using System;
using System.Collections.Generic;
using System.Numerics;
using AcDream.App.UI;

namespace AcDream.App.UI.Layout;

/// <summary>
/// Per-window controller for the Character window (LayoutDesc 0x2100002E, gmCharacterInfoUI).
///
/// <para>Retail fills a single scrollable <c>UIElement_Text</c> element (id 0x1000011d,
/// <c>m_pMainText</c>) by calling a sequence of Update* methods that each
/// <c>AppendStringInfo</c> into the same element. This controller replicates that report
/// structure using acdream's <see cref="UiText.LinesProvider"/>.</para>
///
/// <para>Section order (ported from <c>gmCharacterInfoUI::Update</c> 0x004ba790):
/// <list type="number">
///   <item>Birth / age / deaths  (<c>UpdatePlayerBirthAgeDeaths</c> 0x004b8cb0)</item>
///   <item>Vitals / endurance    (<c>UpdateEnduranceInfo</c> 0x004b8eb0)</item>
///   <item>Innate attributes     (<c>UpdateInnateAttributeInfo</c> 0x004b87e0):
///         InqAttribute 1,2,4,3,5,6 = Strength, Endurance, Quickness, Coordination, Focus, Self</item>
///   <item>Skills summary        (<c>UpdateFakeSkills</c> 0x004b8930)</item>
///   <item>Augmentations         (<c>UpdateAugmentations</c> 0x004b9000)</item>
///   <item>Burden / load         (<c>UpdateLoad</c> 0x004b8a20)</item>
/// </list>
/// Each section is separated by a blank line (retail: <c>AppendStringInfo(m_pMainText, &amp;var_120)</c>
/// with an empty StringInfo between sections).</para>
///
/// <para>StringInfo resolution is NOT ported — the full dat string-table lookup is a
/// later refinement. For this pilot, labels are composed directly from the well-known
/// AC attribute / stat names confirmed in the decomp string literals and data identifiers.</para>
/// </summary>
public static class CharacterController
{
    /// <summary>Dat element id for the main report text (m_pMainText). Confirmed in
    /// <c>gmCharacterInfoUI::PostInit</c> 0x004b86f0: <c>GetChildRecursive(this, 0x1000011d)</c>.</summary>
    public const uint MainTextId = 0x1000011du;

    /// <summary>White body text — matches retail's default UIElement_Text foreground.</summary>
    private static readonly Vector4 BodyColor   = new(1f, 1f, 1f, 1f);

    /// <summary>Yellow section header — retail uses a different StringInfo color per section header.</summary>
    private static readonly Vector4 HeaderColor = new(1f, 0.85f, 0.35f, 1f);

    /// <summary>
    /// Bind the character report text element found in <paramref name="layout"/> to
    /// <paramref name="data"/>. The report is regenerated each frame via
    /// <see cref="UiText.LinesProvider"/> so the Studio or a live session can push a fresh
    /// <see cref="CharacterSheet"/> without re-binding.
    ///
    /// <para>The element must resolve as a <see cref="UiText"/> (Type 12 in the dat).
    /// If 0x1000011d is absent from the layout the bind is a no-op — partial layouts
    /// (e.g. test fakes) don't cause errors.</para>
    /// </summary>
    /// <param name="layout">Imported 0x2100002E layout tree.</param>
    /// <param name="data">Provider returning the current <see cref="CharacterSheet"/>.</param>
    /// <param name="datFont">Retail dat font forwarded from the render stack. May be null
    /// (falls back to the BitmapFont debug path).</param>
    public static void Bind(
        ImportedLayout layout,
        Func<CharacterSheet> data,
        UiDatFont? datFont = null)
    {
        // Retail's gmCharacterInfoUI CREATES m_pMainText (0x1000011d) at RUNTIME — it is NOT a static
        // element in any LayoutDesc (confirmed: acdream's dat-import of 0x2100002E AND 0x2100006E both
        // lack it; only a runtime UI-tree capture has it). So replicate that: build the report text
        // element ourselves and place it in the panel body, exactly as the gm*UI does at runtime.
        var root = layout.Root;
        if (root is null) return;

        var text = new UiText
        {
            EventId      = MainTextId,
            Name         = "m_pMainText",
            Left         = 12f,
            Top          = 44f,                                   // below the window header row
            Width        = System.Math.Max(40f, root.Width  - 24f),
            Height       = System.Math.Max(40f, root.Height - 56f),
            Anchors      = AnchorEdges.None,
            ZOrder       = 1_000_000,                             // draw above the static chrome
            DatFont      = datFont,
            ClickThrough = false,
        };
        text.LinesProvider = () => BuildReport(data());
        root.AddChild(text);
    }

    // ── Report builder ────────────────────────────────────────────────────────

    /// <summary>
    /// Build the complete character report as a line list.
    /// Order mirrors <c>gmCharacterInfoUI::Update</c> (0x004ba790).
    /// </summary>
    private static IReadOnlyList<UiText.Line> BuildReport(CharacterSheet s)
    {
        var lines = new List<UiText.Line>();

        // ── Section 1: Birth / age / deaths  (UpdatePlayerBirthAgeDeaths 0x004b8cb0) ──
        // Retail InqInt(0x62) = DateOfBirth (unix timestamp); InqInt(0x7d) = TotalPlayTime;
        // InqInt(0x2b) = NumDeaths.
        AppendHeader(lines, s.Name);
        Append(lines, $"Level {s.Level}");
        if (s.Race is not null)
            Append(lines, s.Race);
        if (s.Heritage is not null)
            Append(lines, s.Heritage);
        if (s.Title is not null)
            Append(lines, s.Title);
        AppendBlank(lines);

        if (s.BirthDate is not null)
            Append(lines, $"Birth: {s.BirthDate}");
        if (s.PlayTime is not null)
            Append(lines, $"Age: {s.PlayTime}");
        Append(lines, $"Deaths: {s.Deaths}");
        AppendBlank(lines);

        // ── Section 2: Vitals / endurance  (UpdateEnduranceInfo 0x004b8eb0) ──
        // Retail InqAttribute(1) = Strength base, InqAttribute(2) = Endurance base.
        // Computes max-stamina tier and max-health tier from (Str+End) and (End+2*End) sums.
        AppendHeader(lines, "Vitals");
        Append(lines, $"Health:  {s.HealthCurrent} / {s.HealthMax}");
        Append(lines, $"Stamina: {s.StaminaCurrent} / {s.StaminaMax}");
        Append(lines, $"Mana:    {s.ManaCurrent} / {s.ManaMax}");
        AppendBlank(lines);

        // ── Section 3: Innate attributes  (UpdateInnateAttributeInfo 0x004b87e0) ──
        // InqAttribute order: 1,2,4,3,5,6 = Strength, Endurance, Quickness, Coordination,
        // Focus, Self (confirmed from the AddVariable_Int sequence in the decomp).
        AppendHeader(lines, "Attributes");
        Append(lines, $"Strength:      {s.Strength}");
        Append(lines, $"Endurance:     {s.Endurance}");
        Append(lines, $"Quickness:     {s.Quickness}");
        Append(lines, $"Coordination:  {s.Coordination}");
        Append(lines, $"Focus:         {s.Focus}");
        Append(lines, $"Self:          {s.Self}");
        AppendBlank(lines);

        // ── Section 4: Skills summary  (UpdateFakeSkills 0x004b8930) ──
        // Retail InqInt(0xb5) = SkillCredits remaining; InqInt(0xc0) = AvailableSkillCredits.
        AppendHeader(lines, "Skills");
        Append(lines, $"Unspent skill credits: {s.UnspentSkillCredits}");
        if (s.SpecializedSkillCredits > 0)
            Append(lines, $"Specialized credits: {s.SpecializedSkillCredits}");
        AppendBlank(lines);

        // ── Section 5: Augmentations  (UpdateAugmentations 0x004b9000) ──
        // Retail InqInt(0x162) = AugmentationStat; string-switch on value 1..0xb + Unknown.
        AppendHeader(lines, "Augmentations");
        if (s.AugmentationName is not null)
            Append(lines, s.AugmentationName);
        else
            Append(lines, "None");
        AppendBlank(lines);

        // ── Section 6: Burden / load  (UpdateLoad 0x004b8a20) ──
        // Retail InqLoad → EncumbranceCapacity(Strength, AugEncumbrance).
        // When load >= 1.0 (overloaded): shows "X burden over capacity; Y% speed penalty".
        // When aug > 0: shows "N augmentations (X.X% bonus)".
        AppendHeader(lines, "Encumbrance");
        Append(lines, $"Burden:    {s.BurdenCurrent}");
        Append(lines, $"Capacity:  {s.BurdenMax}");
        if (s.BurdenMax > 0)
        {
            int pct = (int)Math.Round(100.0 * s.BurdenCurrent / s.BurdenMax);
            Append(lines, $"Load:      {pct}%");
        }

        return lines;
    }

    // ── Line helpers ──────────────────────────────────────────────────────────

    private static void AppendHeader(List<UiText.Line> lines, string text)
        => lines.Add(new UiText.Line(text, HeaderColor));

    private static void Append(List<UiText.Line> lines, string text)
        => lines.Add(new UiText.Line(text, BodyColor));

    private static void AppendBlank(List<UiText.Line> lines)
        => lines.Add(new UiText.Line(string.Empty, BodyColor));
}