using System.Net;
using System.Reflection;
using AcDream.Core.Chat;
using AcDream.Core.Combat;
using AcDream.Core.Items;
using AcDream.Core.Net;
using AcDream.Core.Player;
using AcDream.Core.Properties;
using AcDream.Core.Social;
using AcDream.Core.Spells;
using AcDream.Runtime.Session;
using AcDream.Runtime.Gameplay;

namespace AcDream.Runtime.Tests.Session;

public sealed class LiveSessionEventRouterTests
{
    [Fact]
    public void CreatedRouterPublishesNoHandlersUntilExplicitAttach()
    {
        using var session = NewSession();
        int baselineGameEvents = session.GameEvents.RegisteredHandlerCount;
        var router = new LiveSessionEventRouter(
            session,
            new LiveEntitySessionSink(
                _ => { }, _ => { }, _ => { }, _ => { }, _ => { }, _ => { },
                _ => { }, _ => { }, _ => { }, _ => { }, _ => { }, _ => { },
                _ => { }),
            new LiveEnvironmentSessionSink(_ => { }, _ => { }),
            NewInventoryBindings(),
            NewCharacterBindings(),
            NewSocialBindings());

        AssertSessionHandlerCounts(session, multiplier: 0);
        Assert.Equal(baselineGameEvents, session.GameEvents.RegisteredHandlerCount);

        router.Attach();
        AssertSessionHandlerCounts(session, multiplier: 1);
        Assert.True(session.GameEvents.RegisteredHandlerCount > baselineGameEvents);

        router.Dispose();
        AssertSessionHandlerCounts(session, multiplier: 0);
        Assert.Equal(baselineGameEvents, session.GameEvents.RegisteredHandlerCount);
    }

    [Fact]
    public void Dispose_DetachesExactHandlersAndSilencesCopiedDelegates()
    {
        using var session = NewSession();
        int baselineGameEvents = session.GameEvents.RegisteredHandlerCount;
        var counters = new Counters();
        var combat = new CombatState();
        var chat = new ChatLog();
        var router = NewRouter(session, counters, combat: combat, chat: chat);

        AssertSessionHandlerCounts(session, multiplier: 1);
        Assert.True(session.GameEvents.RegisteredHandlerCount > baselineGameEvents);
        Action<double> copiedTime = EventDelegate<Action<double>>(
            session,
            nameof(session.ServerTimeUpdated));
        Action<uint> copiedTeleport = EventDelegate<Action<uint>>(
            session,
            nameof(session.TeleportStarted));
        Action<WorldSession.PlayerIntPropertyUpdate> copiedPlayerInt =
            EventDelegate<Action<WorldSession.PlayerIntPropertyUpdate>>(
                session,
                nameof(session.PlayerIntPropertyUpdated));
        Action<CombatState.DamageDealt> copiedDamage =
            EventDelegate<CombatState, Action<CombatState.DamageDealt>>(
                combat,
                nameof(combat.DamageDealtAccepted));
        copiedTime(123d);
        copiedTeleport(0x50000001u);
        copiedPlayerInt(new WorldSession.PlayerIntPropertyUpdate(
            CombatStateWiring.CombatModePropertyId,
            (int)CombatMode.Melee));
        copiedDamage(new CombatState.DamageDealt("Drudge", 1u, 5u, 0.1f));
        Assert.Equal(1, counters.ServerTime);
        Assert.Equal(1, counters.Teleport);
        Assert.Equal(CombatMode.Melee, combat.CurrentMode);
        Assert.Equal(1, chat.Count);

        router.Dispose();
        router.Dispose();
        AssertSessionHandlerCounts(session, multiplier: 0);
        Assert.Equal(baselineGameEvents, session.GameEvents.RegisteredHandlerCount);

        copiedTime(456d);
        copiedTeleport(0x50000002u);
        copiedPlayerInt(new WorldSession.PlayerIntPropertyUpdate(
            CombatStateWiring.CombatModePropertyId,
            (int)CombatMode.Magic));
        copiedDamage(new CombatState.DamageDealt("Drudge", 1u, 7u, 0.2f));
        Assert.Equal(1, counters.ServerTime);
        Assert.Equal(1, counters.Teleport);
        Assert.Equal(CombatMode.Melee, combat.CurrentMode);
        Assert.Equal(1, chat.Count);
    }

    // ── Campaign CH slice CH2: 0xF7E0 ServerMessage routes through AddText ──

    [Fact]
    public void ServerMessage_RoutesThroughAddText_WithWireChatTypeVerbatim_WhenWired()
    {
        using var session = NewSession();
        var chat = new ChatLog();
        var reported = new List<(string Text, RetailLogTextType Type)>();
        var social = new LiveSocialSessionBindings(
            chat,
            new TurbineChatState(),
            new FriendsState(),
            new SquelchState(),
            (text, type) => reported.Add((text, type)));
        var router = new LiveSessionEventRouter(
            session,
            new LiveEntitySessionSink(
                _ => { }, _ => { }, _ => { }, _ => { }, _ => { }, _ => { },
                _ => { }, _ => { }, _ => { }, _ => { }, _ => { }, _ => { },
                _ => { }),
            new LiveEnvironmentSessionSink(_ => { }, _ => { }),
            NewInventoryBindings(),
            NewCharacterBindings(),
            social);
        router.Attach();

        // 0x1A carried verbatim -- retail's Handle_Communication__TextboxString
        // @0x0057D3A0 feeds the RAW wire chatType into AddTextToScroll.
        EventDelegate<Action<AcDream.Core.Net.Messages.ServerMessage.Parsed>>(
            session, nameof(session.ServerMessageReceived))(
            new AcDream.Core.Net.Messages.ServerMessage.Parsed("You are too encumbered to carry that!", 0x1Au));

        var (text, type) = Assert.Single(reported);
        Assert.Equal("You are too encumbered to carry that!", text);
        Assert.Equal(RetailLogTextType.ClientLocal, type);
        Assert.Equal(0, chat.Count);

        router.Dispose();
    }

    [Fact]
    public void ServerMessage_FallsBackToChatDirectly_WhenNoRouterWired()
    {
        using var session = NewSession();
        var chat = new ChatLog();
        var router = NewRouter(session, new Counters(), chat: chat);

        EventDelegate<Action<AcDream.Core.Net.Messages.ServerMessage.Parsed>>(
            session, nameof(session.ServerMessageReceived))(
            new AcDream.Core.Net.Messages.ServerMessage.Parsed("fallback path", 0x00u));

        Assert.Equal(1, chat.Count);
        Assert.Equal("fallback path", chat.Snapshot()[0].Text);

        router.Dispose();
    }

    [Fact]
    public void NestedRouters_DisposeOlderFirstLeavesOnlyNewerRouter()
    {
        using var session = NewSession();
        int baselineGameEvents = session.GameEvents.RegisteredHandlerCount;
        var first = new Counters();
        var second = new Counters();
        var routerA = NewRouter(session, first);
        var routerB = NewRouter(session, second);

        AssertSessionHandlerCounts(session, multiplier: 2);
        EventDelegate<Action<double>>(session, nameof(session.ServerTimeUpdated))(1d);
        Assert.Equal(1, first.ServerTime);
        Assert.Equal(1, second.ServerTime);

        routerA.Dispose();
        AssertSessionHandlerCounts(session, multiplier: 1);
        EventDelegate<Action<double>>(session, nameof(session.ServerTimeUpdated))(2d);
        Assert.Equal(1, first.ServerTime);
        Assert.Equal(2, second.ServerTime);

        routerB.Dispose();
        AssertSessionHandlerCounts(session, multiplier: 0);
        Assert.Equal(baselineGameEvents, session.GameEvents.RegisteredHandlerCount);
    }

    [Fact]
    public void NestedRouters_DisposeNewerFirstLeavesOnlyOlderRouter()
    {
        using var session = NewSession();
        int baselineGameEvents = session.GameEvents.RegisteredHandlerCount;
        var first = new Counters();
        var second = new Counters();
        var routerA = NewRouter(session, first);
        var routerB = NewRouter(session, second);

        routerB.Dispose();
        AssertSessionHandlerCounts(session, multiplier: 1);
        EventDelegate<Action<double>>(session, nameof(session.ServerTimeUpdated))(1d);
        Assert.Equal(1, first.ServerTime);
        Assert.Equal(0, second.ServerTime);

        routerA.Dispose();
        AssertSessionHandlerCounts(session, multiplier: 0);
        Assert.Equal(baselineGameEvents, session.GameEvents.RegisteredHandlerCount);
    }

    [Fact]
    public void ThrowingSink_DoesNotCorruptLaterTeardown()
    {
        using var session = NewSession();
        int baselineGameEvents = session.GameEvents.RegisteredHandlerCount;
        var router = NewRouter(
            session,
            new Counters { ThrowOnServerTime = true });

        Assert.Throws<InvalidOperationException>(() =>
            EventDelegate<Action<double>>(
                session,
                nameof(session.ServerTimeUpdated))(1d));

        router.Dispose();
        AssertSessionHandlerCounts(session, multiplier: 0);
        Assert.Equal(baselineGameEvents, session.GameEvents.RegisteredHandlerCount);
    }

    [Fact]
    public void ConstructionFailure_UnwindsEveryPriorRegistration()
    {
        using var session = NewSession();
        int baselineGameEvents = session.GameEvents.RegisteredHandlerCount;

        Assert.Throws<InvalidOperationException>(() => NewRouter(
            session,
            new Counters(),
            step =>
            {
                if (step == 20)
                    throw new InvalidOperationException("injected construction failure");
            }));

        AssertSessionHandlerCounts(session, multiplier: 0);
        Assert.Equal(baselineGameEvents, session.GameEvents.RegisteredHandlerCount);
    }

    // ── Campaign P Slice P1 (2026-07-30): burden/stamina recompute wiring ─

    [Fact]
    public void ObjectTablePropertyChange_RecomputesAndPushesBurden()
    {
        using var session = NewSession();
        const uint playerGuid = 0x50000001u;
        var objects = new ClientObjectTable();
        var character = new RuntimeCharacterState();
        int movementStatsUpdated = 0;

        var router = new LiveSessionEventRouter(
            session,
            NoOpEntitySink(),
            NoOpEnvironmentSink(),
            new LiveInventorySessionBindings(
                objects,
                PlayerGuid: () => playerGuid,
                OnShortcuts: null,
                OnUseDone: null,
                ItemMana: new ItemManaState(),
                ExternalContainers: new ExternalContainerState()),
            new LiveCharacterSessionBindings(
                new CombatState(),
                character,
                ResolveSkillFormulaBonus: null,
                OnSkillsUpdated: null,
                OnConfirmationRequest: null,
                OnConfirmationDone: null,
                ClientTime: () => 0d,
                OnMovementStatsUpdated: () => movementStatsUpdated++),
            NewSocialBindings());

        router.Attach();

        // Strength=100, no augmentation -> capacity=15000 (BurdenMath).
        character.LocalPlayer.OnAttributeUpdate(
            atType: 1u, ranks: 90u, start: 10u, xp: 0u);
        Assert.Equal(1, movementStatsUpdated);
        Assert.Equal(0f, character.MovementSkills.Burden, precision: 4);

        // EncumbranceVal (property 5) = 7500 -> load = 7500/15000 = 0.5.
        var props = new PropertyBundle();
        props.Ints[(uint)PropertyInt.EncumbranceVal] = 7500;
        objects.UpsertProperties(playerGuid, props);

        Assert.True(movementStatsUpdated >= 2);
        Assert.Equal(0.5f, character.MovementSkills.Burden, precision: 4);

        router.Dispose();
    }

    [Fact]
    public void StrengthEnchantmentChange_RecomputesBurdenWithoutBaseAttributeUpdate()
    {
        using var session = NewSession();
        const uint playerGuid = 0x50000001u;
        var objects = new ClientObjectTable();
        var character = new RuntimeCharacterState();
        character.InstallSpellMetadata(SpellTable.LoadFromReader(new StringReader(
            "Spell ID,Name,Flags [Hex]\n42,Strength Test,0x4\n")));
        int movementStatsUpdated = 0;

        var router = new LiveSessionEventRouter(
            session,
            NoOpEntitySink(),
            NoOpEnvironmentSink(),
            new LiveInventorySessionBindings(
                objects,
                PlayerGuid: () => playerGuid,
                OnShortcuts: null,
                OnUseDone: null,
                ItemMana: new ItemManaState(),
                ExternalContainers: new ExternalContainerState()),
            new LiveCharacterSessionBindings(
                new CombatState(),
                character,
                ResolveSkillFormulaBonus: null,
                OnSkillsUpdated: null,
                OnConfirmationRequest: null,
                OnConfirmationDone: null,
                ClientTime: () => 0d,
                OnMovementStatsUpdated: () => movementStatsUpdated++),
            NewSocialBindings());

        router.Attach();
        character.LocalPlayer.OnAttributeUpdate(
            atType: 1u, ranks: 90u, start: 10u, xp: 0u);
        var props = new PropertyBundle();
        props.Ints[(uint)PropertyInt.EncumbranceVal] = 16500;
        objects.UpsertProperties(playerGuid, props);
        Assert.Equal(1.1f, character.MovementSkills.Burden, precision: 4);

        int beforeBuff = movementStatsUpdated;
        character.Spellbook.OnEnchantmentAdded(new ActiveEnchantmentRecord(
            SpellId: 42u,
            LayerId: 1u,
            Duration: 60d,
            CasterGuid: playerGuid,
            StatModType: (uint)EnchantmentMath.EnchantmentTypeFlag.Attribute,
            StatModKey: 1u,
            StatModValue: 1.2f,
            Bucket: 1u));

        Assert.Equal(120, character.LocalPlayer.GetEffectiveAttribute(
            LocalPlayerState.AttributeKind.Strength));
        Assert.Equal(16500f / 18000f, character.MovementSkills.Burden, precision: 4);
        Assert.Equal(beforeBuff + 1, movementStatsUpdated);

        int beforePurge = movementStatsUpdated;
        character.Spellbook.OnPurgeAll();

        Assert.Equal(100, character.LocalPlayer.GetEffectiveAttribute(
            LocalPlayerState.AttributeKind.Strength));
        Assert.Equal(1.1f, character.MovementSkills.Burden, precision: 4);
        Assert.Equal(beforePurge + 1, movementStatsUpdated);

        router.Dispose();
    }

    [Fact]
    public void ObjectTablePropertyChange_RecomputesMovementSkillAugmentations()
    {
        using var session = NewSession();
        const uint playerGuid = 0x50000001u;
        var objects = new ClientObjectTable();
        var character = new RuntimeCharacterState();
        character.LocalPlayer.OnSkillUpdate(
            RuntimeCharacterState.RunSkillId,
            ranks: 0u,
            status: 3u,
            xp: 0u,
            init: 0u,
            resistance: 0u,
            lastUsed: 0d,
            formulaBonus: 200u);
        character.UpdateMovementSkillBase(
            runSkillBase: 200,
            jumpSkillBase: -1);

        var router = new LiveSessionEventRouter(
            session,
            NoOpEntitySink(),
            NoOpEnvironmentSink(),
            new LiveInventorySessionBindings(
                objects,
                PlayerGuid: () => playerGuid,
                OnShortcuts: null,
                OnUseDone: null,
                ItemMana: new ItemManaState(),
                ExternalContainers: new ExternalContainerState()),
            new LiveCharacterSessionBindings(
                new CombatState(),
                character,
                ResolveSkillFormulaBonus: null,
                OnSkillsUpdated: null,
                OnConfirmationRequest: null,
                OnConfirmationDone: null,
                ClientTime: () => 0d),
            NewSocialBindings());
        router.Attach();

        var properties = new PropertyBundle();
        properties.Ints[(uint)PropertyInt.LumAugAllSkills] = 2;
        properties.Ints[(uint)PropertyInt.AugmentationJackOfAllTrades] = 1;
        properties.Ints[(uint)PropertyInt.LumAugSkilledSpec] = 3;
        objects.UpsertProperties(playerGuid, properties);

        Assert.Equal(213, character.MovementSkills.RunSkill);
        router.Dispose();
    }

    [Fact]
    public void StaminaVitalChange_PushesCurrentStamina()
    {
        using var session = NewSession();
        var character = new RuntimeCharacterState();
        int movementStatsUpdated = 0;

        var router = new LiveSessionEventRouter(
            session,
            NoOpEntitySink(),
            NoOpEnvironmentSink(),
            NewInventoryBindings(),
            new LiveCharacterSessionBindings(
                new CombatState(),
                character,
                ResolveSkillFormulaBonus: null,
                OnSkillsUpdated: null,
                OnConfirmationRequest: null,
                OnConfirmationDone: null,
                ClientTime: () => 0d,
                OnMovementStatsUpdated: () => movementStatsUpdated++),
            NewSocialBindings());

        router.Attach();
        Assert.Equal(-1, character.MovementSkills.CurrentStamina);

        character.LocalPlayer.OnVitalUpdate(
            vitalId: 8u, ranks: 40u, start: 20u, xp: 0u, current: 45u);

        Assert.Equal(1, movementStatsUpdated);
        Assert.Equal(45, character.MovementSkills.CurrentStamina);

        router.Dispose();
    }

    private static LiveEntitySessionSink NoOpEntitySink() => new(
        Spawned: _ => { },
        Deleted: _ => { },
        PickedUp: _ => { },
        MotionUpdated: _ => { },
        PositionUpdated: _ => { },
        VectorUpdated: _ => { },
        StateUpdated: _ => { },
        ParentUpdated: _ => { },
        TeleportStarted: _ => { },
        AppearanceUpdated: _ => { },
        PlayPhysicsScript: _ => { },
        PlayPhysicsScriptType: _ => { },
        SoundEvent: _ => { });

    private static LiveEnvironmentSessionSink NoOpEnvironmentSink() => new(
        EnvironChanged: _ => { },
        ServerTimeUpdated: _ => { });

    private static LiveSessionEventRouter NewRouter(
        WorldSession session,
        Counters counters,
        Action<int>? constructionCheckpoint = null,
        CombatState? combat = null,
        ChatLog? chat = null)
    {
        var router = new LiveSessionEventRouter(
            session,
            new LiveEntitySessionSink(
                Spawned: _ => { },
                Deleted: _ => { },
                PickedUp: _ => { },
                MotionUpdated: _ => { },
                PositionUpdated: _ => { },
                VectorUpdated: _ => { },
                StateUpdated: _ => { },
                ParentUpdated: _ => { },
                TeleportStarted: _ => counters.Teleport++,
                AppearanceUpdated: _ => { },
                PlayPhysicsScript: _ => { },
                PlayPhysicsScriptType: _ => { },
                SoundEvent: _ => { }),
            new LiveEnvironmentSessionSink(
                EnvironChanged: _ => { },
                ServerTimeUpdated: _ =>
                {
                    if (counters.ThrowOnServerTime)
                        throw new InvalidOperationException("injected sink failure");
                    counters.ServerTime++;
                }),
            NewInventoryBindings(),
            NewCharacterBindings(combat),
            NewSocialBindings(chat),
            constructionCheckpoint);
        try
        {
            router.Attach();
            return router;
        }
        catch
        {
            router.Dispose();
            throw;
        }
    }

    private static LiveInventorySessionBindings NewInventoryBindings() => new(
        new ClientObjectTable(),
        PlayerGuid: () => 0x50000001u,
        OnShortcuts: null,
        OnUseDone: null,
        ItemMana: new ItemManaState(),
        ExternalContainers: new ExternalContainerState());

    private static LiveCharacterSessionBindings NewCharacterBindings(
        CombatState? combat = null) => new(
        combat ?? new CombatState(),
        new RuntimeCharacterState(),
        ResolveSkillFormulaBonus: null,
        OnSkillsUpdated: null,
        OnConfirmationRequest: null,
        OnConfirmationDone: null,
        ClientTime: () => 0d);

    private static LiveSocialSessionBindings NewSocialBindings(
        ChatLog? chat = null) => new(
        chat ?? new ChatLog(),
        new TurbineChatState(),
        new FriendsState(),
        new SquelchState());

    private static WorldSession NewSession() =>
        new(new IPEndPoint(IPAddress.Loopback, 9));

    private static void AssertSessionHandlerCounts(
        WorldSession session,
        int multiplier)
    {
        string[] directEvents =
        [
            nameof(session.EntitySpawned),
            nameof(session.EntityDeleted),
            nameof(session.EntityPickedUp),
            nameof(session.MotionUpdated),
            nameof(session.PositionUpdated),
            nameof(session.VectorUpdated),
            nameof(session.StateUpdated),
            nameof(session.ParentUpdated),
            nameof(session.TeleportStarted),
            nameof(session.AppearanceUpdated),
            nameof(session.PlayPhysicsScriptReceived),
            nameof(session.PlayPhysicsScriptTypeReceived),
            nameof(session.EnvironChanged),
            nameof(session.ServerTimeUpdated),
            nameof(session.SpeechHeard),
            nameof(session.ServerMessageReceived),
            nameof(session.EmoteHeard),
            nameof(session.SoulEmoteHeard),
            nameof(session.PlayerKilledReceived),
            nameof(session.TurbineChatReceived),
            nameof(session.VitalUpdated),
            nameof(session.VitalCurrentUpdated),
        ];
        foreach (string eventName in directEvents)
            Assert.Equal(multiplier, HandlerCount(session, eventName));

        Assert.Equal(multiplier, HandlerCount(session, nameof(session.ObjectIntPropertyUpdated)));
        Assert.Equal(multiplier * 2, HandlerCount(session, nameof(session.PlayerIntPropertyUpdated)));
        Assert.Equal(multiplier, HandlerCount(session, nameof(session.PlayerInt64PropertyUpdated)));
        Assert.Equal(multiplier, HandlerCount(session, nameof(session.StackSizeUpdated)));
        Assert.Equal(multiplier, HandlerCount(session, nameof(session.InventoryObjectRemoved)));
    }

    private static int HandlerCount(WorldSession session, string eventName) =>
        (EventField(session, eventName).GetValue(session) as MulticastDelegate)?
            .GetInvocationList()
            .Length ?? 0;

    private static TDelegate EventDelegate<TDelegate>(
        WorldSession session,
        string eventName)
        where TDelegate : Delegate =>
        Assert.IsType<TDelegate>(EventField(session, eventName).GetValue(session));

    private static TDelegate EventDelegate<TOwner, TDelegate>(
        TOwner owner,
        string eventName)
        where TOwner : class
        where TDelegate : Delegate =>
        Assert.IsType<TDelegate>(
            typeof(TOwner).GetField(
                eventName,
                BindingFlags.Instance | BindingFlags.NonPublic)?.GetValue(owner));

    private static FieldInfo EventField(WorldSession session, string eventName) =>
        typeof(WorldSession).GetField(
            eventName,
            BindingFlags.Instance | BindingFlags.NonPublic)
        ?? throw new InvalidOperationException($"event field {eventName} not found");

    private sealed class Counters
    {
        public int ServerTime;
        public int Teleport;
        public bool ThrowOnServerTime;
    }
}