using System.Globalization;
using System.Numerics;
using AcDream.Content;
using AcDream.Core.Net.Messages;
using DatReaderWriter;
using DatReaderWriter.DBObjs;
using DatReaderWriter.Types;

namespace AcDream.App.UI.Layout;

public enum CreatureAppraisalValueStyle
{
    Normal,
    Positive,
    Negative,
    Incomplete,
}

public readonly record struct CreatureAppraisalRow(
    string Label,
    string Value,
    CreatureAppraisalValueStyle Style);

/// <summary>
/// Pure projection of retail's six <c>AttributeInfoRegion</c> and three
/// <c>Attribute2ndInfoRegion</c> tokens. Ordering and formatting come from
/// <c>BasicCreatureExamineUI</c> and the two Update overloads at
/// 0x004F1D90/0x004F1E80.
/// </summary>
public static class CreatureAppraisalRows
{
    private const string Unknown = "???";

    public static IReadOnlyList<CreatureAppraisalRow> Build(
        AppraiseInfoParser.CreatureProfile profile,
        bool success)
    {
        return
        [
            Primary("Strength", profile.Strength, 0, profile, success),
            Primary("Endurance", profile.Endurance, 1, profile, success),
            Primary("Coordination", profile.Coordination, 3, profile, success),
            Primary("Quickness", profile.Quickness, 2, profile, success),
            Primary("Focus", profile.Focus, 4, profile, success),
            Primary("Self", profile.Self, 5, profile, success),
            Secondary(
                "Health",
                profile.Health,
                profile.HealthMax,
                showPercent: true,
                enchantmentBit: 6,
                profile,
                success),
            Secondary(
                "Stamina",
                profile.Stamina,
                profile.StaminaMax,
                showPercent: false,
                enchantmentBit: 7,
                profile,
                success),
            Secondary(
                "Mana",
                profile.Mana,
                profile.ManaMax,
                showPercent: false,
                enchantmentBit: 8,
                profile,
                success),
        ];
    }

    private static CreatureAppraisalRow Primary(
        string label,
        uint? value,
        int enchantmentBit,
        AppraiseInfoParser.CreatureProfile profile,
        bool success)
        => new(
            label,
            value is > 0
                ? value.Value.ToString(CultureInfo.CurrentCulture)
                : Unknown,
            Style(enchantmentBit, profile, success));

    private static CreatureAppraisalRow Secondary(
        string label,
        uint? current,
        uint? maximum,
        bool showPercent,
        int enchantmentBit,
        AppraiseInfoParser.CreatureProfile profile,
        bool success)
    {
        string value = Unknown;
        if (current is > 0 && maximum is > 0)
        {
            int percent = RoundedPercent(current.Value, maximum.Value);
            if (success)
            {
                value = showPercent
                    ? $"{current.Value.ToString(CultureInfo.CurrentCulture)}/{maximum.Value.ToString(CultureInfo.CurrentCulture)} ({percent.ToString(CultureInfo.CurrentCulture)} %)"
                    : $"{current.Value.ToString(CultureInfo.CurrentCulture)}/{maximum.Value.ToString(CultureInfo.CurrentCulture)}";
            }
            else if (showPercent)
            {
                value = $"{percent.ToString(CultureInfo.CurrentCulture)} %";
            }
        }

        return new CreatureAppraisalRow(
            label,
            value,
            Style(enchantmentBit, profile, success));
    }

    private static int RoundedPercent(uint numerator, uint denominator)
        => denominator == 0u
            ? 0
            : (int)Math.Min(
                int.MaxValue,
                ((100L * numerator) + denominator / 2L) / denominator);

    private static CreatureAppraisalValueStyle Style(
        int bit,
        AppraiseInfoParser.CreatureProfile profile,
        bool success)
    {
        if (!success)
            return CreatureAppraisalValueStyle.Incomplete;

        ushort highlight = profile.AttributeHighlights ?? 0;
        if ((highlight & (1 << bit)) == 0)
            return CreatureAppraisalValueStyle.Normal;

        ushort color = profile.AttributeColors ?? 0;
        return (color & (1 << bit)) != 0
            ? CreatureAppraisalValueStyle.Positive
            : CreatureAppraisalValueStyle.Negative;
    }
}

/// <summary>
/// Instantiates LayoutDesc 0x2100006B's InfoRegion token template
/// 0x10000166, matching <c>UIElement_ListBox::AddItemFromTemplateList</c>.
/// </summary>
public sealed class CreatureAppraisalRowTemplateFactory
{
    public const uint TemplateId = 0x10000166u;
    public const uint LabelId = 0x1000012Au;
    public const uint ValueId = 0x1000012Bu;

    private readonly ElementInfo _template;
    private readonly Func<uint, (uint Texture, int Width, int Height)> _resolveSprite;
    private readonly UiDatFont? _defaultFont;
    private readonly IReadOnlyDictionary<uint, UiDatFont?> _fonts;

    public CreatureAppraisalRowTemplateFactory(
        ElementInfo template,
        Func<uint, (uint Texture, int Width, int Height)> resolveSprite,
        UiDatFont? defaultFont,
        IReadOnlyDictionary<uint, UiDatFont?>? fonts = null)
    {
        _template = template ?? throw new ArgumentNullException(nameof(template));
        _resolveSprite = resolveSprite ?? throw new ArgumentNullException(nameof(resolveSprite));
        _defaultFont = defaultFont;
        _fonts = fonts ?? new Dictionary<uint, UiDatFont?>();
    }

    public float Width => _template.Width;
    public float Height => _template.Height;

    public static CreatureAppraisalRowTemplateFactory? TryLoad(
        IDatReaderWriter dats,
        Func<uint, (uint Texture, int Width, int Height)> resolveSprite,
        UiDatFont? defaultFont,
        Func<uint, UiDatFont?>? resolveFont)
    {
        ElementInfo? template = LayoutImporter.ImportInfos(
            dats,
            AppraisalUiController.LayoutId,
            TemplateId);
        if (template is null
            || Find(template, LabelId) is null
            || Find(template, ValueId) is null
            || template.Width <= 0f
            || template.Height <= 0f)
        {
            return null;
        }

        var fonts = new Dictionary<uint, UiDatFont?>();
        CaptureFonts(template, resolveFont, fonts);
        return new CreatureAppraisalRowTemplateFactory(
            template,
            resolveSprite,
            defaultFont,
            fonts);
    }

    public UiTemplateListSlot Create(CreatureAppraisalRow row)
    {
        ImportedLayout content = LayoutImporter.Build(
            _template,
            _resolveSprite,
            _defaultFont,
            did => _fonts.TryGetValue(did, out UiDatFont? font)
                ? font
                : _defaultFont);
        UiText label = Required<UiText>(content, LabelId);
        UiText value = Required<UiText>(content, ValueId);
        label.LinesProvider = () =>
            [new UiText.Line(row.Label, label.DefaultColor)];
        value.LinesProvider = () =>
            [new UiText.Line(row.Value, ResolveColor(row.Style, value.DefaultColor))];

        return new UiTemplateListSlot(
            content,
            entryId: 0u,
            content.Root is IUiDatStateful stateful
                ? stateful.ActiveRetailStateId
                : UiStateInfo.DirectStateId,
            selectedState: null);
    }

    private static Vector4 ResolveColor(
        CreatureAppraisalValueStyle style,
        Vector4 normal)
    {
        // Retail selects one of four authored FontInfo entries here. Keep the
        // semantic state in the row model, but do not invent substitute RGB
        // values while that FontInfo-list binding remains unported (AP-110).
        _ = style;
        return normal;
    }

    private static T Required<T>(ImportedLayout content, uint id)
        where T : UiElement
        => content.FindElement(id) as T
            ?? throw new InvalidOperationException(
                $"Retail creature appraisal template element 0x{id:X8} did not resolve to {typeof(T).Name}.");

    private static ElementInfo? Find(ElementInfo root, uint id)
    {
        if (root.Id == id)
            return root;
        foreach (ElementInfo child in root.Children)
            if (Find(child, id) is { } found)
                return found;
        return null;
    }

    private static void CaptureFonts(
        ElementInfo info,
        Func<uint, UiDatFont?>? resolveFont,
        Dictionary<uint, UiDatFont?> fonts)
    {
        if (info.FontDid != 0u && !fonts.ContainsKey(info.FontDid))
            fonts[info.FontDid] = resolveFont?.Invoke(info.FontDid);
        foreach (ElementInfo child in info.Children)
            CaptureFonts(child, resolveFont, fonts);
    }
}

/// <summary>
/// Retail <c>AppraisalSystem::InqCreatureDisplayName @ 0x005B59E0</c> resolves
/// creature enum 0x10000005 through portal EnumMapper 0x2200000E and replaces
/// underscores with spaces.
/// </summary>
public sealed class CreatureDisplayNameResolver
{
    public const uint MapperDid = 0x2200000Eu;
    private readonly IReadOnlyDictionary<uint, string> _names;

    public CreatureDisplayNameResolver(
        IReadOnlyDictionary<uint, string> names)
    {
        _names = names ?? throw new ArgumentNullException(nameof(names));
    }

    public static CreatureDisplayNameResolver Load(IDatReaderWriter dats)
    {
        ArgumentNullException.ThrowIfNull(dats);
        var names = new Dictionary<uint, string>();
        var visited = new HashSet<uint>();
        uint did = MapperDid;
        while (did != 0u && visited.Add(did))
        {
            EnumMapper? mapper = dats.Get<EnumMapper>(did);
            if (mapper is null)
                break;
            foreach ((uint id, PStringBase<byte> text) in mapper.IdToStringMap)
                names.TryAdd(id, text.Value.Replace('_', ' '));
            did = mapper.BaseEnumMap;
        }
        return new CreatureDisplayNameResolver(names);
    }

    public string Resolve(int creatureType)
        => creatureType > 0
            && _names.TryGetValue((uint)creatureType, out string? name)
                ? name
                : string.Empty;
}