# Systemd service for the FastAPI web application (Gunicorn + Uvicorn workers).
#
# Install: sudo cp this file to /etc/systemd/system/crop-ai-api.service
# then:
#   sudo systemctl daemon-reload
#   sudo systemctl enable crop-ai-api
#   sudo systemctl start crop-ai-api
#   sudo systemctl status crop-ai-api
#
# Logs: journalctl -u crop-ai-api -f
#
# Replace /opt/crop-ai-system with the actual deployment path on the VPS,
# and `cropai` with the dedicated non-root system user this service
# should run as (create with: sudo useradd -r -s /bin/false cropai).

[Unit]
Description=AI Crop Decision Support System - FastAPI web application
After=network.target postgresql.service redis-server.service
Wants=postgresql.service redis-server.service

[Service]
Type=notify
User=cropai
Group=cropai
WorkingDirectory=/opt/crop-ai-system
EnvironmentFile=/opt/crop-ai-system/.env

# 4 worker processes is a reasonable starting point for a modest VPS
# (2-4 CPU cores). Tune with: workers = (2 x CPU cores) + 1, but cap it
# based on available RAM — each worker holds its own Python process
# memory, though note the heavy ML models live in Celery workers, not
# here, so these web workers stay relatively light.
ExecStart=/opt/crop-ai-system/venv/bin/gunicorn app.main:app \
    --workers 4 \
    --worker-class uvicorn.workers.UvicornWorker \
    --bind 127.0.0.1:8000 \
    --timeout 30 \
    --graceful-timeout 30 \
    --keep-alive 5 \
    --access-logfile /opt/crop-ai-system/logs/gunicorn-access.log \
    --error-logfile /opt/crop-ai-system/logs/gunicorn-error.log \
    --log-level info

ExecReload=/bin/kill -s HUP $MAINPID
Restart=on-failure
RestartSec=5

# Hardening
NoNewPrivileges=true
PrivateTmp=true
ProtectSystem=strict
ReadWritePaths=/opt/crop-ai-system/logs

[Install]
WantedBy=multi-user.target