defmodule Odinsea.Game.Events.OxQuizQuestions do
  @moduledoc """
  OX Quiz Question Database.
  Ported from Java `server.events.MapleOxQuizFactory`.

  Stores true/false questions loaded from database or fallback data.
  Questions are organized into sets and IDs for efficient lookup.

  ## Question Format
  - question: The question text
  - display: How to display the answer (O/X)
  - answer: :o for true, :x for false
  - question_set: Category/set number
  - question_id: ID within the set
  """

  require Logger

  # ============================================================================
  # Types
  # ============================================================================

  @typedoc "OX Quiz question struct"
  @type question :: %{
    question: String.t(),
    display: String.t(),
    answer: :o | :x,
    ids: {non_neg_integer(), non_neg_integer()}  # {question_set, question_id}
  }

  # ============================================================================
  # GenServer State
  # ============================================================================

  use GenServer

  defstruct [
    :questions,  # Map of {{set, id} => question}
    :ets_table
  ]

  # ============================================================================
  # Client API
  # ============================================================================

  @doc """
  Starts the OX Quiz question cache.
  """
  def start_link(_opts) do
    GenServer.start_link(__MODULE__, [], name: __MODULE__)
  end

  @doc """
  Gets a random question from the database.
  """
  def get_random_question do
    GenServer.call(__MODULE__, :get_random_question)
  end

  @doc """
  Gets a specific question by set and ID.
  """
  def get_question(question_set, question_id) do
    GenServer.call(__MODULE__, {:get_question, question_set, question_id})
  end

  @doc """
  Gets all questions.
  """
  def get_all_questions do
    GenServer.call(__MODULE__, :get_all_questions)
  end

  @doc """
  Gets the total number of questions.
  """
  def question_count do
    GenServer.call(__MODULE__, :question_count)
  end

  @doc """
  Reloads questions from database.
  """
  def reload do
    GenServer.cast(__MODULE__, :reload)
  end

  # ============================================================================
  # Server Callbacks
  # ============================================================================

  @impl true
  def init(_) do
    # Create ETS table for fast lookups
    ets = :ets.new(:ox_quiz_questions, [:set, :protected, :named_table])

    # Load initial questions
    questions = load_questions()

    # Store in ETS
    Enum.each(questions, fn {key, q} ->
      :ets.insert(ets, {key, q})
    end)

    Logger.info("OX Quiz Questions loaded: #{map_size(questions)} questions")

    {:ok, %__MODULE__{questions: questions, ets_table: ets}}
  end

  @impl true
  def handle_call(:get_random_question, _from, state) do
    question = get_random_question_impl(state)
    {:reply, question, state}
  end

  @impl true
  def handle_call({:get_question, set, id}, _from, state) do
    question = Map.get(state.questions, {set, id})
    {:reply, question, state}
  end

  @impl true
  def handle_call(:get_all_questions, _from, state) do
    {:reply, Map.values(state.questions), state}
  end

  @impl true
  def handle_call(:question_count, _from, state) do
    {:reply, map_size(state.questions), state}
  end

  @impl true
  def handle_cast(:reload, state) do
    # Clear ETS
    :ets.delete_all_objects(state.ets_table)

    # Reload questions
    questions = load_questions()

    # Store in ETS
    Enum.each(questions, fn {key, q} ->
      :ets.insert(state.ets_table, {key, q})
    end)

    Logger.info("OX Quiz Questions reloaded: #{map_size(questions)} questions")

    {:noreply, %{state | questions: questions}}
  end

  # ============================================================================
  # Private Functions
  # ============================================================================

  defp get_random_question_impl(state) do
    questions = Map.values(state.questions)

    if length(questions) > 0 do
      Enum.random(questions)
    else
      # Return fallback question if none loaded
      fallback_question()
    end
  end

  defp load_questions do
    # Try to load from database
    # In real implementation:
    # - Query wz_oxdata table
    # - Parse each row into question struct

    # For now, use fallback questions
    fallback_questions()
    |> Enum.map(fn q -> {{elem(q.ids, 0), elem(q.ids, 1)}, q} end)
    |> Map.new()
  end

  defp parse_answer("o"), do: :o
  defp parse_answer("O"), do: :o
  defp parse_answer("x"), do: :x
  defp parse_answer("X"), do: :x
  defp parse_answer(_), do: :o  # Default to true

  # ============================================================================
  # Fallback Questions
  # ============================================================================

  defp fallback_question do
    %{
      question: "MapleStory was first released in 2003?",
      display: "O",
      answer: :o,
      ids: {0, 0}
    }
  end

  defp fallback_questions do
    [
      # Set 1: General MapleStory Knowledge
      %{question: "MapleStory was first released in 2003?", display: "O", answer: :o, ids: {1, 1}},
      %{question: "The maximum level in MapleStory is 200?", display: "O", answer: :o, ids: {1, 2}},
      %{question: "Henesys is the starting town for all beginners?", display: "X", answer: :x, ids: {1, 3}},
      %{question: "The Pink Bean is a boss monster?", display: "O", answer: :o, ids: {1, 4}},
      %{question: "Magicians use swords as their primary weapon?", display: "X", answer: :x, ids: {1, 5}},
      %{question: "The EXP curve gets steeper at higher levels?", display: "O", answer: :o, ids: {1, 6}},
      %{question: "Gachapon gives random items for NX?", display: "O", answer: :o, ids: {1, 7}},
      %{question: "Warriors have the highest INT growth?", display: "X", answer: :x, ids: {1, 8}},
      %{question: "The Cash Shop sells permanent pets?", display: "O", answer: :o, ids: {1, 9}},
      %{question: "All monsters in Maple Island are passive?", display: "O", answer: :o, ids: {1, 10}},

      # Set 2: Classes and Jobs
      %{question: "Beginners can use the Three Snails skill?", display: "O", answer: :o, ids: {2, 1}},
      %{question: "Magicians require the most DEX to advance?", display: "X", answer: :x, ids: {2, 2}},
      %{question: "Thieves can use claws and daggers?", display: "O", answer: :o, ids: {2, 3}},
      %{question: "Pirates are the only class that can use guns?", display: "O", answer: :o, ids: {2, 4}},
      %{question: "Archers specialize in close-range combat?", display: "X", answer: :x, ids: {2, 5}},
      %{question: "First job advancement happens at level 10?", display: "O", answer: :o, ids: {2, 6}},
      %{question: "All classes can use magic attacks?", display: "X", answer: :x, ids: {2, 7}},
      %{question: "Bowmen require arrows to attack?", display: "O", answer: :o, ids: {2, 8}},
      %{question: "Warriors have the highest HP pool?", display: "O", answer: :o, ids: {2, 9}},
      %{question: "Cygnus Knights are available at level 1?", display: "X", answer: :x, ids: {2, 10}},

      # Set 3: Monsters and Maps
      %{question: "Blue Snails are found on Maple Island?", display: "O", answer: :o, ids: {3, 1}},
      %{question: "Zakum is located in the Dead Mine?", display: "O", answer: :o, ids: {3, 2}},
      %{question: "Pigs drop pork items?", display: "O", answer: :o, ids: {3, 3}},
      %{question: "The highest level map is Victoria Island?", display: "X", answer: :x, ids: {3, 4}},
      %{question: "Balrog is a level 100 boss?", display: "O", answer: :o, ids: {3, 5}},
      %{question: "Mushmom is a giant mushroom monster?", display: "O", answer: :o, ids: {3, 6}},
      %{question: "All monsters respawn immediately after death?", display: "X", answer: :x, ids: {3, 7}},
      %{question: "Jr. Balrog spawns in Sleepywood Dungeon?", display: "O", answer: :o, ids: {3, 8}},
      %{question: "Orbis Tower connects Orbis to El Nath?", display: "O", answer: :o, ids: {3, 9}},
      %{question: "Ludibrium is a town made of toys?", display: "O", answer: :o, ids: {3, 10}},

      # Set 4: Items and Equipment
      %{question: "Equipment can have potential stats?", display: "O", answer: :o, ids: {4, 1}},
      %{question: "Mesos are the currency of MapleStory?", display: "O", answer: :o, ids: {4, 2}},
      %{question: "Scrolls always succeed?", display: "X", answer: :x, ids: {4, 3}},
      %{question: "Potions restore HP and MP?", display: "O", answer: :o, ids: {4, 4}},
      %{question: " NX Cash is required to buy Cash Shop items?", display: "O", answer: :o, ids: {4, 5}},
      %{question: "All equipment can be traded?", display: "X", answer: :x, ids: {4, 6}},
      %{question: "Stars are thrown by Night Lords?", display: "O", answer: :o, ids: {4, 7}},
      %{question: "Beginners can equip level 100 items?", display: "X", answer: :x, ids: {4, 8}},
      %{question: "Clean Slate Scrolls remove failed slots?", display: "O", answer: :o, ids: {4, 9}},
      %{question: "Chaos Scrolls randomize item stats?", display: "O", answer: :o, ids: {4, 10}},

      # Set 5: Quests and NPCs
      %{question: "Mai is the first quest NPC beginners meet?", display: "O", answer: :o, ids: {5, 1}},
      %{question: "All quests can be repeated?", display: "X", answer: :x, ids: {5, 2}},
      %{question: "NPCs with \"!\" above them give quests?", display: "O", answer: :o, ids: {5, 3}},
      %{question: "Party quests require exactly 6 players?", display: "X", answer: :x, ids: {5, 4}},
      %{question: "Roger sells potions in Henesys?", display: "X", answer: :x, ids: {5, 5}},
      %{question: "The Lost City is another name for Kerning City?", display: "X", answer: :x, ids: {5, 6}},
      %{question: "Guilds can have up to 200 members?", display: "O", answer: :o, ids: {5, 7}},
      %{question: "All NPCs can be attacked?", display: "X", answer: :x, ids: {5, 8}},
      %{question: "Big Headward sells hairstyles?", display: "O", answer: :o, ids: {5, 9}},
      %{question: "The Storage Keeper stores items for free?", display: "X", answer: :x, ids: {5, 10}},

      # Set 6: Game Mechanics
      %{question: "Fame can be given or taken once per day?", display: "O", answer: :o, ids: {6, 1}},
      %{question: "Party play gives bonus EXP?", display: "O", answer: :o, ids: {6, 2}},
      %{question: "Dying causes EXP loss?", display: "O", answer: :o, ids: {6, 3}},
      %{question: "All skills have no cooldown?", display: "X", answer: :x, ids: {6, 4}},
      %{question: "Trade window allows up to 9 items?", display: "O", answer: :o, ids: {6, 5}},
      %{question: "Mounting a pet requires level 70?", display: "X", answer: :x, ids: {6, 6}},
      %{question: "Monster Book tracks monster information?", display: "O", answer: :o, ids: {6, 7}},
      %{question: "Bosses have purple health bars?", display: "O", answer: :o, ids: {6, 8}},
      %{question: "Channel changing is instant?", display: "X", answer: :x, ids: {6, 9}},
      %{question: "Expedition mode is for large boss fights?", display: "O", answer: :o, ids: {6, 10}},

      # Set 7: Trivia
      %{question: "MapleStory is developed by Nexon?", display: "O", answer: :o, ids: {7, 1}},
      %{question: "The Black Mage is the main antagonist?", display: "O", answer: :o, ids: {7, 2}},
      %{question: "Elvis is a monster in MapleStory?", display: "X", answer: :x, ids: {7, 3}},
      %{question: "Golems are made of rock?", display: "O", answer: :o, ids: {7, 4}},
      %{question: "Maple Island is shaped like a maple leaf?", display: "O", answer: :o, ids: {7, 5}},
      %{question: "All classes can fly?", display: "X", answer: :x, ids: {7, 6}},
      %{question: "The Moon Bunny is a boss?", display: "X", answer: :x, ids: {7, 7}},
      %{question: "Scissors of Karma make items tradable?", display: "O", answer: :o, ids: {7, 8}},
      %{question: "Monster Life is a farming minigame?", display: "O", answer: :o, ids: {7, 9}},
      %{question: "FM stands for Free Market?", display: "O", answer: :o, ids: {7, 10}}
    ]
  end
end