using System.Numerics;
using AcDream.App.UI;
using AcDream.App.UI.Layout;
using AcDream.Runtime;

namespace AcDream.App.Tests.UI.Layout;

/// <summary>
/// Campaign CT slice CT3: hermetic (no DAT, no live runtime) tests for
/// <see cref="CharacterTitlesController"/>. Binding-seam coverage
/// (<c>feedback_test_the_binding_seam.md</c>) uses the REAL committed
/// <c>character_2100002E.json</c> fixture — verified (2026-08-24) to already
/// carry the whole Titles page subtree, including the ListBox's own
/// authored <c>TemplateList</c> entry pointing at <c>(0x2100005E,
/// 0x10000536)</c> — so every element this controller binds except the row
/// template ITSELF (a separate LayoutDesc CT1 could only reach via a live
/// DAT probe, with no committed fixture yet) comes from the real imported
/// tree, not a hand-built stand-in.
/// </summary>
public sealed class CharacterTitlesControllerTests
{
    // Row template ground truth (docs/research/2026-08-24-campaign-ct-dat-
    // ground-truth.md §3): LayoutDesc 0x2100005E, element 0x10000536 — a
    // 270x24 Type-3 container with DirectState/Highlight media and one
    // Type-0xC text child (0x10000537).
    private const uint RowTemplateLayoutId = 0x2100005Eu;
    private const uint RowTemplateElementId = 0x10000536u;
    private const uint RowTextId = 0x10000537u;
    private const uint RowNormalSprite = 0x06004CCAu;
    private const uint RowHighlightSprite = 0x06001AAFu;

    private static ElementInfo BuildRowTemplateInfo()
    {
        var info = new ElementInfo
        {
            Id = RowTemplateElementId,
            Type = 3u,
            Width = 270f,
            Height = 24f,
        };
        info.StateMedia[""] = (RowNormalSprite, 3);
        info.StateMedia["Highlight"] = (RowHighlightSprite, 1);
        info.Children.Add(new ElementInfo
        {
            Id = RowTextId,
            Type = 0xCu,
            Width = 270f,
            Height = 24f,
            HJustify = HJustify.Left,
            FontColor = Vector4.One,
        });
        return info;
    }

    private static UiElement? FakeRowTemplateResolver(uint layoutId, uint elementId)
        => LayoutImporter.Build(BuildRowTemplateInfo(), static _ => (0u, 0, 0), null).Root;

    private sealed class Harness
    {
        public required ImportedLayout Layout;
        public required UiTemplateListBox ListBox;
        public required UiText DisplayText;
        public required UiButton SetDisplayButton;
        public required RuntimeCharacterTitleState Titles;
        public required Dictionary<uint, string> Names;
        public required List<uint> SentTitleIds;
        public required CharacterTitlesController Controller;

        public IReadOnlyList<UiElement> Rows =>
            ListBox.ViewportForTest?.Children ?? [];

        public string RowText(UiElement row) =>
            ((UiText)UiElement.FindDescendant(row, RowTextId)!).LinesProvider().Single().Text;

        public uint RowMedia(UiElement row) =>
            ((UiDatElement)row).ActiveMedia().File;
    }

    // ── Binding seam ─────────────────────────────────────────────────────

    [Fact]
    public void Bind_FindsEveryTitlesPageElement_InTheRealImportedFixture()
    {
        Harness h = BindWithEarnedTitles([], displayTitleId: 0u);

        Assert.NotNull(h.Controller);
        Assert.Equal(CharacterTitlesController.TitleListBoxId, h.ListBox.DatElementId);
        Assert.Equal(CharacterTitlesController.CurrentDisplayTitleTextId, h.DisplayText.DatElementId);
        Assert.Equal(CharacterTitlesController.SetDisplayButtonId, h.SetDisplayButton.DatElementId);
        // The authored scrollbar (0x10000533, the ListBox's own
        // ScrollbarElementId) must actually be wired to the list's scroll
        // model, not merely present.
        var scrollbar = Assert.IsType<UiScrollbar>(
            h.Layout.FindElement(h.ListBox.ScrollbarElementId));
        Assert.Same(h.ListBox.Scroll, scrollbar.Model);
    }

    [Fact]
    public void Fixture_PageCaptions_ResolveToNonEmptyText()
    {
        // Pins this class's own remarks claim (CT3 fix round item 5b):
        // LayoutImporter.BuildText already resolves every element's
        // authored StringInfo caption at import time, so the Titles page's
        // two static captions (0x1000052E/0x10000531) must actually carry a
        // resolvable authored StringInfo -- not silently come through as
        // empty/missing text -- even though this controller never touches
        // either element itself. FixtureLoader.LoadCharacter() passes NO
        // string resolver (it needs no live DAT for structural conformance
        // checks elsewhere), so this test rebuilds the SAME committed
        // fixture with a stub resolver that stands in for
        // DatStringResolver.Resolve -- exercising the real
        // ResolveAuthoredString → stringResolve pipeline
        // (DatWidgetFactory.cs) without needing a live StringTable.
        static string? StubResolve(UiStringInfoValue info) =>
            info.TableId != 0u && info.StringId != 0u ? "<resolved>" : null;
        ImportedLayout layout = LayoutImporter.Build(
            FixtureLoader.LoadCharacterInfos(),
            static _ => (0u, 0, 0),
            null,
            stringResolve: StubResolve);

        var currentTitleCaption = Assert.IsType<UiText>(layout.FindElement(0x1000052Eu));
        var titlesEarnedCaption = Assert.IsType<UiText>(layout.FindElement(0x10000531u));

        Assert.Equal("<resolved>", currentTitleCaption.LinesProvider()[0].Text);
        Assert.Equal("<resolved>", titlesEarnedCaption.LinesProvider()[0].Text);
    }

    [Fact]
    public void Bind_MissingListBox_ReturnsNullWithoutThrowing()
    {
        var root = new UiPanel();
        var titles = new RuntimeCharacterTitleState();

        CharacterTitlesController? controller = CharacterTitlesController.Bind(
            root,
            titles,
            static _ => null,
            FakeRowTemplateResolver,
            static _ => new RuntimeCommandResult(RuntimeCommandStatus.Inactive, default));

        Assert.Null(controller);
    }

    [Fact]
    public void RowTemplateResolver_ReceivesTheFixturesOwnAuthoredTemplateIds()
    {
        // The REAL fixture's ListBox (0x10000532) authors TemplateList =
        // [(0x2100005E, 0x10000536)] (dat property 0x64) — this proves the
        // controller's AddItemFromTemplateList(0) call actually reads that
        // authored entry rather than a hardcoded pair of its own.
        var seen = new List<(uint LayoutId, uint ElementId)>();
        UiElement? Recording(uint layoutId, uint elementId)
        {
            seen.Add((layoutId, elementId));
            return FakeRowTemplateResolver(layoutId, elementId);
        }

        BindWithEarnedTitles(
            [1u], displayTitleId: 0u,
            names: new() { [1u] = "Adventurer" },
            rowResolver: Recording);

        (uint layoutId, uint elementId) = Assert.Single(seen);
        Assert.Equal(RowTemplateLayoutId, layoutId);
        Assert.Equal(RowTemplateElementId, elementId);
    }

    private static Harness BindWithEarnedTitles(
        IReadOnlyList<uint> earnedIds,
        uint displayTitleId,
        Dictionary<uint, string>? names = null,
        Func<uint, uint, UiElement?>? rowResolver = null)
    {
        ImportedLayout layout = FixtureLoader.LoadCharacter();
        var titles = new RuntimeCharacterTitleState();
        titles.ReplaceTable(displayTitleId, earnedIds.ToArray());
        Dictionary<uint, string> resolvedNames = names ?? new Dictionary<uint, string>();
        var sent = new List<uint>();

        RuntimeCommandResult SendSetTitle(uint id)
        {
            sent.Add(id);
            return new RuntimeCommandResult(RuntimeCommandStatus.Accepted, default);
        }

        string? ResolveTitle(uint id) =>
            resolvedNames.TryGetValue(id, out string? name) ? name : null;

        CharacterTitlesController? controller = CharacterTitlesController.Bind(
            layout.Root,
            titles,
            ResolveTitle,
            rowResolver ?? FakeRowTemplateResolver,
            SendSetTitle);
        Assert.NotNull(controller);

        var listBox = Assert.IsType<UiTemplateListBox>(
            layout.FindElement(CharacterTitlesController.TitleListBoxId));
        var displayText = Assert.IsType<UiText>(
            layout.FindElement(CharacterTitlesController.CurrentDisplayTitleTextId));
        var button = Assert.IsType<UiButton>(
            layout.FindElement(CharacterTitlesController.SetDisplayButtonId));

        return new Harness
        {
            Layout = layout,
            ListBox = listBox,
            DisplayText = displayText,
            SetDisplayButton = button,
            Titles = titles,
            Names = resolvedNames,
            SentTitleIds = sent,
            Controller = controller!,
        };
    }

    // ── Row sort + content ──────────────────────────────────────────────

    [Fact]
    public void Rows_AreSortedAlphabeticallyByResolvedTitleText()
    {
        Harness h = BindWithEarnedTitles(
            [13u, 5u, 1u],
            displayTitleId: 0u,
            names: new()
            {
                [1u] = "Adventurer",
                [5u] = "Life Mage",
                [13u] = "War Mage",
            });

        Assert.Equal(3, h.Rows.Count);
        Assert.Equal(
            ["Adventurer", "Life Mage", "War Mage"],
            h.Rows.Select(h.RowText));
    }

    [Fact]
    public void Rows_UnresolvedTitle_ProducesNoRow()
    {
        // AddTitleToList @0x0049A840 early-outs (@0x0049a873/@0x0049a914):
        // retail never creates a row for an id GetCharacterTitleFromID
        // fails to resolve -- "Unknown" is exclusively the display-title
        // text's own Refresh fallback literal (below), never a row's
        // (CT3 fix round -- this was previously ported backwards).
        Harness h = BindWithEarnedTitles(
            [99u],
            displayTitleId: 0u,
            names: []);

        Assert.Empty(h.Rows);
    }

    [Fact]
    public void Rows_TitleIdZero_ProducesNoRow()
    {
        // Same early-out (@0x0049a873), the OTHER guarded case: retail
        // never creates a row for id 0 even if a resolver were somehow
        // willing to answer for it.
        Harness h = BindWithEarnedTitles(
            [0u, 1u],
            displayTitleId: 0u,
            names: new() { [0u] = "Should Never Appear", [1u] = "Adventurer" });

        UiElement row = Assert.Single(h.Rows);
        Assert.Equal("Adventurer", h.RowText(row));
    }

    // ── Selection + highlight ─────────────────────────────────────────────

    [Fact]
    public void SelectingARow_AppliesHighlightMedia_AndDeselectsTheOthers()
    {
        Harness h = BindWithEarnedTitles(
            [1u, 5u],
            displayTitleId: 0u,
            names: new() { [1u] = "Adventurer", [5u] = "Life Mage" });
        UiElement first = h.Rows[0];
        UiElement second = h.Rows[1];

        ((UiDatElement)first).OnClick!();

        Assert.Equal(RowHighlightSprite, h.RowMedia(first));
        Assert.Equal(RowNormalSprite, h.RowMedia(second));

        ((UiDatElement)second).OnClick!();

        Assert.Equal(RowNormalSprite, h.RowMedia(first));
        Assert.Equal(RowHighlightSprite, h.RowMedia(second));
    }

    // ── Ghost truth table (UpdateButtons @0x0049A500, CORRECTED direction) ─

    [Fact]
    public void Ghost_NoSelection_ButtonIsGhosted()
    {
        Harness h = BindWithEarnedTitles([1u], displayTitleId: 0u, names: new() { [1u] = "Adventurer" });

        Assert.False(h.SetDisplayButton.Enabled);
    }

    [Fact]
    public void Ghost_SelectedRowEqualsCurrentDisplayTitle_ButtonIsGhosted()
    {
        Harness h = BindWithEarnedTitles(
            [1u, 5u], displayTitleId: 5u,
            names: new() { [1u] = "Adventurer", [5u] = "Life Mage" });
        // Sorted order: Adventurer(1), Life Mage(5) — select the row whose
        // id equals the current display title (5).
        UiElement lifeMageRow = h.Rows.Single(r => h.RowText(r) == "Life Mage");

        ((UiDatElement)lifeMageRow).OnClick!();

        Assert.False(h.SetDisplayButton.Enabled);
    }

    [Fact]
    public void Ghost_SelectedRowDiffersFromCurrentDisplayTitle_ButtonIsNormal()
    {
        Harness h = BindWithEarnedTitles(
            [1u, 5u], displayTitleId: 5u,
            names: new() { [1u] = "Adventurer", [5u] = "Life Mage" });
        UiElement adventurerRow = h.Rows.Single(r => h.RowText(r) == "Adventurer");

        ((UiDatElement)adventurerRow).OnClick!();

        Assert.True(h.SetDisplayButton.Enabled);
    }

    // ── Click -> SetTitle wire send ────────────────────────────────────────

    [Fact]
    public void ClickingSetDisplay_SendsExactlyOneSetTitleWithTheSelectedId_AndMutatesNothingLocally()
    {
        Harness h = BindWithEarnedTitles(
            [1u, 13u], displayTitleId: 1u,
            names: new() { [1u] = "Adventurer", [13u] = "War Mage" });
        UiElement warMageRow = h.Rows.Single(r => h.RowText(r) == "War Mage");
        ((UiDatElement)warMageRow).OnClick!();
        List<UiElement> rowsBeforeClick = h.Rows.ToList();

        h.SetDisplayButton.OnClick!();

        Assert.Equal([13u], h.SentTitleIds);
        // No optimistic local mutation — CT2's own contract (ACE sends no
        // echo when re-setting the current title; the display title only
        // ever changes from a DisplayTitleChanged event).
        Assert.Equal(1u, h.Titles.DisplayTitleId);
        Assert.Equal("Adventurer", h.DisplayText.LinesProvider().Single().Text);
        // The click is wire-only: no RebuildRows, no selection change. The
        // row set is the SAME instances in the same order, and War Mage
        // stays selected/highlighted/enabled exactly as before the click.
        Assert.Equal(rowsBeforeClick, h.Rows);
        Assert.Equal(RowHighlightSprite, h.RowMedia(warMageRow));
        Assert.True(h.SetDisplayButton.Enabled);
    }

    [Fact]
    public void ClickingSetDisplay_WhileGhosted_SendsNothing()
    {
        Harness h = BindWithEarnedTitles([1u], displayTitleId: 0u, names: new() { [1u] = "Adventurer" });

        // No row selected -> Ghosted. A direct OnClick invocation bypasses
        // UiButton's own Enabled-gated event routing, so this exercises the
        // controller's own belt-and-braces re-check.
        h.SetDisplayButton.OnClick!();

        Assert.Empty(h.SentTitleIds);
    }

    // ── Wire events ─────────────────────────────────────────────────────

    [Fact]
    public void TableReplaced_RebuildsRows_AndClearsSelection()
    {
        Harness h = BindWithEarnedTitles(
            [1u], displayTitleId: 0u, names: new() { [1u] = "Adventurer", [13u] = "War Mage" });
        ((UiDatElement)h.Rows[0]).OnClick!();
        Assert.True(h.SetDisplayButton.Enabled); // selected, differs from display(0)

        h.Titles.ReplaceTable(0u, [13u]);

        Assert.Equal(["War Mage"], h.Rows.Select(h.RowText));
        // The previously-selected row no longer exists post-rebuild -> back
        // to the no-selection Ghosted state.
        Assert.False(h.SetDisplayButton.Enabled);
    }

    [Fact]
    public void TableReplaced_ClearsSelection_EvenWhenTheSelectedIdIsStillEarned()
    {
        // BLOCKER fix (CT3 fix round): Refresh @0x0049abc0 calls
        // SetSelectedItem(nullptr, 1) (@0x0049ac5a) UNCONDITIONALLY, before
        // it repopulates the list -- a still-earned selected id is no
        // defense. A byte-identical resend must still dark out the row and
        // re-ghost the button (this test used to assert the OPPOSITE and
        // was wrong).
        Harness h = BindWithEarnedTitles(
            [1u, 5u], displayTitleId: 0u,
            names: new() { [1u] = "Adventurer", [5u] = "Life Mage" });
        UiElement lifeMageRow = h.Rows.Single(r => h.RowText(r) == "Life Mage");
        ((UiDatElement)lifeMageRow).OnClick!();
        Assert.True(h.SetDisplayButton.Enabled);

        // Same table resent (retail's own Refresh() is unconditional —
        // CT2 review anchor 1) — the id (5) is STILL earned afterward, yet
        // the selection must still be dropped.
        h.Titles.ReplaceTable(0u, [1u, 5u]);

        UiElement rebuiltLifeMageRow = h.Rows.Single(r => h.RowText(r) == "Life Mage");
        Assert.Equal(RowNormalSprite, h.RowMedia(rebuiltLifeMageRow));
        Assert.False(h.SetDisplayButton.Enabled);
    }

    [Fact]
    public void DisplayTitleChanged_ClearsSelection_EvenWhenTheSelectedIdIsStillEarned()
    {
        // The display-change twin of the TableReplaced test above: 0x002B's
        // display half is retail's OTHER Refresh() call site, so it carries
        // the same unconditional SetSelectedItem(nullptr, 1) (@0x0049ac5a).
        // This handler never calls RebuildRows (the row SET does not
        // change), so it specifically proves the highlight is re-applied
        // via ApplyRowHighlights even without a rebuild. Selecting a
        // DIFFERENT id than the one becoming the new display title isolates
        // this from the already-covered "selection == new display title"
        // ghost case (DisplayTitleChanged_UpdatesTextAndReevaluatesGhost):
        // id 1 remains earned and still differs from the new display id 5,
        // yet selection must still clear.
        Harness h = BindWithEarnedTitles(
            [1u, 5u], displayTitleId: 0u,
            names: new() { [1u] = "Adventurer", [5u] = "Life Mage" });
        UiElement adventurerRow = h.Rows.Single(r => h.RowText(r) == "Adventurer");
        ((UiDatElement)adventurerRow).OnClick!();
        Assert.Equal(RowHighlightSprite, h.RowMedia(adventurerRow));
        Assert.True(h.SetDisplayButton.Enabled); // selected(1) != display(0)

        h.Titles.ApplyUpdateTitle(5u, setAsDisplay: true);

        Assert.Equal(RowNormalSprite, h.RowMedia(adventurerRow));
        Assert.False(h.SetDisplayButton.Enabled);
    }

    [Fact]
    public void TitleAdded_PreservesSelection()
    {
        // RecvNotice_AddCharacterTitle @0x0049a990 splices the new row into
        // mTitleList without ever touching m_pSelectedItem -- a DIFFERENT
        // retail method from Refresh, and the one case that must NOT clear
        // selection. This is the case most at risk from the blocker fix
        // above (it would be trivial to over-clear on every wire event).
        Harness h = BindWithEarnedTitles(
            [1u], displayTitleId: 0u,
            names: new() { [1u] = "Adventurer", [13u] = "War Mage" });
        UiElement adventurerRow = Assert.Single(h.Rows);
        ((UiDatElement)adventurerRow).OnClick!();
        Assert.Equal(RowHighlightSprite, h.RowMedia(adventurerRow));
        Assert.True(h.SetDisplayButton.Enabled);

        h.Titles.ApplyUpdateTitle(13u, setAsDisplay: false);

        UiElement rebuiltAdventurerRow = h.Rows.Single(r => h.RowText(r) == "Adventurer");
        Assert.Equal(RowHighlightSprite, h.RowMedia(rebuiltAdventurerRow));
        Assert.True(h.SetDisplayButton.Enabled);
    }

    [Fact]
    public void TitleAdded_InsertsExactlyOneRow_PreservingExistingRowsInSortedOrder()
    {
        Harness h = BindWithEarnedTitles(
            [1u], displayTitleId: 0u,
            names: new() { [1u] = "Adventurer", [5u] = "Life Mage" });
        Assert.Single(h.Rows);

        h.Titles.ApplyUpdateTitle(5u, setAsDisplay: false);

        Assert.Equal(["Adventurer", "Life Mage"], h.Rows.Select(h.RowText));
    }

    [Fact]
    public void DisplayTitleChanged_UpdatesTextAndReevaluatesGhost()
    {
        Harness h = BindWithEarnedTitles(
            [1u, 5u], displayTitleId: 0u,
            names: new() { [1u] = "Adventurer", [5u] = "Life Mage" });
        UiElement lifeMageRow = h.Rows.Single(r => h.RowText(r) == "Life Mage");
        ((UiDatElement)lifeMageRow).OnClick!();
        Assert.True(h.SetDisplayButton.Enabled); // selected(5) != display(0)

        // Simulates the server echo (0x002B UpdateTitle, setAsDisplay=true)
        // that a real Set-as-Display send would eventually produce.
        h.Titles.ApplyUpdateTitle(5u, setAsDisplay: true);

        Assert.Equal("Life Mage", h.DisplayText.LinesProvider().Single().Text);
        // Selection now equals the (new) current display title -> Ghosted.
        Assert.False(h.SetDisplayButton.Enabled);
    }

    [Fact]
    public void DisplayTitleText_UnresolvedId_ShowsRetailUnknownLiteral()
    {
        Harness h = BindWithEarnedTitles([1u], displayTitleId: 77u, names: new() { [1u] = "Adventurer" });

        Assert.Equal("Unknown", h.DisplayText.LinesProvider().Single().Text);
    }

    [Fact]
    public void DisplayTitleText_NoDisplayTitleSet_ShowsRetailUnknownLiteral()
    {
        Harness h = BindWithEarnedTitles([1u], displayTitleId: 0u, names: new() { [1u] = "Adventurer" });

        Assert.Equal("Unknown", h.DisplayText.LinesProvider().Single().Text);
    }

    // ── Lifecycle ───────────────────────────────────────────────────────

    [Fact]
    public void Dispose_UnsubscribesFromTitleEvents()
    {
        Harness h = BindWithEarnedTitles([1u], displayTitleId: 0u, names: new() { [1u] = "Adventurer" });

        h.Controller.Dispose();

        // Must not throw, and must not rebuild the (now-orphaned) rows.
        h.Titles.ReplaceTable(0u, [1u, 5u]);
        Assert.Single(h.Rows);
    }
}