using Omika.Diagnostics.Models;
using Omika.Diagnostics.Queries;
using Omika.Diagnostics.Tests.Fakes;

namespace Omika.Diagnostics.Tests;

/// <summary>
/// Tâche 6 — Télémétrie : nouvelles dimensions de groupement (Platform/Level normalisé/
/// Priority/Source) et statistiques de durée (AVG/MIN/MAX en SQL, NULL ignorés). Tests
/// sur <see cref="FakeDiagnosticEventRepository"/> ; la production exécute les mêmes
/// contrats via GROUP BY / INITCAP(LOWER(...)) / AVG/MAX.
/// </summary>
public class DiagnosticTelemetryTests
{
    private static readonly DateTimeOffset From = new(2025, 1, 1, 0, 0, 0, TimeSpan.Zero);
    private static readonly DateTimeOffset To = new(2025, 2, 1, 0, 0, 0, TimeSpan.Zero);

    private static DiagnosticEventRecord Ev(
        string eventCode = "TEST",
        DateTimeOffset? ts = null,
        string? component = null,
        string level = "Info",
        string priority = "P2",
        string? platform = null,
        string? source = null,
        long? durationMs = null) =>
        new()
        {
            EventId = Guid.NewGuid(),
            EventCode = eventCode,
            TimestampUtc = ts ?? From.AddMinutes(1),
            Component = component,
            Level = level,
            Priority = priority,
            Platform = platform,
            Source = source ?? DiagnosticSources.Mobile,
            DurationMs = durationMs,
            IngestedAtUtc = DateTimeOffset.UtcNow
        };

    private static DiagnosticAggregateQuery All(int limit = DiagnosticAggregateDefaults.MaxLimit) =>
        new() { FromUtc = From, ToUtc = To, Limit = limit };

    // ------------------------------------------------- T1 : groupement Platform ----
    [Fact]
    public async Task CountGrouped_Platform_ReturnsGroups()
    {
        var repo = new FakeDiagnosticEventRepository();
        await repo.InsertBatchAsync(new[]
        {
            Ev("A", platform: "Android"),
            Ev("B", platform: "Android"),
            Ev("C", platform: "iOS")
        });

        IReadOnlyList<DiagnosticGroupCount> result = await repo.CountGroupedAsync(
            DiagnosticGroupDimension.Platform, All());

        Assert.Equal(2, result.Count);
        Assert.Contains(result, g => g.Key == "Android" && g.Count == 2);
        Assert.Contains(result, g => g.Key == "iOS" && g.Count == 1);
    }

    // ---------------------------------- T2 : groupement Level normalisé (casse) ----
    [Fact]
    public async Task CountGrouped_Level_IsCaseInsensitive()
    {
        var repo = new FakeDiagnosticEventRepository();
        await repo.InsertBatchAsync(new[]
        {
            Ev("A", level: "Error"),
            Ev("B", level: "error"),   // minuscule (ServerDiagnosticMiddleware)
            Ev("C", level: "ERROR"),
            Ev("D", level: "Info")
        });

        IReadOnlyList<DiagnosticGroupCount> result = await repo.CountGroupedAsync(
            DiagnosticGroupDimension.Level, All());

        Assert.Equal(2, result.Count);
        Assert.Contains(result, g => g.Key == "Error" && g.Count == 3);
        Assert.Contains(result, g => g.Key == "Info" && g.Count == 1);
    }

    // ----------------------------------------------- T3 : groupement Priority ----
    [Fact]
    public async Task CountGrouped_Priority_ReturnsGroups()
    {
        var repo = new FakeDiagnosticEventRepository();
        await repo.InsertBatchAsync(new[]
        {
            Ev("A", priority: "P0"),
            Ev("B", priority: "P0"),
            Ev("C", priority: "P1")
        });

        IReadOnlyList<DiagnosticGroupCount> result = await repo.CountGroupedAsync(
            DiagnosticGroupDimension.Priority, All());

        Assert.Equal(2, result.Count);
        Assert.Contains(result, g => g.Key == "P0" && g.Count == 2);
        Assert.Contains(result, g => g.Key == "P1" && g.Count == 1);
    }

    // ---------------------------------------------- T4 : durée moyenne ----
    [Fact]
    public async Task GetDurationStats_Average_IsCorrect()
    {
        var repo = new FakeDiagnosticEventRepository();
        await repo.InsertBatchAsync(new[]
        {
            Ev("A", durationMs: 100),
            Ev("A", durationMs: 200)
        });

        DiagnosticDurationStats? stats = await repo.GetDurationStatsAsync(All());

        Assert.NotNull(stats);
        Assert.Equal(2, stats.Count);
        Assert.Equal(150, stats.AverageMs);
    }

    // ---------------------------------------------- T5 : durée max ----
    [Fact]
    public async Task GetDurationStats_Max_IsCorrect()
    {
        var repo = new FakeDiagnosticEventRepository();
        await repo.InsertBatchAsync(new[]
        {
            Ev("A", durationMs: 100),
            Ev("A", durationMs: 350)
        });

        DiagnosticDurationStats? stats = await repo.GetDurationStatsAsync(All());

        Assert.NotNull(stats);
        Assert.Equal(350, stats.MaxMs);
        Assert.Equal(100, stats.MinMs);
    }

    // ---------------------------------------------- T6 : durée NULL ignorée ----
    [Fact]
    public async Task GetDurationStats_NullDurations_AreIgnored()
    {
        var repo = new FakeDiagnosticEventRepository();
        await repo.InsertBatchAsync(new[]
        {
            Ev("A", durationMs: 100),
            Ev("B", durationMs: null), // sans durée
            Ev("C", durationMs: 200)
        });

        DiagnosticDurationStats? stats = await repo.GetDurationStatsAsync(All());

        Assert.NotNull(stats);
        Assert.Equal(2, stats.Count);
        Assert.Equal(150, stats.AverageMs);
        Assert.Equal(100, stats.MinMs);
        Assert.Equal(200, stats.MaxMs);
    }

    // ---------------------------------------------- T7 : aucune durée → null ----
    [Fact]
    public async Task GetDurationStats_NoDurations_ReturnsNull()
    {
        var repo = new FakeDiagnosticEventRepository();
        await repo.InsertBatchAsync(new[]
        {
            Ev("A", durationMs: null),
            Ev("B", durationMs: null)
        });

        DiagnosticDurationStats? stats = await repo.GetDurationStatsAsync(All());

        Assert.Null(stats);
    }

    // ---------------------------------------------- T8 : période appliquée ----
    [Fact]
    public async Task GetDurationStats_RespectsPeriod()
    {
        var repo = new FakeDiagnosticEventRepository();
        await repo.InsertBatchAsync(new[]
        {
            Ev("A", From.AddMinutes(-5), durationMs: 999), // avant → exclu
            Ev("A", From.AddMinutes(5), durationMs: 100),  // dans
            Ev("A", To.AddMinutes(5), durationMs: 999)     // après → exclu
        });

        DiagnosticDurationStats? stats = await repo.GetDurationStatsAsync(All());

        Assert.NotNull(stats);
        Assert.Equal(1, stats.Count);
        Assert.Equal(100, stats.AverageMs);
    }

    // ---------------------------------------------- T9 : filtre EventCode ----
    [Fact]
    public async Task GetDurationStats_RespectsEventCodeFilter()
    {
        var repo = new FakeDiagnosticEventRepository();
        await repo.InsertBatchAsync(new[]
        {
            Ev("A", durationMs: 100),
            Ev("B", durationMs: 900)
        });

        DiagnosticDurationStats? stats = await repo.GetDurationStatsAsync(
            new DiagnosticAggregateQuery { FromUtc = From, ToUtc = To, EventCode = "A" });

        Assert.NotNull(stats);
        Assert.Equal(1, stats.Count);
        Assert.Equal(100, stats.AverageMs);
    }

    // ---------------------------------------------- T10 : top lentes limité ----
    [Fact]
    public async Task GetTopDurationByEventCode_RespectsLimitAndSort()
    {
        var repo = new FakeDiagnosticEventRepository();
        await repo.InsertBatchAsync(new[]
        {
            Ev("FAST", durationMs: 10),
            Ev("SLOW", durationMs: 500),
            Ev("MEDIUM", durationMs: 250)
        });

        IReadOnlyList<DiagnosticDurationByEventCode> result = await repo.GetTopDurationByEventCodeAsync(
            new DiagnosticAggregateQuery { FromUtc = From, ToUtc = To, Limit = 2 });

        Assert.Equal(2, result.Count);
        Assert.Equal("SLOW", result[0].EventCode);   // moyenne décroissante
        Assert.Equal("MEDIUM", result[1].EventCode);
    }

    [Fact]
    public async Task GetTopDurationByEventCode_ExcludesNullDurations()
    {
        var repo = new FakeDiagnosticEventRepository();
        await repo.InsertBatchAsync(new[]
        {
            Ev("A", durationMs: 100),
            Ev("B", durationMs: null) // sans durée → ne doit pas apparaître
        });

        IReadOnlyList<DiagnosticDurationByEventCode> result = await repo.GetTopDurationByEventCodeAsync(All());

        DiagnosticDurationByEventCode item = Assert.Single(result);
        Assert.Equal("A", item.EventCode);
    }
}