using System;
using System.Reflection;
using System.Runtime.CompilerServices;
using HarmonyLib;
using NeoModLoader.services;

namespace IdleSpectator;

/// <summary>
/// World-session bind for the life-saga roster and durable memory.
/// Clears on map load-complete and when the live bind key changes; same-map
/// spectator re-enable does not wipe.
/// </summary>
public static class LifeSagaSession
{
    private static readonly FieldInfo LoadCounterField =
        AccessTools.Field(typeof(MapBox), "_load_counter");

    private static object _boundWorld;
    private static string _boundKey = "";
    private static int _epoch;
    private static float _nextBindKeyCheckAt;

    public static int Epoch => _epoch;

    public static string BoundKey => _boundKey ?? "";

    /// <summary>Clear roster + memory + saga UI and rebind to the current world.</summary>
    public static void ResetForWorldChange(string reason = null)
    {
        LifeSagaRoster.Clear();
        LifeSagaMemory.ClearSession();
        LifeSagaViewController.Clear();
        LifeSagaRail.Clear();
        LifeSagaPanel.Clear();
        NarrativeStoryStore.Clear();
        NarrativePersistence.ResetTransient();
        _epoch++;

        object world = SafeWorld();
        _boundWorld = world;
        _boundKey = ComputeBindKey(world);
        _nextBindKeyCheckAt = 0f;
        LifeSagaMemory.NoteBoundWorld(world);

        if (!string.IsNullOrEmpty(reason))
        {
            LogService.LogInfo(
                $"[IdleSpectator] Life saga session reset ({reason}) key='{_boundKey}' epoch={_epoch}");
        }
    }

    /// <summary>
    /// Bind or reset when the world identity / bind key changes.
    /// No-op when the same map session is still live (spectator toggle safe).
    /// </summary>
    public static void EnsureBound()
    {
        object world = SafeWorld();
        if (ReferenceEquals(world, _boundWorld))
        {
            // Same world object: throttle key recompute. Load/clear Harmony patches
            // still force ResetForWorldChange immediately.
            float now = UnityEngine.Time.unscaledTime;
            if (now < _nextBindKeyCheckAt)
            {
                return;
            }

            _nextBindKeyCheckAt = now + 2f;
        }

        string key = ComputeBindKey(world);
        if (ReferenceEquals(world, _boundWorld)
            && string.Equals(key, _boundKey, StringComparison.Ordinal))
        {
            return;
        }

        ResetForWorldChange(world == null ? "world-null" : "bind-key");
    }

    /// <summary>
    /// Map load finished on the live MapBox instance.
    /// Always wipe even when the world reference and name look unchanged.
    /// </summary>
    public static void OnWorldLoadFinished()
    {
        ResetForWorldChange("load-complete");
        NarrativePersistence.LoadCurrentWorld();
    }

    /// <summary>Stable save identity: excludes object hashes and load counters.</summary>
    public static string ComputePersistentKey(object worldObj)
    {
        MapBox world = worldObj as MapBox;
        if (world == null) return "";

        string name = "";
        string seed = "";
        int width = 0;
        int height = 0;
        try
        {
            name = world.map_stats?.name ?? "";
        }
        catch
        {
            name = "";
        }

        try
        {
            seed = MapBox.current_world_seed_id.ToString();
            width = MapBox.width;
            height = MapBox.height;
        }
        catch
        {
            // Retain whatever stable fragments were available.
        }

        return name + "|" + seed + "|" + width + "x" + height;
    }

    public static string ComputeBindKey(object worldObj)
    {
        MapBox world = worldObj as MapBox;
        if (world == null)
        {
            return "";
        }

        string name = "";
        string seed = "";
        int statsId = 0;
        int loadCounter = 0;
        int width = 0;
        int height = 0;
        try
        {
            MapStats stats = world.map_stats;
            if (stats != null)
            {
                name = stats.name ?? "";
                statsId = RuntimeHelpers.GetHashCode(stats);
            }
        }
        catch
        {
            name = "";
        }

        try
        {
            seed = MapBox.current_world_seed_id.ToString();
        }
        catch
        {
            seed = "";
        }

        try
        {
            width = MapBox.width;
            height = MapBox.height;
        }
        catch
        {
            width = 0;
            height = 0;
        }

        try
        {
            if (LoadCounterField != null)
            {
                object raw = LoadCounterField.GetValue(world);
                if (raw is int i)
                {
                    loadCounter = i;
                }
                else if (raw != null)
                {
                    loadCounter = Convert.ToInt32(raw);
                }
            }
        }
        catch
        {
            loadCounter = 0;
        }

        return $"{name}|{seed}|{statsId}|{loadCounter}|{width}x{height}";
    }

    private static object SafeWorld()
    {
        try
        {
            return World.world;
        }
        catch
        {
            return null;
        }
    }
}