using System.IO;
using System.Text.Json;
using AcDream.App.UI.Layout;

namespace AcDream.App.Tests.UI.Layout;

/// <summary>
/// Loads the committed layout ElementInfo fixtures and builds widget trees —
/// no dats required. Fixtures were generated from the real portal.dat and
/// serialized with <see cref="System.Text.Json"/>.
/// </summary>
public static class FixtureLoader
{
    private static readonly JsonSerializerOptions _opts = new()
    {
        IncludeFields = true,
    };

    /// <summary>
    /// Deserializes the committed <c>vitals_2100006C.json</c> fixture (copied to
    /// the test output directory via the csproj <c>CopyToOutputDirectory</c> item)
    /// into an <see cref="ElementInfo"/> tree, then builds and returns the
    /// <see cref="ImportedLayout"/> using a null-returning sprite resolver and no
    /// dat font — sufficient for conformance checks on tree structure and slice ids.
    /// </summary>
    public static ImportedLayout LoadVitals()
    {
        var root = LoadVitalsInfos();
        return LayoutImporter.Build(root, _ => (0u, 0, 0), null);
    }

    /// <summary>
    /// Deserializes the committed <c>vitals_2100006C.json</c> fixture into a raw
    /// <see cref="ElementInfo"/> tree WITHOUT calling <see cref="LayoutImporter.Build"/>.
    /// Use this when the test needs to inspect the resolved <see cref="ElementInfo"/>
    /// tree directly (e.g. inheritance-resolution checks) without exercising the
    /// widget factory.
    /// </summary>
    public static AcDream.App.UI.Layout.ElementInfo LoadVitalsInfos()
        => LoadInfos("vitals_2100006C.json");

    /// <summary>
    /// Deserializes the committed <c>chat_21000006.json</c> fixture into a raw
    /// <see cref="ElementInfo"/> tree and builds the <see cref="ImportedLayout"/>
    /// using a null-returning sprite resolver and no dat font — sufficient for
    /// conformance checks on tree structure and resolved types.
    /// </summary>
    public static ImportedLayout LoadChat()
        => LayoutImporter.Build(LoadChatInfos(), _ => (0u, 0, 0), null);

    /// <summary>
    /// Deserializes the committed <c>chat_21000006.json</c> fixture into a raw
    /// <see cref="ElementInfo"/> tree WITHOUT calling <see cref="LayoutImporter.Build"/>.
    /// Use this when the test needs to inspect the resolved <see cref="ElementInfo"/>
    /// tree directly (e.g. resolved Type values per element id).
    /// </summary>
    public static AcDream.App.UI.Layout.ElementInfo LoadChatInfos()
        => LoadInfos("chat_21000006.json");

    /// <summary>Builds the committed retail radar LayoutDesc 0x21000074 fixture.</summary>
    public static ImportedLayout LoadRadar()
        => LayoutImporter.Build(LoadRadarInfos(), _ => (0u, 0, 0), null);

    /// <summary>Returns the resolved ElementInfo tree for retail radar LayoutDesc 0x21000074.</summary>
    public static AcDream.App.UI.Layout.ElementInfo LoadRadarInfos()
        => LoadInfos("radar_21000074.json");

    public static ImportedLayout LoadToolbar()
        => LayoutImporter.Build(LoadToolbarInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadToolbarInfos()
        => LoadInfos("toolbar_21000016.json");

    public static ImportedLayout LoadInventory()
        => LayoutImporter.Build(LoadInventoryInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadInventoryInfos()
        => LoadInfos("inventory_21000023.json");

    public static ImportedLayout LoadPaperdoll()
        => LayoutImporter.Build(LoadPaperdollInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadPaperdollInfos()
        => LoadInfos("paperdoll_21000024.json");

    public static ImportedLayout LoadCharacter()
        => LayoutImporter.Build(LoadCharacterInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadCharacterInfos()
        => LoadInfos("character_2100002E.json");

    public static ImportedLayout LoadCombat()
        => LayoutImporter.Build(LoadCombatInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadCombatInfos()
        => LoadInfos("combat_21000073.json");

    public static ImportedLayout LoadSpellbook()
        => LayoutImporter.Build(LoadSpellbookInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadSpellbookInfos()
        => LoadInfos("spellbook_21000034.json");

    public static ElementInfo LoadComponentCategoryTemplateInfos()
        => LoadInfos("component_category_21000033_10000466.json");

    public static ElementInfo LoadComponentRowTemplateInfos()
        => LoadInfos("component_row_21000033_10000467.json");

    public static ImportedLayout LoadPowerbar()
        => LayoutImporter.Build(LoadPowerbarInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadPowerbarInfos()
        => LoadInfos("powerbar_21000072.json");

    public static ImportedLayout LoadConfirmationDialog()
        => LayoutImporter.Build(LoadConfirmationDialogInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadConfirmationDialogInfos()
        => LoadInfos("dialogs_2100003C.json");

    public static ImportedLayout LoadFpsDisplay()
        => LayoutImporter.Build(LoadFpsDisplayInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadFpsDisplayInfos()
        => LoadInfos("smartbox_fps_2100000F.json");

    public static ImportedLayout LoadPositiveEffects()
        => LayoutImporter.Build(LoadPositiveEffectsInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadPositiveEffectsInfos()
        => LoadInfos("effects_positive_2100001B.json");

    public static ImportedLayout LoadNegativeEffects()
        => LayoutImporter.Build(LoadNegativeEffectsInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadNegativeEffectsInfos()
        => LoadInfos("effects_negative_2100001B.json");

    public static ElementInfo LoadEffectRowTemplateInfos()
        => LoadInfos("effects_row_2100001B_10000128.json");

    public static ImportedLayout LoadCharacterInformation()
        => LayoutImporter.Build(
            LoadCharacterInformationInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadCharacterInformationInfos()
        => LoadInfos("character_info_2100006E_10000183.json");

    public static ImportedLayout LoadIndicators()
        => LayoutImporter.Build(LoadIndicatorsInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadIndicatorsInfos()
        => LoadInfos("indicators_21000071.json");

    public static ImportedLayout LoadLinkStatus()
        => LayoutImporter.Build(LoadLinkStatusInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadLinkStatusInfos()
        => LoadInfos("link_status_2100001D.json");

    public static ImportedLayout LoadVitae()
        => LayoutImporter.Build(LoadVitaeInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadVitaeInfos()
        => LoadInfos("vitae_21000020.json");

    public static ImportedLayout LoadMiniGame()
        => LayoutImporter.Build(LoadMiniGameInfos(), _ => (0u, 0, 0), null);

    public static ElementInfo LoadMiniGameInfos()
        => LoadInfos("mini_game_2100001E.json");

    // ── Shared loader ────────────────────────────────────────────────────────

    private static AcDream.App.UI.Layout.ElementInfo LoadInfos(string fileName)
    {
        var path = Path.Combine(AppContext.BaseDirectory, "UI", "Layout", "fixtures", fileName);
        if (!File.Exists(path)) throw new FileNotFoundException($"fixture not found at: {path}");
        var bytes = File.ReadAllBytes(path);
        // Strip UTF-8 BOM (EF BB BF) if present so JsonSerializer.Deserialize<T>(ReadOnlySpan<byte>)
        // does not reject the first byte.
        ReadOnlySpan<byte> span = bytes;
        if (span.Length >= 3 && span[0] == 0xEF && span[1] == 0xBB && span[2] == 0xBF)
            span = span[3..];
        return JsonSerializer.Deserialize<AcDream.App.UI.Layout.ElementInfo>(span, _opts)
            ?? throw new InvalidOperationException($"fixture deserialized to null: {path}");
    }
}