# OCR Application Deployment Guide

This guide describes how to deploy the OCR application on a Linux host (e.g., Ubuntu/Debian).

## Architecture
- **Backend**: Containerized (FastAPI, Python 3.9).
- **Database**: Containerized (PostgreSQL 15).
- **Frontend**: Static files (Angular) served by Host Nginx.
- **Reverse Proxy**: Host Nginx proxies requests to Frontend (Static) and Backend (API).

## Prerequisites
- **Deployment Host**: Docker & Docker Compose, Nginx.
- **Build Machine**: Node.js & NPM (to run the package script).

---

## 1. Full Stack Deployment (Docker)

The app connects to your **existing Postgres container** (`postgres-db`) in the `arbit-app_arbit-network`.

1.  **Create the Database**:
    Since we are using an existing postgres instance, we must manually create the `ocr_db`.
    ```bash
    # Run this on your host to create the DB inside the existing container
    docker exec -it postgres-db psql -U postgres -c "CREATE DATABASE ocr_db;"
    ```

2.  **Navigate to the packaged directory**:
    ```bash
    cd ocr_build
    ```

3.  **Verify Environment**:
    Ensure `.env.prod` exists and points to `DB_HOST=postgres-db`.
    **Also configure your Email credentials** in `.env.prod` if you want the Mailbox feature to work (Gmail requires an App Password).
    ```bash
    cat .env.prod
    ```

4.  **Start App Containers**:
    This will start `ocr_backend` and `ocr_frontend`.
    ```bash
    # Build and start in detached mode
    docker-compose up -d --build
    ```

5.  **Verify Status**:
    ```bash
    docker-compose ps
    ```
    You should see `ocr_backend` and `ocr_frontend` running.

---

## 2. Nginx Configuration (Host Reverse Proxy)

Since the Frontend is now running in a container on port 8080 (serving `/ocrf/`), we configure the Host Nginx to proxy traffic to it.

1.  **Create Config File**:
    Copy the provided config to `/etc/nginx/sites-available/ocr`.
    ```bash
    sudo cp nginx_host.conf /etc/nginx/sites-available/ocr
    ```

2.  **Enable Site**:
    ```bash
    sudo ln -s /etc/nginx/sites-available/ocr /etc/nginx/sites-enabled/
    ```

3.  **Test & Reload**:
    ```bash
    sudo nginx -t
    sudo systemctl reload nginx
    ```

---

## 3. Verification

- **Url**: `http://app.technobeesolutions.in/ocrf/` (Proxies to Frontend Container)
- **API**: `http://app.technobeesolutions.in/ocrb/` (Proxies to Backend Container)

---

## 4. Troubleshooting

- **Logs**:
    ```bash
    docker-compose logs -f backend
    ```
- **Database**:
    Connect via the existing container:
    ```bash
    docker exec -it postgres-db psql -U postgres -d ocr_db
    ```