using Godot;
using System;
using System.Collections.Generic;
using Chessistics.Engine.Model;
using Chessistics.Scripts.Pieces;

namespace Chessistics.Scripts.UI;

public partial class PieceStockPanel : VBoxContainer
{
    [Signal]
    public delegate void PieceSelectedEventHandler(int kindIndex);

    private readonly Dictionary<PieceKind, (Button button, Label countLabel, int remaining)> _entries = new();
    private PieceKind? _selectedKind;

    public PieceKind? SelectedKind => _selectedKind;

    private static readonly Color NormalBg = new("#2A2A2E");
    private static readonly Color SelectedBg = new("#3D6B8E");
    private static readonly Color HoverBg = new("#353538");
    private static readonly Color DisabledBg = new("#1E1E20");
    private static readonly Color BorderNormal = new("#444448");
    private static readonly Color BorderSelected = new("#5A9ECC");

    public void Setup(IReadOnlyList<PieceStock> stock)
    {
        foreach (var child in GetChildren())
            child.QueueFree();
        _entries.Clear();
        _selectedKind = null;

        var title = new Label { Text = "PIECES" };
        title.AddThemeFontSizeOverride("font_size", 16);
        title.AddThemeColorOverride("font_color", new Color("#B8942A"));
        AddChild(title);

        AddChild(new HSeparator());

        foreach (var entry in stock)
        {
            var hbox = new HBoxContainer();
            hbox.AddThemeConstantOverride("separation", 8);

            // Color dot matching piece color
            var dot = new ColorRect
            {
                CustomMinimumSize = new Vector2(10, 10),
                Size = new Vector2(10, 10),
                Color = PieceView.GetPieceColor(entry.Kind),
                MouseFilter = Control.MouseFilterEnum.Ignore
            };
            var dotCenter = new CenterContainer { CustomMinimumSize = new Vector2(14, 32) };
            dotCenter.AddChild(dot);
            hbox.AddChild(dotCenter);

            var button = new Button
            {
                Text = GetPieceName(entry.Kind),
                CustomMinimumSize = new Vector2(120, 32),
                ToggleMode = false, // We manage selection state ourselves
                FocusMode = FocusModeEnum.None // Prevent spacebar from activating buttons
            };
            ApplyButtonStyle(button, false);

            var countLabel = new Label { Text = $"x{entry.Count}" };
            countLabel.AddThemeFontSizeOverride("font_size", 13);
            countLabel.AddThemeColorOverride("font_color", new Color("#999999"));

            var kind = entry.Kind;
            button.Pressed += () => OnPieceButtonPressed(kind);

            hbox.AddChild(button);
            hbox.AddChild(countLabel);
            AddChild(hbox);

            _entries[entry.Kind] = (button, countLabel, entry.Count);
        }
    }

    private void OnPieceButtonPressed(PieceKind kind)
    {
        if (_selectedKind == kind)
        {
            _selectedKind = null;
            UpdateButtonStates();
            return;
        }

        _selectedKind = kind;
        UpdateButtonStates();
        EmitSignal(SignalName.PieceSelected, (int)kind);
    }

    private void UpdateButtonStates()
    {
        foreach (var (k, (button, _, remaining)) in _entries)
        {
            bool selected = k == _selectedKind;
            button.Disabled = remaining <= 0;
            ApplyButtonStyle(button, selected);
        }
    }

    private static void ApplyButtonStyle(Button button, bool selected)
    {
        var bg = selected ? SelectedBg : NormalBg;
        var border = selected ? BorderSelected : BorderNormal;

        var normal = MakeStyle(bg, border);
        var hover = MakeStyle(selected ? SelectedBg.Lightened(0.1f) : HoverBg, border);
        var disabled = MakeStyle(DisabledBg, new Color("#2A2A2E"));

        button.AddThemeStyleboxOverride("normal", normal);
        button.AddThemeStyleboxOverride("hover", hover);
        button.AddThemeStyleboxOverride("pressed", MakeStyle(bg.Darkened(0.15f), border));
        button.AddThemeStyleboxOverride("disabled", disabled);
        button.AddThemeFontSizeOverride("font_size", 12);
        button.AddThemeColorOverride("font_color", selected ? Colors.White : new Color("#CCCCCC"));
        button.AddThemeColorOverride("font_disabled_color", new Color("#555555"));
    }

    private static StyleBoxFlat MakeStyle(Color bg, Color border)
    {
        return new StyleBoxFlat
        {
            BgColor = bg,
            BorderColor = border,
            BorderWidthBottom = 1, BorderWidthTop = 1,
            BorderWidthLeft = 1, BorderWidthRight = 1,
            CornerRadiusTopLeft = 4, CornerRadiusTopRight = 4,
            CornerRadiusBottomLeft = 4, CornerRadiusBottomRight = 4,
            ContentMarginLeft = 8, ContentMarginRight = 8,
            ContentMarginTop = 4, ContentMarginBottom = 4
        };
    }

    public void UpdateCount(PieceKind kind, int remaining)
    {
        if (!_entries.TryGetValue(kind, out var entry)) return;
        _entries[kind] = (entry.button, entry.countLabel, remaining);
        entry.countLabel.Text = $"x{remaining}";
        entry.button.Disabled = remaining <= 0;
    }

    public void ClearSelection()
    {
        _selectedKind = null;
        UpdateButtonStates();
    }

    private static string GetPieceName(PieceKind kind) => kind switch
    {
        PieceKind.Pawn => "Pion",
        PieceKind.Rook => "Tour II",
        PieceKind.Bishop => "Fou II",
        PieceKind.Knight => "Cavalier",
        PieceKind.Queen => "Dame",
        _ => kind.ToString()
    };
}