using Microsoft.EntityFrameworkCore;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Admin.Services;
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;

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

[Trait("Category", "Unit")]
public sealed class PermissionProbeServiceTests
{
    [Fact]
    public async Task Probe_Grants_When_ClusterLevelRow_CoversRequiredFlag()
    {
        using var ctx = NewContext();
        SeedAcl(ctx, gen: 1, cluster: "c1",
            scopeKind: NodeAclScopeKind.Cluster, scopeId: null,
            group: "cn=operators", flags: NodePermissions.Browse | NodePermissions.Read);
        var svc = new PermissionProbeService(ctx);

        var result = await svc.ProbeAsync(
            generationId: 1,
            ldapGroup: "cn=operators",
            scope: new NodeScope { ClusterId = "c1", NamespaceId = "ns-1", Kind = NodeHierarchyKind.Equipment },
            required: NodePermissions.Read,
            CancellationToken.None);

        result.Granted.ShouldBeTrue();
        result.Matches.Count.ShouldBe(1);
        result.Matches[0].LdapGroup.ShouldBe("cn=operators");
        result.Matches[0].Scope.ShouldBe(NodeAclScopeKind.Cluster);
    }

    [Fact]
    public async Task Probe_Denies_When_NoGroupMatches()
    {
        using var ctx = NewContext();
        SeedAcl(ctx, 1, "c1", NodeAclScopeKind.Cluster, null, "cn=operators", NodePermissions.Read);
        var svc = new PermissionProbeService(ctx);

        var result = await svc.ProbeAsync(1, "cn=random-group",
            new NodeScope { ClusterId = "c1", Kind = NodeHierarchyKind.Equipment },
            NodePermissions.Read, CancellationToken.None);

        result.Granted.ShouldBeFalse();
        result.Matches.ShouldBeEmpty();
        result.Effective.ShouldBe(NodePermissions.None);
    }

    [Fact]
    public async Task Probe_Denies_When_Effective_Missing_RequiredFlag()
    {
        using var ctx = NewContext();
        SeedAcl(ctx, 1, "c1", NodeAclScopeKind.Cluster, null, "cn=operators", NodePermissions.Browse | NodePermissions.Read);
        var svc = new PermissionProbeService(ctx);

        var result = await svc.ProbeAsync(1, "cn=operators",
            new NodeScope { ClusterId = "c1", Kind = NodeHierarchyKind.Equipment },
            required: NodePermissions.WriteOperate,
            CancellationToken.None);

        result.Granted.ShouldBeFalse();
        result.Effective.ShouldBe(NodePermissions.Browse | NodePermissions.Read);
    }

    [Fact]
    public async Task Probe_Ignores_Rows_From_OtherClusters()
    {
        using var ctx = NewContext();
        SeedAcl(ctx, 1, "c1", NodeAclScopeKind.Cluster, null, "cn=operators", NodePermissions.Read);
        SeedAcl(ctx, 1, "c2", NodeAclScopeKind.Cluster, null, "cn=operators", NodePermissions.WriteOperate);
        var svc = new PermissionProbeService(ctx);

        var c1Result = await svc.ProbeAsync(1, "cn=operators",
            new NodeScope { ClusterId = "c1", Kind = NodeHierarchyKind.Equipment },
            NodePermissions.WriteOperate, CancellationToken.None);

        c1Result.Granted.ShouldBeFalse("c2's WriteOperate grant must NOT leak into c1's probe");
    }

    [Fact]
    public async Task Probe_UsesOnlyRows_From_Specified_Generation()
    {
        using var ctx = NewContext();
        SeedAcl(ctx, gen: 1, cluster: "c1", NodeAclScopeKind.Cluster, null, "cn=operators", NodePermissions.Read);
        SeedAcl(ctx, gen: 2, cluster: "c1", NodeAclScopeKind.Cluster, null, "cn=operators", NodePermissions.WriteOperate);
        var svc = new PermissionProbeService(ctx);

        var gen1 = await svc.ProbeAsync(1, "cn=operators",
            new NodeScope { ClusterId = "c1", Kind = NodeHierarchyKind.Equipment },
            NodePermissions.WriteOperate, CancellationToken.None);
        var gen2 = await svc.ProbeAsync(2, "cn=operators",
            new NodeScope { ClusterId = "c1", Kind = NodeHierarchyKind.Equipment },
            NodePermissions.WriteOperate, CancellationToken.None);

        gen1.Granted.ShouldBeFalse();
        gen2.Granted.ShouldBeTrue();
    }

    private static void SeedAcl(
        OtOpcUaConfigDbContext ctx, long gen, string cluster,
        NodeAclScopeKind scopeKind, string? scopeId, string group, NodePermissions flags)
    {
        ctx.NodeAcls.Add(new NodeAcl
        {
            NodeAclRowId = Guid.NewGuid(),
            NodeAclId = $"acl-{Guid.NewGuid():N}"[..16],
            GenerationId = gen,
            ClusterId = cluster,
            LdapGroup = group,
            ScopeKind = scopeKind,
            ScopeId = scopeId,
            PermissionFlags = flags,
        });
        ctx.SaveChanges();
    }

    private static OtOpcUaConfigDbContext NewContext()
    {
        var opts = new DbContextOptionsBuilder<OtOpcUaConfigDbContext>()
            .UseInMemoryDatabase(Guid.NewGuid().ToString())
            .Options;
        return new OtOpcUaConfigDbContext(opts);
    }
}