defmodule Odinsea.Channel.Handler.BBS do
  @moduledoc """
  Handles Guild BBS (Bulletin Board System) operations.

  Ported from: src/handling/channel/handler/BBSHandler.java

  The Guild BBS allows guild members to:
  - Create and edit threads/posts
  - Reply to threads
  - Delete threads and replies (with permission checks)
  - List threads with pagination
  - View individual threads with replies

  ## Main Handlers
  - handle_bbs_operation/2 - All BBS operations (CRUD)
  """

  require Logger

  alias Odinsea.Net.Packet.In
  alias Odinsea.Game.Character
  alias Odinsea.World.Guild
  alias Odinsea.Channel.Packets

  # ============================================================================
  # BBS Operations
  # ============================================================================

  @doc """
  Handles all BBS operations (CP_BBS_OPERATION / 0xCD).

  Actions:
  - 0: Create new post / Edit existing post
  - 1: Delete a thread
  - 2: List threads (pagination)
  - 3: Display thread with replies
  - 4: Add reply to thread
  - 5: Delete reply from thread

  Reference: BBSHandler.BBSOperation()
  """
  def handle_bbs_operation(packet, client_pid) do
    case Character.get_state_by_client(client_pid) do
      {:ok, character_id, char_state} ->
        guild_id = char_state.guild_id
        
        if guild_id <= 0 do
          Logger.debug("BBS operation rejected: character #{character_id} not in guild")
          :ok
        else
          action = In.decode_byte(packet)
          handle_bbs_action(action, packet, client_pid, character_id, char_state, guild_id)
        end

      {:error, reason} ->
        Logger.warn("Failed to handle BBS operation: #{inspect(reason)}")
    end
  end

  # ============================================================================
  # Individual Actions
  # ============================================================================

  # Action 0: Create or edit post
  defp handle_bbs_action(0, packet, client_pid, character_id, char_state, guild_id) do
    is_edit = In.decode_byte(packet) > 0
    
    local_thread_id = if is_edit do
      In.decode_int(packet)
    else
      0
    end
    
    is_notice = In.decode_byte(packet) > 0
    title = In.decode_string(packet) |> correct_length(25)
    text = In.decode_string(packet) |> correct_length(600)
    icon = In.decode_int(packet)
    
    # Validate icon
    valid_icon = validate_icon(icon, character_id)
    
    if valid_icon do
      if is_edit do
        # Edit existing thread
        edit_thread(guild_id, local_thread_id, title, text, icon, character_id, char_state.guild_rank)
      else
        # Create new thread
        create_thread(guild_id, title, text, icon, is_notice, character_id)
      end
      
      # Send updated thread list
      list_threads(client_pid, guild_id, 0)
    end
    
    Logger.debug("BBS create/edit: guild #{guild_id}, edit=#{is_edit}, notice=#{is_notice}, icon=#{icon}, character #{character_id}")
    :ok
  end

  # Action 1: Delete thread
  defp handle_bbs_action(1, packet, client_pid, character_id, char_state, guild_id) do
    local_thread_id = In.decode_int(packet)
    
    delete_thread(guild_id, local_thread_id, character_id, char_state.guild_rank)
    
    Logger.debug("BBS delete thread: guild #{guild_id}, thread #{local_thread_id}, character #{character_id}")
    :ok
  end

  # Action 2: List threads (pagination)
  defp handle_bbs_action(2, packet, client_pid, character_id, _char_state, guild_id) do
    start = In.decode_int(packet)
    
    list_threads(client_pid, guild_id, start * 10)
    
    Logger.debug("BBS list threads: guild #{guild_id}, start #{start}, character #{character_id}")
    :ok
  end

  # Action 3: Display thread
  defp handle_bbs_action(3, packet, client_pid, character_id, _char_state, guild_id) do
    local_thread_id = In.decode_int(packet)
    
    display_thread(client_pid, guild_id, local_thread_id)
    
    Logger.debug("BBS display thread: guild #{guild_id}, thread #{local_thread_id}, character #{character_id}")
    :ok
  end

  # Action 4: Add reply
  defp handle_bbs_action(4, packet, client_pid, character_id, _char_state, guild_id) do
    # Check rate limit (60 seconds between replies)
    # TODO: Implement rate limiting via CheatTracker
    
    local_thread_id = In.decode_int(packet)
    text = In.decode_string(packet) |> correct_length(25)
    
    add_reply(guild_id, local_thread_id, text, character_id)
    
    # Refresh thread display
    display_thread(client_pid, guild_id, local_thread_id)
    
    Logger.debug("BBS add reply: guild #{guild_id}, thread #{local_thread_id}, character #{character_id}")
    :ok
  end

  # Action 5: Delete reply
  defp handle_bbs_action(5, packet, client_pid, character_id, char_state, guild_id) do
    local_thread_id = In.decode_int(packet)
    reply_id = In.decode_int(packet)
    
    delete_reply(guild_id, local_thread_id, reply_id, character_id, char_state.guild_rank)
    
    # Refresh thread display
    display_thread(client_pid, guild_id, local_thread_id)
    
    Logger.debug("BBS delete reply: guild #{guild_id}, thread #{local_thread_id}, reply #{reply_id}, character #{character_id}")
    :ok
  end

  # Unknown action
  defp handle_bbs_action(action, _packet, _client_pid, character_id, _char_state, guild_id) do
    Logger.warning("Unknown BBS action #{action} from character #{character_id}, guild #{guild_id}")
    :ok
  end

  # ============================================================================
  # BBS Backend Operations
  # ============================================================================

  defp create_thread(guild_id, title, text, icon, is_notice, character_id) do
    # TODO: Call World.Guild.addBBSThread
    # Returns: local_thread_id
    Logger.debug("Create BBS thread: guild #{guild_id}, title '#{title}', character #{character_id}")
    :ok
  end

  defp edit_thread(guild_id, local_thread_id, title, text, icon, character_id, guild_rank) do
    # TODO: Call World.Guild.editBBSThread
    # Permission: thread owner OR guild rank <= 2
    Logger.debug("Edit BBS thread: guild #{guild_id}, thread #{local_thread_id}, character #{character_id}")
    :ok
  end

  defp delete_thread(guild_id, local_thread_id, character_id, guild_rank) do
    # TODO: Call World.Guild.deleteBBSThread
    # Permission: thread owner OR guild rank <= 2 (masters/jr masters)
    Logger.debug("Delete BBS thread: guild #{guild_id}, thread #{local_thread_id}, character #{character_id}")
    :ok
  end

  defp list_threads(client_pid, guild_id, start) do
    # TODO: Get threads from World.Guild.getBBS
    # TODO: Build thread list packet
    # packet = Packets.bbs_thread_list(threads, start)
    # send(client_pid, {:send_packet, packet})
    :ok
  end

  defp display_thread(client_pid, guild_id, local_thread_id) do
    # TODO: Get thread from World.Guild.getBBS
    # TODO: Find thread by local_thread_id
    # TODO: Build show thread packet
    # packet = Packets.show_thread(thread)
    # send(client_pid, {:send_packet, packet})
    :ok
  end

  defp add_reply(guild_id, local_thread_id, text, character_id) do
    # TODO: Call World.Guild.addBBSReply
    Logger.debug("Add BBS reply: guild #{guild_id}, thread #{local_thread_id}, character #{character_id}")
    :ok
  end

  defp delete_reply(guild_id, local_thread_id, reply_id, character_id, guild_rank) do
    # TODO: Call World.Guild.deleteBBSReply
    # Permission: reply owner OR guild rank <= 2
    Logger.debug("Delete BBS reply: guild #{guild_id}, thread #{local_thread_id}, reply #{reply_id}, character #{character_id}")
    :ok
  end

  # ============================================================================
  # Helper Functions
  # ============================================================================

  # Truncates string to max length if needed
  defp correct_length(string, max_size) when is_binary(string) do
    if String.length(string) > max_size do
      String.slice(string, 0, max_size)
    else
      string
    end
  end

  # Validates icon selection
  # Icons 0x64-0x6A (100-106) require NX items (5290000-5290006)
  defp validate_icon(icon, character_id) do
    cond do
      # NX icons - require specific items
      icon >= 0x64 and icon <= 0x6A ->
        # TODO: Check if player has item 5290000 + (icon - 0x64)
        # For now, allow all
        true
        
      # Standard icons (0-2)
      icon >= 0 and icon <= 2 ->
        true
        
      # Invalid icon
      true ->
        Logger.warning("Invalid BBS icon #{icon} from character #{character_id}")
        false
    end
  end
end