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

namespace Theriapolis.GodotHost.Scenes.Steps;

/// <summary>
/// Step II — Species. Direct port of <c>StepSpecies</c> in
/// <c>src/steps.jsx</c> plus the Phase 6.5 hybrid extension. Hybrid mode
/// uses a single unified grid (M6.16) — sire and dam species lists are
/// merged, and each card carries either a Sire or Dam toggle in its
/// header matching the clade it belongs to (sire/dam clades are
/// guaranteed disjoint by StepClade's parent-conflict rule).
/// </summary>
public partial class StepSpecies : VBoxContainer, IStep
{
    private CharacterDraft _draft = null!;
    private VBoxContainer _purebredSection = null!;
    private VBoxContainer _hybridSection = null!;
    private GridContainer _purebredGrid = null!;
    private GridContainer _hybridGrid = null!;

    // Phase B species trait + detriment pickers — single-pick per lineage.
    private VBoxContainer _pickSection = null!;
    private VBoxContainer _sirePickCol = null!;
    private VBoxContainer _damPickCol = null!;
    private string _sirePicksBuiltFor = "";
    private string _damPicksBuiltFor = "";

    public void Bind(CharacterDraft draft)
    {
        _draft = draft;
        // Defer Refresh so it runs after the click callback that triggered
        // Changed completes — Free() called on a card mid-callback returns
        // without freeing, leaving a stale duplicate in the grid.
        _draft.Changed += () => Callable.From(Refresh).CallDeferred();
        Build();
    }

    public string? Validate() => WizardValidation.Validate(1, _draft);

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

        var intro = new VBoxContainer();
        intro.AddThemeConstantOverride("separation", 6);
        AddChild(intro);
        intro.AddChild(new Label { Text = "FOLIO II · SPECIES", ThemeTypeVariation = "Eyebrow" });
        intro.AddChild(new Label { Text = "Choose a Species",   ThemeTypeVariation = "H2" });
        intro.AddChild(new Label
        {
            Text = "Refine your line. Species inherits the clade's traits and adds its "
                 + "own — body size, base movement speed, and species-specific abilities. "
                 + "Hybrid characters pick one species per parent lineage.",
            AutowrapMode = TextServer.AutowrapMode.WordSmart,
        });

        _purebredSection = new VBoxContainer();
        _purebredSection.AddThemeConstantOverride("separation", 6);
        AddChild(_purebredSection);
        _purebredGrid = MakeGrid();
        _purebredSection.AddChild(_purebredGrid);

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

        _hybridSection.AddChild(new Label
        {
            Text = "Pick one species per parent lineage. Sire's clade species "
                 + "are listed first, then Dam's — click any card to pick it.",
            AutowrapMode = TextServer.AutowrapMode.WordSmart,
        });
        _hybridGrid = MakeGrid();
        _hybridSection.AddChild(_hybridGrid);

        // Phase B species pickers: one trait + one detriment per parent.
        _pickSection = new VBoxContainer();
        _pickSection.AddThemeConstantOverride("separation", 8);
        _hybridSection.AddChild(_pickSection);
        _pickSection.AddChild(new Label { Text = "SPECIES TRAITS & DETRIMENTS", ThemeTypeVariation = "Eyebrow" });
        _pickSection.AddChild(new Label
        {
            Text = "Pick one species trait and one species detriment from each parent. "
                 + "GMs may rule that traits express partially in hybrids.",
            AutowrapMode = TextServer.AutowrapMode.WordSmart,
        });

        var pickGrid = new HBoxContainer { SizeFlagsHorizontal = SizeFlags.ExpandFill };
        pickGrid.AddThemeConstantOverride("separation", 16);
        _pickSection.AddChild(pickGrid);

        _sirePickCol = new VBoxContainer { SizeFlagsHorizontal = SizeFlags.ExpandFill };
        _sirePickCol.AddThemeConstantOverride("separation", 6);
        pickGrid.AddChild(_sirePickCol);

        _damPickCol = new VBoxContainer { SizeFlagsHorizontal = SizeFlags.ExpandFill };
        _damPickCol.AddThemeConstantOverride("separation", 6);
        pickGrid.AddChild(_damPickCol);

        Refresh();
    }

    private static GridContainer MakeGrid()
    {
        // Single-column layout: each card spans the wizard's content width
        // and surfaces the species' description text. Matches StepClade.
        var grid = new GridContainer { Columns = 1, SizeFlagsHorizontal = SizeFlags.ExpandFill };
        grid.AddThemeConstantOverride("v_separation", 12);
        return grid;
    }

    private void Refresh()
    {
        if (_purebredGrid is null) return;
        bool hybrid = _draft.IsHybrid;
        _purebredSection.Visible = !hybrid;
        _hybridSection.Visible = hybrid;

        if (hybrid)
        {
            RefreshHybridGrid();

            SyncSpeciesPicks(_sirePickCol, ref _sirePicksBuiltFor, "sire",
                _draft.SireSpeciesId, _draft.SireChosenSpeciesTrait, _draft.SireChosenSpeciesDetriment);
            SyncSpeciesPicks(_damPickCol, ref _damPicksBuiltFor, "dam",
                _draft.DamSpeciesId, _draft.DamChosenSpeciesTrait, _draft.DamChosenSpeciesDetriment);
        }
        else
        {
            RefreshPurebredGrid();
        }
    }

    private void OnPurebredSpeciesPicked(string speciesId) =>
        _draft.Patch(new Godot.Collections.Dictionary { { "species_id", speciesId } });

    private void OnLineageSpeciesPicked(string lineage, string speciesId) =>
        _draft.Patch(new Godot.Collections.Dictionary
        {
            { lineage + "_species_id", speciesId },
            // Species swap invalidates the previously-picked trait/detriment.
            { lineage + "_chosen_species_trait", "" },
            { lineage + "_chosen_species_detriment", "" },
        });

    /// <summary>
    /// Mutate-in-place sync for the species-pick column (one trait button
    /// group + one detriment button group, radio-style).
    /// </summary>
    private void SyncSpeciesPicks(VBoxContainer col, ref string builtFor,
                                   string lineage, string speciesId,
                                   string chosenTrait, string chosenDetriment)
    {
        if (speciesId == builtFor)
        {
            UpdateRadioGroup(col, "trait", chosenTrait);
            UpdateRadioGroup(col, "detriment", chosenDetriment);
            return;
        }

        foreach (var c in col.GetChildren()) c.Free();
        builtFor = speciesId;

        var sp = CodexContent.SpeciesById(speciesId);
        col.AddChild(new Label
        {
            Text = lineage.ToUpperInvariant() + (sp is null ? "" : " — " + sp.Name),
            ThemeTypeVariation = "Eyebrow",
        });
        if (sp is null)
        {
            col.AddChild(new Label { Text = "(pick a species above)" });
            return;
        }

        col.AddChild(new Label { Text = "Trait", ThemeTypeVariation = "Eyebrow" });
        BuildRadioGroup(col, "trait", lineage, sp.Traits, chosenTrait,
            (lin, id) => OnSpeciesPickToggled(lin, "trait", id), isDetriment: false);

        col.AddChild(new Label { Text = "Detriment", ThemeTypeVariation = "Eyebrow" });
        if (sp.Detriments.Length == 0)
        {
            col.AddChild(new Label { Text = "(none)" });
        }
        else
        {
            BuildRadioGroup(col, "detriment", lineage, sp.Detriments, chosenDetriment,
                (lin, id) => OnSpeciesPickToggled(lin, "detriment", id), isDetriment: true);
        }
    }

    private static void BuildRadioGroup(VBoxContainer parent, string kind, string lineage,
                                         Theriapolis.Core.Data.TraitDef[] options, string selected,
                                         System.Action<string, string> onPicked, bool isDetriment)
    {
        var holder = new VBoxContainer { Name = $"{kind}_group" };
        holder.AddThemeConstantOverride("separation", 4);
        parent.AddChild(holder);

        foreach (var t in options)
        {
            string captured = t.Id;
            string capturedName = t.Name;
            string capturedDesc = t.Description;
            var btn = new Button
            {
                Text = t.Name,
                ToggleMode = true,
                ButtonPressed = t.Id == selected,
                FocusMode = Control.FocusModeEnum.None,
                SizeFlagsHorizontal = SizeFlags.ExpandFill,
                Name = t.Id,
            };
            // Single Pressed signal handles both directions: if the
            // button is now pressed (its own click flipped it on),
            // commit the pick; if it's now off, clear the field.
            // Reading btn.ButtonPressed lets us avoid the stale-closure
            // bug from capturing `selected` at build time.
            var btnRef = btn;
            btn.Pressed += () =>
                onPicked(lineage, btnRef.ButtonPressed ? captured : "");
            btn.MouseEntered += () =>
                PopoverLayer.Instance?.ShowFor(btnRef, capturedName, capturedDesc,
                    isDetriment ? "" : "trait", isDetriment);
            btn.MouseExited += () =>
                PopoverLayer.Instance?.ScheduleClose();
            holder.AddChild(btn);
        }
    }

    private static void UpdateRadioGroup(VBoxContainer col, string kind, string selected)
    {
        // Find the holder by Name. Bail silently if missing — a species
        // with no detriments has no detriment_group node.
        var holder = col.GetNodeOrNull<VBoxContainer>($"{kind}_group");
        if (holder is null) return;
        foreach (var child in holder.GetChildren())
        {
            if (child is Button btn)
            {
                bool want = btn.Name == selected;
                if (btn.ButtonPressed != want) btn.SetPressedNoSignal(want);
            }
        }
    }

    private void OnSpeciesPickToggled(string lineage, string kind, string traitId)
    {
        string field = lineage + "_chosen_species_" + kind;
        _draft.Patch(new Godot.Collections.Dictionary { { field, traitId } });
    }

    private void RefreshPurebredGrid()
    {
        foreach (var c in _purebredGrid.GetChildren()) c.Free();
        if (string.IsNullOrEmpty(_draft.CladeId)) return;
        foreach (var sp in CodexContent.SpeciesOfClade(_draft.CladeId))
            _purebredGrid.AddChild(BuildCard(sp, sp.Id == _draft.SpeciesId,
                spId => OnPurebredSpeciesPicked(spId)));
    }

    /// <summary>
    /// Hybrid mode: rebuild the unified grid with sire-clade species
    /// followed by dam-clade species. Sire and dam clades are
    /// guaranteed distinct by StepClade's parent-conflict rule, so the
    /// species lists are disjoint — each card unambiguously belongs to
    /// one lineage. Full rebuild on every Refresh is safe because Bind
    /// installs Refresh as a deferred callback.
    /// </summary>
    private void RefreshHybridGrid()
    {
        foreach (var c in _hybridGrid.GetChildren()) c.Free();
        AddHybridLineageBlock("sire", _draft.SireCladeId, _draft.SireSpeciesId);
        AddHybridLineageBlock("dam",  _draft.DamCladeId,  _draft.DamSpeciesId);
    }

    private void AddHybridLineageBlock(string lineage, string cladeId, string selectedSpeciesId)
    {
        if (string.IsNullOrEmpty(cladeId)) return;
        var clade = CodexContent.Clade(cladeId);
        string headerLabel = (lineage == "sire" ? "SIRE" : "DAM")
            + (clade is null ? "" : " — " + clade.Name.ToUpperInvariant());
        _hybridGrid.AddChild(new Label { Text = headerLabel, ThemeTypeVariation = "Eyebrow" });

        foreach (var sp in CodexContent.SpeciesOfClade(cladeId))
            _hybridGrid.AddChild(BuildCard(sp, sp.Id == selectedSpeciesId,
                spId => OnLineageSpeciesPicked(lineage, spId)));
    }

    private static Control BuildCard(SpeciesDef sp, bool selected, System.Action<string> onClick)
    {
        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)
                onClick(sp.Id);
        };

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

        box.AddChild(new Label { Text = sp.Name, ThemeTypeVariation = "CardName" });
        box.AddChild(new Label
        {
            Text = $"{sp.Size.ToUpperInvariant()} · {sp.BaseSpeedFt} FT/TURN",
            ThemeTypeVariation = "CardMeta",
        });

        if (!string.IsNullOrEmpty(sp.Description))
        {
            box.AddChild(new Label
            {
                Text = sp.Description,
                AutowrapMode = TextServer.AutowrapMode.WordSmart,
                MouseFilter = Control.MouseFilterEnum.Pass,
            });
        }

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

        if (sp.Traits.Length > 0 || sp.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 sp.Traits)
                chips.AddChild(new TraitChip { TraitName = t.Name, Description = t.Description });
            foreach (var d in sp.Detriments)
                chips.AddChild(new TraitChip { TraitName = d.Name, Description = d.Description, Detriment = true });
        }

        return card;
    }
}