using Newtonsoft.Json.Linq;
using RudderSdk.Core;
using RudderSdk.Core.Abstractions;
using RudderSdk.Core.Models;
using RudderSdk.Core.Models.Auth;
using RudderSdk.Core.Models.Scenarios;

using Xunit;

namespace RudderSdk.Core.Tests;

public sealed class ScenarioServiceTests
{
    [Fact]
    public async Task TriggerAsync_Emits_Returned_Effects()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect>
            {
                Effect("run-1", "n1", "notification"),
                Effect("run-2", "n2", "notification")
            }
        });
        var client = CreateClient(transport);
        var notifications = new List<NotificationEffect>();
        client.Effects.OnNotification += notifications.Add;

        await client.Scenario.TriggerAsync("login");

        Assert.Equal(2, notifications.Count);
        Assert.Equal("n1", notifications[0].NodeId);
        Assert.Equal("n2", notifications[1].NodeId);
    }

    [Fact]
    public async Task TriggerAsync_Dedups_By_RunId_And_NodeId()
    {
        var transport = new FakeTransport();
        var effect = Effect("run-1", "n1", "notification");
        transport.Enqueue(new TriggerScenarioResponse { Effects = new List<PendingEffect> { effect } });
        transport.Enqueue(new TriggerScenarioResponse { Effects = new List<PendingEffect> { Effect("run-1", "n1", "notification") } });
        var client = CreateClient(transport);
        var notifications = 0;
        client.Effects.OnNotification += _ => notifications++;

        await client.Scenario.TriggerAsync("login");
        await client.Scenario.TriggerAsync("login");

        Assert.Equal(1, notifications);
    }

    [Fact]
    public async Task Completing_Notification_Posts_Output_And_Ingests_Next_Effect()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "n1", "notification", new { title = "hi", message = "there" }) }
        });
        transport.Enqueue(new HandleScenarioCallbackResponse
        {
            Effect = JObject.FromObject(Effect("run-1", "store", "store"))
        });
        var client = CreateClient(transport);
        NotificationEffect? notification = null;
        StoreOfferEffect? store = null;
        client.Effects.OnNotification += e => notification = e;
        client.Effects.OnStoreOffer += e => store = e;

        await client.Scenario.TriggerAsync("login");
        Assert.Equal("hi", notification!.Title);
        Assert.Equal("there", notification.Message);
        await notification.DoneAsync();

        var callback = Assert.IsType<HandleScenarioCallbackRequest>(
            transport.Calls.Single(call => call.Path == "/sdk/v1/scenarios/callback").Request);
        Assert.Equal("n1", callback.NodeId);
        Assert.Equal("output", callback.Handle);
        Assert.Equal("run-1", callback.RunId);
        Assert.NotNull(store);
        Assert.Equal("store", store!.NodeId);
    }

    [Fact]
    public async Task Completing_Last_Effect_Raises_ScenarioCompleted()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "n1", "notification") }
        });
        transport.Enqueue(new HandleScenarioCallbackResponse());
        var client = CreateClient(transport);
        NotificationEffect? notification = null;
        ScenarioCompletedEffect? completed = null;
        client.Effects.OnNotification += e => notification = e;
        client.Effects.OnScenarioCompleted += e => completed = e;

        await client.Scenario.TriggerAsync("login");
        await notification!.DoneAsync();

        Assert.NotNull(completed);
        Assert.Equal("run-1", completed!.RunId);
        Assert.Equal("scenario-1", completed.ScenarioId);
    }

    [Fact]
    public async Task Emits_Typed_Events_For_All_Supported_Interactive_Node_Types()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect>
            {
                Effect("run-1", "n1", "notification"),
                Effect("run-2", "n2", "store"),
                Effect("run-3", "n3", "quest"),
                Effect("run-4", "n4", "leaderboard"),
                Effect("run-5", "n5", "battlepass"),
                Effect("run-6", "n6", "battlepass_level", new { levelNumber = 3 }),
                Effect("run-7", "n7", "wait", waitDeadline: new DateTimeOffset(2026, 5, 30, 10, 30, 0, TimeSpan.Zero))
            }
        });
        var client = CreateClient(transport);
        var notification = 0;
        var store = 0;
        var quest = 0;
        var leaderboard = 0;
        var battlePass = 0;
        var battlePassLevel = 0;
        var wait = 0;
        WaitEffect? waitEffect = null;
        BattlePassLevelEffect? levelEffect = null;
        client.Effects.OnNotification += _ => notification++;
        client.Effects.OnStoreOffer += _ => store++;
        client.Effects.OnQuest += _ => quest++;
        client.Effects.OnLeaderboard += _ => leaderboard++;
        client.Effects.OnBattlePass += _ => battlePass++;
        client.Effects.OnBattlePassLevel += e => { battlePassLevel++; levelEffect = e; };
        client.Effects.OnWait += e => { wait++; waitEffect = e; };

        await client.Scenario.TriggerAsync("login");

        Assert.Equal(1, notification);
        Assert.Equal(1, store);
        Assert.Equal(1, quest);
        Assert.Equal(1, leaderboard);
        Assert.Equal(1, battlePass);
        Assert.Equal(1, battlePassLevel);
        Assert.Equal(1, wait);
        Assert.Equal(3, levelEffect!.Level);
        Assert.Equal(new DateTimeOffset(2026, 5, 30, 10, 30, 0, TimeSpan.Zero), waitEffect!.DeadlineUtc);
    }

    [Fact]
    public async Task Store_Purchase_And_Decline_Post_Matching_Handles()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "store", "store") }
        });
        transport.Enqueue(new HandleScenarioCallbackResponse());
        var client = CreateClient(transport);
        StoreOfferEffect? store = null;
        client.Effects.OnStoreOffer += e => store = e;

        await client.Scenario.TriggerAsync("login");
        await store!.PurchaseAsync();

        var callback = Assert.IsType<HandleScenarioCallbackRequest>(
            transport.Calls.Single(call => call.Path == "/sdk/v1/scenarios/callback").Request);
        Assert.Equal("onPurchase", callback.Handle);
        Assert.True(store.IsResolved);

        store.Decline();
        Assert.Equal(1, transport.Calls.Count(call => call.Path == "/sdk/v1/scenarios/callback"));
    }

    [Fact]
    public async Task Leaderboard_End_Posts_OnEnd()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "lb", "leaderboard") }
        });
        transport.Enqueue(new HandleScenarioCallbackResponse());
        var client = CreateClient(transport);
        LeaderboardEffect? leaderboard = null;
        client.Effects.OnLeaderboard += e => leaderboard = e;

        await client.Scenario.TriggerAsync("login");
        await leaderboard!.EndAsync();

        var callback = Assert.IsType<HandleScenarioCallbackRequest>(
            transport.Calls.Single(call => call.Path == "/sdk/v1/scenarios/callback").Request);
        Assert.Equal("onEnd", callback.Handle);
    }

    [Fact]
    public async Task Leaderboard_Claim_Posts_OnClaim()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "lb", "leaderboard") }
        });
        transport.Enqueue(new HandleScenarioCallbackResponse());
        var client = CreateClient(transport);
        LeaderboardEffect? leaderboard = null;
        client.Effects.OnLeaderboard += e => leaderboard = e;

        await client.Scenario.TriggerAsync("login");
        await leaderboard!.ClaimAsync();

        var callback = Assert.IsType<HandleScenarioCallbackRequest>(
            transport.Calls.Single(call => call.Path == "/sdk/v1/scenarios/callback").Request);
        Assert.Equal("onClaim", callback.Handle);
    }

    [Fact]
    public async Task Quest_Progress_Completed_Response_Ingests_Next_Effect()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "quest", "quest", new { name = "wins" }) }
        });
        transport.Enqueue(new UpdateScenarioCounterResponse
        {
            Completed = true,
            Effect = JObject.FromObject(Effect("run-1", "done", "notification"))
        });
        var client = CreateClient(transport);
        QuestEffect? quest = null;
        NotificationEffect? notification = null;
        client.Effects.OnQuest += e => quest = e;
        client.Effects.OnNotification += e => notification = e;

        await client.Scenario.TriggerAsync("login");
        Assert.Equal("wins", quest!.Name);
        await quest.ReportProgressAsync("wins", 1);

        var counter = Assert.IsType<UpdateScenarioCounterRequest>(
            transport.Calls.Single(call => call.Path == "/sdk/v1/scenarios/counter").Request);
        Assert.Equal("quest", counter.NodeId);
        Assert.Equal("wins", counter.CounterKey);
        Assert.Equal(1, counter.Amount);
        Assert.NotNull(notification);
        Assert.Equal("done", notification!.NodeId);
    }

    [Fact]
    public async Task Quest_Progress_Completed_Without_Next_Raises_ScenarioCompleted()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "quest", "quest") }
        });
        transport.Enqueue(new UpdateScenarioCounterResponse { Completed = true });
        var client = CreateClient(transport);
        QuestEffect? quest = null;
        var completed = 0;
        client.Effects.OnQuest += e => quest = e;
        client.Effects.OnScenarioCompleted += _ => completed++;

        await client.Scenario.TriggerAsync("login");
        await quest!.ReportProgressAsync("wins", 1);

        Assert.Equal(1, completed);
    }

    [Fact]
    public async Task Quest_Progress_Failure_Does_Not_Fail_The_Run()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "quest", "quest") }
        });
        transport.Enqueue(new InvalidOperationException("boom"));
        var logger = new FakeLogger();
        var client = CreateClient(transport, logger: logger);
        QuestEffect? quest = null;
        var failed = 0;
        client.Effects.OnQuest += e => quest = e;
        client.Effects.OnScenarioFailed += _ => failed++;

        await client.Scenario.TriggerAsync("login");
        await quest!.ReportProgressAsync("wins", 1);

        Assert.Equal(0, failed);
        Assert.Contains(logger.Messages, m =>
            m.Level == RudderLogLevel.Warning && m.Message.Contains("counter update failed"));
    }

    [Fact]
    public async Task Unknown_Run_Drops_Effects_And_Raises_Failed()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "n1", "notification") }
        });
        transport.Enqueue(new RudderNotFoundException(404, RudderErrorCodes.UnknownRun, "unknown"));
        var client = CreateClient(transport);
        NotificationEffect? notification = null;
        ScenarioFailedEffect? failure = null;
        client.Effects.OnNotification += e => notification = e;
        client.Effects.OnScenarioFailed += e => failure = e;

        await client.Scenario.TriggerAsync("login");
        await notification!.DoneAsync();

        Assert.NotNull(failure);
        Assert.Equal("run-1", failure!.RunId);
        Assert.Equal("n1", failure.NodeId);
        Assert.IsType<RudderNotFoundException>(failure.Exception);
    }

    [Fact]
    public async Task Expired_Run_Drops_Effects()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "n1", "notification") }
        });
        transport.Enqueue(new RudderApiException(400, RudderErrorCodes.RunExpired, "expired"));
        var client = CreateClient(transport);
        NotificationEffect? notification = null;
        ScenarioFailedEffect? failure = null;
        client.Effects.OnNotification += e => notification = e;
        client.Effects.OnScenarioFailed += e => failure = e;

        await client.Scenario.TriggerAsync("login");
        await notification!.DoneAsync();

        Assert.NotNull(failure);
        Assert.Equal("run-1", failure!.RunId);
    }

    [Fact]
    public async Task Unknown_Nodes_Fail_The_Run()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "future", "future_node") }
        });
        var logger = new FakeLogger();
        var client = CreateClient(transport, logger: logger);
        ScenarioFailedEffect? failure = null;
        client.Effects.OnScenarioFailed += e => failure = e;

        await client.Scenario.TriggerAsync("login");

        Assert.NotNull(failure);
        Assert.Equal("future", failure!.NodeId);
        Assert.Contains(logger.Messages, m =>
            m.Level == RudderLogLevel.Warning && m.Message.Contains("Unsupported scenario node type 'future_node'"));
    }

    [Fact]
    public async Task Wait_Deadline_Refreshes_Pending_Without_Posting_Callback()
    {
        var clock = new FakeClock(new DateTimeOffset(2026, 5, 30, 10, 0, 0, TimeSpan.Zero));
        var transport = new FakeTransport();
        transport.Enqueue(new ListPendingScenarioEffectsResponse { Effects = new List<PendingEffect>() });
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect>
            {
                Effect("run-1", "wait", "wait", waitDeadline: clock.UtcNow.AddMinutes(30))
            }
        });
        var client = CreateClient(transport, clock: clock);
        client.Update(0);
        await Task.Delay(50);
        Assert.Equal(1, transport.Calls.Count(call => call.Path == "/sdk/v1/scenarios/pending"));

        await client.Scenario.TriggerAsync("login");
        client.Update(0);
        await Task.Delay(50);
        Assert.Equal(1, transport.Calls.Count(call => call.Path == "/sdk/v1/scenarios/pending"));
        Assert.DoesNotContain(transport.Calls, call => call.Path == "/sdk/v1/scenarios/callback");

        transport.Enqueue(new ListPendingScenarioEffectsResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "done", "notification") }
        });
        var notifications = 0;
        client.Effects.OnNotification += _ => notifications++;
        clock.UtcNow = clock.UtcNow.AddMinutes(31);
        client.Update(0);
        await Task.Delay(50);

        Assert.Equal(2, transport.Calls.Count(call => call.Path == "/sdk/v1/scenarios/pending"));
        Assert.Equal(1, notifications);
        Assert.DoesNotContain(transport.Calls, call => call.Path == "/sdk/v1/scenarios/callback");
    }

    [Fact]
    public async Task Heartbeat_Refreshes_Pending_After_30_Seconds()
    {
        var clock = new FakeClock(new DateTimeOffset(2026, 5, 30, 10, 0, 0, TimeSpan.Zero));
        var transport = new FakeTransport();
        transport.Enqueue(new ListPendingScenarioEffectsResponse { Effects = new List<PendingEffect>() });
        var client = CreateClient(transport, clock: clock);

        client.Update(0);
        await Task.Delay(50);
        Assert.Equal(1, transport.Calls.Count(call => call.Path == "/sdk/v1/scenarios/pending"));

        clock.UtcNow = clock.UtcNow.AddSeconds(29);
        client.Update(0);
        await Task.Delay(50);
        Assert.Equal(1, transport.Calls.Count(call => call.Path == "/sdk/v1/scenarios/pending"));

        transport.Enqueue(new ListPendingScenarioEffectsResponse { Effects = new List<PendingEffect>() });
        clock.UtcNow = clock.UtcNow.AddSeconds(1);
        client.Update(0);
        await Task.Delay(50);
        Assert.Equal(2, transport.Calls.Count(call => call.Path == "/sdk/v1/scenarios/pending"));
    }

    [Fact]
    public async Task Login_Fetches_Pending_On_Next_Update()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new LoginViaDeviceResponse
        {
            AccessToken = "access-token",
            RefreshToken = "refresh-token"
        });
        transport.Enqueue(new ListPendingScenarioEffectsResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "n1", "notification") }
        });
        var tokenStore = new FakeTokenStore();
        var client = CreateClient(transport, tokenStore: tokenStore);
        var notifications = 0;
        client.Effects.OnNotification += _ => notifications++;

        await client.Auth.LoginWithDeviceAsync("en", "en");
        Assert.Equal(0, notifications);

        client.Update(0);
        await Task.Delay(50);

        Assert.Equal(1, notifications);
        Assert.Contains(transport.Calls, call => call.Method == "GET" && call.Path == "/sdk/v1/scenarios/pending");
    }

    [Fact]
    public async Task BattlePass_LevelUp_Posts_OnLevelUp()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "bp", "battlepass") }
        });
        transport.Enqueue(new HandleScenarioCallbackResponse());
        var client = CreateClient(transport);
        BattlePassEffect? battlePass = null;
        client.Effects.OnBattlePass += e => battlePass = e;

        await client.Scenario.TriggerAsync("login");
        await battlePass!.LevelUpAsync();

        var callback = Assert.IsType<HandleScenarioCallbackRequest>(
            transport.Calls.Single(call => call.Path == "/sdk/v1/scenarios/callback").Request);
        Assert.Equal("onLevelUp", callback.Handle);
    }

    [Fact]
    public async Task BattlePassLevel_Claim_Posts_OnComplete()
    {
        var transport = new FakeTransport();
        transport.Enqueue(new TriggerScenarioResponse
        {
            Effects = new List<PendingEffect> { Effect("run-1", "bpl", "battlepass_level", new { levelNumber = 2 }) }
        });
        transport.Enqueue(new HandleScenarioCallbackResponse());
        var client = CreateClient(transport);
        BattlePassLevelEffect? level = null;
        client.Effects.OnBattlePassLevel += e => level = e;

        await client.Scenario.TriggerAsync("login");
        await level!.ClaimAsync();

        var callback = Assert.IsType<HandleScenarioCallbackRequest>(
            transport.Calls.Single(call => call.Path == "/sdk/v1/scenarios/callback").Request);
        Assert.Equal("onComplete", callback.Handle);
        Assert.Equal(2, level.Level);
    }

    private static RudderClient CreateClient(
        FakeTransport transport,
        FakeClock? clock = null,
        IRudderLogger? logger = null,
        FakeTokenStore? tokenStore = null)
    {
        return new RudderClient(new RudderClientOptions
        {
            BaseUrl = "http://localhost:8082",
            ProjectKey = "project-key",
            Transport = transport,
            TokenStore = tokenStore ?? new FakeTokenStore { AccessToken = "access-token" },
            DeviceIdProvider = new FakeDeviceIdProvider(),
            Clock = clock ?? new FakeClock(DateTimeOffset.UtcNow),
            Logger = logger
        });
    }

    private static PendingEffect Effect(string runId, string nodeId, string type, object? data = null, DateTimeOffset? waitDeadline = null)
    {
        return new PendingEffect
        {
            RunId = runId,
            ScenarioId = "scenario-1",
            NodeId = nodeId,
            Type = type,
            Data = data == null ? new JObject() : JObject.FromObject(data),
            WaitDeadline = waitDeadline
        };
    }

    private sealed class FakeTransport : IRudderTransport
    {
        private readonly Queue<object> _responses = new();
        public List<FakeCall> Calls { get; } = new();

        public void Enqueue(object response) => _responses.Enqueue(response);

        public Task<TResponse> SendAsync<TRequest, TResponse>(
            string method,
            string path,
            TRequest? request,
            string? accessToken,
            CancellationToken cancellationToken = default)
        {
            Calls.Add(new FakeCall(method, path, request, accessToken));
            if (_responses.Count == 0)
                return Task.FromResult(default(TResponse)!);

            var next = _responses.Dequeue();
            if (next is Exception ex)
                return Task.FromException<TResponse>(ex);

            return Task.FromResult((TResponse)next);
        }
    }

    private sealed class FakeCall
    {
        public FakeCall(string method, string path, object? request, string? accessToken)
        {
            Method = method;
            Path = path;
            Request = request;
            AccessToken = accessToken;
        }

        public string Method { get; }
        public string Path { get; }
        public object? Request { get; }
        public string? AccessToken { get; }
    }

    private sealed class FakeTokenStore : ITokenStore
    {
        public string? AccessToken { get; set; }
        public string? RefreshToken { get; set; }
        public string? GetAccessToken() => AccessToken;
        public string? GetRefreshToken() => RefreshToken;
        public void SaveTokens(string accessToken, string refreshToken)
        {
            AccessToken = accessToken;
            RefreshToken = refreshToken;
        }
        public void Clear()
        {
            AccessToken = null;
            RefreshToken = null;
        }
    }

    private sealed class FakeDeviceIdProvider : IDeviceIdProvider
    {
        public string DeviceId => "device-id";
    }

    private sealed class FakeClock : IClock
    {
        public FakeClock(DateTimeOffset utcNow) => UtcNow = utcNow;
        public DateTimeOffset UtcNow { get; set; }
    }

    private sealed class FakeLogger : IRudderLogger
    {
        public List<(RudderLogLevel Level, string Message)> Messages { get; } = new();
        public void Log(RudderLogLevel level, string message) => Messages.Add((level, message));
    }
}