#!/bin/bash
# Install Multi-Model Chatbot as systemd service
# This script must be run with sudo privileges

set -e  # Exit on error

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

# Check if running as root
if [ "$EUID" -ne 0 ]; then
    echo -e "${RED}Error: This script must be run as root (use sudo)${NC}"
    exit 1
fi

# Get the actual user (not root)
ACTUAL_USER=${SUDO_USER:-$USER}
if [ "$ACTUAL_USER" = "root" ]; then
    echo -e "${RED}Error: Please run with sudo as a regular user, not as root${NC}"
    exit 1
fi

# Get current directory
CURRENT_DIR=$(pwd)
SERVICE_FILE="chatbot.service"

echo -e "${GREEN}=== Multi-Model Chatbot Service Installer ===${NC}"
echo ""

# Check if service file exists
if [ ! -f "$SERVICE_FILE" ]; then
    echo -e "${RED}Error: $SERVICE_FILE not found in current directory${NC}"
    exit 1
fi

# Check if venv exists
if [ ! -d "venv" ]; then
    echo -e "${YELLOW}Warning: venv directory not found${NC}"
    echo -e "${YELLOW}Please create virtual environment first:${NC}"
    echo "  python -m venv venv"
    echo "  source venv/bin/activate"
    echo "  pip install -r requirements-local.txt"
    exit 1
fi

# Check if app.py exists
if [ ! -f "app.py" ]; then
    echo -e "${RED}Error: app.py not found in current directory${NC}"
    exit 1
fi

# Create customized service file
TEMP_SERVICE="/tmp/chatbot-temp.service"
cp "$SERVICE_FILE" "$TEMP_SERVICE"

# Replace placeholders
sed -i "s|YOUR_USERNAME|$ACTUAL_USER|g" "$TEMP_SERVICE"
sed -i "s|/path/to/simple-chatbot-gradio|$CURRENT_DIR|g" "$TEMP_SERVICE"

echo -e "${GREEN}✓ Service file configured:${NC}"
echo "  User: $ACTUAL_USER"
echo "  Directory: $CURRENT_DIR"
echo ""

# Create log directory if not exists
LOG_DIR="/var/log"
if [ ! -d "$LOG_DIR" ]; then
    mkdir -p "$LOG_DIR"
fi

# Set log file permissions
touch /var/log/chatbot.log
touch /var/log/chatbot-error.log
chown $ACTUAL_USER:$ACTUAL_USER /var/log/chatbot.log
chown $ACTUAL_USER:$ACTUAL_USER /var/log/chatbot-error.log
chmod 644 /var/log/chatbot.log
chmod 644 /var/log/chatbot-error.log

echo -e "${GREEN}✓ Log files created${NC}"

# Copy service file to systemd directory
cp "$TEMP_SERVICE" /etc/systemd/system/chatbot.service
rm "$TEMP_SERVICE"

echo -e "${GREEN}✓ Service file installed to /etc/systemd/system/chatbot.service${NC}"

# Reload systemd daemon
systemctl daemon-reload
echo -e "${GREEN}✓ Systemd daemon reloaded${NC}"

# Enable service
systemctl enable chatbot.service
echo -e "${GREEN}✓ Service enabled (will start on boot)${NC}"

# Ask if user wants to start now
echo ""
read -p "Do you want to start the service now? (y/n) " -n 1 -r
echo ""
if [[ $REPLY =~ ^[Yy]$ ]]; then
    systemctl start chatbot.service
    sleep 2
    systemctl status chatbot.service
    echo ""
    echo -e "${GREEN}✓ Service started successfully${NC}"
    echo -e "${GREEN}✓ Access chatbot at: http://0.0.0.0:7860${NC}"
fi

echo ""
echo -e "${GREEN}=== Installation Complete ===${NC}"
echo ""
echo "Useful commands:"
echo "  sudo systemctl start chatbot    # Start service"
echo "  sudo systemctl stop chatbot     # Stop service"
echo "  sudo systemctl restart chatbot  # Restart service"
echo "  sudo systemctl status chatbot   # Check status"
echo "  sudo journalctl -u chatbot -f   # View live logs"
echo "  tail -f /var/log/chatbot.log    # View application logs"
echo ""