using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.AdminUI.Acls;
using ZB.MOM.WW.OtOpcUa.Configuration.Enums;
using ZB.MOM.WW.OtOpcUa.Core.Authorization;

namespace ZB.MOM.WW.OtOpcUa.AdminUI.Tests.Acls;

/// <summary>
///     #520 stage 7 — the ACL scope picker's trees and the authoring-time checks behind them.
/// </summary>
/// <remarks>
///     The defect this stage closes is not a crash: it is that a grant could be authored, saved, deployed
///     and sealed green while resolving to nothing. So the tests that matter are the ones asserting a
///     <em>rejection</em> — and each is paired with the neighbouring case that must still be accepted, or
///     a service that rejected everything would pass the lot.
/// </remarks>
public sealed class AclScopeServiceTests
{
    // --- The picker's trees ------------------------------------------------------------------------

    /// <summary>
    ///     The raw tree is rooted at the cluster and every level offers the scope kind that level grants
    ///     at. Without the kinds the picker would be a browser, not a picker.
    /// </summary>
    [Fact]
    public async Task The_raw_tree_carries_a_scope_kind_at_every_level()
    {
        var svc = AclScopeTestDb.NewService();

        var roots = await svc.LoadRootsAsync(AclScopeTestDb.ClusterId);

        var cluster = roots.Raw.ShouldHaveSingleItem();
        cluster.ScopeKind.ShouldBe(NodeAclScopeKind.Cluster);

        var folder = (await svc.LoadChildrenAsync(cluster)).ShouldHaveSingleItem();
        folder.ScopeKind.ShouldBe(NodeAclScopeKind.RawFolder);
        folder.ScopeId.ShouldBe(AclScopeTestDb.FolderId);

        var driver = (await svc.LoadChildrenAsync(folder)).ShouldHaveSingleItem();
        driver.ScopeKind.ShouldBe(NodeAclScopeKind.RawDriver);
        driver.ScopeId.ShouldBe(AclScopeTestDb.DriverId);

        var device = (await svc.LoadChildrenAsync(driver)).ShouldHaveSingleItem();
        device.ScopeKind.ShouldBe(NodeAclScopeKind.RawDevice);
        device.ScopeId.ShouldBe(AclScopeTestDb.DeviceId);

        var group = (await svc.LoadChildrenAsync(device)).ShouldHaveSingleItem();
        group.ScopeKind.ShouldBe(NodeAclScopeKind.RawTagGroup);
        group.ScopeId.ShouldBe(AclScopeTestDb.TagGroupId);

        var tag = (await svc.LoadChildrenAsync(group)).ShouldHaveSingleItem();
        tag.ScopeKind.ShouldBe(NodeAclScopeKind.Tag);
        tag.ScopeId.ShouldBe(AclScopeTestDb.TagId);
    }

    /// <summary>
    ///     A cluster row produces NO scope id. The deploy gate rejects a Cluster grant that carries one
    ///     (<c>NodeAclScopeIdUnexpected</c>), so a picker that set the cluster id there would author a row
    ///     that cannot be deployed.
    /// </summary>
    [Fact]
    public async Task The_cluster_row_produces_no_scope_id()
    {
        var svc = AclScopeTestDb.NewService();

        var cluster = (await svc.LoadRootsAsync(AclScopeTestDb.ClusterId)).Raw.ShouldHaveSingleItem();

        cluster.ScopeId.ShouldBeNull();
        (await svc.CheckScopeAsync(AclScopeTestDb.ClusterId, cluster.ScopeKind!.Value, cluster.ScopeId))
            .Ok.ShouldBeTrue();
    }

    /// <summary>
    ///     Another cluster's nodes are structurally unreachable through the picker — the counterpart of the
    ///     deploy gate's cross-cluster rule. Reachability, not just discouragement, is the point: the SIDE
    ///     driver exists and resolves, so only the rooting keeps it out.
    /// </summary>
    [Fact]
    public async Task The_picker_cannot_reach_another_clusters_nodes()
    {
        var svc = AclScopeTestDb.NewService();

        var roots = await svc.LoadRootsAsync(AclScopeTestDb.ClusterId);
        var reachable = await FlattenAsync(svc, roots);

        reachable.ShouldNotContain(AclScopeTestDb.OtherDriverId);

        // …and it is a real driver, so the absence is the rooting rather than the id being unknown.
        var side = await svc.LoadRootsAsync(AclScopeTestDb.OtherClusterId);
        (await FlattenAsync(svc, side)).ShouldContain(AclScopeTestDb.OtherDriverId);
    }

    /// <summary>The UNS side offers area, line and equipment.</summary>
    [Fact]
    public async Task The_uns_tree_offers_area_line_and_equipment()
    {
        var svc = AclScopeTestDb.NewService();

        var area = (await svc.LoadRootsAsync(AclScopeTestDb.ClusterId)).Uns.ShouldHaveSingleItem();
        area.ScopeKind.ShouldBe(NodeAclScopeKind.UnsArea);
        area.ScopeId.ShouldBe(AclScopeTestDb.AreaId);

        var line = area.Children.ShouldHaveSingleItem();
        line.ScopeKind.ShouldBe(NodeAclScopeKind.UnsLine);
        line.ScopeId.ShouldBe(AclScopeTestDb.LineId);

        var equipment = line.Children.ShouldHaveSingleItem();
        equipment.ScopeKind.ShouldBe(NodeAclScopeKind.Equipment);
        equipment.ScopeId.ShouldBe(AclScopeTestDb.EquipmentId);
    }

    /// <summary>
    ///     An unknown cluster yields empty trees rather than the whole fleet. A picker that fell back to
    ///     everything would hand an operator another cluster's nodes at the one moment they are least
    ///     likely to notice.
    /// </summary>
    [Fact]
    public async Task An_unknown_cluster_yields_empty_trees()
    {
        var svc = AclScopeTestDb.NewService();

        var roots = await svc.LoadRootsAsync("NO-SUCH-CLUSTER");

        roots.Raw.ShouldBeEmpty();
        roots.Uns.ShouldBeEmpty();
    }

    // --- The authoring-time scope check ------------------------------------------------------------

    /// <summary>
    ///     THE test for this stage. Every scope kind resolves when pointed at its own entity type, and the
    ///     SAME id under a neighbouring kind does not — which is precisely the row the old free-text field
    ///     could produce, and which saved, deployed and authorized nobody.
    /// </summary>
    [Theory]
    [InlineData(NodeAclScopeKind.RawFolder, AclScopeTestDb.FolderId)]
    [InlineData(NodeAclScopeKind.RawDriver, AclScopeTestDb.DriverId)]
    [InlineData(NodeAclScopeKind.RawDevice, AclScopeTestDb.DeviceId)]
    [InlineData(NodeAclScopeKind.RawTagGroup, AclScopeTestDb.TagGroupId)]
    [InlineData(NodeAclScopeKind.Tag, AclScopeTestDb.TagId)]
    [InlineData(NodeAclScopeKind.UnsArea, AclScopeTestDb.AreaId)]
    [InlineData(NodeAclScopeKind.UnsLine, AclScopeTestDb.LineId)]
    [InlineData(NodeAclScopeKind.Equipment, AclScopeTestDb.EquipmentId)]
    public async Task A_kind_resolves_its_own_entity_and_nothing_else(NodeAclScopeKind kind, string id)
    {
        var svc = AclScopeTestDb.NewService();

        (await svc.CheckScopeAsync(AclScopeTestDb.ClusterId, kind, id))
            .Ok.ShouldBeTrue($"{kind} '{id}' names a real entity of that type");

        // The same id under a different kind must not resolve. RawDevice is the neighbour for every raw
        // kind and UnsArea for every UNS one; both are real kinds with real rows, so a service that
        // ignored the kind entirely would pass the line above and fail here.
        var neighbour = kind is NodeAclScopeKind.UnsArea or NodeAclScopeKind.UnsLine or NodeAclScopeKind.Equipment
            ? (kind == NodeAclScopeKind.UnsArea ? NodeAclScopeKind.UnsLine : NodeAclScopeKind.UnsArea)
            : (kind == NodeAclScopeKind.RawDevice ? NodeAclScopeKind.RawDriver : NodeAclScopeKind.RawDevice);

        (await svc.CheckScopeAsync(AclScopeTestDb.ClusterId, neighbour, id))
            .Ok.ShouldBeFalse($"'{id}' is not a {neighbour}");
    }

    /// <summary>An id that names nothing is rejected, and the message says so.</summary>
    [Fact]
    public async Task A_scope_id_that_names_nothing_is_rejected()
    {
        var svc = AclScopeTestDb.NewService();

        var check = await svc.CheckScopeAsync(
            AclScopeTestDb.ClusterId, NodeAclScopeKind.RawDevice, "DEV-typo");

        check.Ok.ShouldBeFalse();
        check.Message.ShouldContain("DEV-typo");
    }

    /// <summary>
    ///     A real id in ANOTHER cluster is rejected, and the message names the cluster that owns it. This
    ///     is the one rejection whose id exists, so a check that only asked "does a row with this id
    ///     exist?" would accept it and confer authority across a cluster boundary.
    /// </summary>
    [Fact]
    public async Task A_scope_in_another_cluster_is_rejected_and_names_its_owner()
    {
        var svc = AclScopeTestDb.NewService();

        var check = await svc.CheckScopeAsync(
            AclScopeTestDb.ClusterId, NodeAclScopeKind.RawDriver, AclScopeTestDb.OtherDriverId);

        check.Ok.ShouldBeFalse();
        check.Message.ShouldContain(AclScopeTestDb.OtherClusterId);

        // Authored under its own cluster, the same row is fine — so the rejection is the boundary, not
        // the driver.
        (await svc.CheckScopeAsync(
                AclScopeTestDb.OtherClusterId, NodeAclScopeKind.RawDriver, AclScopeTestDb.OtherDriverId))
            .Ok.ShouldBeTrue();
    }

    /// <summary>
    ///     A row whose parent chain is broken exists but is owned by no cluster, so it resolves to no path.
    ///     Checked separately from a missing row because the two reach the rejection by different routes.
    /// </summary>
    [Fact]
    public async Task An_entity_whose_parent_chain_is_broken_is_rejected()
    {
        var svc = AclScopeTestDb.NewService();

        (await svc.CheckScopeAsync(
                AclScopeTestDb.ClusterId, NodeAclScopeKind.Equipment, AclScopeTestDb.OrphanEquipmentId))
            .Ok.ShouldBeFalse();

        // The healthy equipment in the same table passes, so the rejection is the broken line and not the
        // Equipment arm being wired to nothing.
        (await svc.CheckScopeAsync(
                AclScopeTestDb.ClusterId, NodeAclScopeKind.Equipment, AclScopeTestDb.EquipmentId))
            .Ok.ShouldBeTrue();
    }

    /// <summary>
    ///     A Cluster grant covers everything and carries no id; one that carries an id means the author
    ///     picked the wrong kind and the grant is BROADER than intended — the direction that must never
    ///     pass silently.
    /// </summary>
    [Fact]
    public async Task A_cluster_grant_carrying_a_scope_id_is_rejected()
    {
        var svc = AclScopeTestDb.NewService();

        (await svc.CheckScopeAsync(AclScopeTestDb.ClusterId, NodeAclScopeKind.Cluster, AclScopeTestDb.DeviceId))
            .Ok.ShouldBeFalse();
        (await svc.CheckScopeAsync(AclScopeTestDb.ClusterId, NodeAclScopeKind.Cluster, null))
            .Ok.ShouldBeTrue();
    }

    /// <summary>Every kind but Cluster needs a target.</summary>
    [Fact]
    public async Task A_narrower_kind_without_a_scope_id_is_rejected()
    {
        var svc = AclScopeTestDb.NewService();

        (await svc.CheckScopeAsync(AclScopeTestDb.ClusterId, NodeAclScopeKind.RawDevice, null))
            .Ok.ShouldBeFalse();
        (await svc.CheckScopeAsync(AclScopeTestDb.ClusterId, NodeAclScopeKind.RawDevice, "   "))
            .Ok.ShouldBeFalse();
    }

    /// <summary>
    ///     The retired v2 kind is rejected whatever its target — including a target that would resolve
    ///     under the kind that replaced it, which is the shape an operator migrating a v2 row produces.
    /// </summary>
    [Fact]
    public async Task The_retired_FolderSegment_kind_is_rejected()
    {
        var svc = AclScopeTestDb.NewService();

        var check = await svc.CheckScopeAsync(
            AclScopeTestDb.ClusterId, NodeAclScopeKind.FolderSegment, AclScopeTestDb.FolderId);

        check.Ok.ShouldBeFalse();
        check.Message.ShouldContain("RawFolder");
    }

    /// <summary>A Namespace grant takes a realm token, in either spelling, and nothing else.</summary>
    [Theory]
    [InlineData("raw", true)]
    [InlineData("uns", true)]
    [InlineData("RAW", true)]
    [InlineData("https://zb.com/otopcua/uns", true)]
    [InlineData("ns=2", false)]
    [InlineData("MAIN", false)]
    public async Task A_namespace_grant_accepts_only_a_realm(string scopeId, bool expected)
    {
        var svc = AclScopeTestDb.NewService();

        (await svc.CheckScopeAsync(AclScopeTestDb.ClusterId, NodeAclScopeKind.Namespace, scopeId))
            .Ok.ShouldBe(expected);
    }

    /// <summary>An ordinal outside the enum comes from a hand-edited row; nothing below it is meaningful.</summary>
    [Fact]
    public async Task An_undefined_scope_kind_is_rejected()
    {
        var svc = AclScopeTestDb.NewService();

        (await svc.CheckScopeAsync(AclScopeTestDb.ClusterId, (NodeAclScopeKind)999, "anything"))
            .Ok.ShouldBeFalse();
    }

    // --- Principals ---------------------------------------------------------------------------------

    /// <summary>The reserved anonymous principal always reaches something — it has no key to count.</summary>
    [Fact]
    public async Task The_anonymous_principal_is_recognised_without_a_key()
    {
        var svc = AclScopeTestDb.NewService();

        var usage = await svc.CheckPrincipalAsync(OpcUaPrincipals.Anonymous);

        usage.IsAnonymous.ShouldBeTrue();
        usage.ReachesSomething.ShouldBeTrue();
    }

    /// <summary>
    ///     Only enabled, unexpired keys count as reaching the principal. An expired key is the case a
    ///     count of rows would get wrong, so the fixture's stale principal has one and nothing else.
    /// </summary>
    [Fact]
    public async Task Only_live_keys_count_towards_a_principal()
    {
        var svc = AclScopeTestDb.NewService(new FixedClock(AclScopeTestDb.Now));

        var live = await svc.CheckPrincipalAsync(AclScopeTestDb.LivePrincipal);
        live.EnabledKeys.ShouldBe(2);
        live.DisabledKeys.ShouldBe(1);
        live.ReachesSomething.ShouldBeTrue();

        var stale = await svc.CheckPrincipalAsync(AclScopeTestDb.StalePrincipal);
        stale.EnabledKeys.ShouldBe(0, "its only key expired yesterday");
        stale.DisabledKeys.ShouldBe(1);
        stale.ReachesSomething.ShouldBeFalse();
    }

    /// <summary>A principal nothing uses reaches nobody — the typo case the hint exists to surface.</summary>
    [Fact]
    public async Task An_unknown_principal_reaches_nobody()
    {
        var svc = AclScopeTestDb.NewService();

        var usage = await svc.CheckPrincipalAsync("scadabridge-dcI"); // capital i, not lowercase L

        usage.EnabledKeys.ShouldBe(0);
        usage.ReachesSomething.ShouldBeFalse();
    }

    /// <summary>The suggestion list covers key principals and the reserved anonymous one.</summary>
    [Fact]
    public async Task Known_principals_include_every_key_principal_and_anonymous()
    {
        var svc = AclScopeTestDb.NewService();

        var known = await svc.LoadKnownPrincipalsAsync();

        known.ShouldContain(AclScopeTestDb.LivePrincipal);
        known.ShouldContain(AclScopeTestDb.StalePrincipal);
        known.ShouldContain(OpcUaPrincipals.Anonymous);
        known.Count.ShouldBe(known.Distinct(StringComparer.OrdinalIgnoreCase).Count(), "three keys share a principal");
    }

    // --- Helpers ------------------------------------------------------------------------------------

    /// <summary>
    ///     A clock pinned to the fixture's <c>Now</c>. Key expiry is the one thing here that moves with the
    ///     wall clock, and a test that let it would go red on its own a day after the fixture was written.
    /// </summary>
    private sealed class FixedClock(DateTime utcNow) : TimeProvider
    {
        public override DateTimeOffset GetUtcNow() => new(utcNow, TimeSpan.Zero);
    }

    /// <summary>Every scope id reachable through the picker for one cluster, both trees, fully expanded.</summary>
    private static async Task<List<string>> FlattenAsync(IAclScopeService svc, AclScopeRoots roots)
    {
        var ids = new List<string>();

        async Task WalkAsync(AclScopeNode node)
        {
            if (node.ScopeId is not null) ids.Add(node.ScopeId);

            var children = node.HasLazyChildren
                ? await svc.LoadChildrenAsync(node)
                : node.Children;

            foreach (var child in children) await WalkAsync(child);
        }

        foreach (var node in roots.Raw.Concat(roots.Uns)) await WalkAsync(node);
        return ids;
    }
}