#!/bin/bash

# Logger Function
log() {
  local message="$1"
  local type="$2"
  local timestamp=$(date '+%Y-%m-%d %H:%M:%S')
  local color
  local endcolor="\033[0m"

  case "$type" in
    "info") color="\033[38;5;79m" ;;
    "success") color="\033[1;32m" ;;
    "error") color="\033[1;31m" ;;
    *) color="\033[1;34m" ;;
  esac

  echo -e "${color}${timestamp} - ${message}${endcolor}"
}

# Error handler function
handle_error() {
  local exit_code=$1
  local error_message="$2"
  log "Error: $error_message (Exit Code: $exit_code)" "error"
  exit $exit_code
}

# Function to check for command availability
command_exists() {
  command -v "$1" &> /dev/null
}

check_os() {
    if ! [ -f "/etc/redhat-release" ]; then
        echo "Error: This script is only supported on RHEL-based systems."
        exit 1
    fi
}

# Function to install the script prerequisites
install_pre_reqs() {
    log "Installing pre-requisites" "info"

    # Run 'yum update'
    if ! yum update -y; then
        handle_error "$?" "Failed to run 'yum update'"
    fi

    # Install required packages
    if ! yum install -y curl ca-certificates gnupg2; then
        handle_error "$?" "Failed to install required packages"
    fi

    # Create directory for keyrings
    if ! mkdir -p /etc/pki/rpm-gpg; then
        handle_error "$?" "Failed to create /etc/pki/rpm-gpg directory"
    fi

    # Remove old keyring if exists
    rm -f /etc/pki/rpm-gpg/nodesource.gpg || true

    # Download and import the NodeSource GPG key
    if ! curl -fsSL https://rpm.nodesource.com/pub/el/NODESOURCE-GPG-SIGNING-KEY-EL | gpg --dearmor -o /etc/pki/rpm-gpg/nodesource.gpg; then
      handle_error "$?" "Failed to download and import the NodeSource GPG key"
    fi
}

# Function to configure the Node.js repository for RHEL
configure_repo() {
    local node_version=$1

    # Create the Nodesource repo file
    cat <<EOF > /etc/yum.repos.d/nodesource.repo
[nodesource]
name=Node.js Packages for Enterprise Linux
baseurl=https://rpm.nodesource.com/pub_$(echo $node_version | tr -d 'x').x/el/\$releasever/\$basearch
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/nodesource.gpg
EOF

    # Run 'yum clean all' and 'yum makecache' to refresh the repository
    if ! yum clean all && yum makecache; then
        handle_error "$?" "Failed to refresh repositories"
    else
        log "Repository configured successfully." "success"
        log "To install Node.js, run: yum install nodejs -y" "info"
    fi
}

# Define Node.js version
NODE_VERSION="20.x"

# Check OS
check_os

# Main execution
install_pre_reqs || handle_error $? "Failed installing pre-requisites"
configure_repo "$NODE_VERSION" || handle_error $? "Failed configuring repository"