#!/bin/bash

# Check if running as root
if [[ $EUID -ne 0 ]]; then
   echo "This script must be run as root" 
   exit 1
fi

# Update and upgrade the system
echo "Updating and upgrading the system..."
apt update && apt upgrade -y

# Install dependencies
echo "Installing dependencies..."
apt install -y python3 python3-pip python3-dev build-essential libxml2 libxml2-dev libxslt1-dev libffi-dev graphviz git libpq-dev libssl-dev redis-server postgresql postgresql-contrib nginx

# Check Python version
echo "Checking Python version. Please ensure this meets the minimum requirements of Python 3.8, 3.9, 3.10 or 3.11.:"
python3 --version

# Prompt user to confirm if the currently installed Python version meets the minimum requirements
read -p "Does the installed Python version meet the minimum requirements of Python 3.8, 3.9, 3.10 or 3.11.? (y/n): " PYTHON_CONFIRM
if [[ $PYTHON_CONFIRM != "y" ]]; then
    echo "Please install the required version of Python and rerun this script."
    exit 1
fi

# Check other system requirements
echo "Checking other system requirements..."
RAM=$(free -m | awk '/Mem/ {print $2}')
CPU=$(grep -c ^processor /proc/cpuinfo)
DISK=$(df -h / | awk 'NR==2 {print $4}')
MIN_RAM=2048  # Minimum RAM in MB
MIN_CPU=2     # Minimum CPU cores
MIN_DISK=10   # Minimum free disk space in GB

# Check RAM
if [ "$RAM" -lt "$MIN_RAM" ]; then
    echo "Error: Insufficient RAM. At least $MIN_RAM MB of RAM is required."
    exit 1
fi

# Check CPU cores
if [ "$CPU" -lt "$MIN_CPU" ]; then
    echo "Error: Insufficient CPU cores. At least $MIN_CPU CPU cores are required."
    exit 1
fi

# Check disk space
DISK_NUM=$(echo "$DISK" | grep -o -E '[0-9]+')
DISK_UNIT=$(echo "$DISK" | grep -o -E '[A-Za-z]+')
if [ "$DISK_UNIT" == "G" ]; then
    if [ "$DISK_NUM" -lt "$MIN_DISK" ]; then
        echo "Error: Insufficient disk space. At least $MIN_DISK GB of free disk space is required."
        exit 1
    fi
else
    echo "Error: Unsupported disk space unit. Please ensure disk space is in GB."
    exit 1
fi

echo "System meets minimum requirements. Proceeding with installation..."

# Add Netbox repository
echo "Adding Netbox repository..."
echo "deb https://packagecloud.io/netbox-community/netbox/ubuntu/ $(lsb_release -sc) main" | tee -a /etc/apt/sources.list.d/netbox-community.list
curl -L https://packagecloud.io/netbox-community/netbox/gpgkey | apt-key add -

# Prompt user for PostgreSQL and Netbox password
read -p "Enter PostgreSQL password for 'netbox' user: " PG_PASSWORD
read -p "Enter password for Netbox application: " NETBOX_PASSWORD

# Create PostgreSQL user and database
echo "Creating PostgreSQL user and database..."
sudo -u postgres psql -c "CREATE DATABASE netbox;"
sudo -u postgres psql -c "CREATE USER netbox WITH PASSWORD '$PG_PASSWORD';"
sudo -u postgres psql -c "GRANT ALL PRIVILEGES ON DATABASE netbox TO netbox;"

# Create new user for Netbox
echo "Creating new user for Netbox..."
useradd -m -s /bin/bash netbox

# Install Netbox
echo "Installing Netbox..."
apt update
apt install -y netbox

# Move into NetBox configuration directory and make a copy of configuration_example.py
echo "Copying Netbox configuration file..."
cd /opt/netbox/netbox/netbox/
cp configuration.example.py configuration.py

# Populate database fields in configuration.py with PostgreSQL information
echo "Populating the Netbox configuration file with prior PostgreSQL information..."
sed -i "s/'USER': '',/'USER': 'netbox',/g" configuration.py
sed -i "s/'NAME': '',/'NAME': 'netbox',/g" configuration.py
sed -i "s/'PASSWORD': '',/'PASSWORD': '$PG_PASSWORD',/g" configuration.py
sed -i "s/'HOST': '',/'HOST': 'localhost',/g" configuration.py

# Generate secret key and parse it into configuration.py
echo "Generating secret key..."
SECRET_KEY=$(python3 /opt/netbox/generate_secret_key.py)
sed -i "s/SECRET_KEY = ''/SECRET_KEY = '$SECRET_KEY'/g" configuration.py

# Prompt user to enter ALLOWED_HOSTS
echo "Please enter manually input the following inforation..."
read -p "Enter ALLOWED_HOSTS (separated by commas): " ALLOWED_HOSTS

# Parse user input into configuration.py
echo "Parsing the entered information to configuration.py..."
sed -i "s/ALLOWED_HOSTS = \[\]/ALLOWED_HOSTS = \[$ALLOWED_HOSTS\]/g" configuration.py
sed -i "s/SECRET_KEY = ''/SECRET_KEY = '$SECRET_KEY'/g" configuration.py

# Perform initial Netbox database migration
echo "Performing initial Netbox database migration..."
sudo -u netbox /opt/netbox/upgrade.sh

# Create directory for Netbox reports
echo "Creating directory for Netbox reports..."
mkdir -p /opt/netbox/netbox/media/reports

# Check if directories exist
echo "Checking if directories exist..."
if [ ! -d "/opt/netbox/netbox/media/reports" ] || [ ! -d "/opt/netbox/netbox/media/" ] || [ ! -d "/opt/netbox/netbox/static/" ]; then
    read -p "Required directories are missing. Do you want to create them? (y/n): " CREATE_DIRS
    if [[ $CREATE_DIRS == "y" ]]; then
        mkdir -p /opt/netbox/netbox/media/reports
        mkdir -p /opt/netbox/netbox/media/
        mkdir -p /opt/netbox/netbox/static/
    else
        echo "Please create the required directories manually and rerun the script."
        exit 1
    fi
fi

# Collect static files
echo "Collecting static files..."
sudo -u netbox /opt/netbox/manage.py collectstatic --no-input

# Set file and directory permissions
echo "Setting file permissions..."
chown -R netbox:netbox /opt/netbox/netbox/media
chown -R netbox:netbox /opt/netbox/netbox/static
chown -R netbox:netbox /opt/netbox/netbox/media/reports

# Enable and start services
echo "Enabling and starting services..."
systemctl enable netbox
systemctl enable redis-server
systemctl enable postgresql
systemctl start netbox
systemctl start redis-server
systemctl start postgresql

# NGINX reverse proxy config
echo "Example NGINX reverse proxy configuration for Netbox:"
echo "
server {
    listen 80;
    server_name netbox.example.com;

    location / {
        proxy_pass http://localhost:8001;
        proxy_set_header X-Forwarded-Host \$server_name;
        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;
    }

    location /static/ {
        alias /opt/netbox/netbox/static/;
    }

    location /media/ {
        alias /opt/netbox/netbox/media/;
    }
}
"

echo "Netbox installation completed successfully!"