namespace Aeshnidae.Challenge;

/// <summary>
/// Challenge runs: a personal copy of a retail shell whose cast is DRAWN rather than
/// written down - N species whose creature-power-index score sits in a band, placed at the
/// shell's own spawn spots, nothing leaving a corpse, a boss at the far end and one chest
/// behind it.
///
/// The three things worth knowing before reading any of it:
///
///   1. Difficulty is the BAND, not the creatures. Resolve (PropertyInt 9053, owned by
///      Aeshnidae.Awakens and never written here) multiplies the target score the roster is
///      drawn around. No creature's numbers are touched, by this mod or by InstancesNoDat's
///      tier scaler, which is exactly why the index was built - see Settings.cs and
///      C:\Aeshnidae\ops\build-creature-index.md.
///
///   2. Reward follows the DRAW. An unlucky soft draw inside a high band pays the soft
///      draw's reward, because what the player fought is the roster, not the dial.
///
///   3. InstancesNoDat does the work. This mod hands it a variant as JSON when a copy opens
///      (Variants.Filling) and it does the rest with the machinery a hand-written variant
///      already used. The only ACE methods patched here are Creature.Die and the world tick.
/// </summary>
public class Mod : IHarmonyMod
{
    public static readonly string Name = typeof(Mod).Assembly.GetName().Name!;

    public static readonly string HarmonyId = $"mod.{Name.ToLowerInvariant()}";

    public static readonly string ModPath = Path.Combine(ModManager.ModPath, Name);

    public static ModContainer? Container => ModManager.GetModContainerByPath(ModPath);

    public static Settings Settings { get; private set; } = new();

    private static Harmony? _harmony;
    private bool _disposed;

    public void Initialize()
    {
        try
        {
            Settings = Settings.Load(ModPath);

            _harmony = new Harmony(HarmonyId);
            _harmony.PatchAllUncategorized(typeof(Mod).Assembly);

            var scored = Index.Load();
            var shells = Shell.LoadAll();

            // Binding installs the filling hook when the mod is enabled. It is retried on
            // every use, so a load order that puts this mod before InstancesNoDat is not a
            // failure - the first copy anybody opens binds it.
            Instances.Refresh();

            ModManager.Log($"[{Name}] loaded - {(Settings.Enabled ? "ENABLED" : "disabled")}, " +
                           $"{scored:N0} scored creatures, {shells} shell(s), " +
                           $"InstancesNoDat: {Instances.Status}");
        }
        catch (Exception ex)
        {
            // Never throw out of Initialize: the mod would stick Inactive with no
            // explanation, and a challenge shell would then open as the retail dungeon
            // with its copies gated to a portal nobody can use.
            ModManager.Log($"[{Name}] failed to initialize: {ex}", ModManager.LogLevel.Error);
        }
    }

    /// <summary>Re-reads Settings.json, the index and every shell, without a restart.</summary>
    public static string Reload()
    {
        Settings = Settings.Load(ModPath);
        var scored = Index.Load();
        var shells = Shell.LoadAll();

        Runs.Clear();
        Instances.Refresh();
        Instances.Hook();

        return $"{(Settings.Enabled ? "enabled" : "disabled")}, {scored:N0} scored creatures, " +
               $"{shells} shell(s), InstancesNoDat: {Instances.Status}";
    }

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    protected virtual void Dispose(bool disposing)
    {
        if (_disposed)
            return;

        if (disposing)
        {
            // The hooks first, and before the patches: they are delegates over methods in
            // THIS assembly stored on static fields in InstancesNoDat's, so leaving one
            // behind would keep this load context alive and would have a copy opened after
            // the reload calling into the old build.
            try { Instances.Unhook(); } catch { /* InstancesNoDat may already be gone */ }

            Runs.Clear();
            Shell.Forget();
            Index.Unload();

            _harmony?.UnpatchAll(HarmonyId);
            _harmony = null;

            ModManager.Log($"[{Name}] shut down");
        }

        _disposed = true;
    }
}