using Microsoft.Data.SqlClient;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
using ZB.MOM.WW.OtOpcUa.Core.AlarmHistorian;

namespace ZB.MOM.WW.OtOpcUa.Driver.Historian.SqlServer.IntegrationTests;

[Collection(SqlHistorianCollection.Name)]
public sealed class AlarmWriterTests(SqlHistorianFixture fx)
{
    private static readonly DateTime T = new DateTime(2026, 10, 9, 1, 2, 3, DateTimeKind.Utc).AddTicks(1234567);

    private (SqlServerAlarmHistorianWriter W, string S) Make(string? connection = null, bool auto = true)
    {
        var s = SqlHistorianFixture.UniqueSchema();
        var o = new SqlServerHistorianOptions { ConnectionString = connection ?? fx.ConnectionString, Schema = s, AutoCreateSchema = auto };
        var c = new SqlHistorianConnection(o);
        return (new SqlServerAlarmHistorianWriter(c, new SqlServerSchemaBootstrapper(c, o)), s);
    }

    private static AlarmHistorianEvent Ev(string kind = "Activated", string type = "LimitAlarm", string? comment = "c") =>
        new("alarm-1", "Plant/Line/Eq", "HiTemp", type, AlarmSeverity.High, kind, "msg", "user", comment, T);

    [Fact]
    public async Task Event_round_trips_and_a_repeat_is_one_row_with_both_Ack()
    {
        fx.SkipIfUnavailable();
        var (w, s) = Make();
        var first = await w.WriteBatchAsync([Ev(), Ev()], CancellationToken.None);
        first.ShouldBe([HistorianWriteOutcome.Ack, HistorianWriteOutcome.Ack]);
        (await w.WriteBatchAsync([Ev()], CancellationToken.None)).ShouldBe([HistorianWriteOutcome.Ack]);
        (await w.WriteBatchAsync([Ev(kind: "Cleared")], CancellationToken.None)).ShouldBe([HistorianWriteOutcome.Ack]);

        await using var c = new SqlConnection(fx.ConnectionString);
        await c.OpenAsync(TestContext.Current.CancellationToken);
        await using var cmd = c.CreateCommand();
        cmd.CommandText = $"SELECT SourceName, AlarmId, AlarmName, AlarmTypeName, Severity, EventKind, Message, UserName, Comment, EventTimeUtc, ReceivedTimeUtc FROM [{s}].Event WHERE EventKind='Activated'";
        await using var r = await cmd.ExecuteReaderAsync(TestContext.Current.CancellationToken);
        (await r.ReadAsync(TestContext.Current.CancellationToken)).ShouldBeTrue();
        r.GetString(0).ShouldBe("Plant/Line/Eq");
        r.GetString(1).ShouldBe("alarm-1");
        r.GetString(2).ShouldBe("HiTemp");
        r.GetString(3).ShouldBe("LimitAlarm");
        r.GetInt32(4).ShouldBe(700);
        r.GetString(6).ShouldBe("msg");
        r.GetString(7).ShouldBe("user");
        r.GetString(8).ShouldBe("c");
        SqlHistorianConnection.GetUtc(r, 9).Ticks.ShouldBe(T.Ticks);
        (DateTime.UtcNow - SqlHistorianConnection.GetUtc(r, 10)).ShouldBeLessThan(TimeSpan.FromMinutes(1));
        (await r.ReadAsync(TestContext.Current.CancellationToken)).ShouldBeFalse();
        await r.CloseAsync();
        cmd.CommandText = $"SELECT COUNT(*) FROM [{s}].Event";
        Convert.ToInt32(await cmd.ExecuteScalarAsync(TestContext.Current.CancellationToken)).ShouldBe(2);
    }

    [Fact]
    public async Task Over_long_AlarmTypeName_is_PermanentFail_and_siblings_still_Ack()
    {
        fx.SkipIfUnavailable();
        var (w, s) = Make();
        var r = await w.WriteBatchAsync([Ev(kind: "A"), Ev(kind: "B", type: new string('t', 101)), Ev(kind: "C", comment: null)], CancellationToken.None);
        r.ShouldBe([HistorianWriteOutcome.Ack, HistorianWriteOutcome.PermanentFail, HistorianWriteOutcome.Ack]);
    }

    [Fact]
    public async Task An_event_reads_back_with_its_type_name_condition_name_and_alarm_id()
    {
        fx.SkipIfUnavailable();
        var s = SqlHistorianFixture.UniqueSchema();
        var o = new SqlServerHistorianOptions { ConnectionString = fx.ConnectionString, Schema = s };
        var c = new SqlHistorianConnection(o);
        var boot = new SqlServerSchemaBootstrapper(c, o);
        var w = new SqlServerAlarmHistorianWriter(c, boot);
        (await w.WriteBatchAsync([Ev()], CancellationToken.None)).ShouldBe([HistorianWriteOutcome.Ack]);

        using var src = new SqlServerHistorianDataSource(c, boot, new SqlServerTagCatalog(c, boot));
        var e = (await src.ReadEventsAsync("Plant/Line/Eq", T.AddMinutes(-1), T.AddMinutes(1), 0, CancellationToken.None))
            .Events.ShouldHaveSingleItem();
        e.EventTypeName.ShouldBe("LimitAlarm");
        e.ConditionName.ShouldBe("HiTemp");
        e.AlarmId.ShouldBe("alarm-1");
    }

    [Fact]
    public async Task A_batch_is_one_statement_per_chunk_and_a_redelivery_converges()
    {
        fx.SkipIfUnavailable();
        var (w, s) = Make();
        var events = Enumerable.Range(0, 400)
            .Select(i => new AlarmHistorianEvent("alarm-1", "Plant/Line/Eq", "HiTemp", "LimitAlarm", AlarmSeverity.High,
                "Activated", $"m{i}", "user", null, T.AddSeconds(i)))
            .ToList();

        (await w.WriteBatchAsync(events, CancellationToken.None)).ShouldAllBe(o => o == HistorianWriteOutcome.Ack);
        w.Statements.ShouldBe(3, "400 events = 150 + 150 + 100, not 400 round trips");

        // Redelivered (the at-least-once drain), with an in-batch duplicate: every event Acks, no row is added.
        var again = events.Append(events[0]).ToList();
        var r = await w.WriteBatchAsync(again, CancellationToken.None);
        r.Count.ShouldBe(401);
        r.ShouldAllBe(o => o == HistorianWriteOutcome.Ack);
        await using var c = new SqlConnection(fx.ConnectionString);
        await c.OpenAsync(TestContext.Current.CancellationToken);
        await using var cmd = c.CreateCommand();
        cmd.CommandText = $"SELECT COUNT(*) FROM [{s}].Event";
        Convert.ToInt32(await cmd.ExecuteScalarAsync(TestContext.Current.CancellationToken)).ShouldBe(400);
    }

    [Fact]
    public async Task Concurrent_writers_of_the_same_event_all_Ack_with_one_row()
    {
        fx.SkipIfUnavailable();
        var (w, s) = Make();
        await w.WriteBatchAsync([Ev(kind: "warm")], CancellationToken.None);
        var rs = await Task.WhenAll(Enumerable.Range(0, 12).Select(_ => Task.Run(() => w.WriteBatchAsync([Ev()], CancellationToken.None))));
        rs.ShouldAllBe(x => x[0] == HistorianWriteOutcome.Ack);
        await using var c = new SqlConnection(fx.ConnectionString);
        await c.OpenAsync(TestContext.Current.CancellationToken);
        await using var cmd = c.CreateCommand();
        cmd.CommandText = $"SELECT COUNT(*) FROM [{s}].Event WHERE EventKind='Activated'";
        Convert.ToInt32(await cmd.ExecuteScalarAsync(TestContext.Current.CancellationToken)).ShouldBe(1);
    }

    [Fact]
    public async Task Unreachable_database_is_RetryPlease_not_an_exception_and_empty_batch_is_empty()
    {
        fx.SkipIfUnavailable();
        var (w, _) = Make(fx.ConnectionString + ";Connect Timeout=1", auto: false);   // schema missing
        (await w.WriteBatchAsync([Ev()], CancellationToken.None)).ShouldBe([HistorianWriteOutcome.RetryPlease]);
        (await w.WriteBatchAsync([], CancellationToken.None)).ShouldBeEmpty();
    }
}