# frozen_string_literal: true

require 'socket'
require 'async'
require 'sequel'
require 'openssl'
require 'securerandom'

# Set up the database
DB = Sequel.sqlite # In-memory database

# Create processors table
DB.create_table :processors do
  primary_key :proto_handler_id
  String :uuid
  String :domain
  Integer :port
end

# Create orchestrators table
DB.create_table :orchestrators do
  primary_key :id
  String :domain
  Integer :port
end

# Create blacklist table
DB.create_table :blacklist do
  primary_key :id
  String :uuid
end

processors = DB[:processors]
orchestrators = DB[:orchestrators]
blacklist = DB[:blacklist]

listen_ip = ENV['LISTEN_IP'] || '0.0.0.0'
listen_port = ENV['LISTEN_PORT'] || 3080

server = TCPServer.new(listen_ip, listen_port)

# This hash will store the recently connected UUIDs with their last validation timestamp
recently_connected = {}

def create_socket(ip, port) # rubocop:disable Metrics/MethodLength
  ip = '127.0.0.1' if ip.downcase == 'loopback'
  if ip =~ Resolv::IPv4::Regex
    TCPSocket.new(ip, port)
  else
    ssl_context = OpenSSL::SSL::SSLContext.new
    ssl_context.verify_mode = OpenSSL::SSL::VERIFY_PEER
    # Add certificate and key configuration here if needed
    tcp_socket = TCPSocket.new(ip, port)
    ssl_socket = OpenSSL::SSL::SSLSocket.new(tcp_socket, ssl_context)
    ssl_socket.sync_close = true
    ssl_socket.connect
    ssl_socket
  end
end

def handle_input(line, processors, orchestrators, blacklist, recently_connected) # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/MethodLength, Metrics/PerceivedComplexity
  command, *args = line.split
  uuid = args.shift if command != 'REGISTER'

  # Check if the UUID is blacklisted
  return 'TERMINATE' if blacklist.where(uuid:).count.positive?

  # Check if the UUID is in the recently connected cache
  if recently_connected[uuid] && Time.now - recently_connected[uuid] < 120
    # UUID is recently connected and within 2 minutes, no need to re-validate
  elsif command != 'REGISTER' && (uuid.nil? || processors.where(uuid:).count.zero?)
    # UUID is not recently connected or is invalid, add to blacklist
    blacklist.insert(uuid:)
    return 'ERROR Unrecognized UUID'
  else
    # UUID is valid, update the recently connected cache
    recently_connected[uuid] = Time.now
  end

  handle_command(command, args, processors, orchestrators)
end

def handle_command(command, args, processors, orchestrators) # rubocop:disable Metrics/MethodLength
  if command.start_with?('ORCHESTRATOR')
    orchestrator_command = command.split('_', 2).last
    orchestrator = orchestrators.first # Assuming you want to pass to the first available orchestrator
    case orchestrator_command
    when 'REQUEST', 'UPSTATE', 'FINISHED'
      orchestrator.puts "#{orchestrator_command} #{args.join(' ')}"
    else
      puts "Unknown orchestrator command: #{orchestrator_command}"
    end
  else
    consumer = processors.where(uuid: args.last).first # Assuming UUID is the last argument for CHANGE and SHUTDOWN
    case command
    when 'CHANGE', 'SHUTDOWN'
      consumer.puts "#{command} #{args.join(' ')}"
    else
      puts "Unknown command: #{command}"
    end
  end
end

def register_orchestrator(line, orchestrators)
  _, domain, port = line.split
  id = orchestrators.max(:id).to_i + 1
  orchestrators.insert(id:, domain:, port:)
  puts "Orchestrator registered with domain: #{domain}, port: #{port}"
end

Async do
  loop do
    Async::Task.new do
      client = server.accept

      begin
        line = client.gets
        # Determine if the connection is from an orchestrator for registration
        if is_orchestrator_registration?(line)
          register_orchestrator(line, orchestrators)
        else
          # Here we handle each line of input from the client
          handle_input(line, processors, blacklist, recently_connected)
        end
      ensure
        # This code will be executed when the fiber is finished, regardless of whether an exception was raised
        client.close
        Async::Task.current.stop
      end
    end
  end
end