using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Oxide.Core;
using Oxide.Core.Plugins;
using UnityEngine;
using UnityEngine.AI;

namespace Oxide.Plugins
{
    /// <summary>
    ///     RunicNPC's stage 2 test harness (docs/runicnpc/PLAN.md §9, stage 2). NEVER SHIPPED: it lives
    ///     in tools/ and is loaded on a rig by hand. It drives RunicNPC only through its API and hooks,
    ///     as any other plugin would, and prints one line per assertion:
    ///
    ///     <code>[rnt] &lt;group&gt;.&lt;check&gt;: PASS|FAIL &lt;detail&gt;</code>
    ///
    ///     Every line is also kept in <c>data/RunicNpcTest.json</c>, read back over the panel.
    ///
    ///     <para>
    ///     <c>rnt.run &lt;group&gt;</c> runs one group: <c>api</c>, <c>hooks</c>, <c>move</c>,
    ///     <c>sentry</c>, <c>sleep</c>, <c>place</c>, or <c>all</c> for each in turn.
    ///     <c>rnt.run place</c> leaves two placements behind for the restart check, and
    ///     <c>rnt.after</c> checks, after a reload or restart, that every placement is back and nothing
    ///     else is. <c>rnt.spawn [n]</c> spawns plugin-owned NPCs, for the check that they die with this plugin, and
    ///     <c>rnt.clear</c> removes everything the harness made.
    ///     </para>
    ///
    ///     <para>
    ///     It needs the hidden Kits kit <c>rnhrevolver</c> (stage 1's: a revolver, pistol ammo and
    ///     burlap). It REPLACES RunicNPC's profiles with its own test set, which marks the server
    ///     managed: back up <c>data/RunicNPC/</c> first and restore it afterwards.
    ///     </para>
    ///
    ///     <para>
    ///     Targets and wake-ups are <b>stand-ins</b>, stage 1's fake players: <c>player.prefab</c> with
    ///     a made-up user id (11400000001 and up), so <c>IsNpc</c> is false. They take no damage.
    ///     </para>
    /// </summary>
    [Info("RunicNpcTest", "Runic Gateway", "0.2.0")]
    [Description("RunicNPC stage 2 tests. A developer tool: never ship it.")]
    internal class RunicNpcTest : RustPlugin
    {
        [PluginReference] private Plugin RunicNPC;

        private const string Kit = "rnhrevolver";
        private const string Owner = "plugin:RunicNpcTest";
        private const string PlayerPrefab = "assets/prefabs/player/player.prefab";
        private const ulong StandInId = 11400000101UL;

        private readonly List<string> _lines = new List<string>();
        private readonly HashSet<BasePlayer> _standIns = new HashSet<BasePlayer>();
        private readonly List<BaseEntity> _built = new List<BaseEntity>();
        private Coroutine _running;
        private int _pass, _fail;

        // What RunicNPC's hooks told us.
        private readonly List<string> _spawned = new List<string>();
        private readonly List<string> _died = new List<string>();
        private readonly List<string> _health = new List<string>();
        private readonly List<string> _despawned = new List<string>();
        private readonly Dictionary<ulong, float> _lastContributors = new Dictionary<ulong, float>();
        private int _hitsOnStandIns;

        private static readonly MethodInfo LifeStoryStart =
            typeof(BasePlayer).GetMethod("LifeStoryStart", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);

        // ---- output ----

        private void Check(string name, bool ok, string detail = "")
        {
            if (ok) _pass++; else _fail++;
            string line = $"{name}: {(ok ? "PASS" : "FAIL")} {detail}";
            _lines.Add(line);
            Puts("[rnt] " + line);
            Interface.Oxide.DataFileSystem.WriteObject(Name, _lines);
        }

        private void Note(string line)
        {
            _lines.Add("# " + line);
            Puts("[rnt] # " + line);
            Interface.Oxide.DataFileSystem.WriteObject(Name, _lines);
        }

        // ---- lifecycle ----

        private void Unload()
        {
            if (_running != null) ServerMgr.Instance.StopCoroutine(_running);
            ClearWorld();
        }

        private void ClearWorld()
        {
            foreach (BasePlayer p in _standIns.ToList())
                if (p != null && !p.IsDestroyed) p.Kill();
            _standIns.Clear();
            foreach (BaseEntity e in _built)
                if (e != null && !e.IsDestroyed) e.Kill();
            _built.Clear();
        }

        // ---- RunicNPC's API, typed ----

        private T Api<T>(string call, params object[] args)
        {
            object r = RunicNPC?.Call(call, args);
            return r is T ? (T)r : default(T);
        }

        private BasePlayer Spawn(Vector3 at, string profile, JObject overrides = null, string owner = Owner) =>
            Api<BasePlayer>("RunicNpc_Spawn", at, profile, owner, overrides);

        private List<Dictionary<string, object>> List(string owner) =>
            Api<List<Dictionary<string, object>>>("RunicNpc_List", owner) ?? new List<Dictionary<string, object>>();

        private Dictionary<string, object> Describe(BasePlayer npc) =>
            npc == null ? null : List(null).FirstOrDefault(d => (ulong)d["netId"] == npc.net.ID.Value);

        private static Vector3 V(object o)
        {
            var d = (Dictionary<string, object>)o;
            return new Vector3(Convert.ToSingle(d["x"]), Convert.ToSingle(d["y"]), Convert.ToSingle(d["z"]));
        }

        private static float Flat(Vector3 a, Vector3 b) => new Vector2(a.x - b.x, a.z - b.z).magnitude;

        // ---- places ----

        private static bool SampleNavmesh(Vector3 p, float r, out NavMeshHit hit) =>
            Rust.Ai.Gen2.RustNavMeshHelpers.SamplePosition(p, out hit, r, Rust.Ai.Gen2.RustNavMeshHelpers.AllAreas);

        private static MonumentInfo[] _monuments;

        /// <summary>The map's monuments. (TerrainMeta.Path.Monuments is internal in Rust's own assembly.)</summary>
        private static MonumentInfo[] Monuments() => _monuments ?? (_monuments = UnityEngine.Object.FindObjectsOfType<MonumentInfo>());

        /// <summary>A flat, dry spot on the navmesh far from every monument; fixed seed, so reruns land in the same field.</summary>
        private static bool FindField(float clear, int seed, out Vector3 at)
        {
            var rng = new System.Random(seed);
            float half = World.Size / 2f - 300f;
            for (int i = 0; i < 4000; i++)
            {
                var p = new Vector3((float)(rng.NextDouble() * 2 - 1) * half, 0f, (float)(rng.NextDouble() * 2 - 1) * half);
                p.y = TerrainMeta.HeightMap.GetHeight(p);
                if (p.y < TerrainMeta.WaterMap.GetHeight(p) + 1f || TerrainMeta.HeightMap.GetSlope(p) > 12f) continue;
                if (Monuments().Any(m => Vector3.Distance(m.transform.position, p) < clear)) continue;
                NavMeshHit hit;
                if (!SampleNavmesh(p, 2f, out hit)) continue;
                // The whole 35 m around it must be walkable too, for the wander and route tests.
                bool open = true;
                for (int k = 0; k < 8 && open; k++)
                {
                    float a = k * Mathf.PI / 4f;
                    NavMeshHit h2;
                    open = SampleNavmesh(hit.position + new Vector3(Mathf.Cos(a), 0f, Mathf.Sin(a)) * 35f, 2f, out h2);
                }

                if (!open) continue;
                at = hit.position;
                return true;
            }

            at = Vector3.zero;
            return false;
        }

        /// <summary>A monument with an AI zone, where Rust's own roam has move points to follow.</summary>
        private static bool FindMonument(out Vector3 at, out string name)
        {
            foreach (MonumentInfo m in Monuments().OrderBy(m => m.name.Contains("military") ? 0 : 1))
            {
                if (m == null) continue;
                AIInformationZone zone = AIInformationZone.GetForPoint(m.transform.position, false);
                if (zone == null) continue;
                NavMeshHit hit;
                if (!SampleNavmesh(m.transform.position, 20f, out hit)) continue;
                at = hit.position;
                name = System.IO.Path.GetFileNameWithoutExtension(m.name);
                return true;
            }

            at = Vector3.zero;
            name = null;
            return false;
        }

        private BasePlayer StandIn(Vector3 at, int index)
        {
            BasePlayer p = GameManager.server.CreateEntity(PlayerPrefab, at) as BasePlayer;
            if (p == null) return null;
            ulong id = StandInId + (ulong)index;
            p.userID = id;
            p.UserIDString = id.ToString();
            p.displayName = "RntStandIn" + index;
            p.enableSaving = false;
            p.Spawn();
            p.EndSleeping();
            LifeStoryStart?.Invoke(p, null);
            _standIns.Add(p);
            return p;
        }

        private void RemoveStandIns()
        {
            foreach (BasePlayer p in _standIns.ToList())
                if (p != null && !p.IsDestroyed) p.Kill();
            _standIns.Clear();
        }

        // ---- hooks: RunicNPC's, counted; and the stand-ins made invulnerable ----

        private void OnRunicNpcSpawned(BasePlayer npc, string profile, string owner) => _spawned.Add($"{profile}/{owner}");

        private void OnRunicNpcDied(BasePlayer npc, string profile, string owner, HitInfo info, Dictionary<ulong, float> contributors)
        {
            _died.Add($"{profile}/{owner}");
            _lastContributors.Clear();
            foreach (KeyValuePair<ulong, float> kv in contributors) _lastContributors[kv.Key] = kv.Value;
        }

        private void OnRunicNpcHealth(BasePlayer npc, string profile, float fraction) => _health.Add($"{profile}@{fraction}");

        private void OnRunicNpcDespawned(BasePlayer npc, string owner) => _despawned.Add(owner);

        private void OnEntityTakeDamage(BaseCombatEntity victim, HitInfo info)
        {
            BasePlayer p = victim as BasePlayer;
            if (p == null || !_standIns.Contains(p) || info == null) return;
            if (info.Initiator is BasePlayer && ((BasePlayer)info.Initiator).IsNpc) _hitsOnStandIns++;
            info.damageTypes.ScaleAll(0f);
        }

        // ---- the profiles and routes the tests use ----

        private static JObject Prof(string movement = "wander", float radius = 15f, string role = "roamer", string kit = Kit, string name = "TRoam") =>
            JObject.FromObject(new
            {
                names = new[] { name },
                kits = new[] { kit },
                prefab = "scientistnpc_roam",
                role,
                movement = new { mode = movement, radius },
                health = 250f,
                damageDealt = 1f,
                damageTaken = new { head = 2f, body = 0.5f, legs = 1f },
                aimCone = 2f,
                ranges = new { sense = 30f, loseTarget = 40f, chase = 40f, attack = 30f },
                visionCone = -0.8f,
                sleepDistance = 160f,
                healthThresholds = new[] { 0.5f }
            });

        private Dictionary<string, string> SetTestProfiles(bool withEach = true)
        {
            var all = new JObject
            {
                ["t_roam"] = Prof(),
                ["t_sentry"] = Prof(role: "sentry", name: "TSentry"),
                ["t_mon"] = Prof("monument", name: "TMon"),
                ["t_route"] = Prof("route:t_loop", name: "TRoute"),
                ["t_bad"] = Prof(kit: "rnt_nokit", name: "TBad")
            };
            JObject leash = Prof(radius: 4f, name: "TLeash");
            leash["ranges"] = JObject.FromObject(new { sense = 40f, loseTarget = 50f, chase = 10f, attack = 4f });
            all["t_leash"] = leash;
            if (withEach)
                all["t_each"] = Prof(name: "TEach");
            return Api<Dictionary<string, string>>("RunicNpc_SetProfiles", all) ?? new Dictionary<string, string> { ["?"] = "no answer" };
        }

        private string SetLoop(Vector3 centre)
        {
            var points = new JArray();
            foreach (Vector3 o in new[] { new Vector3(12, 0, 12), new Vector3(-12, 0, 12), new Vector3(-12, 0, -12), new Vector3(12, 0, -12) })
            {
                NavMeshHit hit;
                SampleNavmesh(centre + o, 3f, out hit);
                points.Add(JObject.FromObject(new { x = hit.position.x, y = hit.position.y, z = hit.position.z }));
            }

            return Api<string>("RunicNpc_SetRoute", "t_loop", JObject.FromObject(new { points, loop = true }));
        }

        // ---- commands ----

        [ConsoleCommand("rnt.run")]
        private void CmdRun(ConsoleSystem.Arg arg)
        {
            if (arg.Connection != null && !arg.IsAdmin) return;
            string group = arg.GetString(0, "all");
            if (_running != null) ServerMgr.Instance.StopCoroutine(_running);
            _running = ServerMgr.Instance.StartCoroutine(Run(group));
            arg.ReplyWith($"rnt: running {group}");
        }

        [ConsoleCommand("rnt.after")]
        private void CmdAfter(ConsoleSystem.Arg arg)
        {
            if (arg.Connection != null && !arg.IsAdmin) return;
            After();
        }

        /// <summary>Spawns n plugin-owned NPCs, for the check that a plugin's NPCs die with it.</summary>
        [ConsoleCommand("rnt.spawn")]
        private void CmdSpawn(ConsoleSystem.Arg arg)
        {
            if (arg.Connection != null && !arg.IsAdmin) return;
            Vector3 field;
            if (!FindField(300f, 2024, out field)) return;
            int n = 0;
            for (int i = 0; i < arg.GetInt(0, 3); i++)
                if (Spawn(field + new Vector3(i * 2f, 0f, -30f), "t_roam") != null) n++;
            arg.ReplyWith($"rnt: spawned {n} as {Owner}");
        }

        [ConsoleCommand("rnt.clear")]
        private void CmdClear(ConsoleSystem.Arg arg)
        {
            if (arg.Connection != null && !arg.IsAdmin) return;
            ClearWorld();
            Api<int>("RunicNpc_DespawnOwner", Owner);
            foreach (string id in new[] { "t_each", "t_group", "t_waitroute", "t_keep1", "t_keep2" })
                Api<bool>("RunicNpc_RemovePlacement", id);
            Api<bool>("RunicNpc_RemoveRoute", "t_loop");
            arg.ReplyWith("rnt: cleared");
        }

        private IEnumerator Run(string group)
        {
            _pass = _fail = 0;
            Note($"run {group} on {(AppDomain.CurrentDomain.GetAssemblies().Any(a => a.GetName().Name.StartsWith("Carbon")) ? "carbon" : "oxide")}, map {World.Size}/{World.Seed}");

            Vector3 field;
            if (!FindField(300f, 2024, out field))
            {
                Check("setup.field", false, "no open field on the navmesh");
                yield break;
            }

            Dictionary<string, string> refused = SetTestProfiles();
            Check("setup.profiles", refused.Count == 1 && refused.ContainsKey("t_bad"), "refused: " + string.Join("; ", refused.Select(kv => kv.Key + ": " + kv.Value).ToArray()));
            string route = SetLoop(field + new Vector3(60f, 0f, 0f));
            Check("setup.route", route == null, route ?? "t_loop set");

            string[] groups = group == "all" ? new[] { "api", "hooks", "move", "sentry", "sleep", "place" } : new[] { group };
            foreach (string g in groups)
            {
                IEnumerator inner = g == "api" ? Api(field)
                    : g == "hooks" ? Hooks(field)
                    : g == "move" ? Move(field)
                    : g == "sentry" ? Sentry(field)
                    : g == "sleep" ? Sleep(field)
                    : g == "place" ? Place(field)
                    : null;
                if (inner == null)
                {
                    Check("setup.group", false, "no group " + g);
                    continue;
                }

                while (inner.MoveNext()) yield return inner.Current;
                Api<int>("RunicNpc_DespawnOwner", Owner);
                RemoveStandIns();
                yield return new WaitForSeconds(1f);
            }

            Note($"done {group}: {_pass} pass, {_fail} fail");
            _running = null;
        }

        // ---- api: every call's answer ----

        private IEnumerator Api(Vector3 field)
        {
            Check("api.version", Api<int>("RunicNpc_ApiVersion") == 2, "RunicNpc_ApiVersion=" + Api<int>("RunicNpc_ApiVersion"));
            JObject profiles = Api<JObject>("RunicNpc_Profiles");
            Check("api.profiles.managed", profiles != null && (bool)profiles["managed"], "managed=" + profiles?["managed"]);
            Check("api.profiles.refused", profiles != null && profiles["refused"]?["t_bad"] != null, "" + profiles?["refused"]);
            string warning = Api<string>("RunicNpc_CostWarning", 10);
            Check("api.costWarning", warning != null && warning.Contains("NPC(s)"), warning);

            BasePlayer npc = Spawn(field, "t_roam");
            Check("api.spawn", npc != null, npc != null ? npc.GetType().Name : "null");
            if (npc == null) yield break;
            yield return new WaitForSeconds(2f);

            Check("api.isRunicNpc", Api<bool>("RunicNpc_IsRunicNpc", npc), "");
            Check("api.profileOf", Api<string>("RunicNpc_ProfileOf", npc) == "t_roam", Api<string>("RunicNpc_ProfileOf", npc));
            Check("api.name", npc.displayName == "TRoam", npc.displayName);
            Check("api.health", Mathf.Approximately(npc.health, 250f) && Mathf.Approximately(npc.MaxHealth(), 250f), $"{npc.health}/{npc.MaxHealth()}");
            Check("api.notSaved", !npc.enableSaving, "enableSaving=" + npc.enableSaving);
            Check("api.isNpc", npc.IsNpc, "IsNpc=" + npc.IsNpc);
            HeldEntity held = npc.GetHeldEntity();
            Check("api.kit", held != null && held.ShortPrefabName.Contains("revolver"), held != null ? held.ShortPrefabName : "nothing held");
            Dictionary<string, object> d = Describe(npc);
            Check("api.list", d != null && (string)d["owner"] == Owner && (string)d["movement"] == "wander", d != null ? $"{d["owner"]} {d["movement"]} {d["state"]}" : "not listed");

            BasePlayer ov = Spawn(field + new Vector3(4, 0, 0), "t_roam", JObject.FromObject(new { health = 500f, names = new[] { "Ov" } }));
            yield return new WaitForSeconds(0.5f);
            Check("api.overrides", ov != null && ov.displayName == "Ov" && Mathf.Approximately(ov.MaxHealth(), 500f), ov != null ? $"{ov.displayName} {ov.MaxHealth()}" : "null");

            Check("api.refuse.placementOwner", Spawn(field, "t_roam", null, "placement:x") == null, "");
            Check("api.refuse.badOwner", Spawn(field, "t_roam", null, "nobody") == null, "");
            Check("api.refuse.unknownProfile", Spawn(field, "nope") == null, "");
            Check("api.refuse.refusedProfile", Spawn(field, "t_bad") == null, "");
            Check("api.refuse.badOverride", Spawn(field, "t_roam", JObject.FromObject(new { health = -5f })) == null, "");
            Check("api.refuse.offMesh", Spawn(field + Vector3.up * 40f, "t_roam") == null, "40 m in the air");

            int listed = List(Owner).Count;
            Check("api.listOwner", listed == 2, "listed " + listed);
            Check("api.despawn", Api<int>("RunicNpc_Despawn", ov.net.ID.Value) == 1, "");
            Check("api.despawnOwner", Api<int>("RunicNpc_DespawnOwner", Owner) == 1, "");
            Check("api.gone", List(Owner).Count == 0, "listed " + List(Owner).Count);
        }

        // ---- hooks: spawned, health threshold with contributors, damage by body part, died, despawned ----

        private IEnumerator Hooks(Vector3 field)
        {
            _spawned.Clear(); _died.Clear(); _health.Clear(); _despawned.Clear();
            BasePlayer shooter = StandIn(field + new Vector3(0, 0, 60), 0);
            BasePlayer npc = Spawn(field, "t_roam");
            yield return new WaitForSeconds(1f);
            Check("hooks.spawned", _spawned.Contains("t_roam/" + Owner), string.Join(",", _spawned.ToArray()));

            // 100 bullet damage with no bone: body, scaled 0.5 → 50 (then Rust's own protection).
            float before = npc.health;
            npc.Hurt(new HitInfo(shooter, npc, Rust.DamageType.Bullet, 100f));
            float body = before - npc.health;
            Check("hooks.damageTaken.body", body > 5f && body <= 50.5f, $"took {body:0.0} of 100 (body scale 0.5)");

            // To below half: the 0.5 threshold fires, once.
            while (npc.health / npc.MaxHealth() > 0.45f)
                npc.Hurt(new HitInfo(shooter, npc, Rust.DamageType.Bullet, 60f));
            npc.Hurt(new HitInfo(shooter, npc, Rust.DamageType.Bullet, 1f));
            Check("hooks.health", _health.Count == 1 && _health[0] == "t_roam@0.5", string.Join(",", _health.ToArray()));

            npc.Hurt(new HitInfo(shooter, npc, Rust.DamageType.Bullet, 5000f));
            yield return new WaitForSeconds(1f);
            Check("hooks.died", _died.Contains("t_roam/" + Owner), string.Join(",", _died.ToArray()));
            Check("hooks.contributors", _lastContributors.ContainsKey(StandInId) && _lastContributors[StandInId] > 240f && _lastContributors[StandInId] <= 250.5f,
                string.Join(",", _lastContributors.Select(kv => kv.Key + "=" + kv.Value.ToString("0")).ToArray()));
            Check("hooks.diedNotDespawned", _despawned.Count == 0, "despawned: " + string.Join(",", _despawned.ToArray()));
            Check("hooks.unregisteredOnDeath", List(Owner).Count == 0, "listed " + List(Owner).Count);

            BasePlayer second = Spawn(field, "t_roam");
            yield return new WaitForSeconds(0.5f);
            Api<int>("RunicNpc_Despawn", second.net.ID.Value);
            Check("hooks.despawned", _despawned.Count == 1 && _despawned[0] == Owner, string.Join(",", _despawned.ToArray()));
        }

        // ---- move: wander stays within its radius, a route visits every point, a monument roams, a leash holds ----

        private IEnumerator Move(Vector3 field)
        {
            // A stand-in 100 m off keeps them awake (inside 160 m) without being sensed (30 m).
            StandIn(field + new Vector3(0, 0, 100), 1);

            BasePlayer wander = Spawn(field, "t_roam");
            BasePlayer route = Spawn(field + new Vector3(60, 0, 0), "t_route");
            Vector3 monument;
            string monumentName;
            BasePlayer mon = null;
            if (FindMonument(out monument, out monumentName))
            {
                StandIn(monument + new Vector3(0, 0, 100), 2);
                mon = Spawn(monument, "t_mon");
            }

            Vector3 home = wander.transform.position;
            Vector3 monHome = mon != null ? mon.transform.position : Vector3.zero;
            float wanderMax = 0f, wanderMoved = 0f, monMax = 0f;
            Route loop = JObject.FromObject(Api<JObject>("RunicNpc_Routes")["t_loop"]).ToObject<Route>();
            var reached = new bool[loop.points.Count];
            var order = new List<int>();

            for (int t = 0; t < 90; t++)
            {
                yield return new WaitForSeconds(1f);
                if (wander != null && !wander.IsDestroyed)
                {
                    float d = Flat(wander.transform.position, home);
                    wanderMax = Mathf.Max(wanderMax, d);
                    wanderMoved = Mathf.Max(wanderMoved, d);
                }

                if (route != null && !route.IsDestroyed)
                    for (int i = 0; i < loop.points.Count; i++)
                        if (Flat(route.transform.position, loop.points[i].V) < 2.5f)
                        {
                            reached[i] = true;
                            if (order.Count == 0 || order[order.Count - 1] != i) order.Add(i);
                        }

                if (mon != null && !mon.IsDestroyed)
                    monMax = Mathf.Max(monMax, Flat(mon.transform.position, monHome));
            }

            Check("move.wander.moves", wanderMoved > 2f, $"furthest {wanderMoved:0.0} m from its spot");
            Check("move.wander.radius", wanderMax <= 15f + 4f, $"furthest {wanderMax:0.0} m, radius 15");
            Check("move.route.everyPoint", reached.All(x => x), "reached " + string.Join("", reached.Select(x => x ? "1" : "0").ToArray()) + " order " + string.Join(">", order.Select(x => x.ToString()).ToArray()));
            bool inOrder = true;
            for (int i = 1; i < order.Count; i++)
                if (order[i] != (order[i - 1] + 1) % loop.points.Count) inOrder = false;
            Check("move.route.inOrder", order.Count >= 3 && inOrder, string.Join(">", order.Select(x => x.ToString()).ToArray()));
            if (mon != null)
                Check("move.monument.roams", monMax > 5f, $"{monumentName}: furthest {monMax:0.0} m (Rust's own roam)");
            else
                Check("move.monument.roams", false, "no monument with an AI zone");

            Api<int>("RunicNpc_DespawnOwner", Owner);
            RemoveStandIns();

            // The leash: chase 10 m from home. A stand-in 25 m off draws it out; past 10 m it must turn back.
            BasePlayer leash = Spawn(field, "t_leash");
            yield return new WaitForSeconds(1f);
            Vector3 leashHome = leash.transform.position;
            StandIn(leashHome + new Vector3(25, 0, 0), 3);
            float leashMax = 0f;
            for (int t = 0; t < 40; t++)
            {
                yield return new WaitForSeconds(1f);
                if (leash == null || leash.IsDestroyed) break;
                leashMax = Mathf.Max(leashMax, Flat(leash.transform.position, leashHome));
            }

            Dictionary<string, object> d2 = Describe(leash);
            int leashes = d2 != null ? Convert.ToInt32(d2["leashes"]) : -1;
            Check("move.chase.pursues", leashMax >= 6f, $"went {leashMax:0.0} m toward a target 25 m off (attack 4, chase 10)");
            Check("move.chase.bounded", leashMax <= 10f + 4f, $"furthest {leashMax:0.0} m, chase 10");
            Check("move.leash.givesUp", leashes >= 1, $"gave up {leashes} time(s) on a target it could not reach");
        }

        // ---- sentry: holds its spot, shoots, and may stand off the navmesh ----

        private IEnumerator Sentry(Vector3 field)
        {
            BasePlayer sentry = Spawn(field, "t_sentry");
            yield return new WaitForSeconds(1f);
            Vector3 spot = sentry.transform.position;
            _hitsOnStandIns = 0;
            StandIn(spot + new Vector3(12, 0, 0), 4);
            float moved = 0f;
            for (int t = 0; t < 40; t++)
            {
                yield return new WaitForSeconds(1f);
                moved = Mathf.Max(moved, Flat(sentry.transform.position, spot));
            }

            Check("sentry.holds", moved < 1f, $"moved {moved:0.00} m in 40 s with a target 12 m off");
            Check("sentry.shoots", _hitsOnStandIns > 0, $"{_hitsOnStandIns} hit(s) on the stand-in");
            Dictionary<string, object> d = Describe(sentry);
            Note("sentry state: " + (d != null ? d["state"] : "?"));
            Api<int>("RunicNpc_DespawnOwner", Owner);
            RemoveStandIns();

            // A player-built floor 4 m up, then a spot truly off the navmesh.
            BaseEntity floor = GameManager.server.CreateEntity("assets/prefabs/building core/floor/floor.prefab", field + new Vector3(0, 4f, 20f));
            if (floor == null)
            {
                Check("sentry.offMesh.floor", false, "the floor prefab made nothing");
                yield break;
            }

            try
            {
                floor.enableSaving = false;
                // An unsupported floor collapses at once under Rust's stability; grounded, it stays up.
                StabilityEntity stable = floor as StabilityEntity;
                if (stable != null) stable.grounded = true;
                floor.Spawn();
            }
            catch (Exception e)
            {
                Check("sentry.offMesh.floor", false, e.ToString());
                yield break;
            }

            _built.Add(floor);

            // Stage 1 read a new floor as off the navmesh, sampling in the frame it spawned. How long
            // does Rust's navmesh take to cover it?
            Vector3 top = floor.transform.position + Vector3.up * 0.1f;
            float spawnedAt = Time.realtimeSinceStartup;
            bool covered = false;
            int frames = 0;
            while (!covered && Time.realtimeSinceStartup - spawnedAt < 10f)
            {
                NavMeshHit onTop;
                covered = SampleNavmesh(top, 1f, out onTop) && Mathf.Abs(onTop.position.y - top.y) < 0.6f;
                if (!covered)
                {
                    frames++;
                    yield return null;
                }
            }

            if (floor == null || floor.IsDestroyed)
            {
                Check("sentry.floor", false, "the floor did not stay up");
                yield break;
            }

            Check("sentry.floor.meshCovers", covered, covered
                ? $"the navmesh covered a new floor 4 m up after {Time.realtimeSinceStartup - spawnedAt:0.00} s ({frames} frames)"
                : "not covered within 10 s");
            BasePlayer roamer = Spawn(top, "t_roam");
            Check("sentry.floor.roamerStandsOnIt", !covered || (roamer != null && Mathf.Abs(roamer.transform.position.y - top.y) < 0.6f),
                roamer != null ? $"a roamer placed at y={roamer.transform.position.y:0.00}, floor {top.y:0.00}" : "refused");
            if (roamer != null) Api<int>("RunicNpc_Despawn", roamer.net.ID.Value);

            // Truly off the navmesh: 40 m up. A roamer is refused; a sentry is placed and stays.
            Vector3 air = field + new Vector3(0f, 40f, -20f);
            Check("sentry.offMesh.roamerRefused", Spawn(air, "t_roam") == null, "40 m up");
            BasePlayer up = Spawn(air, "t_sentry");
            Check("sentry.offMesh.sentryPlaced", up != null, "");
            if (up != null)
            {
                StandIn(field + new Vector3(0, 0, 100), 5);
                yield return new WaitForSeconds(20f);
                bool there = up != null && !up.IsDestroyed && Vector3.Distance(up.transform.position, air) < 1.5f;
                Check("sentry.offMesh.stays", there, up != null && !up.IsDestroyed ? $"{Vector3.Distance(up.transform.position, air):0.00} m from its spot after 20 s" : "gone");
            }
        }

        // ---- sleep: walk home past 160 m of any player, then sleep; wake when one comes back ----

        private IEnumerator Sleep(Vector3 field)
        {
            BasePlayer keeper = StandIn(field + new Vector3(0, 0, 100), 6);
            BasePlayer npc = Spawn(field, "t_roam", JObject.FromObject(new { movement = new { mode = "wander", radius = 30f } }));
            yield return new WaitForSeconds(1f);
            Vector3 home = npc.transform.position;

            // Let it wander off its spot.
            float away = 0f;
            for (int t = 0; t < 60 && away < 8f; t++)
            {
                yield return new WaitForSeconds(1f);
                away = Flat(npc.transform.position, home);
            }

            Check("sleep.awayFirst", away >= 3f, $"{away:0.0} m from home before the players leave");
            keeper.Kill();
            _standIns.Remove(keeper);

            string rest = "";
            bool sawGoingHome = false;
            float maxStep = 0f;
            Vector3 last = npc.transform.position;
            for (int t = 0; t < 90; t++)
            {
                yield return new WaitForSeconds(1f);
                maxStep = Mathf.Max(maxStep, Flat(npc.transform.position, last));
                last = npc.transform.position;
                rest = (string)Describe(npc)["rest"];
                if (rest == "GoingHome") sawGoingHome = true;
                if (rest == "Asleep") break;
            }

            float fromHome = Flat(npc.transform.position, home);
            Check("sleep.walksHome", sawGoingHome || away < 3f, "saw GoingHome=" + sawGoingHome);
            Check("sleep.asleep", rest == "Asleep", "rest=" + rest);
            Check("sleep.atHome", fromHome <= 3f, $"{fromHome:0.0} m from home");
            Check("sleep.walkedNotTeleported", maxStep < 8f, $"largest step {maxStep:0.0} m per second");

            // Still for 10 s asleep.
            Vector3 sleptAt = npc.transform.position;
            yield return new WaitForSeconds(10f);
            Check("sleep.still", Flat(npc.transform.position, sleptAt) < 0.5f, "");

            StandIn(field + new Vector3(0, 0, 100), 7);
            yield return new WaitForSeconds(4f);
            rest = (string)Describe(npc)["rest"];
            Check("sleep.wakes", rest == "Awake", "rest=" + rest);
        }

        // ---- place: each and group respawn, a missing profile waits, a missing route waits ----

        private IEnumerator Place(Vector3 field)
        {
            Vector3 a = field + new Vector3(-40, 0, 0);
            Vector3 b = field + new Vector3(-40, 0, 30);
            StandIn(field + new Vector3(-40, 0, 110), 8);
            Check("place.set.each", Api<string>("RunicNpc_SetPlacement", "t_each", Placement("t_each", a, 3, 20f, "each")) == null, "");
            Check("place.set.group", Api<string>("RunicNpc_SetPlacement", "t_group", Placement("t_roam", b, 3, 20f, "group")) == null, "");
            yield return new WaitForSeconds(4f);

            List<Dictionary<string, object>> each = List("placement:t_each");
            List<Dictionary<string, object>> group = List("placement:t_group");
            Check("place.spawned", each.Count == 3 && group.Count == 3, $"each {each.Count}, group {group.Count}");

            // each: kill one; the other two stay, and it alone returns after ~20 s.
            var survivors = new HashSet<ulong>(each.Skip(1).Select(x => (ulong)x["netId"]));
            Kill((ulong)each[0]["netId"]);
            yield return new WaitForSeconds(2f);
            Check("place.each.down", List("placement:t_each").Count == 2, "" + List("placement:t_each").Count);
            yield return new WaitForSeconds(22f);
            List<Dictionary<string, object>> after = List("placement:t_each");
            Check("place.each.back", after.Count == 3 && survivors.All(id => after.Any(x => (ulong)x["netId"] == id)), $"{after.Count} alive, survivors kept={survivors.All(id => after.Any(x => (ulong)x["netId"] == id))}");

            // group: kill one; nothing returns while two live. Kill the rest; all three return together.
            Kill((ulong)group[0]["netId"]);
            yield return new WaitForSeconds(24f);
            Check("place.group.waitsForAll", List("placement:t_group").Count == 2, "" + List("placement:t_group").Count);
            foreach (Dictionary<string, object> x in List("placement:t_group")) Kill((ulong)x["netId"]);
            yield return new WaitForSeconds(10f);
            Check("place.group.notEarly", List("placement:t_group").Count == 0, "" + List("placement:t_group").Count);
            yield return new WaitForSeconds(14f);
            Check("place.group.back", List("placement:t_group").Count == 3, "" + List("placement:t_group").Count);

            // D237: remove t_each's profile. Its NPCs despawn and the placement waits; restore it and they return.
            SetTestProfiles(withEach: false);
            yield return new WaitForSeconds(2f);
            Dictionary<string, object> row = Row("t_each");
            Check("place.missingProfile.waits", List("placement:t_each").Count == 0 && row != null && row["waiting"] != null, row != null ? "" + row["waiting"] : "no row");
            SetTestProfiles();
            yield return new WaitForSeconds(4f);
            Check("place.missingProfile.returns", List("placement:t_each").Count == 3, "" + List("placement:t_each").Count);

            JObject waitRoute = Placement("t_roam", a, 1, 20f, "each");
            waitRoute["movement"] = JObject.FromObject(new { mode = "route:t_nope", radius = 0f });
            Check("place.set.routeOverride", Api<string>("RunicNpc_SetPlacement", "t_waitroute", waitRoute) == null, "");
            yield return new WaitForSeconds(2f);
            row = Row("t_waitroute");
            Check("place.missingRoute.waits", row != null && ("" + row["waiting"]).Contains("route"), row != null ? "" + row["waiting"] : "no row");
            Api<bool>("RunicNpc_RemovePlacement", "t_waitroute");

            Check("place.remove", Api<bool>("RunicNpc_RemovePlacement", "t_group") && List("placement:t_group").Count == 0, "");
            Check("place.refuse.badRespawnMode", Api<string>("RunicNpc_SetPlacement", "t_x", Placement("t_roam", a, 1, 20f, "sometimes")) != null, "");

            // Leave two for rnt.after, across a reload or a restart.
            Api<bool>("RunicNpc_RemovePlacement", "t_each");
            Api<string>("RunicNpc_SetPlacement", "t_keep1", Placement("t_roam", a, 2, 30f, "each"));
            Api<string>("RunicNpc_SetPlacement", "t_keep2", Placement("t_sentry", b, 1, 30f, "each"));
            Note("left placements t_keep1 (2) and t_keep2 (1) for rnt.after");
        }

        private static JObject Placement(string profile, Vector3 at, int count, float respawn, string mode) =>
            JObject.FromObject(new { profile, position = new { x = at.x, y = at.y, z = at.z }, yaw = 0f, count, respawn, respawnMode = mode });

        private Dictionary<string, object> Row(string id) =>
            (Api<List<Dictionary<string, object>>>("RunicNpc_Placements") ?? new List<Dictionary<string, object>>()).FirstOrDefault(r => (string)r["id"] == id);

        private static void Kill(ulong netId)
        {
            BasePlayer p = BaseNetworkable.serverEntities.Find(new NetworkableId(netId)) as BasePlayer;
            if (p != null && !p.IsDead()) p.Hurt(new HitInfo(null, p, Rust.DamageType.Bullet, 10000f));
        }

        /// <summary>
        ///     After a reload or restart: every placement is back to its count, every RunicNPC entity in
        ///     the world is one RunicNPC lists, and no plain scientist stands at a placement's spot (the
        ///     saved-subclass symptom stage 1 found).
        /// </summary>
        private void After()
        {
            _pass = _fail = 0;
            List<Dictionary<string, object>> rows = Api<List<Dictionary<string, object>>>("RunicNpc_Placements") ?? new List<Dictionary<string, object>>();
            foreach (Dictionary<string, object> r in rows)
            {
                JObject p = (JObject)r["placement"];
                Check($"after.placement.{r["id"]}", Convert.ToInt32(r["alive"]) == (int)p["count"], $"{r["alive"]}/{p["count"]} alive, waiting={r["waiting"] ?? "-"}");
            }

            var listed = new HashSet<ulong>(List(null).Select(d => (ulong)d["netId"]));
            List<BasePlayer> world = BaseNetworkable.serverEntities.OfType<BasePlayer>().Where(p => p.GetType().Name == "RunicNpcPlayer").ToList();
            Check("after.worldMatchesRegistry", world.Count == listed.Count && world.All(p => listed.Contains(p.net.ID.Value)), $"world {world.Count}, listed {listed.Count}");

            int strays = 0;
            foreach (Dictionary<string, object> r in rows)
            {
                Vector3 at = V(((JObject)r["placement"])["position"].ToObject<Dictionary<string, object>>());
                strays += BaseNetworkable.serverEntities.OfType<ScientistNPC>().Count(s => s.GetType() == typeof(ScientistNPC) && Vector3.Distance(s.transform.position, at) < 25f);
            }

            Check("after.noSavedScientists", strays == 0, strays + " plain scientist(s) at placement spots");
            Check("after.pluginOwnedGone", List(Owner).Count == 0, List(Owner).Count + " left for " + Owner);
            Note($"after: {_pass} pass, {_fail} fail");
        }

        /// <summary>A route, as RunicNpc_Routes returns it.</summary>
        private sealed class Route
        {
            public List<P> points = new List<P>();
            public bool loop;
        }

        private sealed class P
        {
            public float x, y, z;
            public Vector3 V => new Vector3(x, y, z);
        }
    }
}