#!/bin/bash
set -e

case "$1" in
    configure)
        # Create sensorpajen system user if it doesn't exist
        if ! getent passwd sensorpajen > /dev/null; then
            useradd --system --no-create-home --shell /usr/sbin/nologin sensorpajen
            echo "Created system user: sensorpajen"
        fi

        # Create config directory with proper permissions
        mkdir -p /etc/sensorpajen
        chown sensorpajen:sensorpajen /etc/sensorpajen
        chmod 750 /etc/sensorpajen

        # Create state directory with proper permissions (writable at runtime)
        mkdir -p /var/lib/sensorpajen
        chown sensorpajen:sensorpajen /var/lib/sensorpajen
        chmod 750 /var/lib/sensorpajen

        # Copy example configs to /etc/sensorpajen if they don't exist
        for sample in sensorpajen.env.example sensors.json.example; do
            source_file="/usr/share/doc/sensorpajen/examples/$sample"
            target_file="/etc/sensorpajen/${sample%.example}"
            
            if [ -f "$source_file" ] && [ ! -f "$target_file" ]; then
                cp "$source_file" "$target_file"
                chown sensorpajen:sensorpajen "$target_file"
                
                # Set restrictive permissions on env file (contains credentials)
                if [ "$sample" = "sensorpajen.env.example" ]; then
                    chmod 600 "$target_file"
                    echo "Created $target_file (edit this file with your MQTT credentials)"
                else
                    chmod 640 "$target_file"
                    echo "Created $target_file"
                fi
            fi
        done

        # Create virtual environment in /opt/sensorpajen
        cd /opt/sensorpajen
        if [ ! -d "venv" ]; then
            echo "Creating Python virtual environment..."
            python3 -m venv venv
            venv/bin/pip install --upgrade pip setuptools wheel
        fi

        # Install Python dependencies from requirements.txt
        echo "Installing Python dependencies..."
        if [ -f "/opt/sensorpajen/requirements.txt" ]; then
            venv/bin/pip install -r /opt/sensorpajen/requirements.txt
        else
            echo "Warning: requirements.txt not found, installing bluepy and paho-mqtt directly"
            venv/bin/pip install bluepy paho-mqtt pybluez
        fi
        
        if [ $? -ne 0 ]; then
            echo "Error: Failed to install dependencies"
            exit 1
        fi

        # Install sensorpajen package itself
        echo "Installing sensorpajen application..."
        cd /opt/sensorpajen
        venv/bin/pip install --no-deps . || {
            echo "Error: Failed to install sensorpajen package"
            exit 1
        }
        cd /

        # Set ownership of application directory BEFORE setting capabilities
        chown -R sensorpajen:sensorpajen /opt/sensorpajen

        # Set Bluetooth capabilities on Python executable (after ownership change)
        PYTHON_PATH=$(readlink -f /opt/sensorpajen/venv/bin/python3)
        if command -v setcap >/dev/null 2>&1; then
            setcap cap_net_raw,cap_net_admin+eip "$PYTHON_PATH" || {
                echo "Warning: setcap failed. You may need to run Bluetooth operations as root."
                echo "Try: sudo setcap cap_net_raw,cap_net_admin+eip $PYTHON_PATH"
            }
        else
            echo "Warning: setcap not found (install libcap2-bin package)"
        fi

        # Install systemd service file
        if [ -f /opt/sensorpajen/debian/sensorpajen.service ]; then
            cp /opt/sensorpajen/debian/sensorpajen.service /etc/systemd/system/
        elif [ -f /usr/share/doc/sensorpajen/sensorpajen.service ]; then
            cp /usr/share/doc/sensorpajen/sensorpajen.service /etc/systemd/system/
        fi

        # Reload systemd
        systemctl daemon-reload

        # Enable service (but don't start - needs configuration first)
        systemctl enable sensorpajen.service || {
            echo "Warning: Could not enable sensorpajen service"
        }

        # Check if configuration is ready
        if [ -f /etc/sensorpajen/sensorpajen.env ] && [ -f /etc/sensorpajen/sensors.json ]; then
            # Check if env file has been configured (not default values)
            if grep -q "MQTT_HOST=192.168.0.114" /etc/sensorpajen/sensorpajen.env; then
                echo ""
                echo "======================================================================"
                echo "  Configuration needed!"
                echo "======================================================================"
                echo "  Edit /etc/sensorpajen/sensorpajen.env with your MQTT settings"
                echo "  Edit /etc/sensorpajen/sensors.json with your sensor list"
                echo "  Then run: sudo systemctl start sensorpajen"
                echo "======================================================================"
                echo ""
            else
                # Configuration appears to be customized, restart service
                systemctl restart sensorpajen.service && {
                    echo "Sensorpajen service started"
                    echo "View logs: sudo journalctl -u sensorpajen -f"
                } || {
                    echo "Failed to start service. Check: sudo systemctl status sensorpajen"
                }
            fi
        else
            echo ""
            echo "======================================================================"
            echo "  Sensorpajen installed successfully!"
            echo "======================================================================"
            echo "  Next steps:"
            echo "    1. Edit /etc/sensorpajen/sensorpajen.env"
            echo "    2. Edit /etc/sensorpajen/sensors.json"
            echo "    3. sudo systemctl start sensorpajen"
            echo "    4. sudo journalctl -u sensorpajen -f"
            echo "======================================================================"
            echo ""
        fi
        ;;

    abort-upgrade|abort-remove|abort-deconfigure)
        ;;

    *)
        echo "postinst called with unknown argument \`$1'" >&2
        exit 1
        ;;
esac

exit 0