using Chickensoft.AutoInject;
using Chickensoft.GodotNodeInterfaces;
using Chickensoft.Introspection;
using GameJamDungeon;
using Godot;
using System.Linq;
using System.Threading.Tasks;

public interface IInventoryMenu : IControl
{
  public void PopulateItems();

  public void ClearItems();
}

[Meta(typeof(IAutoNode))]
public partial class InventoryMenu : Control, IInventoryMenu
{
  public override void _Notification(int what) => this.Notify(what);

  [Dependency]
  public IGameRepo GameRepo => this.DependOn<IGameRepo>();

  [Dependency]
  public IGame Game => this.DependOn<IGame>();

  // Player Info
  [Node] public Label FloorLabel { get; set; } = default!;
  [Node] public Label CurrentLevelLabel { get; set; } = default!;
  [Node] public Label EXPValue { get; set; } = default!;
  [Node] public Label HPValue { get; set; } = default!;
  [Node] public Label HPBonusLabel { get; set; } = default!;
  [Node] public Label VTValue { get; set; } = default!;
  [Node] public Label VTBonusLabel { get; set; } = default!;
  [Node] public Label ATKValue { get; set; } = default!;
  [Node] public Label ATKBonusLabel { get; set; } = default!;
  [Node] public Label DEFValue { get; set; } = default!;
  [Node] public Label DEFBonusLabel { get; set; } = default!;
  [Node] public Label ItemDescriptionTitle { get; set; } = default!;
  [Node] public Label ItemEffectLabel { get; set; } = default!;

  // Item Menu
  [Node] public Label BackArrow { get; set; } = default!;
  [Node] public Label ForwardArrow { get; set; } = default!;
  [Node] public Control ItemsPage { get; set; } = default!;

  // User Prompt Menu
  [Node] public Label UseItemPrompt { get; set; } = default!;
  [Node] public Button UseButton { get; set; } = default!;
  [Node] public Button ThrowButton { get; set; } = default!;
  [Node] public Button DropButton { get; set; } = default!;

  public void OnReady()
  {
    UseButton.Pressed += UseButtonPressed;
    ThrowButton.Pressed += ThrowButtonPressed;
    DropButton.Pressed += DropButtonPressed;
  }

  private InventoryPageNumber _currentPageNumber = InventoryPageNumber.FirstPage;

  private string ITEM_SLOT_SCENE = "res://src/inventory_menu/ItemSlot.tscn";

  private const int _itemsPerPage = 10;

  private int _currentIndex = 0;

  private IItemSlot[] ItemSlots => ItemsPage.GetChildren().OfType<IItemSlot>().ToArray();

  public void PopulateItems()
  {
    PopulateInventory();
    PopulatePlayerInfo();
  }

  public void ClearItems()
  {
    foreach (var item in ItemSlots)
      ItemsPage.RemoveChildEx(item);

    HideUserActionPrompt();
  }

  public void PopulatePlayerInfo()
  {
    FloorLabel.Text = $"Level {GameRepo.CurrentFloor:D2}";

    var currentLevel = GameRepo.PlayerStatInfo.Value.CurrentLevel;
    CurrentLevelLabel.Text = $"Level {currentLevel:D2}";

    var currentHP = GameRepo.PlayerStatInfo.Value.CurrentHP;
    var maxHP = GameRepo.PlayerStatInfo.Value.MaximumHP;

    HPValue.Text = $"{currentHP}/{maxHP}";

    var currentVT = GameRepo.PlayerStatInfo.Value.CurrentVT;
    var maxVT = GameRepo.PlayerStatInfo.Value.MaximumVT;

    VTValue.Text = $"{currentVT}/{maxVT}";

    var currentAttack = GameRepo.PlayerStatInfo.Value.CurrentAttack;
    var maxAttack = GameRepo.PlayerStatInfo.Value.MaxAttack;

    ATKValue.Text = $"{currentAttack}/{maxAttack}";

    var currentDefense = GameRepo.PlayerStatInfo.Value.CurrentDefense;
    var maxDefense = GameRepo.PlayerStatInfo.Value.MaxDefense;
    DEFValue.Text = $"{currentDefense}/{maxDefense}";

    var atkBonus = GameRepo.PlayerStatInfo.Value.BonusAttack;
    var defBonus = GameRepo.PlayerStatInfo.Value.BonusDefense;

    ATKBonusLabel.Text = atkBonus != 0 ? $"{atkBonus:+0;-#}" : "...";
    DEFBonusLabel.Text = defBonus != 0 ? $"{defBonus:+0;-#}" : "...";

    // TODO: Change font style when EXP Bonus effect is active
    var currentExp = GameRepo.PlayerStatInfo.Value.CurrentEXP;
    var expToNextLevel = GameRepo.PlayerStatInfo.Value.EXPToNextLevel;
    EXPValue.Text = $"{currentExp}/{expToNextLevel}";

    if (ItemSlots.Any())
    {
      var item = ItemSlots.ElementAt(_currentIndex).Item;
      ItemDescriptionTitle.Text = $"{item.Info.Name}";
      ItemEffectLabel.Text = $"{item.Info.Description}";
    }
  }

  public override void _UnhandledInput(InputEvent @event)
  {
    if (ItemSlots.Length == 0)
      return;

    var inventory = GameRepo.InventoryItems.Value;

    if (@event.IsActionPressed(GameInputs.UiRight) && _currentPageNumber == InventoryPageNumber.FirstPage && inventory.Count > _itemsPerPage)
      ChangeInventoryPage(InventoryPageNumber.SecondPage);

    if (@event.IsActionPressed(GameInputs.UiLeft) && _currentPageNumber == InventoryPageNumber.SecondPage)
      ChangeInventoryPage(InventoryPageNumber.FirstPage);

    if (@event.IsActionPressed(GameInputs.UiDown))
    {
      SetToUnselectedStyle(ItemSlots.ElementAt(_currentIndex));
      _currentIndex = new[] { _currentIndex + 1, _itemsPerPage - 1, ItemSlots.Length - 1 }.Min();
      SetToSelectedStyle(ItemSlots.ElementAt(_currentIndex));
    }

    if (@event.IsActionPressed(GameInputs.UiUp))
    {
      SetToUnselectedStyle(ItemSlots.ElementAt(_currentIndex));
      _currentIndex = new[] { _currentIndex - 1, 0 }.Max();
      SetToSelectedStyle(ItemSlots.ElementAt(_currentIndex));
    }

    if (@event.IsActionPressed(GameInputs.UiAccept))
    {
      if (ItemSlots.Length == 0 || GetViewport().GuiGetFocusOwner() is Button)
        return;
      DisplayUserActionPrompt();
    }
  }

  private void DisplayUserActionPrompt()
  {
    ItemDescriptionTitle.Hide();
    ItemEffectLabel.Hide();
    UseItemPrompt.Show();
    UseButton.Show();
    ThrowButton.Show();
    DropButton.Show();

    var currentItem = ItemSlots.ElementAt(_currentIndex).Item;

    if (currentItem is IEquipable equipable)
    {
      var isEquipped = GameRepo.IsItemEquipped(equipable);
      UseButton.Text = isEquipped ? "Unequip" : "Equip";
      ThrowButton.Disabled = isEquipped ? true : false;
      ThrowButton.FocusMode = isEquipped ? FocusModeEnum.None : FocusModeEnum.All;
      DropButton.Disabled = isEquipped ? true : false;
      DropButton.FocusMode = isEquipped ? FocusModeEnum.None : FocusModeEnum.All;
    }
    else
    {
      UseButton.Text = "Use";
    }

    UseButton.GrabFocus();
  }

  private async Task HideUserActionPrompt()
  {
    ItemDescriptionTitle.Show();
    ItemEffectLabel.Show();
    UseItemPrompt.Hide();
    UseButton.Hide();
    ThrowButton.Hide();
    DropButton.Hide();
  }

  private async void ChangeInventoryPage(InventoryPageNumber pageToChangeTo)
  {
    ClearItems();
    await ToSignal(GetTree().CreateTimer(0.1f), "timeout");
    _currentIndex = 0;
    _currentPageNumber = pageToChangeTo;
    PopulateItems();
  }

  private void PopulateInventory()
  {
    var inventory = GameRepo.InventoryItems.Value;
    var numberOfItemsToDisplay = _currentPageNumber == InventoryPageNumber.FirstPage ? Mathf.Min(inventory.Count, _itemsPerPage) : Mathf.Min(inventory.Count - _itemsPerPage, _itemsPerPage);
    var indexToStart = _currentPageNumber == InventoryPageNumber.FirstPage ? 0 : _itemsPerPage - 1;

    ForwardArrow.Text = "";
    BackArrow.Text = "";

    if (_currentPageNumber == InventoryPageNumber.FirstPage && inventory.Count > _itemsPerPage)
    {
      ForwardArrow.Text = "►";
      BackArrow.Text = "";
    }
    if (_currentPageNumber == InventoryPageNumber.SecondPage)
    {
      ForwardArrow.Text = "";
      BackArrow.Text = "◄";
    }


    for (var i = 0; i < numberOfItemsToDisplay; i++)
    {
      var item = inventory.ElementAt(i + indexToStart);
      var itemScene = GD.Load<PackedScene>(ITEM_SLOT_SCENE);
      var itemSlot = itemScene.Instantiate<IItemSlot>();
      itemSlot.Item = item;
      ItemsPage.AddChildEx(itemSlot);

      if (itemSlot.Item is IEquipable equipable && GameRepo.IsItemEquipped(equipable))
        itemSlot.SetEquippedItemStyle();
    }

    if (ItemSlots.Any())
    {
      ItemSlots.ElementAt(_currentIndex).SetSelectedItemStyle();
      if (ItemSlots.ElementAt(_currentIndex).Item is IEquipable equipable && GameRepo.IsItemEquipped(equipable))
        ItemSlots.ElementAt(_currentIndex).SetEquippedSelectedItemStyle();
    }
  }

  private async void SetToUnselectedStyle(IItemSlot itemSlot)
  {
    await ToSignal(GetTree().CreateTimer(0.1f), "timeout");
    itemSlot.SetItemStyle();
    if (itemSlot.Item is IEquipable equipable && GameRepo.IsItemEquipped(equipable))
      itemSlot.SetEquippedItemStyle();
  }

  private async void SetToSelectedStyle(IItemSlot itemSlot)
  {
    await ToSignal(GetTree().CreateTimer(0.1f), "timeout");
    itemSlot.SetSelectedItemStyle();
    if (itemSlot.Item is IEquipable newEquipable && GameRepo.IsItemEquipped(newEquipable))
      itemSlot.SetEquippedSelectedItemStyle();
    ItemDescriptionTitle.Text = $"{itemSlot.Item.Info.Name}";
    ItemEffectLabel.Text = $"{itemSlot.Item.Info.Description}";
  }

  private async void EquipOrUnequipItem()
  {
    var itemSlot = ItemSlots[_currentIndex];
    await ToSignal(GetTree().CreateTimer(0.2f), "timeout");
    if (itemSlot.Item is IEquipable equipableItem)
    {
      if (GameRepo.IsItemEquipped(equipableItem))
      {
        GameRepo.UnequipItem(equipableItem);
        itemSlot.SetSelectedItemStyle();
      }
      else
      {
        GameRepo.EquipItem(equipableItem);
        itemSlot.SetEquippedSelectedItemStyle();
      }

      UpdateStatBonusInfo();
    }
  }

  private void UpdateStatBonusInfo()
  {
    var atkBonus = GameRepo.PlayerStatInfo.Value.BonusAttack;
    ATKBonusLabel.Text = atkBonus != 0 ? $"{atkBonus:+0;-#}" : "...";
    var defBonus = GameRepo.PlayerStatInfo.Value.BonusDefense;
    DEFBonusLabel.Text = defBonus != 0 ? $"{defBonus:+0;-#}" : "...";

    var currentHP = GameRepo.PlayerStatInfo.Value.CurrentHP;
    var maxHP = GameRepo.PlayerStatInfo.Value.MaximumHP;

    HPValue.Text = $"{currentHP}/{maxHP}";

    var currentVT = GameRepo.PlayerStatInfo.Value.CurrentVT;
    var maxVT = GameRepo.PlayerStatInfo.Value.MaximumVT;

    VTValue.Text = $"{currentVT}/{maxVT}";
  }

  private async void UseButtonPressed()
  {
    var currentItem = ItemSlots[_currentIndex].Item;
    if (currentItem is IEquipable)
      EquipOrUnequipItem();
    if (currentItem is ConsumableItem consumable)
      consumable.Use();

    // TODO: Replace with animation player (for visual effects/sound effects?)
    await ToSignal(GetTree().CreateTimer(0.25f), "timeout");
    await HideUserActionPrompt();
    PopulatePlayerInfo();
  }

  private async void ThrowButtonPressed()
  {
    var currentItem = ItemSlots[_currentIndex].Item;

    if (_currentIndex >= ItemSlots.Length - 1)
      _currentIndex--;
    if (_currentIndex <= 0)
      _currentIndex = 0;
    Game.ToggleInventory();
    currentItem.Throw();
  }

  private async void DropButtonPressed()
  {
    var currentItem = ItemSlots[_currentIndex].Item;

    if (_currentIndex >= ItemSlots.Length - 1)
      _currentIndex--;
    if (_currentIndex <= 0)
      _currentIndex = 0;

    Game.ToggleInventory();
    currentItem.Drop();
  }

  private enum InventoryPageNumber
  {
    FirstPage,
    SecondPage
  }
}