using Akka.Cluster;
using Akka.TestKit.Xunit2;
using Microsoft.EntityFrameworkCore;
using ZB.MOM.WW.OtOpcUa.Configuration;

namespace ZB.MOM.WW.OtOpcUa.Runtime.Tests.Harness;

/// <summary>
/// Mirrors the ControlPlane test harness: single-node Akka cluster (self-join) + in-memory
/// EF Core <see cref="OtOpcUaConfigDbContext"/> via an <see cref="IDbContextFactory{TContext}"/>.
/// </summary>
public abstract class RuntimeActorTestBase : TestKit
{
    /// <summary>
    ///     Shared upper bound for a <b>presence</b> wait (<c>AwaitAssert</c> / <c>AwaitCondition</c>).
    /// </summary>
    /// <remarks>
    ///     <para><b>A budget, not a delay.</b> These helpers poll and return the instant the condition holds,
    ///     so the value is how long to wait before giving up. Raising it costs nothing on the happy path and
    ///     <em>cannot</em> make a genuinely failing assertion pass — it only changes how quickly a real
    ///     breakage is reported. That is the opposite of an <b>absence</b> window (<c>ExpectNoMsg</c>,
    ///     settle-then-assert), where the elapsed time IS the assertion and every millisecond is spent on
    ///     every run. Absence windows keep their own short, individually-calibrated literals and must not be
    ///     routed through here.</para>
    ///     <para><b>Why it exists (Gitea #500).</b> This assembly runs 44 Akka test classes roughly 14-way
    ///     parallel, each with its own <see cref="TestKit"/> ActorSystem. Budgets of 300–500 ms sized on an
    ///     idle machine are comfortable in isolation and marginal under that contention: three consecutive
    ///     30-run verification rounds each surfaced a <em>different</em> test failing on one, in three
    ///     different files. Fixing them one at a time was chasing a distribution rather than a defect.</para>
    /// </remarks>
    protected static readonly TimeSpan PresenceBudget = TimeSpan.FromSeconds(15);

    /// <summary>Gets the Akka test HOCON configuration string for single-node cluster setup.</summary>
    protected static string AkkaTestHocon => @"
akka {
    loglevel = ""WARNING""
    extensions = [
        ""Akka.Cluster.Tools.PublishSubscribe.DistributedPubSubExtensionProvider, Akka.Cluster.Tools""
    ]
    actor {
        provider = ""Akka.Cluster.ClusterActorRefProvider, Akka.Cluster""
    }
    remote.dot-netty.tcp {
        hostname = ""127.0.0.1""
        port = 0
    }
    cluster {
        seed-nodes = []
        roles = [""driver""]
        min-nr-of-members = 1
        run-coordinated-shutdown-when-down = off
    }
}";

    /// <summary>Initializes a new instance of the RuntimeActorTestBase class with Akka test setup.</summary>
    protected RuntimeActorTestBase() : base(AkkaTestHocon)
    {
        var cluster = Akka.Cluster.Cluster.Get(Sys);
        cluster.Join(cluster.SelfAddress);
        AwaitCondition(() => cluster.State.Members.Any(m => m.Status == MemberStatus.Up),
            TimeSpan.FromSeconds(5));
    }

    /// <summary>Creates a new in-memory database factory for testing.</summary>
    /// <param name="dbName">The database name, or null to generate a unique name.</param>
    /// <returns>An IDbContextFactory for the in-memory database.</returns>
    protected static IDbContextFactory<OtOpcUaConfigDbContext> NewInMemoryDbFactory(string? dbName = null)
    {
        dbName ??= Guid.NewGuid().ToString("N");
        return new InMemoryConfigDbFactory(dbName);
    }

    private sealed class InMemoryConfigDbFactory(string dbName) : IDbContextFactory<OtOpcUaConfigDbContext>
    {
        /// <summary>Creates a new in-memory database context.</summary>
        /// <returns>A new OtOpcUaConfigDbContext instance.</returns>
        public OtOpcUaConfigDbContext CreateDbContext()
        {
            var opts = new DbContextOptionsBuilder<OtOpcUaConfigDbContext>()
                .UseInMemoryDatabase(dbName)
                .Options;
            return new OtOpcUaConfigDbContext(opts);
        }
    }
}
