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

namespace Theriapolis.GodotHost.Scenes.Steps;

/// <summary>
/// Step I — Clade. Direct port of <c>StepClade</c> in
/// <c>src/steps.jsx</c>, plus the Phase 6.5 hybrid-origin extension
/// per port plan §10: a Hybrid toggle splits the picker into Sire +
/// Dam grids, each independent. The dominant-parent radio drives
/// <see cref="CharacterDraft.EffectiveCladeId"/> for downstream steps.
///
/// Cards are built once and mutated in place (Modulate update only) on
/// selection change — tearing down + rebuilding inside the click
/// callback chain caused duplicates because Free() defers when the
/// freed node is currently mid-signal.
/// </summary>
public partial class StepClade : VBoxContainer, IStep
{
    private CharacterDraft _draft = null!;
    private CheckBox _hybridToggle = null!;
    private VBoxContainer _purebredSection = null!;
    private VBoxContainer _hybridSection = null!;
    private OptionButton _dominantToggle = null!;

    private readonly Dictionary<string, PanelContainer> _purebredCards = new();
    private readonly Dictionary<string, PanelContainer> _sireCards = new();
    private readonly Dictionary<string, PanelContainer> _damCards = new();

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

    public string? Validate() => WizardValidation.Validate(0, _draft);

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

        var intro = new VBoxContainer();
        intro.AddThemeConstantOverride("separation", 6);
        AddChild(intro);
        intro.AddChild(new Label { Text = "FOLIO I · CLADE" });
        intro.AddChild(new Label { Text = "Choose a Clade" });
        intro.AddChild(new Label
        {
            Text = "The broad mammalian family of your line. Clade defines the largest "
                 + "strokes — predator or prey, communal or solitary, scent-driven or "
                 + "sight-driven. Hybrid characters blend two lineages.",
            AutowrapMode = TextServer.AutowrapMode.WordSmart,
        });

        var toggleRow = new HBoxContainer();
        toggleRow.AddThemeConstantOverride("separation", 12);
        AddChild(toggleRow);
        _hybridToggle = new CheckBox { Text = "Hybrid Origin (two parent lineages)" };
        _hybridToggle.Toggled += OnHybridToggled;
        toggleRow.AddChild(_hybridToggle);

        // Purebred section
        _purebredSection = new VBoxContainer();
        _purebredSection.AddThemeConstantOverride("separation", 6);
        AddChild(_purebredSection);
        var purebredGrid = MakeGrid();
        _purebredSection.AddChild(purebredGrid);
        PopulateGrid(purebredGrid, _purebredCards, OnPurebredCladePicked);

        // Hybrid section
        _hybridSection = new VBoxContainer();
        _hybridSection.AddThemeConstantOverride("separation", 16);
        AddChild(_hybridSection);

        _hybridSection.AddChild(new Label { Text = "SIRE — Paternal Lineage" });
        var sireGrid = MakeGrid();
        _hybridSection.AddChild(sireGrid);
        PopulateGrid(sireGrid, _sireCards, id => OnLineageCladePicked("sire", id));

        _hybridSection.AddChild(new Label { Text = "DAM — Maternal Lineage" });
        var damGrid = MakeGrid();
        _hybridSection.AddChild(damGrid);
        PopulateGrid(damGrid, _damCards, id => OnLineageCladePicked("dam", id));

        var dominantRow = new HBoxContainer();
        dominantRow.AddThemeConstantOverride("separation", 8);
        _hybridSection.AddChild(dominantRow);
        dominantRow.AddChild(new Label { Text = "DOMINANT LINEAGE" });
        _dominantToggle = new OptionButton();
        _dominantToggle.AddItem("Sire", 0);
        _dominantToggle.AddItem("Dam", 1);
        _dominantToggle.ItemSelected += OnDominantSelected;
        dominantRow.AddChild(_dominantToggle);

        Refresh();
    }

    private static GridContainer MakeGrid()
    {
        var grid = new GridContainer { Columns = 3, SizeFlagsHorizontal = SizeFlags.ShrinkCenter };
        grid.AddThemeConstantOverride("h_separation", 16);
        grid.AddThemeConstantOverride("v_separation", 16);
        return grid;
    }

    private void PopulateGrid(GridContainer grid, Dictionary<string, PanelContainer> cardMap, System.Action<string> onClick)
    {
        foreach (var clade in CodexContent.Clades)
        {
            var card = BuildCard(clade, onClick);
            cardMap[clade.Id] = card;
            grid.AddChild(card);
        }
    }

    private void OnHybridToggled(bool pressed)
    {
        var patch = new Godot.Collections.Dictionary { { "is_hybrid", pressed } };
        if (pressed)
        {
            patch["clade_id"] = "";
            patch["species_id"] = "";
        }
        else
        {
            patch["sire_clade_id"] = "";
            patch["sire_species_id"] = "";
            patch["dam_clade_id"] = "";
            patch["dam_species_id"] = "";
        }
        ClearBackgroundIfInvalidated(patch);
        _draft.Patch(patch);
    }

    private void OnDominantSelected(long index)
    {
        _draft.Patch(new Godot.Collections.Dictionary
        {
            { "dominant_parent", index == 0 ? "sire" : "dam" },
        });
    }

    private void Refresh()
    {
        if (_hybridToggle is null) return;

        bool hybrid = _draft.IsHybrid;
        if (_hybridToggle.ButtonPressed != hybrid) _hybridToggle.SetPressedNoSignal(hybrid);
        _purebredSection.Visible = !hybrid;
        _hybridSection.Visible = hybrid;

        UpdateSelection(_purebredCards, _draft.CladeId);
        UpdateSelection(_sireCards, _draft.SireCladeId);
        UpdateSelection(_damCards, _draft.DamCladeId);

        int dominantIdx = _draft.DominantParent == "dam" ? 1 : 0;
        if (_dominantToggle.Selected != dominantIdx) _dominantToggle.Select(dominantIdx);
    }

    private static void UpdateSelection(Dictionary<string, PanelContainer> cards, string selectedId)
    {
        foreach (var (id, card) in cards)
            card.Modulate = id == selectedId ? new Color(1f, 0.95f, 0.85f) : Colors.White;
    }

    private void OnPurebredCladePicked(string cladeId)
    {
        string speciesId = _draft.SpeciesId;
        var sp = CodexContent.SpeciesById(speciesId);
        if (sp is null || !string.Equals(sp.CladeId, cladeId, System.StringComparison.OrdinalIgnoreCase))
            speciesId = "";
        var patch = new Godot.Collections.Dictionary
        {
            { "clade_id",   cladeId },
            { "species_id", speciesId },
        };
        ClearBackgroundIfInvalidated(patch);
        _draft.Patch(patch);
    }

    private void OnLineageCladePicked(string lineage, string cladeId)
    {
        var patch = new Godot.Collections.Dictionary
        {
            { lineage + "_clade_id", cladeId },
        };
        string currentSpecies = lineage == "sire" ? _draft.SireSpeciesId : _draft.DamSpeciesId;
        var sp = CodexContent.SpeciesById(currentSpecies);
        if (sp is null || !string.Equals(sp.CladeId, cladeId, System.StringComparison.OrdinalIgnoreCase))
            patch[lineage + "_species_id"] = "";
        ClearBackgroundIfInvalidated(patch);
        _draft.Patch(patch);
    }

    /// <summary>
    /// Clade changes can make a previously-valid background unavailable
    /// (e.g. picking Felidae while Pack-Raised is selected). Build the
    /// hypothetical post-patch state via Resource.Duplicate, run it
    /// through BackgroundAvailability, and clear background_id in the
    /// patch if the rule no longer matches.
    /// </summary>
    private void ClearBackgroundIfInvalidated(Godot.Collections.Dictionary patch)
    {
        if (string.IsNullOrEmpty(_draft.BackgroundId)) return;

        var future = (CharacterDraft)_draft.Duplicate();
        // Apply the same patch we're about to commit, in-place on the copy.
        future.Patch(patch);
        if (!BackgroundAvailability.IsAvailable(_draft.BackgroundId, future))
            patch["background_id"] = "";
    }

    private PanelContainer BuildCard(CladeDef clade, System.Action<string> onClick)
    {
        var card = new PanelContainer
        {
            CustomMinimumSize = new Vector2(200, 0),
            MouseFilter = MouseFilterEnum.Stop,
        };
        card.GuiInput += (InputEvent e) =>
        {
            if (e is InputEventMouseButton mb && mb.Pressed && mb.ButtonIndex == MouseButton.Left)
                onClick(clade.Id);
        };

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

        box.AddChild(new Label { Text = clade.Name });
        box.AddChild(new Label { Text = clade.Kind.ToUpperInvariant() });

        if (clade.AbilityMods.Count > 0)
        {
            var modsRow = new HBoxContainer();
            modsRow.AddThemeConstantOverride("separation", 8);
            box.AddChild(modsRow);
            foreach (var (k, v) in clade.AbilityMods)
                modsRow.AddChild(new Label { Text = $"{k} {(v >= 0 ? "+" : "")}{v}" });
        }

        if (clade.Traits.Length > 0 || clade.Detriments.Length > 0)
        {
            var chips = new HFlowContainer { MouseFilter = MouseFilterEnum.Pass };
            chips.AddThemeConstantOverride("h_separation", 6);
            chips.AddThemeConstantOverride("v_separation", 4);
            box.AddChild(chips);
            foreach (var t in clade.Traits)
                chips.AddChild(new TraitChip { TraitName = t.Name, Description = t.Description });
            foreach (var d in clade.Detriments)
                chips.AddChild(new TraitChip { TraitName = d.Name, Description = d.Description, Detriment = true });
        }

        return card;
    }
}