using ProjectM.Simulation;
using UnityEngine;
using UnityEngine.TextCore.Text;
using UnityEngine.UIElements;

namespace ProjectM.Client
{
    /// <summary>
    /// Curated Synty sci-fi-soldier HUD skin — serialized <see cref="Sprite"/> + <see cref="Font"/> references
    /// harvested from the InterfaceSciFiSoldierHUD / InterfaceCore packs and authored into
    /// <c>Assets/_Project/Resources/HudTheme.asset</c>. Those source sprites/fonts live under
    /// <c>Assets/Synty/…</c> (NOT a Resources folder), so a serialized asset like this is the build-safe way to
    /// pull a curated subset into the player build (the dependency walker follows the refs). Loaded null-safe via
    /// <see cref="Get"/> (mirrors <see cref="MenuUi.LoadPanelSettings"/>); EVERY consumer must null-check the theme
    /// AND each field and fall back to the flat-color HUD, so a missing asset/ref never breaks (or magenta-s) the
    /// HUD. Fonts are applied as cached SDF font definitions: a <see cref="FontAsset"/> is built once per font from
    /// the serialized <see cref="Font"/> (crisp at any size, supports outlines) and re-built per play session (the
    /// static cache is reset on play-enter, like the project's other static presentation bridges).
    /// </summary>
    [CreateAssetMenu(menuName = "ProjectM/HUD Theme", fileName = "HudTheme")]
    public class HudTheme : ScriptableObject
    {
        [Header("Fonts")]
        public Font DisplayFont;    // Orbitron-ExtraBold — numerics + phase words (the HUD's authoritative voice)
        public Font BodyFont;       // Exo 2.0 SemiBold — labels
        public Font BodyLightFont;  // Exo 2.0 Regular — captions / hints

        [Header("Panels & meters")]
        public Sprite PanelBox;     // 9-sliced card background (tinted per cluster)
        public Sprite BarTrack;     // bar fill skin
        public Sprite Vignette;     // radial edge gradient (low-HP / hurt flash / downed)
        public Sprite Glow;         // soft glow accent (selection / pulse)
        public Sprite PipActive;    // filled hex pip (goal meter)
        public Sprite PipInactive;  // empty hex pip

        [Header("Status / info icons")]
        public Sprite HealthIcon;
        public Sprite ShieldIcon;
        public Sprite ThreatIcon;
        public Sprite GoalIcon;
        public Sprite CooldownIcon;
        public Sprite LocationBaseIcon;
        public Sprite LocationExpeditionIcon;

        [Header("Resource icons")]
        public Sprite AetherIcon;
        public Sprite OreIcon;
        public Sprite BioIcon;

        [Header("Structure icons")]
        public Sprite TurretIcon;
        public Sprite WallIcon;
        public Sprite PylonIcon;
        public Sprite HarvesterIcon;
        public Sprite FabricatorIcon;
        public Sprite ConveyorIcon;

        [Header("Build-mode control glyphs")]
        public Sprite KbmPlace;     // LMB
        public Sprite KbmCancel;    // RMB
        public Sprite PadPlace;     // gamepad A / south
        public Sprite PadCancel;    // gamepad B / east
        public Sprite PadRotate;    // gamepad LB
        public Sprite PadExit;      // gamepad Menu / start

        // ---- null-safe load + cache (mirrors MenuUi.LoadPanelSettings Resources idiom) ----
        static HudTheme _cached;
        static bool _tried;

        /// <summary>The loaded theme, or null if the asset is missing. Callers MUST null-check this and each field.</summary>
        public static HudTheme Get()
        {
            if (_tried) return _cached;
            _tried = true;
            _cached = Resources.Load<HudTheme>("HudTheme");
            return _cached;
        }

        /// <summary>Icon for a <see cref="StructureType"/> byte (null → caller falls back to the structure name text).</summary>
        public Sprite StructureIcon(byte type)
        {
            switch (type)
            {
                case StructureType.Turret: return TurretIcon;
                case StructureType.Wall: return WallIcon;
                case StructureType.Pylon: return PylonIcon;
                case StructureType.Harvester: return HarvesterIcon;
                case StructureType.Fabricator: return FabricatorIcon;
                case StructureType.Conveyor: return ConveyorIcon;
                default: return null;
            }
        }

        // ---- cached SDF font definitions (one FontAsset per font, built once, reset per play session) ----
        static FontAsset _displayFa, _bodyFa, _bodyLightFa;
        static bool _displayTried, _bodyTried, _bodyLightTried;

        /// <summary>Apply the display font (Orbitron) to a style, if available. No-op otherwise (stock font).</summary>
        public void ApplyDisplay(IStyle style) => Apply(style, DisplayFont, ref _displayFa, ref _displayTried);

        /// <summary>Apply the body font (Exo 2.0 SemiBold) to a style, if available.</summary>
        public void ApplyBody(IStyle style) => Apply(style, BodyFont, ref _bodyFa, ref _bodyTried);

        /// <summary>Apply the light body font (Exo 2.0 Regular) to a style, if available.</summary>
        public void ApplyBodyLight(IStyle style) => Apply(style, BodyLightFont, ref _bodyLightFa, ref _bodyLightTried);

        static void Apply(IStyle style, Font font, ref FontAsset fa, ref bool tried)
        {
            if (!tried)
            {
                tried = true;
                if (font != null) fa = FontAsset.CreateFontAsset(font); // dynamic SDF atlas, built once per session
            }
            if (fa != null)
                style.unityFontDefinition = new StyleFontDefinition(FontDefinition.FromSDFFont(fa));
        }

        // Fast-enter-playmode keeps statics alive across sessions; the runtime FontAssets are destroyed on play-exit,
        // so a stale cache would reference a destroyed atlas. Reset everything so it re-loads/re-builds per session.
        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.SubsystemRegistration)]
        static void ResetStatics()
        {
            _cached = null; _tried = false;
            _displayFa = _bodyFa = _bodyLightFa = null;
            _displayTried = _bodyTried = _bodyLightTried = false;
        }
    }
}