using Godot;
using System.Linq;
using Theriapolis.Core.Data;
using Theriapolis.GodotHost.Scenes.Widgets;
using Theriapolis.GodotHost.UI;

namespace Theriapolis.GodotHost.Scenes.Steps;

/// <summary>
/// Step IV — Subclass. New vs the React prototype (which is pre-Phase
/// 6.5); per port plan §10, dedicated step rather than inline picker.
/// Cards filtered by the chosen class's <c>SubclassIds</c>. Selecting
/// commits via Patch(subclass_id).
/// </summary>
public partial class StepSubclass : VBoxContainer, IStep
{
    private CharacterDraft _draft = null!;
    private GridContainer _grid = null!;

    public void Bind(CharacterDraft draft)
    {
        _draft = draft;
        _draft.Changed += () => Callable.From(Refresh).CallDeferred();
        Build();
    }

    public string? Validate()
    {
        if (string.IsNullOrEmpty(_draft?.SubclassId)) return "Pick a subclass.";
        var sub = System.Array.Find(CodexContent.Subclasses, s => s.Id == _draft.SubclassId);
        if (sub is null || !string.Equals(sub.ClassId, _draft.ClassId, System.StringComparison.OrdinalIgnoreCase))
            return "Selected subclass doesn't belong to the current calling.";
        return null;
    }

    private void Build()
    {
        AddThemeConstantOverride("separation", 16);

        var intro = new VBoxContainer();
        intro.AddThemeConstantOverride("separation", 6);
        AddChild(intro);
        intro.AddChild(new Label { Text = "FOLIO IV · SUBCLASS", ThemeTypeVariation = "Eyebrow" });
        intro.AddChild(new Label { Text = "Choose a Subclass",   ThemeTypeVariation = "H2" });
        intro.AddChild(new Label
        {
            Text = "Specialization within your calling. Subclass features unlock at "
                 + "level 3 and beyond, but the choice is locked in now — only subclasses "
                 + "available to your chosen calling are shown.",
            AutowrapMode = TextServer.AutowrapMode.WordSmart,
        });

        _grid = new GridContainer { Columns = 1, SizeFlagsHorizontal = SizeFlags.ExpandFill };
        _grid.AddThemeConstantOverride("v_separation", 12);
        AddChild(_grid);

        Refresh();
    }

    private void Refresh()
    {
        if (_grid is null) return;
        foreach (var c in _grid.GetChildren()) c.QueueFree();

        var cls = CodexContent.Class(_draft.ClassId);
        if (cls is null) return;

        foreach (var subId in cls.SubclassIds)
        {
            var sub = System.Array.Find(CodexContent.Subclasses, s => s.Id == subId);
            if (sub is not null) _grid.AddChild(BuildCard(sub));
        }
    }

    private Control BuildCard(SubclassDef sub)
    {
        bool selected = _draft.SubclassId == sub.Id;

        var card = CodexCard.Make();
        card.SizeFlagsHorizontal = Control.SizeFlags.ExpandFill;
        CodexCard.SetSelected(card, selected);

        card.GuiInput += (InputEvent e) =>
        {
            if (e is InputEventMouseButton mb && mb.Pressed && mb.ButtonIndex == MouseButton.Left)
                _draft.Patch(new Godot.Collections.Dictionary { { "subclass_id", sub.Id } });
        };

        var box = new VBoxContainer { MouseFilter = MouseFilterEnum.Pass };
        box.AddThemeConstantOverride("separation", 6);
        card.AddChild(box);

        box.AddChild(new Label { Text = sub.Name, ThemeTypeVariation = "CardName" });
        if (!string.IsNullOrEmpty(sub.Flavor))
        {
            box.AddChild(new Label
            {
                Text = sub.Flavor,
                AutowrapMode = TextServer.AutowrapMode.WordSmart,
                ThemeTypeVariation = "CardBody",
            });
        }

        // Level-3 features (the first unlock for any subclass).
        var l3 = sub.LevelFeatures.FirstOrDefault(e => e.Level == 3);
        if (l3?.Features.Length > 0)
        {
            var featChips = new HFlowContainer { MouseFilter = MouseFilterEnum.Pass };
            featChips.AddThemeConstantOverride("h_separation", 6);
            featChips.AddThemeConstantOverride("v_separation", 4);
            box.AddChild(featChips);

            foreach (var fid in l3.Features)
            {
                if (!sub.FeatureDefinitions.TryGetValue(fid, out var fd)) continue;
                if (fd.Kind == "stub") continue;
                featChips.AddChild(new TraitChip
                {
                    TraitName = fd.Name,
                    Description = fd.Description,
                    Tag = "L3 · " + fd.Kind,
                });
            }
        }

        return card;
    }
}
