#!/bin/bash

# Agent Manager - Systemd Service Installation Script
# This script installs the agent-manager as a systemd service

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

# Print functions
print_info() {
    echo -e "${GREEN}[INFO]${NC} $1"
}

print_warning() {
    echo -e "${YELLOW}[WARNING]${NC} $1"
}

print_error() {
    echo -e "${RED}[ERROR]${NC} $1"
}

# Check if running as root
if [ "$EUID" -eq 0 ]; then
    print_error "Please do not run this script as root or with sudo"
    print_info "The script will prompt for sudo password when needed"
    exit 1
fi

# Detect the project directory (where this script is located)
SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
PROJECT_DIR="$SCRIPT_DIR"

print_info "Project directory detected: $PROJECT_DIR"

# Detect current user and group
CURRENT_USER="$USER"
CURRENT_GROUP="$(id -gn)"

print_info "Service will run as user: $CURRENT_USER"
print_info "Service will run as group: $CURRENT_GROUP"

# Check if systemd is available
if ! command -v systemctl &> /dev/null; then
    print_error "systemd is not available on this system"
    print_error "This script requires a systemd-based Linux distribution"
    exit 1
fi

# Check if Node.js is installed
if ! command -v node &> /dev/null; then
    print_error "Node.js is not installed"
    print_error "Please install Node.js >= 18.0.0 before running this script"
    exit 1
fi

# Check Node.js version
NODE_VERSION=$(node --version | cut -d'v' -f2)
NODE_MAJOR_VERSION=$(echo "$NODE_VERSION" | cut -d'.' -f1)

if [ "$NODE_MAJOR_VERSION" -lt 18 ]; then
    print_error "Node.js version $NODE_VERSION is not supported"
    print_error "Please install Node.js >= 18.0.0"
    exit 1
fi

print_info "Node.js version: $NODE_VERSION (OK)"

# Detect node path
NODE_PATH=$(which node)
print_info "Node.js path: $NODE_PATH"

# Check if service file exists
if [ ! -f "$PROJECT_DIR/agent-manager.service" ]; then
    print_error "Service file not found: $PROJECT_DIR/agent-manager.service"
    exit 1
fi

# Check if .env file exists
if [ ! -f "$PROJECT_DIR/.env" ]; then
    print_warning ".env file not found"
    if [ -f "$PROJECT_DIR/.env.example" ]; then
        print_info "Creating .env from .env.example"
        cp "$PROJECT_DIR/.env.example" "$PROJECT_DIR/.env"
        print_warning "Please edit .env file to configure your settings"
    else
        print_error "Neither .env nor .env.example found"
        print_error "Please create .env file before installing the service"
        exit 1
    fi
fi

# Check if commands.json exists
if [ ! -f "$PROJECT_DIR/commands.json" ]; then
    print_warning "commands.json file not found"
    if [ -f "$PROJECT_DIR/commands.json.example" ]; then
        print_info "Creating commands.json from commands.json.example"
        cp "$PROJECT_DIR/commands.json.example" "$PROJECT_DIR/commands.json"
        print_warning "Please edit commands.json to configure your webhook commands"
    else
        print_error "Neither commands.json nor commands.json.example found"
        print_error "Please create commands.json before installing the service"
        exit 1
    fi
fi

# Create temporary service file with substitutions
TEMP_SERVICE_FILE=$(mktemp)
print_info "Creating service file with correct paths..."

# Read the template and substitute variables
sed -e "s|WorkingDirectory=.*|WorkingDirectory=$PROJECT_DIR|g" \
    -e "s|User=.*|User=$CURRENT_USER|g" \
    -e "s|Group=.*|Group=$CURRENT_GROUP|g" \
    -e "s|ExecStart=.*|ExecStart=$NODE_PATH src/index.js|g" \
    -e "s|ReadWritePaths=.*|ReadWritePaths=$PROJECT_DIR|g" \
    "$PROJECT_DIR/agent-manager.service" > "$TEMP_SERVICE_FILE"

print_info "Service file prepared with the following settings:"
echo "  - WorkingDirectory: $PROJECT_DIR"
echo "  - User: $CURRENT_USER"
echo "  - Group: $CURRENT_GROUP"
echo "  - ExecStart: $NODE_PATH src/index.js"
echo "  - ReadWritePaths: $PROJECT_DIR"
echo ""

# Confirm installation
read -p "Do you want to proceed with the installation? (y/N): " -n 1 -r
echo
if [[ ! $REPLY =~ ^[Yy]$ ]]; then
    print_warning "Installation cancelled"
    rm "$TEMP_SERVICE_FILE"
    exit 0
fi

# Install the service file
print_info "Installing service file..."
sudo cp "$TEMP_SERVICE_FILE" /etc/systemd/system/agent-manager.service
rm "$TEMP_SERVICE_FILE"

# Set correct permissions
sudo chmod 644 /etc/systemd/system/agent-manager.service

# Reload systemd
print_info "Reloading systemd daemon..."
sudo systemctl daemon-reload

# Enable the service
print_info "Enabling agent-manager service..."
sudo systemctl enable agent-manager

# Ask if user wants to start the service now
echo ""
read -p "Do you want to start the service now? (Y/n): " -n 1 -r
echo
if [[ ! $REPLY =~ ^[Nn]$ ]]; then
    print_info "Starting agent-manager service..."
    sudo systemctl start agent-manager

    # Wait a moment for the service to start
    sleep 2

    # Check service status
    if sudo systemctl is-active --quiet agent-manager; then
        print_info "✓ Service installed and started successfully!"
        echo ""
        print_info "Service status:"
        sudo systemctl status agent-manager --no-pager -l
    else
        print_error "Service failed to start. Checking logs..."
        echo ""
        sudo journalctl -u agent-manager -n 50 --no-pager
        exit 1
    fi
else
    print_info "✓ Service installed successfully (not started)"
    print_info "To start the service later, run: sudo systemctl start agent-manager"
fi

echo ""
print_info "Useful commands:"
echo "  - Check status:    sudo systemctl status agent-manager"
echo "  - View logs:       journalctl -u agent-manager -f -n100"
echo "  - Stop service:    sudo systemctl stop agent-manager"
echo "  - Restart service: sudo systemctl restart agent-manager"
echo "  - Disable service: sudo systemctl disable agent-manager"
echo "  - Uninstall:       ./uninstall.sh"
echo ""
print_info "Installation complete!"