#!/usr/bin/env bash
# Production startup (gunicorn). Pick the service and port:
#
#   ./run-prod.sh               # main app on 8000
#   ./run-prod.sh main 8000     # main app on 8000
#   ./run-prod.sh sensors 8001  # sensors app on 8001 (localhost only)
#
# SECRET_KEY resolution (main app sessions):
#   1. SECRET_KEY environment variable (takes precedence),
#   2. .secret_key file next to this script (created once on first start),
#   3. otherwise a random key is generated and saved to .secret_key.
#
# The sensors API is open to every user on the local machine. To expose it
# on the network explicitly set HOST=0.0.0.0 (or BIND).
set -euo pipefail
cd "$(dirname "$0")"

APP="${1:-${APP:-main}}"
PORT="${2:-${PORT:-}}"

case "$APP" in
    main)
        MODULE="app:create_app"
        DEFAULT_PORT=8000
        DEFAULT_HOST="0.0.0.0"
        ;;
    sensors)
        MODULE="sensors_app:create_app"
        DEFAULT_PORT=8001
        DEFAULT_HOST="127.0.0.1"
        ;;
    *)
        echo "Usage: $0 [main|sensors] [port]" >&2
        exit 2
        ;;
esac

PORT="${PORT:-$DEFAULT_PORT}"
HOST="${HOST:-$DEFAULT_HOST}"

# Prevent the main app from proxying to itself. Without an explicit
# SENSORS_API_URL the client targets localhost:8001, so main must not listen
# there as well.
if [ "$APP" = "main" ] && [ -z "${SENSORS_API_URL:-}" ] && [ "$PORT" = "8001" ]; then
    echo "Refusing to start main on port 8001: SENSORS_API_URL would default to" >&2
    echo "http://localhost:8001 and the app would call itself recursively." >&2
    echo "Use another port (for example 8000) or set SENSORS_API_URL explicitly." >&2
    exit 2
fi

if [ "$APP" = "main" ]; then
    SECRET_FILE=".secret_key"
    if [ -z "${SECRET_KEY:-}" ]; then
        if [ -f "$SECRET_FILE" ]; then
            SECRET_KEY="$(cat "$SECRET_FILE")"
        else
            SECRET_KEY="$(python3 -c 'import secrets; print(secrets.token_hex(32))')"
            printf '%s' "$SECRET_KEY" > "$SECRET_FILE"
            chmod 600 "$SECRET_FILE"
            echo "Generated a new SECRET_KEY, saved to $SECRET_FILE" >&2
        fi
        export SECRET_KEY
    fi
fi

# Each service runs migrations for its own database.
if [ -x ".venv/bin/alembic" ]; then
    ALEMBIC=".venv/bin/alembic"
else
    ALEMBIC="alembic"
fi
if [ "$APP" = "main" ]; then
    "$ALEMBIC" -c alembic_users.ini upgrade head
else
    "$ALEMBIC" -c alembic.ini upgrade head
fi

if [ -x ".venv/bin/gunicorn" ]; then
    GUNICORN=".venv/bin/gunicorn"
else
    GUNICORN="gunicorn"
fi

export BIND="${BIND:-$HOST:$PORT}"
echo "Starting $APP app on http://$BIND" >&2
# Gunicorn needs the factory call syntax ("module:create_app()"), otherwise it
# treats create_app itself as the WSGI callable.
exec "$GUNICORN" -c gunicorn.conf.py "$MODULE()"