#!/bin/bash
# Service setup module for Transmission RSS Manager Installation

# Setup systemd service
function setup_service() {
  log "INFO" "Setting up systemd service..."
  
  # Ensure required variables are set
  if [ -z "$SERVICE_NAME" ]; then
    log "ERROR" "SERVICE_NAME variable is not set"
    exit 1
  fi
  
  if [ -z "$USER" ]; then
    log "ERROR" "USER variable is not set"
    exit 1
  fi
  
  if [ -z "$INSTALL_DIR" ]; then
    log "ERROR" "INSTALL_DIR variable is not set"
    exit 1
  fi
  
  if [ -z "$CONFIG_DIR" ]; then
    log "ERROR" "CONFIG_DIR variable is not set"
    exit 1
  fi
  
  if [ -z "$PORT" ]; then
    log "ERROR" "PORT variable is not set"
    exit 1
  fi
  
  # Check if systemd is available
  if ! command -v systemctl &> /dev/null; then
    log "ERROR" "systemd is not available on this system"
    log "INFO" "Please set up the service manually using your system's service manager"
    return 1
  fi
  
  # Check if service file already exists
  SERVICE_FILE="/etc/systemd/system/$SERVICE_NAME.service"
  if [ -f "$SERVICE_FILE" ] && [ "$IS_UPDATE" = true ]; then
    log "INFO" "Service file already exists. Preserving existing service configuration."
    
    # Extract existing JWT_SECRET if present to maintain session consistency
    EXISTING_JWT_SECRET=$(grep "Environment=JWT_SECRET=" "$SERVICE_FILE" | cut -d'=' -f3)
    
    # Extract existing PORT if it differs from the configured one
    EXISTING_PORT=$(grep "Environment=PORT=" "$SERVICE_FILE" | cut -d'=' -f3)
    if [ -n "$EXISTING_PORT" ] && [ "$EXISTING_PORT" != "$PORT" ]; then
      log "INFO" "Using existing port configuration: $EXISTING_PORT"
      PORT=$EXISTING_PORT
    fi
    
    # Create backup of existing service file
    backup_file "$SERVICE_FILE"
    
    # Update the service file while preserving key settings
    cat > "$SERVICE_FILE" << EOF
[Unit]
Description=Transmission RSS Manager
After=network.target transmission-daemon.service
Wants=network-online.target

[Service]
Type=simple
User=$USER
WorkingDirectory=$INSTALL_DIR
ExecStart=/usr/bin/node $INSTALL_DIR/server.js
Restart=always
RestartSec=10
StandardOutput=journal
StandardError=journal
Environment=PORT=$PORT
Environment=NODE_ENV=production
Environment=DEBUG_ENABLED=false
Environment=LOG_FILE=$INSTALL_DIR/logs/transmission-rss-manager.log
Environment=CONFIG_DIR=$CONFIG_DIR
EOF

    # Preserve the existing JWT_SECRET if available
    if [ -n "$EXISTING_JWT_SECRET" ]; then
      echo "Environment=JWT_SECRET=$EXISTING_JWT_SECRET" >> "$SERVICE_FILE"
    else
      echo "# Generate a random JWT secret for security" >> "$SERVICE_FILE"
      echo "Environment=JWT_SECRET=$(openssl rand -hex 32)" >> "$SERVICE_FILE"
    fi

    # Close the service file definition
    cat >> "$SERVICE_FILE" << EOF

[Install]
WantedBy=multi-user.target
EOF

  else
    # For fresh installations, create a new service file
    log "INFO" "Creating new service file"
    
    # Create backup of existing service file if it exists
    if [ -f "$SERVICE_FILE" ]; then
      backup_file "$SERVICE_FILE"
    fi
    
    # Create systemd service file
    cat > "$SERVICE_FILE" << EOF
[Unit]
Description=Transmission RSS Manager
After=network.target transmission-daemon.service
Wants=network-online.target

[Service]
Type=simple
User=$USER
WorkingDirectory=$INSTALL_DIR
ExecStart=/usr/bin/node $INSTALL_DIR/server.js
Restart=always
RestartSec=10
StandardOutput=journal
StandardError=journal
Environment=PORT=$PORT
Environment=NODE_ENV=production
Environment=DEBUG_ENABLED=false
Environment=LOG_FILE=$INSTALL_DIR/logs/transmission-rss-manager.log
Environment=CONFIG_DIR=$CONFIG_DIR
# Generate a random JWT secret for security
Environment=JWT_SECRET=$(openssl rand -hex 32)

[Install]
WantedBy=multi-user.target
EOF
  fi

  # Create logs directory
  mkdir -p "$INSTALL_DIR/logs"
  chown -R $USER:$USER "$INSTALL_DIR/logs"

  # Check if file was created successfully
  if [ ! -f "$SERVICE_FILE" ]; then
    log "ERROR" "Failed to create systemd service file"
    return 1
  fi
  
  log "INFO" "Setting up Nginx reverse proxy..."
  
  # Check if nginx is installed
  if ! command -v nginx &> /dev/null; then
    log "ERROR" "Nginx is not installed"
    log "INFO" "Skipping Nginx configuration. Please configure your web server manually."
    
    # Reload systemd and enable service
    systemctl daemon-reload
    systemctl enable "$SERVICE_NAME"
    
    log "INFO" "Systemd service has been created and enabled."
    log "INFO" "The service will start automatically after installation."
    return 0
  fi
  
  # Detect nginx configuration directory
  NGINX_AVAILABLE_DIR=""
  NGINX_ENABLED_DIR=""
  
  if [ -d "/etc/nginx/sites-available" ] && [ -d "/etc/nginx/sites-enabled" ]; then
    # Debian/Ubuntu style
    NGINX_AVAILABLE_DIR="/etc/nginx/sites-available"
    NGINX_ENABLED_DIR="/etc/nginx/sites-enabled"
  elif [ -d "/etc/nginx/conf.d" ]; then
    # CentOS/RHEL style
    NGINX_AVAILABLE_DIR="/etc/nginx/conf.d"
    NGINX_ENABLED_DIR="/etc/nginx/conf.d"
  else
    log "WARN" "Unable to determine Nginx configuration directory"
    log "INFO" "Please configure Nginx manually"
    
    # Reload systemd and enable service
    systemctl daemon-reload
    systemctl enable "$SERVICE_NAME"
    
    log "INFO" "Systemd service has been created and enabled."
    log "INFO" "The service will start automatically after installation."
    return 0
  fi
  
  # Check if default nginx file exists, back it up if it does
  if [ -f "$NGINX_ENABLED_DIR/default" ]; then
    backup_file "$NGINX_ENABLED_DIR/default"
    if [ -f "$NGINX_ENABLED_DIR/default.bak" ]; then
      log "INFO" "Backed up default nginx configuration."
    fi
  fi
  
  # Create nginx configuration file
  NGINX_CONFIG_FILE="$NGINX_AVAILABLE_DIR/$SERVICE_NAME.conf"
  cat > "$NGINX_CONFIG_FILE" << EOF
server {
    listen 80;
    server_name _;
    
    location / {
        proxy_pass http://127.0.0.1:$PORT;
        proxy_http_version 1.1;
        proxy_set_header Upgrade \$http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host \$host;
        proxy_cache_bypass \$http_upgrade;
        proxy_set_header X-Real-IP \$remote_addr;
        proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto \$scheme;
    }
}
EOF

  log "INFO" "Nginx configured to proxy connections from port 80 to port $PORT"
  log "INFO" "You can access Transmission RSS Manager at http://your-server-ip/ (port 80) via Nginx"

  # Check if Debian/Ubuntu style (need symlink between available and enabled)
  if [ "$NGINX_AVAILABLE_DIR" != "$NGINX_ENABLED_DIR" ]; then
    # Create symbolic link to enable the site (if it doesn't already exist)
    if [ ! -h "$NGINX_ENABLED_DIR/$SERVICE_NAME.conf" ]; then
      ln -sf "$NGINX_CONFIG_FILE" "$NGINX_ENABLED_DIR/"
    fi
  fi

  # Test nginx configuration
  if nginx -t; then
    # Reload nginx
    systemctl reload nginx
    log "INFO" "Nginx configuration has been set up successfully."
  else
    log "ERROR" "Nginx configuration test failed. Please check the configuration manually."
    log "WARN" "You may need to correct the configuration before the web interface will be accessible."
  fi
  
  # Check for port conflicts
  if ss -lnt | grep ":$PORT " &> /dev/null; then
    log "WARN" "Port $PORT is already in use. This may cause conflicts with the service."
    log "WARN" "The service will fail to start. Please stop any service using port $PORT and try again."
  else
    log "INFO" "You can access the web interface at: http://localhost:$PORT or http://your-server-ip:$PORT"
    log "INFO" "You may need to configure your firewall to allow access to port $PORT"
  fi
  
  # Reload systemd
  systemctl daemon-reload
  
  # Enable the service to start on boot
  systemctl enable "$SERVICE_NAME"
  
  log "INFO" "Systemd service has been created and enabled."
  log "INFO" "The service will start automatically after installation."
}