defmodule Odinsea.Game.QuestAction do
  @moduledoc """
  Quest Action module - defines rewards and effects for quest completion.

  Actions are executed when:
  - Starting a quest (start_actions)
  - Completing a quest (complete_actions)

  ## Action Types

  - `:exp` - Experience points reward
  - `:money` - Meso reward
  - `:item` - Item rewards (can be job/gender restricted)
  - `:pop` - Fame reward
  - `:sp` - Skill points reward
  - `:skill` - Learn specific skills
  - `:nextQuest` - Start another quest automatically
  - `:buffItemID` - Apply buff from item effect
  - `:infoNumber` - Info quest update
  - `:quest` - Update other quest states

  ## Trait EXP Types

  - `:charmEXP` - Charm trait experience
  - `:charismaEXP` - Charisma trait experience
  - `:craftEXP` - Craft (smithing) trait experience
  - `:insightEXP` - Insight trait experience
  - `:senseEXP` - Sense trait experience
  - `:willEXP` - Will trait experience

  ## Job Restrictions

  Items and skills can be restricted by job using job encoding:
  - Bit flags for job categories (Warrior, Magician, Bowman, Thief, Pirate, etc.)
  - Supports both 5-byte and simple encodings

  ## Gender Restrictions

  Items can be restricted by gender:
  - `0` - Male only
  - `1` - Female only
  - `2` - Both (no restriction)
  """

  alias Odinsea.Game.Quest

  @type t :: %__MODULE__{
          type: atom(),
          value: any(),
          applicable_jobs: [integer()],
          int_store: integer()
        }

  defstruct [:type, :value, :applicable_jobs, :int_store]

  defmodule QuestItem do
    @moduledoc "Quest item reward structure"

    @type t :: %__MODULE__{
            item_id: integer(),
            count: integer(),
            period: integer(),
            gender: integer(),
            job: integer(),
            job_ex: integer(),
            prop: integer()
          }

    defstruct [
      :item_id,
      :count,
      period: 0,
      gender: 2,
      job: -1,
      job_ex: -1,
      prop: -2
    ]
  end

  ## Public API

  @doc "Creates a new quest action"
  @spec new(atom(), any(), keyword()) :: t()
  def new(type, value, opts \\ []) do
    %__MODULE__{
      type: type,
      value: value,
      applicable_jobs: Keyword.get(opts, :applicable_jobs, []),
      int_store: Keyword.get(opts, :int_store, 0)
    }
  end

  @doc "Builds an action from a map (JSON deserialization)"
  @spec from_map(map()) :: t()
  def from_map(map) do
    type = parse_type(Map.get(map, :type, Map.get(map, "type", "undefined")))

    {value, applicable_jobs, int_store} = parse_action_data(type, map)

    %__MODULE__{
      type: type,
      value: value,
      applicable_jobs: applicable_jobs,
      int_store: int_store
    }
  end

  @doc "Parses a WZ action name into an atom"
  @spec parse_type(String.t() | atom()) :: atom()
  def parse_type(type) when is_atom(type), do: type

  def parse_type(type_str) when is_binary(type_str) do
    case String.downcase(type_str) do
      "exp" -> :exp
      "item" -> :item
      "nextquest" -> :nextQuest
      "money" -> :money
      "quest" -> :quest
      "skill" -> :skill
      "pop" -> :pop
      "buffitemid" -> :buffItemID
      "infonumber" -> :infoNumber
      "sp" -> :sp
      "charismaexp" -> :charismaEXP
      "charmexp" -> :charmEXP
      "willexp" -> :willEXP
      "insightexp" -> :insightEXP
      "senseexp" -> :senseEXP
      "craftexp" -> :craftEXP
      "job" -> :job
      _ -> :undefined
    end
  end

  @doc "Runs start actions for a quest"
  @spec run_start(t(), Odinsea.Game.Character.t()) :: Odinsea.Game.Character.t()
  def run_start(%__MODULE__{} = action, character) do
    do_run_start(action.type, action, character)
  end

  @doc "Runs end/complete actions for a quest"
  @spec run_end(t(), Odinsea.Game.Character.t()) :: Odinsea.Game.Character.t()
  def run_end(%__MODULE__{} = action, character) do
    do_run_end(action.type, action, character)
  end

  @doc "Checks if character can receive this action's rewards (inventory space, etc.)"
  @spec check_end(t(), Odinsea.Game.Character.t()) :: boolean()
  def check_end(%__MODULE__{} = action, character) do
    do_check_end(action.type, action, character)
  end

  @doc "Checks if an item reward can be given to this character"
  @spec can_get_item?(QuestItem.t(), Odinsea.Game.Character.t()) :: boolean()
  def can_get_item?(%QuestItem{} = item, character) do
    # Check gender restriction
    gender_ok = 
      if item.gender != 2 && item.gender >= 0 do
        character_gender = Map.get(character, :gender, 0)
        item.gender == character_gender
      else
        true
      end

    if not gender_ok do
      false
    else
      # Check job restriction
      if item.job > 0 do
        character_job = Map.get(character, :job, 0)
        job_codes = get_job_by_5byte_encoding(item.job)

        job_found =
          Enum.any?(job_codes, fn code ->
            div(code, 100) == div(character_job, 100)
          end)

        if not job_found and item.job_ex > 0 do
          job_codes_ex = get_job_by_simple_encoding(item.job_ex)

          job_found =
            Enum.any?(job_codes_ex, fn code ->
              rem(div(code, 100), 10) == rem(div(character_job, 100), 10)
            end)
        end

        job_found
      else
        true
      end
    end
  end

  @doc "Gets job list from 5-byte encoding"
  @spec get_job_by_5byte_encoding(integer()) :: [integer()]
  def get_job_by_5byte_encoding(encoded) do
    []
    |> add_job_if(encoded, 0x1, 0)
    |> add_job_if(encoded, 0x2, 100)
    |> add_job_if(encoded, 0x4, 200)
    |> add_job_if(encoded, 0x8, 300)
    |> add_job_if(encoded, 0x10, 400)
    |> add_job_if(encoded, 0x20, 500)
    |> add_job_if(encoded, 0x400, 1000)
    |> add_job_if(encoded, 0x800, 1100)
    |> add_job_if(encoded, 0x1000, 1200)
    |> add_job_if(encoded, 0x2000, 1300)
    |> add_job_if(encoded, 0x4000, 1400)
    |> add_job_if(encoded, 0x8000, 1500)
    |> add_job_if(encoded, 0x20000, 2001)
    |> add_job_if(encoded, 0x20000, 2200)
    |> add_job_if(encoded, 0x100000, 2000)
    |> add_job_if(encoded, 0x100000, 2001)
    |> add_job_if(encoded, 0x200000, 2100)
    |> add_job_if(encoded, 0x400000, 2200)
    |> add_job_if(encoded, 0x40000000, 3000)
    |> add_job_if(encoded, 0x40000000, 3200)
    |> add_job_if(encoded, 0x40000000, 3300)
    |> add_job_if(encoded, 0x40000000, 3500)
    |> Enum.uniq()
  end

  @doc "Gets job list from simple encoding"
  @spec get_job_by_simple_encoding(integer()) :: [integer()]
  def get_job_by_simple_encoding(encoded) do
    []
    |> add_job_if(encoded, 0x1, 200)
    |> add_job_if(encoded, 0x2, 300)
    |> add_job_if(encoded, 0x4, 400)
    |> add_job_if(encoded, 0x8, 500)
  end

  ## Private Functions

  defp add_job_if(list, encoded, flag, job) do
    if Bitwise.band(encoded, flag) != 0 do
      [job | list]
    else
      list
    end
  end

  defp parse_action_data(:exp, map) do
    int_store = Map.get(map, :value, Map.get(map, "value", Map.get(map, :int_store, 0)))
    {int_store, [], int_store}
  end

  defp parse_action_data(:money, map) do
    int_store = Map.get(map, :value, Map.get(map, "value", Map.get(map, :int_store, 0)))
    {int_store, [], int_store}
  end

  defp parse_action_data(:pop, map) do
    int_store = Map.get(map, :value, Map.get(map, "value", Map.get(map, :int_store, 0)))
    {int_store, [], int_store}
  end

  defp parse_action_data(:sp, map) do
    int_store = Map.get(map, :value, Map.get(map, "value", Map.get(map, :int_store, 0)))

    applicable_jobs =
      map
      |> Map.get(:applicable_jobs, Map.get(map, "applicable_jobs", []))
      |> parse_job_list()

    {int_store, applicable_jobs, int_store}
  end

  defp parse_action_data(:item, map) do
    items =
      map
      |> Map.get(:value, Map.get(map, "value", []))
      |> parse_item_list()

    {items, [], 0}
  end

  defp parse_action_data(:skill, map) do
    skills =
      map
      |> Map.get(:value, Map.get(map, "value", []))
      |> parse_skill_list()

    applicable_jobs =
      map
      |> Map.get(:applicable_jobs, Map.get(map, "applicable_jobs", []))
      |> parse_job_list()

    {skills, applicable_jobs, 0}
  end

  defp parse_action_data(:quest, map) do
    quests =
      map
      |> Map.get(:value, Map.get(map, "value", []))
      |> parse_quest_state_list()

    {quests, [], 0}
  end

  defp parse_action_data(:nextQuest, map) do
    int_store = Map.get(map, :value, Map.get(map, "value", Map.get(map, :int_store, 0)))
    {int_store, [], int_store}
  end

  defp parse_action_data(:buffItemID, map) do
    int_store = Map.get(map, :value, Map.get(map, "value", Map.get(map, :int_store, 0)))
    {int_store, [], int_store}
  end

  defp parse_action_data(:infoNumber, map) do
    int_store = Map.get(map, :value, Map.get(map, "value", Map.get(map, :int_store, 0)))
    {int_store, [], int_store}
  end

  # Trait EXP actions
  defp parse_action_data(type, map)
       when type in [:charmEXP, :charismaEXP, :craftEXP, :insightEXP, :senseEXP, :willEXP] do
    int_store = Map.get(map, :value, Map.get(map, "value", Map.get(map, :int_store, 0)))
    {int_store, [], int_store}
  end

  defp parse_action_data(_type, map) do
    {Map.get(map, :value, nil), [], 0}
  end

  defp parse_job_list(nil), do: []
  defp parse_job_list(list) when is_list(list), do: list
  defp parse_job_list(map) when is_map(map), do: Map.values(map)

  defp parse_item_list(items) when is_list(items) do
    Enum.map(items, fn item_data ->
      %QuestItem{
        item_id: Map.get(item_data, :id, Map.get(item_data, "id", Map.get(item_data, :item_id, 0))),
        count: Map.get(item_data, :count, Map.get(item_data, "count", 1)),
        period: Map.get(item_data, :period, Map.get(item_data, "period", 0)),
        gender: Map.get(item_data, :gender, Map.get(item_data, "gender", 2)),
        job: Map.get(item_data, :job, Map.get(item_data, "job", -1)),
        job_ex: Map.get(item_data, :jobEx, Map.get(item_data, :job_ex, Map.get(item_data, "jobEx", -1))),
        prop: Map.get(item_data, :prop, Map.get(item_data, "prop", -2))
      }
    end)
  end

  defp parse_item_list(_), do: []

  defp parse_skill_list(skills) when is_list(skills) do
    Enum.map(skills, fn skill_data ->
      %{
        skill_id: Map.get(skill_data, :id, Map.get(skill_data, "id", 0)),
        skill_level: Map.get(skill_data, :skill_level, Map.get(skill_data, "skillLevel", 0)),
        master_level: Map.get(skill_data, :master_level, Map.get(skill_data, "masterLevel", 0))
      }
    end)
  end

  defp parse_skill_list(_), do: []

  defp parse_quest_state_list(quests) when is_list(quests) do
    Enum.map(quests, fn quest_data ->
      {
        Map.get(quest_data, :id, Map.get(quest_data, "id", 0)),
        Map.get(quest_data, :state, Map.get(quest_data, "state", 0))
      }
    end)
  end

  defp parse_quest_state_list(quests) when is_map(quests) do
    Enum.map(quests, fn {id, state} ->
      {String.to_integer(id), state}
    end)
  end

  defp parse_quest_state_list(_), do: []

  # Start action implementations

  defp do_run_start(:exp, %{int_store: exp} = _action, character) do
    # Apply EXP with quest rate multiplier
    # Full implementation would check GameConstants.getExpRate_Quest and trait bonuses
    apply_exp(character, exp)
  end

  defp do_run_start(:money, %{int_store: meso} = _action, character) do
    current_meso = Map.get(character, :meso, 0)
    Map.put(character, :meso, current_meso + meso)
  end

  defp do_run_start(:pop, %{int_store: fame} = _action, character) do
    current_fame = Map.get(character, :fame, 0)
    Map.put(character, :fame, current_fame + fame)
  end

  defp do_run_start(:item, %{value: items} = action, character) do
    # Filter items by job/gender restrictions
    applicable_items =
      items
      |> Enum.filter(fn item -> can_get_item?(item, character) end)
      |> select_items_by_prop()

    # Add items to inventory (simplified - full implementation needs inventory manipulation)
    Enum.reduce(applicable_items, character, fn item, char ->
      add_item_to_character(char, item)
    end)
  end

  defp do_run_start(:sp, %{int_store: sp, applicable_jobs: jobs} = _action, character) do
    apply_skill_points(character, sp, jobs)
  end

  defp do_run_start(:skill, %{value: skills, applicable_jobs: jobs} = _action, character) do
    apply_skills(character, skills, jobs)
  end

  defp do_run_start(:quest, %{value: quest_states} = _action, character) do
    Enum.reduce(quest_states, character, fn {quest_id, state}, char ->
      update_quest_state(char, quest_id, state)
    end)
  end

  defp do_run_start(:nextQuest, %{int_store: next_quest_id} = _action, character) do
    # Queue next quest
    current_next = Map.get(character, :next_quest, nil)

    if current_next == nil do
      Map.put(character, :next_quest, next_quest_id)
    else
      character
    end
  end

  # Trait EXP start actions
  defp do_run_start(type, %{int_store: exp} = _action, character)
       when type in [:charmEXP, :charismaEXP, :craftEXP, :insightEXP, :senseEXP, :willEXP] do
    trait_name =
      case type do
        :charmEXP -> :charm
        :charismaEXP -> :charisma
        :craftEXP -> :craft
        :insightEXP -> :insight
        :senseEXP -> :sense
        :willEXP -> :will
      end

    apply_trait_exp(character, trait_name, exp)
  end

  defp do_run_start(_type, _action, character), do: character

  # End action implementations (mostly same as start but without forfeiture check)

  defp do_run_end(:exp, %{int_store: exp} = _action, character) do
    apply_exp(character, exp)
  end

  defp do_run_end(:money, %{int_store: meso} = _action, character) do
    current_meso = Map.get(character, :meso, 0)
    Map.put(character, :meso, current_meso + meso)
  end

  defp do_run_end(:pop, %{int_store: fame} = _action, character) do
    current_fame = Map.get(character, :fame, 0)
    Map.put(character, :fame, current_fame + fame)
  end

  defp do_run_end(:item, %{value: items} = action, character) do
    applicable_items =
      items
      |> Enum.filter(fn item -> can_get_item?(item, character) end)
      |> select_items_by_prop()

    Enum.reduce(applicable_items, character, fn item, char ->
      add_item_to_character(char, item)
    end)
  end

  defp do_run_end(:sp, %{int_store: sp, applicable_jobs: jobs} = _action, character) do
    apply_skill_points(character, sp, jobs)
  end

  defp do_run_end(:skill, %{value: skills, applicable_jobs: jobs} = _action, character) do
    apply_skills(character, skills, jobs)
  end

  defp do_run_end(:quest, %{value: quest_states} = _action, character) do
    Enum.reduce(quest_states, character, fn {quest_id, state}, char ->
      update_quest_state(char, quest_id, state)
    end)
  end

  defp do_run_end(:nextQuest, %{int_store: next_quest_id} = _action, character) do
    current_next = Map.get(character, :next_quest, nil)

    if current_next == nil do
      Map.put(character, :next_quest, next_quest_id)
    else
      character
    end
  end

  defp do_run_end(:buffItemID, %{int_store: item_id} = _action, character) when item_id > 0 do
    # Apply item buff effect
    # Full implementation would get item effect from ItemInformationProvider
    character
  end

  # Trait EXP end actions
  defp do_run_end(type, %{int_store: exp} = _action, character)
       when type in [:charmEXP, :charismaEXP, :craftEXP, :insightEXP, :senseEXP, :willEXP] do
    trait_name =
      case type do
        :charmEXP -> :charm
        :charismaEXP -> :charisma
        :craftEXP -> :craft
        :insightEXP -> :insight
        :senseEXP -> :sense
        :willEXP -> :will
      end

    apply_trait_exp(character, trait_name, exp)
  end

  defp do_run_end(_type, _action, character), do: character

  # Check end implementations

  defp do_check_end(:item, %{value: items} = action, character) do
    # Check if character has inventory space for items
    applicable_items =
      items
      |> Enum.filter(fn item -> can_get_item?(item, character) end)
      |> select_items_by_prop()

    # Count items by inventory type
    needed_slots =
      Enum.reduce(applicable_items, %{equip: 0, use: 0, setup: 0, etc: 0, cash: 0}, fn item, acc ->
        inv_type = get_inventory_type(item.item_id)
        Map.update(acc, inv_type, 1, &(&1 + 1))
      end)

    # Check available space (simplified)
    inventory = Map.get(character, :inventory, %{})

    Enum.all?(needed_slots, fn {type, count} ->
      current_items = Map.get(inventory, type, [])
      max_slots = get_max_slots(type)
      length(current_items) + count <= max_slots
    end)
  end

  defp do_check_end(:money, %{int_store: meso} = _action, character) do
    current_meso = Map.get(character, :meso, 0)

    cond do
      meso > 0 and current_meso + meso > 2_147_483_647 ->
        # Would overflow
        false

      meso < 0 and current_meso < abs(meso) ->
        # Not enough meso
        false

      true ->
        true
    end
  end

  defp do_check_end(_type, _action, _character), do: true

  # Helper functions

  defp select_items_by_prop(items) do
    # Handle probability-based item selection
    # Items with prop > 0 are selected randomly
    # Items with prop == -1 are selection-based (user chooses)
    # Items with prop == -2 are always given

    {random_items, other_items} =
      Enum.split_with(items, fn item -> item.prop > 0 end)

    if length(random_items) > 0 do
      # Create weighted pool
      pool =
        Enum.flat_map(random_items, fn item ->
          List.duplicate(item, item.prop)
        end)

      selected = Enum.random(pool)
      [selected | other_items]
    else
      other_items
    end
  end

  defp add_item_to_character(character, %QuestItem{} = item) do
    inventory = Map.get(character, :inventory, %{})
    inv_type = get_inventory_type(item.item_id)

    new_item = %{
      item_id: item.item_id,
      quantity: item.count,
      position: find_next_slot(inventory, inv_type),
      expiration: if(item.period > 0, do: System.system_time(:second) + item.period * 60, else: -1)
    }

    updated_inventory =
      Map.update(inventory, inv_type, [new_item], fn items ->
        [new_item | items]
      end)

    Map.put(character, :inventory, updated_inventory)
  end

  defp get_inventory_type(item_id) do
    prefix = div(item_id, 1_000_000)

    case prefix do
      1 -> :equip
      2 -> :use
      3 -> :setup
      4 -> :etc
      5 -> :cash
      _ -> :etc
    end
  end

  defp get_max_slots(type) do
    case type do
      :equip -> 24
      :use -> 80
      :setup -> 80
      :etc -> 80
      :cash -> 40
      _ -> 80
    end
  end

  defp find_next_slot(inventory, type) do
    items = Map.get(inventory, type, [])
    positions = Enum.map(items, & &1.position)

    Enum.find(1..100, fn slot ->
      slot not in positions
    end) || 0
  end

  defp apply_exp(character, base_exp) do
    level = Map.get(character, :level, 1)

    # Apply quest EXP rate
    exp_rate = 1.0  # Would get from GameConstants

    # Apply trait bonus (Sense trait gives quest EXP bonus)
    traits = Map.get(character, :traits, %{})
    sense_level = Map.get(traits, :sense, 0)
    trait_bonus = 1.0 + (sense_level * 3 / 1000)

    final_exp = trunc(base_exp * exp_rate * trait_bonus)

    # Add EXP to character
    current_exp = Map.get(character, :exp, 0)
    Map.put(character, :exp, current_exp + final_exp)
  end

  defp apply_skill_points(character, sp, jobs) do
    character_job = Map.get(character, :job, 0)

    # Find most applicable job
    applicable_job =
      jobs
      |> Enum.filter(fn job -> character_job >= job end)
      |> Enum.max(fn -> 0 end)

    sp_type =
      if applicable_job == 0 do
        # Beginner SP
        0
      else
        # Get skill book based on job
        get_skill_book(applicable_job)
      end

    current_sp = Map.get(character, :sp, [])
    updated_sp = List.replace_at(current_sp, sp_type, (Enum.at(current_sp, sp_type, 0) || 0) + sp)

    Map.put(character, :sp, updated_sp)
  end

  defp get_skill_book(job) do
    # Get skill book index for job
    cond do
      job >= 1000 and job < 2000 -> 1
      job >= 2000 and job < 3000 -> 2
      job >= 3000 and job < 4000 -> 3
      job >= 4000 and job < 5000 -> 4
      true -> 0
    end
  end

  defp apply_skills(character, skills, applicable_jobs) do
    character_job = Map.get(character, :job, 0)

    # Check if any job matches
    job_matches = Enum.any?(applicable_jobs, fn job -> character_job == job end)

    if job_matches or applicable_jobs == [] do
      current_skills = Map.get(character, :skills, %{})
      current_master_levels = Map.get(character, :skill_master_levels, %{})

      Enum.reduce(skills, character, fn skill, char ->
        skill_id = skill.skill_id
        skill_level = skill.skill_level
        master_level = skill.master_level

        # Get current levels
        current_level = Map.get(current_skills, skill_id, 0)
        current_master = Map.get(current_master_levels, skill_id, 0)

        # Update with max of current/new
        new_skills = Map.put(current_skills, skill_id, max(skill_level, current_level))
        new_masters = Map.put(current_master_levels, skill_id, max(master_level, current_master))

        char
        |> Map.put(:skills, new_skills)
        |> Map.put(:skill_master_levels, new_masters)
      end)
    else
      character
    end
  end

  defp update_quest_state(character, quest_id, state) do
    quest_progress = Map.get(character, :quest_progress, %{})
    updated_progress = Map.put(quest_progress, quest_id, state)
    Map.put(character, :quest_progress, updated_progress)
  end

  defp apply_trait_exp(character, trait_name, exp) do
    traits = Map.get(character, :traits, %{})
    current_exp = Map.get(traits, trait_name, 0)
    updated_traits = Map.put(traits, trait_name, current_exp + exp)
    Map.put(character, :traits, updated_traits)
  end
end