using Microsoft.EntityFrameworkCore;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Cluster;
using ZB.MOM.WW.OtOpcUa.Configuration;
using ZB.MOM.WW.OtOpcUa.Configuration.Entities;
using ZB.MOM.WW.OtOpcUa.Configuration.Enums;
using ZB.MOM.WW.OtOpcUa.Core.Authorization;
using ZB.MOM.WW.OtOpcUa.OpcUaServer.Security;
using ZB.MOM.WW.OtOpcUa.Host.OpcUa;

namespace ZB.MOM.WW.OtOpcUa.Host.Tests.OpcUa;

/// <summary>
///     The key source for a node WITH a ConfigDb (#520 stage 2) — an admin-role node, including a fused
///     admin+driver one.
/// </summary>
/// <remarks>
///     <para>
///         <b>Why cluster confinement is tested here and not on <c>ArtifactApiKeyStore</c>.</b> The two
///         stores read different things. The artifact store's snapshot was already narrowed to the node's
///         own cluster by <c>DeploymentArtifact.ParseDataPlaneAuthority</c>
///         (<c>ClusterFilterMode.ScopeTo</c>), so it cannot see another cluster's rows at all. This store
///         queries the fleet-wide ConfigDb, so the confinement is its own job — and until it was added, a
///         Cluster-scoped grant authored in ANY cluster conferred an interim server-wide role on a fused
///         central node.
///     </para>
///     <para>
///         The in-memory EF provider is the convention in the ControlPlane/Runtime test projects; nothing
///         here touches the central SQL Server. Note it compares strings with LINQ-to-Objects ordinal
///         semantics, NOT SQL Server's case-insensitive collation — which is exactly why the ClusterId
///         match is done explicitly with <see cref="StringComparison.OrdinalIgnoreCase"/> in the store
///         rather than left to the provider. <see cref="A_ClusterId_matches_case_insensitively"/> pins it.
///     </para>
/// </remarks>
public sealed class ConfigDbApiKeyStoreTests
{
    private const string ThisCluster = "SITE-A";
    private const string OtherCluster = "SITE-B";
    private static readonly DateTime Now = new(2026, 7, 31, 12, 0, 0, DateTimeKind.Utc);

    /// <summary>
    ///     THE REGRESSION TEST. A Cluster-scoped grant authored in another cluster must not reach this
    ///     node — it would collapse into a server-wide <c>WriteOperate</c> role via
    ///     <c>ApiKeyInterimRoleMapper</c>, i.e. write authority granted in SITE-B taking effect in SITE-A.
    /// </summary>
    [Fact]
    public async Task A_cluster_scoped_grant_from_another_cluster_confers_nothing()
    {
        var factory = NewInMemoryDbFactory();
        Seed(factory,
            keys: [Key("abc", "scadabridge-dcl")],
            acls: [Acl("acl-other", OtherCluster, "scadabridge-dcl", NodeAclScopeKind.Cluster, NodePermissions.WriteOperate)]);

        var found = await new ConfigDbApiKeyStore(factory, ThisCluster).FindAsync("abc", Now, default);

        // The KEY still resolves — keys are fleet-wide credentials (ApiKey carries no ClusterId); it is
        // the grants that are cluster-bound. Asserting a null lookup here would pass for the wrong reason.
        found.ShouldNotBeNull();
        found!.Grants.ShouldBeEmpty();
    }

    /// <summary>
    ///     The positive control for the test above: without it, a "fix" that returned no grants at all
    ///     would pass.
    /// </summary>
    [Fact]
    public async Task A_cluster_scoped_grant_in_this_cluster_still_confers_its_permissions()
    {
        var factory = NewInMemoryDbFactory();
        Seed(factory,
            keys: [Key("abc", "scadabridge-dcl")],
            acls:
            [
                Acl("acl-mine", ThisCluster, "scadabridge-dcl", NodeAclScopeKind.Cluster, NodePermissions.WriteOperate),
                Acl("acl-other", OtherCluster, "scadabridge-dcl", NodeAclScopeKind.Cluster, NodePermissions.WriteOperate),
            ]);

        var found = await new ConfigDbApiKeyStore(factory, ThisCluster).FindAsync("abc", Now, default);

        found!.Grants.ShouldHaveSingleItem().NodeAclId.ShouldBe("acl-mine");
    }

    /// <summary>
    ///     A legacy / single-cluster node carries no <c>cluster-{ClusterId}</c> role, so its ClusterId is
    ///     null and NO filter applies — mirroring the artifact path's <c>ClusterFilterMode.None</c>.
    ///     Failing closed here would silently strip every grant on an existing deployment.
    /// </summary>
    [Fact]
    public async Task A_node_with_no_cluster_scoped_role_sees_every_cluster_scoped_grant()
    {
        var factory = NewInMemoryDbFactory();
        Seed(factory,
            keys: [Key("abc", "p")],
            acls:
            [
                Acl("acl-a", ThisCluster, "p", NodeAclScopeKind.Cluster, NodePermissions.Read),
                Acl("acl-b", OtherCluster, "p", NodeAclScopeKind.Cluster, NodePermissions.WriteOperate),
            ]);

        var found = await new ConfigDbApiKeyStore(factory, clusterId: null).FindAsync("abc", Now, default);

        found!.Grants.Select(g => g.NodeAclId).ShouldBe(["acl-a", "acl-b"], ignoreOrder: true);
    }

    /// <summary>
    ///     The node's ClusterId comes from its role suffix, and that arrives in either the operator's
    ///     spelling (<c>Cluster:Roles</c> binds verbatim) or lower-cased (<c>OTOPCUA_ROLES</c> goes through
    ///     <c>RoleParser.Parse</c>, which calls <c>ToLowerInvariant</c>). The ACL row's ClusterId is
    ///     authored independently. A case-sensitive match would therefore strip every grant on a node
    ///     configured the second way — so the match is OrdinalIgnoreCase, the same comparison
    ///     <c>DeploymentArtifact.ParseDataPlaneAuthority</c> uses.
    /// </summary>
    [Fact]
    public async Task A_ClusterId_matches_case_insensitively()
    {
        var factory = NewInMemoryDbFactory();
        Seed(factory,
            keys: [Key("abc", "p")],
            acls: [Acl("acl-mine", "SITE-A", "p", NodeAclScopeKind.Cluster, NodePermissions.Read)]);

        var found = await new ConfigDbApiKeyStore(factory, "site-a").FindAsync("abc", Now, default);

        found!.Grants.ShouldHaveSingleItem().NodeAclId.ShouldBe("acl-mine");
    }

    /// <summary>
    ///     <c>FindGrantsAsync</c> is the anonymous principal's path — no credential, so it never goes
    ///     through <c>FindAsync</c>. It must be confined to the node's cluster too.
    /// </summary>
    [Fact]
    public async Task Anonymous_grants_are_cluster_confined_on_their_own_path()
    {
        var factory = NewInMemoryDbFactory();
        Seed(factory,
            keys: [],
            acls:
            [
                Acl("acl-anon-mine", ThisCluster, OpcUaPrincipals.Anonymous, NodeAclScopeKind.Cluster, NodePermissions.Read),
                Acl("acl-anon-other", OtherCluster, OpcUaPrincipals.Anonymous, NodeAclScopeKind.Cluster, NodePermissions.WriteOperate),
            ]);

        var grants = await new ConfigDbApiKeyStore(factory, ThisCluster)
            .FindGrantsAsync(OpcUaPrincipals.Anonymous, default);

        grants.ShouldHaveSingleItem().NodeAclId.ShouldBe("acl-anon-mine");
    }

    /// <summary>
    ///     Narrower-than-Cluster scopes ARE returned (#520 stage 5 widened this) — the cluster filter is
    ///     now the only narrowing this store performs.
    /// </summary>
    /// <remarks>
    ///     The scope-kind filter that used to sit alongside it was redundant: <c>ApiKeyInterimRoleMapper</c>
    ///     applies exactly that filter itself, so removing it changes no role — pinned below — while a
    ///     truncated <c>Grants</c> collection would have quietly misled anything that read it once scope
    ///     started being enforced.
    /// </remarks>
    [Fact]
    public async Task A_narrower_scope_in_this_cluster_is_returned()
    {
        var factory = NewInMemoryDbFactory();
        Seed(factory,
            keys: [Key("abc", "p")],
            acls:
            [
                Acl("acl-cluster", ThisCluster, "p", NodeAclScopeKind.Cluster, NodePermissions.AlarmAcknowledge),
                Acl("acl-equipment", ThisCluster, "p", NodeAclScopeKind.Equipment, NodePermissions.WriteOperate),
            ]);

        var found = await new ConfigDbApiKeyStore(factory, ThisCluster).FindAsync("abc", Now, default);

        found!.Grants.Select(g => g.NodeAclId).ShouldBe(["acl-cluster", "acl-equipment"], ignoreOrder: true);

        // Both grants now reach the mapper, and it still takes flags from the CLUSTER-scoped one only:
        // AlarmAck is conferred, WriteOperate is not. The two grants carry different flags precisely so
        // this cannot pass by accident — which is why widening the store is safe with enforcement off.
        ApiKeyInterimRoleMapper.Map(found.Grants, "p").ShouldBe([OpcUaDataPlaneRoles.AlarmAck]);
    }

    /// <summary>
    ///     The ClusterId derivation itself: the same one <c>ClusterRoleInfo</c> performs for
    ///     <c>IClusterRoleInfo.ClusterId</c>, off the node's OWN configured roles.
    /// </summary>
    [Fact]
    public void ResolveClusterId_reads_the_nodes_own_cluster_scoped_role()
    {
        ConfigDbApiKeyStore.ResolveClusterId(new AkkaClusterOptions { Roles = ["driver", "cluster-SITE-A"] })
            .ShouldBe("SITE-A");
        ConfigDbApiKeyStore.ResolveClusterId(new AkkaClusterOptions { Roles = ["admin", "driver"] })
            .ShouldBeNull();
        ConfigDbApiKeyStore.ResolveClusterId(new AkkaClusterOptions())
            .ShouldBeNull();
    }

    private static void Seed(
        IDbContextFactory<OtOpcUaConfigDbContext> factory,
        IReadOnlyList<ApiKey> keys,
        IReadOnlyList<NodeAcl> acls)
    {
        using var db = factory.CreateDbContext();
        db.ApiKeys.AddRange(keys);
        db.NodeAcls.AddRange(acls);
        db.SaveChanges();
    }

    private static ApiKey Key(string id, string principal) => new()
    {
        ApiKeyRowId = Guid.NewGuid(),
        ApiKeyId = id,
        Name = id,
        SecretHash = "hash",
        Principal = principal,
        Enabled = true,
        CreatedUtc = Now.AddDays(-1),
    };

    private static NodeAcl Acl(
        string id, string clusterId, string principal, NodeAclScopeKind scope, NodePermissions flags) => new()
    {
        NodeAclRowId = Guid.NewGuid(),
        NodeAclId = id,
        ClusterId = clusterId,
        Principal = principal,
        ScopeKind = scope,
        PermissionFlags = flags,
    };

    private static IDbContextFactory<OtOpcUaConfigDbContext> NewInMemoryDbFactory() =>
        new InMemoryConfigDbFactory(Guid.NewGuid().ToString("N"));

    private sealed class InMemoryConfigDbFactory(string dbName) : IDbContextFactory<OtOpcUaConfigDbContext>
    {
        /// <summary>Creates a context over this test's own in-memory database.</summary>
        /// <returns>A new <see cref="OtOpcUaConfigDbContext"/>.</returns>
        public OtOpcUaConfigDbContext CreateDbContext() =>
            new(new DbContextOptionsBuilder<OtOpcUaConfigDbContext>().UseInMemoryDatabase(dbName).Options);
    }
}