yes | — | `True` or `False` |
+| `ALLOWED_HOSTS` | Yes | — | Comma-separated hostnames |
+| `DATABASE_URL` | Yes | — | PostgreSQL connection string |
+| `HS_CODE_SEARCH_THRESHOLD` | No | `0.1` | Minimum trigram similarity score (0–1) |
+| `GUNICORN_WORKERS` | No | `3` | Number of Gunicorn worker processes |
+
+## API Reference
+
+### Search HS Codes
+
+`GET /api/v1/hs-codes/?q=<query>`
+
+Search HS codes by description or code using trigram similarity. Results are ordered by relevance, with description weighted 2× higher than the code.
+
+**Parameters**
+
+| Parameter | Required | Description |
+|---|---|---|
+| `q` | Yes | Search term |
+
+**Response `200`**
+```json
+[
+  {
+    "id": 1,
+    "hs_code": "8471.30.00",
+    "description": "Portable automatic data processing machines",
+    "created_at": "2026-01-01T00:00:00Z",
+    "hs_code_file": 1
+  }
+]
+```
+
+**Response `400` — missing query**
+```json
+{"q": ["This query parameter is required."]}
+```
+
+### Health Check
+
+`GET /api/v1/health/`
+
+**Response `200`**
+```json
+{"status": "healthy"}
+```
+
+## Code Formatting
+
+This project uses [Black](https://black.readthedocs.io/) for code formatting, enforced via pre-commit.
+
+**Install pre-commit hooks**
+```bash
+pip install pre-commit
+pre-commit install
+```
+
+**Run manually**
+```bash
+black .
+```
+
+**Check without modifying**
+```bash
+black --check .
+```
+
+Black is pinned at `24.8.0` in `.pre-commit-config.yaml`.
+
+## Tests
+
+**Run all tests**
+```bash
+python manage.py test app
+```
+
+**Run a specific test class**
+```bash
+python manage.py test app.tests.HsCodeUploadViewTest
+```
+
+**Run a single test**
+```bash
+python manage.py test app.tests.HsCodeUploadViewTest.test_upload_valid_csv_returns_201
+```
+
+**Test coverage by area**
+
+| Area | Tests |
+|---|---|
+| File decoding | UTF-8, BOM stripping, bad encoding |
+| CSV parsing | Valid CSV, missing columns, empty file |
+| Object building | Blank row skipping, whitespace trimming |
+| Upload service | Full flow, duplicates, partial duplicates |
+| Upload view | 201/400 responses, duplicate handling |
+| Search view | Missing `q`, fuzzy match, no results |
+| Health check | 200 response, no auth required |
+| Model | Unique constraint, cascade delete |
+| Permissions | Admin/Staff allowed, unknown role/unauthenticated denied |
+
+## Deployment
+
+Deployment is handled via GitHub Actions. On every push to `main`:
+
+1. The **CI** workflow runs all 40 tests against a PostgreSQL service container.
+2. On CI success, the **Deploy Production** workflow SSHs into the VPS and deploys the latest build.
+
+**Required GitHub Secrets**
+
+| Secret | Description |
+|---|---|
+| `VPS_HOST` | VPS IP or hostname |
+| `VPS_USER` | SSH username |
+| `VPS_SSH_KEY` | Private SSH key |
+| `VPS_PORT` | SSH port (usually `22`) |
+
+The deploy script polls `GET /api/v1/health/` for up to 100 seconds after startup before marking the deployment as succeeded or failed.