using Akka.Actor;
using Akka.TestKit.Xunit2;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging.Abstractions;
using ScadaLink.AuditLog.Central;
using ScadaLink.Commons.Entities.Audit;
using ScadaLink.Commons.Interfaces.Repositories;
using ScadaLink.Commons.Messages.Audit;
using ScadaLink.Commons.Types.Audit;
using ScadaLink.Commons.Types.Enums;
using ScadaLink.ConfigurationDatabase;
using ScadaLink.ConfigurationDatabase.Repositories;
using ScadaLink.ConfigurationDatabase.Tests.Migrations;

namespace ScadaLink.AuditLog.Tests.Central;

/// <summary>
/// Bundle D D2 tests for <see cref="AuditLogIngestActor"/>. Uses the same
/// <see cref="MsSqlMigrationFixture"/> as the M1 repository tests so the actor
/// exercises real <see cref="AuditLogRepository.InsertIfNotExistsAsync"/>
/// against a partitioned MSSQL schema (the only way to verify the
/// IngestedAtUtc stamp + duplicate-key idempotency end to end).
/// </summary>
public class AuditLogIngestActorTests : TestKit, IClassFixture<MsSqlMigrationFixture>
{
    private readonly MsSqlMigrationFixture _fixture;

    public AuditLogIngestActorTests(MsSqlMigrationFixture fixture)
    {
        _fixture = fixture;
    }

    private ScadaLinkDbContext CreateContext()
    {
        var options = new DbContextOptionsBuilder<ScadaLinkDbContext>()
            .UseSqlServer(_fixture.ConnectionString)
            .Options;
        return new ScadaLinkDbContext(options);
    }

    private static string NewSiteId() =>
        "test-bundle-d2-" + Guid.NewGuid().ToString("N").Substring(0, 8);

    private static AuditEvent NewEvent(string siteId, Guid? id = null) => new()
    {
        EventId = id ?? Guid.NewGuid(),
        OccurredAtUtc = new DateTime(2026, 5, 20, 10, 0, 0, DateTimeKind.Utc),
        Channel = AuditChannel.ApiOutbound,
        Kind = AuditKind.ApiCall,
        Status = AuditStatus.Delivered,
        SourceSiteId = siteId,
    };

    private IActorRef CreateActor(IAuditLogRepository repository) =>
        Sys.ActorOf(Props.Create(() => new AuditLogIngestActor(
            repository,
            NullLogger<AuditLogIngestActor>.Instance)));

    [SkippableFact]
    public async Task Receive_BatchOf5_Calls_Repo_5Times_Acks_All_5()
    {
        Skip.IfNot(_fixture.Available, _fixture.SkipReason);

        var siteId = NewSiteId();
        var events = Enumerable.Range(0, 5).Select(_ => NewEvent(siteId)).ToList();

        await using var context = CreateContext();
        var repo = new AuditLogRepository(context);
        var actor = CreateActor(repo);

        actor.Tell(new IngestAuditEventsCommand(events), TestActor);

        var reply = ExpectMsg<IngestAuditEventsReply>(TimeSpan.FromSeconds(10));
        Assert.Equal(5, reply.AcceptedEventIds.Count);
        Assert.True(events.Select(e => e.EventId).ToHashSet().SetEquals(reply.AcceptedEventIds.ToHashSet()));

        // Verify rows landed in MSSQL.
        await using var readContext = CreateContext();
        var rows = await readContext.Set<AuditEvent>()
            .Where(e => e.SourceSiteId == siteId)
            .ToListAsync();
        Assert.Equal(5, rows.Count);
    }

    [SkippableFact]
    public async Task Receive_BatchWith_AlreadyExistingEvent_AcksAll_NoDoubleInsert()
    {
        Skip.IfNot(_fixture.Available, _fixture.SkipReason);

        var siteId = NewSiteId();
        var pre = NewEvent(siteId);

        // Pre-insert one event directly via the repo so the actor sees it
        // already present when it processes the batch.
        await using (var seedContext = CreateContext())
        {
            var seedRepo = new AuditLogRepository(seedContext);
            await seedRepo.InsertIfNotExistsAsync(pre);
        }

        // Build the batch including the pre-existing event plus 2 new ones.
        var fresh1 = NewEvent(siteId);
        var fresh2 = NewEvent(siteId);
        var batch = new List<AuditEvent> { pre, fresh1, fresh2 };

        await using var context = CreateContext();
        var repo = new AuditLogRepository(context);
        var actor = CreateActor(repo);

        actor.Tell(new IngestAuditEventsCommand(batch), TestActor);

        var reply = ExpectMsg<IngestAuditEventsReply>(TimeSpan.FromSeconds(10));
        // All 3 acked under idempotent first-write-wins.
        Assert.Equal(3, reply.AcceptedEventIds.Count);

        // Verify no double-insert.
        await using var readContext = CreateContext();
        var count = await readContext.Set<AuditEvent>()
            .Where(e => e.SourceSiteId == siteId)
            .CountAsync();
        Assert.Equal(3, count);
    }

    [SkippableFact]
    public async Task Receive_Sets_IngestedAtUtc_Before_Insert()
    {
        Skip.IfNot(_fixture.Available, _fixture.SkipReason);

        var siteId = NewSiteId();
        var events = Enumerable.Range(0, 3).Select(_ => NewEvent(siteId)).ToList();

        var before = DateTime.UtcNow.AddSeconds(-1);

        await using var context = CreateContext();
        var repo = new AuditLogRepository(context);
        var actor = CreateActor(repo);

        actor.Tell(new IngestAuditEventsCommand(events), TestActor);
        ExpectMsg<IngestAuditEventsReply>(TimeSpan.FromSeconds(10));

        var after = DateTime.UtcNow.AddSeconds(1);

        await using var readContext = CreateContext();
        var rows = await readContext.Set<AuditEvent>()
            .Where(e => e.SourceSiteId == siteId)
            .ToListAsync();

        Assert.Equal(3, rows.Count);
        Assert.All(rows, r =>
        {
            Assert.NotNull(r.IngestedAtUtc);
            Assert.InRange(r.IngestedAtUtc!.Value, before, after);
        });
    }

    [SkippableFact]
    public async Task Receive_RepoThrowsForOneEvent_Other4StillPersisted()
    {
        Skip.IfNot(_fixture.Available, _fixture.SkipReason);

        var siteId = NewSiteId();
        var events = Enumerable.Range(0, 5).Select(_ => NewEvent(siteId)).ToList();
        var poisonId = events[2].EventId;

        // Wrapper repo that throws only when the poison EventId is being
        // inserted. The four neighbours must still land in MSSQL.
        await using var context = CreateContext();
        var realRepo = new AuditLogRepository(context);
        var wrappedRepo = new ThrowingRepository(realRepo, poisonId);
        var actor = CreateActor(wrappedRepo);

        actor.Tell(new IngestAuditEventsCommand(events), TestActor);
        var reply = ExpectMsg<IngestAuditEventsReply>(TimeSpan.FromSeconds(10));

        // The actor catches the throw per-row, so 4 ids are accepted and 1 is
        // left out.
        Assert.Equal(4, reply.AcceptedEventIds.Count);
        Assert.DoesNotContain(poisonId, reply.AcceptedEventIds);

        await using var readContext = CreateContext();
        var rows = await readContext.Set<AuditEvent>()
            .Where(e => e.SourceSiteId == siteId)
            .ToListAsync();
        Assert.Equal(4, rows.Count);
        Assert.DoesNotContain(rows, r => r.EventId == poisonId);
    }

    /// <summary>
    /// Tiny test double that delegates to a real repository but throws on a
    /// specified EventId. Used to verify per-row failure isolation: one bad
    /// row must not cause the rest of the batch to be lost.
    /// </summary>
    private sealed class ThrowingRepository : IAuditLogRepository
    {
        private readonly IAuditLogRepository _inner;
        private readonly Guid _poisonId;

        public ThrowingRepository(IAuditLogRepository inner, Guid poisonId)
        {
            _inner = inner;
            _poisonId = poisonId;
        }

        public Task InsertIfNotExistsAsync(AuditEvent evt, CancellationToken ct = default)
        {
            if (evt.EventId == _poisonId)
            {
                throw new InvalidOperationException("simulated repo failure for poison row");
            }
            return _inner.InsertIfNotExistsAsync(evt, ct);
        }

        public Task<IReadOnlyList<AuditEvent>> QueryAsync(
            AuditLogQueryFilter filter, AuditLogPaging paging, CancellationToken ct = default) =>
            _inner.QueryAsync(filter, paging, ct);

        public Task<long> SwitchOutPartitionAsync(DateTime monthBoundary, CancellationToken ct = default) =>
            _inner.SwitchOutPartitionAsync(monthBoundary, ct);

        public Task<IReadOnlyList<DateTime>> GetPartitionBoundariesOlderThanAsync(
            DateTime threshold, CancellationToken ct = default) =>
            _inner.GetPartitionBoundariesOlderThanAsync(threshold, ct);

        public Task<ScadaLink.Commons.Types.AuditLogKpiSnapshot> GetKpiSnapshotAsync(
            TimeSpan window, DateTime? nowUtc = null, CancellationToken ct = default) =>
            _inner.GetKpiSnapshotAsync(window, nowUtc, ct);
    }
}