using ZB.MOM.WW.ScadaBridge.Commons.Entities.Kpi;
using ZB.MOM.WW.ScadaBridge.ConfigurationDatabase;
using ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Repositories;

namespace ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Tests.Repositories;

/// <summary>
/// M6 (K2) coverage for <see cref="KpiHistoryRepository"/> over the in-memory SQLite
/// harness. Exercises the bulk write, the single-series query (including the
/// null-ScopeKey Global match), and the retention purge.
/// </summary>
public class KpiHistoryRepositoryTests
{
    // Fixed UTC base so the time assertions are deterministic.
    private static readonly DateTime Base = new(2026, 6, 1, 0, 0, 0, DateTimeKind.Utc);

    private static ScadaBridgeDbContext NewContext() => SqliteTestHelper.CreateInMemoryContext();

    private static KpiSample Sample(
        string source, string metric, string scope, string? scopeKey, double value, DateTime capturedAtUtc) =>
        new()
        {
            Source = source,
            Metric = metric,
            Scope = scope,
            ScopeKey = scopeKey,
            Value = value,
            CapturedAtUtc = capturedAtUtc,
        };

    [Fact]
    public async Task GetRawSeriesAsync_ReturnsOnlyMatchingSeries_InAscendingTimeOrder()
    {
        await using var ctx = NewContext();
        var repo = new KpiHistoryRepository(ctx);

        // Two metrics ("queueDepth", "parkedCount") under one source; the target
        // series ("queueDepth", Global, null key) has two points at different
        // timestamps — inserted out of order to prove the OrderBy.
        await repo.RecordSamplesAsync(new[]
        {
            // Target series — Global / null ScopeKey, two points (later first).
            Sample("NotificationOutbox", "queueDepth", "Global", null, value: 7, capturedAtUtc: Base.AddMinutes(10)),
            Sample("NotificationOutbox", "queueDepth", "Global", null, value: 3, capturedAtUtc: Base.AddMinutes(5)),
            // Different metric — must be excluded.
            Sample("NotificationOutbox", "parkedCount", "Global", null, value: 99, capturedAtUtc: Base.AddMinutes(5)),
            // Same metric but a Site scope with a non-null key — must be excluded
            // from the Global (null-key) query.
            Sample("NotificationOutbox", "queueDepth", "Site", "plant-a", value: 42, capturedAtUtc: Base.AddMinutes(5)),
        });

        var series = await repo.GetRawSeriesAsync(
            "NotificationOutbox", "queueDepth", "Global", scopeKey: null,
            fromUtc: Base, toUtc: Base.AddMinutes(60));

        // Only the two Global/null-key queueDepth points, ascending by capture time.
        Assert.Equal(2, series.Count);
        Assert.Equal(Base.AddMinutes(5), series[0].BucketStartUtc);
        Assert.Equal(3, series[0].Value);
        Assert.Equal(Base.AddMinutes(10), series[1].BucketStartUtc);
        Assert.Equal(7, series[1].Value);
    }

    [Fact]
    public async Task GetRawSeriesAsync_SiteScopedKey_MatchesOnlyThatKey()
    {
        await using var ctx = NewContext();
        var repo = new KpiHistoryRepository(ctx);

        await repo.RecordSamplesAsync(new[]
        {
            Sample("SiteCallAudit", "buffered", "Site", "plant-a", value: 5, capturedAtUtc: Base.AddMinutes(5)),
            Sample("SiteCallAudit", "buffered", "Site", "plant-b", value: 8, capturedAtUtc: Base.AddMinutes(5)),
            // A Global (null-key) row with the same metric must NOT leak into a
            // site-keyed query.
            Sample("SiteCallAudit", "buffered", "Global", null, value: 13, capturedAtUtc: Base.AddMinutes(5)),
        });

        var series = await repo.GetRawSeriesAsync(
            "SiteCallAudit", "buffered", "Site", scopeKey: "plant-a",
            fromUtc: Base, toUtc: Base.AddMinutes(60));

        Assert.Single(series);
        Assert.Equal(5, series[0].Value);
    }

    [Fact]
    public async Task GetRawSeriesAsync_HonorsTimeWindowBounds()
    {
        await using var ctx = NewContext();
        var repo = new KpiHistoryRepository(ctx);

        await repo.RecordSamplesAsync(new[]
        {
            Sample("Health", "ageSeconds", "Global", null, value: 1, capturedAtUtc: Base),
            Sample("Health", "ageSeconds", "Global", null, value: 2, capturedAtUtc: Base.AddMinutes(30)),
            // Outside the [from, to] window — excluded.
            Sample("Health", "ageSeconds", "Global", null, value: 3, capturedAtUtc: Base.AddMinutes(120)),
        });

        var series = await repo.GetRawSeriesAsync(
            "Health", "ageSeconds", "Global", scopeKey: null,
            fromUtc: Base, toUtc: Base.AddMinutes(60));

        Assert.Equal(2, series.Count);
        Assert.Equal(new[] { 1d, 2d }, series.Select(p => p.Value).ToArray());
    }

    [Fact]
    public async Task PurgeOlderThanAsync_DeletesOnlyRowsOlderThanCutoff_AndReturnsCount()
    {
        await using var ctx = NewContext();
        var repo = new KpiHistoryRepository(ctx);

        await repo.RecordSamplesAsync(new[]
        {
            // Two rows strictly older than the cutoff — should be purged.
            Sample("NotificationOutbox", "queueDepth", "Global", null, value: 1, capturedAtUtc: Base.AddDays(-10)),
            Sample("NotificationOutbox", "queueDepth", "Global", null, value: 2, capturedAtUtc: Base.AddDays(-8)),
            // One row AT the cutoff — strictly-older predicate keeps it.
            Sample("NotificationOutbox", "queueDepth", "Global", null, value: 3, capturedAtUtc: Base.AddDays(-7)),
            // One row newer than the cutoff — kept.
            Sample("NotificationOutbox", "queueDepth", "Global", null, value: 4, capturedAtUtc: Base.AddDays(-1)),
        });

        var cutoff = Base.AddDays(-7);
        var deleted = await repo.PurgeOlderThanAsync(cutoff);

        Assert.Equal(2, deleted);

        var remaining = await repo.GetRawSeriesAsync(
            "NotificationOutbox", "queueDepth", "Global", scopeKey: null,
            fromUtc: Base.AddDays(-30), toUtc: Base.AddDays(30));

        // The cutoff row (==) and the newer row survive.
        Assert.Equal(2, remaining.Count);
        Assert.Equal(new[] { 3d, 4d }, remaining.Select(p => p.Value).ToArray());
    }
}