defmodule Odinsea.Application do
  @moduledoc """
  Main application supervisor for Odinsea.
  Ported from Java Program.java and ServerStart.java.
  """

  use Application

  require Logger

  @impl true
  def start(_type, _args) do
    Logger.info("Starting Odinsea Server v#{version()}")

    # Log server configuration
    log_configuration()

    children = [
      # Database repository
      Odinsea.Repo,

      # Redis connection pool
      {Redix, name: :redix, host: redis_config()[:host], port: redis_config()[:port]},

      # Registry for player lookups
      {Registry, keys: :unique, name: Odinsea.PlayerRegistry},

      # Registry for channel lookups
      {Registry, keys: :unique, name: Odinsea.Channel.Registry},

      # Registry for character processes (in-game players)
      {Registry, keys: :unique, name: Odinsea.CharacterRegistry},

      # Registry for map instances {map_id, channel_id} => pid
      {Registry, keys: :unique, name: Odinsea.MapRegistry},

      # Dynamic supervisor for client connections
      {DynamicSupervisor, strategy: :one_for_one, name: Odinsea.ClientSupervisor},

      # Dynamic supervisor for map instances
      {DynamicSupervisor, strategy: :one_for_one, name: Odinsea.MapSupervisor},

      # Game world supervisor
      Odinsea.World.Supervisor,

      # Login server
      Odinsea.Login.Listener,

      # Channel servers (dynamic based on config)
      {Odinsea.Channel.Supervisor, game_config()[:channels]},

      # Cash shop server
      Odinsea.Shop.Listener
    ]

    opts = [strategy: :one_for_one, name: Odinsea.Supervisor]
    Supervisor.start_link(children, opts)
  end

  @impl true
  def prep_stop(state) do
    Logger.info("Odinsea server shutting down...")
    # Perform graceful shutdown tasks
    :ok
  end

  @doc """
  Returns the server version.
  """
  def version do
    "0.1.0-#{Odinsea.Constants.Server.server_revision()}"
  end

  @doc """
  Returns the current unix timestamp in milliseconds.
  """
  def current_time do
    System.system_time(:millisecond)
  end

  @doc """
  Returns uptime in milliseconds.
  """
  def uptime do
    current_time() - Application.get_env(:odinsea, :start_time, current_time())
  end

  defp log_configuration do
    server = server_config()
    rates = Application.get_env(:odinsea, :rates, [])

    Logger.info("""
    Server Configuration:
      Name: #{server[:name]}
      Host: #{server[:host]}
      Revision: #{server[:revision]}
      EXP Rate: #{rates[:exp]}x
      Meso Rate: #{rates[:meso]}x
    """)

    login = login_config()
    Logger.info("Login Server: port=#{login[:port]}, limit=#{login[:user_limit]}")

    game = game_config()
    Logger.info("Game Channels: count=#{game[:channels]}")

    shop = shop_config()
    Logger.info("Cash Shop: port=#{shop[:port]}")
  end

  defp server_config, do: Application.get_env(:odinsea, :server, [])
  defp login_config, do: Application.get_env(:odinsea, :login, [])
  defp game_config, do: Application.get_env(:odinsea, :game, [])
  defp shop_config, do: Application.get_env(:odinsea, :shop, [])
  defp redis_config, do: Application.get_env(:odinsea, :redis, [])
end