defmodule Odinsea.Channel.Handler.MonsterCarnival do
  @moduledoc """
  Handles Monster Carnival (CPQ - Carnival Party Quest) operations.

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

  CPQ is a PvP-style party quest where two parties compete:
  - Summon monsters to send to the opposing team
  - Use debuff skills on the opposing team
  - Deploy guardians for defense

  ## Tabs
  - 0: Summon monsters
  - 1: Use debuff skills
  - 2: Summon guardians

  ## Main Handlers
  - handle_monster_carnival/2 - All CPQ operations
  """

  require Logger

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

  # ============================================================================
  # CPQ Operations
  # ============================================================================

  @doc """
  Handles all Monster Carnival operations (CP_MONSTER_CARNIVAL / 0x125).

  Tabs:
  - 0: Summon monsters (mob list index)
  - 1: Use debuff skills (skill list index)
  - 2: Summon guardians (guardian index)

  Reference: MonsterCarnivalHandler.MonsterCarnival()
  """
  def handle_monster_carnival(packet, client_pid) do
    case Character.get_state_by_client(client_pid) do
      {:ok, character_id, char_state} ->
        # Check if in carnival party
        if char_state.carnival_party == nil do
          Logger.debug("Monster Carnival rejected: character #{character_id} not in carnival party")
          send(client_pid, {:send_packet, Packets.enable_actions()})
          :ok
        else
          tab = In.decode_byte(packet)
          num = In.decode_int(packet)
          
          handle_carnival_tab(tab, num, client_pid, character_id, char_state)
        end

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

  # ============================================================================
  # Tab Handlers
  # ============================================================================

  # Tab 0: Summon monsters
  defp handle_carnival_tab(0, num, client_pid, character_id, char_state) do
    map_id = char_state.map
    team = char_state.carnival_party.team
    available_cp = char_state.carnival_party.available_cp
    
    # TODO: Get mob list for map
    # mobs = Map.get_mobs_to_spawn(map_id)
    
    # TODO: Validate num is valid index
    # TODO: Check available CP >= mob_cost
    
    # If valid:
    # - Spawn monster for opposing team
    # - Deduct CP
    # - Update CP displays
    # - Broadcast summon message
    
    Logger.debug("CPQ summon mob: index #{num}, team #{team}, map #{map_id}, character #{character_id}")
    
    # Send enable actions (success or failure)
    send(client_pid, {:send_packet, Packets.enable_actions()})
    :ok
  end

  # Tab 1: Use debuff skills
  defp handle_carnival_tab(1, num, client_pid, character_id, char_state) do
    map_id = char_state.map
    team = char_state.carnival_party.team
    available_cp = char_state.carnival_party.available_cp
    
    # TODO: Get skill list for map
    # skills = Map.get_skill_ids(map_id)
    
    # TODO: Validate num is valid index
    # TODO: Get skill from MapleCarnivalFactory
    # TODO: Check available CP >= skill.cp_loss
    
    # If valid:
    # - Apply debuff to opposing team
    # - Deduct CP
    # - Update CP displays
    # - Broadcast skill usage
    
    Logger.debug("CPQ debuff: index #{num}, team #{team}, map #{map_id}, character #{character_id}")
    
    # Send enable actions (success or failure)
    send(client_pid, {:send_packet, Packets.enable_actions()})
    :ok
  end

  # Tab 2: Summon guardians
  defp handle_carnival_tab(2, num, client_pid, character_id, char_state) do
    map_id = char_state.map
    team = char_state.carnival_party.team
    available_cp = char_state.carnival_party.available_cp
    
    # TODO: Get guardian skill from MapleCarnivalFactory
    # skill = MapleCarnivalFactory.getGuardian(num)
    
    # TODO: Check available CP >= skill.cp_loss
    
    # If valid:
    # - Spawn carnival reactor (guardian)
    # - Deduct CP
    # - Update CP displays
    # - Broadcast summon message
    
    Logger.debug("CPQ guardian: index #{num}, team #{team}, map #{map_id}, character #{character_id}")
    
    # Send enable actions (success or failure)
    send(client_pid, {:send_packet, Packets.enable_actions()})
    :ok
  end

  # Unknown tab
  defp handle_carnival_tab(tab, num, client_pid, character_id, _char_state) do
    Logger.warning("Unknown CPQ tab #{tab} (num #{num}) from character #{character_id}")
    send(client_pid, {:send_packet, Packets.enable_actions()})
    :ok
  end

  # ============================================================================
  # CP Management
  # ============================================================================

  @doc """
  Updates CP display for a player.
  
  party_cp: true = show party CP, false = show personal CP
  """
  def update_cp(client_pid, available_cp, total_cp, team, party_cp \\ false) do
    # TODO: Build CP update packet
    # packet = Packets.cp_update(available_cp, total_cp, team, party_cp)
    # send(client_pid, {:send_packet, packet})
    :ok
  end

  @doc """
  Broadcasts player summoned message to map.
  """
  def broadcast_summon(map_id, player_name, tab, num) do
    # TODO: Build summon broadcast packet
    # packet = Packets.player_summoned(player_name, tab, num)
    # Map.broadcast_packet(map_id, packet, exclude: player_id)
    :ok
  end

  @doc """
  Distributes CP to carnival party members.
  """
  def distribute_cp(carnival_party, cp_amount) do
    # TODO: Add CP to party total
    # TODO: Update each member's display
    :ok
  end
end