using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using Shouldly;
using Xunit;

namespace ZB.MOM.WW.OtOpcUa.Cluster.Tests;

/// <summary>
///     Gitea #532 — <c>AkkaClusterOptions.Roles</c> must actually apply the <c>OTOPCUA_ROLES</c> fallback
///     its own XML doc has always described.
/// </summary>
/// <remarks>
///     <para>
///         These go through <c>AddOtOpcUaCluster</c> + a real service provider rather than calling
///         <c>RoleParser.ResolveEffectiveRoles</c> directly, because the defect was never in the parsing —
///         it was that nothing <em>called</em> it on the way to the bound options. A unit test of the
///         helper alone would have passed against the broken tree.
///     </para>
///     <para>
///         The consequence being pinned: <c>BuildClusterOptions</c> feeds <c>Roles</c> straight to Akka as
///         the node's gossiped member roles. Empty there means a node that joins, comes Up, serves OPC UA
///         — and is invisible to <c>RoleLeader</c>, to <c>MembersWithRole("driver")</c>, to every
///         role-scoped singleton, and to <c>ConfigPublishCoordinator</c>'s expected-ack set. The field
///         symptom was "no driver-role nodes are Up" with nothing wrong in the node's own logs
///         (<c>docs/deployments/wonder-app-vd03-makino-z-34184.md</c>).
///     </para>
/// </remarks>
[Collection(RoleEnvironmentCollection.Name)]
public class AkkaClusterOptionsRoleFallbackTests
{
    private static AkkaClusterOptions Bind(params (string Key, string Value)[] settings)
    {
        var configuration = new ConfigurationBuilder()
            .AddInMemoryCollection(settings.ToDictionary(s => s.Key, s => (string?)s.Value))
            .Build();

        var services = new ServiceCollection();
        services.AddLogging();
        services.AddOtOpcUaCluster(configuration);

        return services.BuildServiceProvider().GetRequiredService<IOptions<AkkaClusterOptions>>().Value;
    }

    [Fact]
    public void Roles_fall_back_to_the_environment_when_Cluster_Roles_is_empty()
    {
        using (new EnvVarScope(RoleParser.RolesEnvVar, "admin,driver"))
        {
            Bind().Roles.ShouldBe(new[] { "admin", "driver" });
        }
    }

    [Fact]
    public void Akka_member_roles_carry_the_fallback()
    {
        // The end that matters. This is the value handed to Akka.Cluster.Hosting, so an empty array here
        // is a role-less member — the exact production shape #532 describes.
        using (new EnvVarScope(RoleParser.RolesEnvVar, "driver"))
        {
            ServiceCollectionExtensions.BuildClusterOptions(Bind()).Roles.ShouldBe(new[] { "driver" });
        }
    }

    [Fact]
    public void Configured_roles_win_over_the_environment()
    {
        // Negative control for the fallback: without this, a PostConfigure that unconditionally
        // overwrote Roles from the environment would pass the test above and silently ignore every
        // deployment's explicit Cluster:Roles.
        using (new EnvVarScope(RoleParser.RolesEnvVar, "admin,driver,cluster-SITE-B"))
        {
            Bind(("Cluster:Roles:0", "driver"), ("Cluster:Roles:1", "cluster-SITE-A")).Roles
                .ShouldBe(new[] { "driver", "cluster-SITE-A" });
        }
    }

    [Fact]
    public void No_roles_from_either_source_stays_empty()
    {
        using (new EnvVarScope(RoleParser.RolesEnvVar, null))
        {
            Bind().Roles.ShouldBeEmpty();
        }
    }

    [Fact]
    public void The_cluster_role_from_the_environment_reaches_the_ClusterId_derivation()
    {
        // The over-grant fix in ConfigDbApiKeyStore reads its ClusterId off these options, and a null
        // ClusterId applies no cluster filter at all — so an env-only node failed OPEN before #532.
        using (new EnvVarScope(RoleParser.RolesEnvVar, "driver,cluster-SITE-A"))
        {
            RoleParser.ClusterIdFromRoles(Bind().Roles).ShouldBe("site-a");
        }
    }

    /// <summary>
    ///     R3-04 (structural identity, choice 3): <c>AkkaClusterOptions.Roles</c> is not a SECOND
    ///     derivation of the role rule — it is the registered <see cref="EffectiveRoles"/> instance's
    ///     <see cref="EffectiveRoles.Gossiped"/> list, verbatim. A mixed-case configured role proves
    ///     both the normalization (plain lowered, cluster suffix preserved) and the identity: the two
    ///     views can never disagree because there is only one derivation.
    /// </summary>
    [Fact]
    public void Bound_options_Roles_IS_the_registered_EffectiveRoles_Gossiped_list()
    {
        var configuration = new ConfigurationBuilder()
            .AddInMemoryCollection(new Dictionary<string, string?>
            {
                ["Cluster:Roles:0"] = "Driver",
                ["Cluster:Roles:1"] = "Cluster-SITE-A",
            })
            .Build();

        var services = new ServiceCollection();
        services.AddLogging();
        services.AddOtOpcUaCluster(configuration);
        var provider = services.BuildServiceProvider();

        var bound = provider.GetRequiredService<IOptions<AkkaClusterOptions>>().Value;
        var effectiveRoles = provider.GetRequiredService<EffectiveRoles>();

        bound.Roles.ShouldBe(new[] { "driver", "cluster-SITE-A" });
        bound.Roles.ShouldBe(effectiveRoles.Gossiped);
    }
}