using ZB.MOM.WW.ScadaBridge.CentralUI.Services;

namespace ZB.MOM.WW.ScadaBridge.CentralUI.Tests.Services;

public class BindingGroupBuilderTests
{
    private static BindingRow Row(string canonical, string? dflt, int? conn, string? ovr) =>
        new(canonical, dflt, conn, ovr);

    [Fact]
    public void Groups_DirectAttributesFirst_ThenModules_InNameOrder()
    {
        var rows = new[]
        {
            Row("RightMESReceiver.MoveInFlag", "MoveInFlag", 1, "MESReceiver_022.MoveInFlag"),
            Row("ChlorineFlow", "ChlorineFlow", 1, "Z28061.ChlorineFlow"),
            Row("LeftMESReceiver.MoveInFlag", "MoveInFlag", 1, "MESReceiver_023.MoveInFlag"),
        };
        var groups = BindingGroupBuilder.Build(rows);
        Assert.Equal(new[] { BindingGroupBuilder.InstanceGroupKey, "LeftMESReceiver", "RightMESReceiver" },
            groups.Select(g => g.Key));
    }

    [Fact]
    public void NestedModule_FoldsIntoFirstSegment_AndKeepsNestedTail()
    {
        var rows = new[]
        {
            Row("LeftReactorSide.AIR_SVC", "AIR_SVC", 1, "Left_002.AIR_SVC"),
            Row("LeftReactorSide.LeakTest.DeltaVac", "DeltaVac", 1, "Left_002.LeakTest.DeltaVac"),
        };
        var g = Assert.Single(BindingGroupBuilder.Build(rows));
        Assert.Equal("LeftReactorSide", g.Key);
        Assert.Equal(new[] { "AIR_SVC", "LeakTest.DeltaVac" }, g.Members.Select(m => m.MemberTail));
        Assert.Equal(new[] { "LeakTest" }, g.NestedModules);
        Assert.Equal("Left_002", g.InferredObject);
    }

    [Fact]
    public void InferredObject_NestedObjectPath()
    {
        var rows = new[]
        {
            Row("LeftDelmiaReceiver.ReadyFlag", "ReadyFlag", 1, "Left_002.DelmiaReceiver.ReadyFlag"),
            Row("LeftDelmiaReceiver.PartNumber", "PartNumber", 1, "Left_002.DelmiaReceiver.PartNumber"),
        };
        Assert.Equal("Left_002.DelmiaReceiver", Assert.Single(BindingGroupBuilder.Build(rows)).InferredObject);
    }

    [Fact]
    public void InferredObject_NullWhenMixed_AndStateMixed()
    {
        var rows = new[]
        {
            Row("M.A", "A", 1, "Obj1.A"),
            Row("M.B", "B", 1, "Obj2.B"),
        };
        var g = Assert.Single(BindingGroupBuilder.Build(rows));
        Assert.Null(g.InferredObject);
        Assert.True(g.IsObjectMixed);
    }

    [Fact]
    public void InferredObject_NullWhenNoOverrides_NotMixed()
    {
        var rows = new[] { Row("M.A", "A", 1, null), Row("M.B", "B", 1, null) };
        var g = Assert.Single(BindingGroupBuilder.Build(rows));
        Assert.Null(g.InferredObject);
        Assert.False(g.IsObjectMixed);
    }

    [Fact]
    public void InstanceGroup_InfersObjectFromOverrides()
    {
        var rows = new[] { Row("ChlorineFlow", "ChlorineFlow", 1, "Z28061.ChlorineFlow"), Row("MachineID", "MachineID", 1, "Z28061.MachineID") };
        var g = Assert.Single(BindingGroupBuilder.Build(rows));
        Assert.Equal(BindingGroupBuilder.InstanceGroupKey, g.Key);
        Assert.Equal("Z28061", g.InferredObject);
    }

    [Fact]
    public void Counts_UnboundAndConnectionState()
    {
        var rows = new[]
        {
            Row("M.A", "A", 1, "O.A"),
            Row("M.B", "B", null, null),
            Row("M.C", "C", 2, "O.C"),
        };
        var g = Assert.Single(BindingGroupBuilder.Build(rows));
        Assert.Equal(3, g.Members.Count);
        Assert.Equal(1, g.UnboundCount);
        Assert.Equal(BindingConnectionState.Mixed, g.ConnectionState);
        Assert.Null(g.CommonConnectionId);
    }

    [Fact]
    public void ConnectionState_SingleWhenAllAgree()
    {
        var rows = new[] { Row("M.A", "A", 1, null), Row("M.B", "B", 1, null) };
        var g = Assert.Single(BindingGroupBuilder.Build(rows));
        Assert.Equal(BindingConnectionState.Single, g.ConnectionState);
        Assert.Equal(1, g.CommonConnectionId);
    }

    [Fact]
    public void MemberTail_OverrideThatDoesNotEndWithTail_CountsAsMixed()
    {
        // An operator typed a reference that does not end in the member tail —
        // the prefix cannot be inferred for that row, so the group is mixed.
        var rows = new[] { Row("M.A", "A", 1, "Obj.A"), Row("M.B", "B", 1, "Obj.Other") };
        Assert.True(Assert.Single(BindingGroupBuilder.Build(rows)).IsObjectMixed);
    }

    [Fact]
    public void ApplyObject_RewritesEveryMember_AndSetsConnection()
    {
        var g = Assert.Single(BindingGroupBuilder.Build(new[]
        {
            Row("RightMESReceiver.MoveInFlag", "MoveInFlag", 1, "MESReceiver_024.MoveInFlag"),
            Row("RightMESReceiver.ScanStateCmd", "ScanStateCmd", null, null),
        }));
        var changes = BindingGroupBuilder.ApplyObject(g, connectionId: 1, objectPath: " MESReceiver_022. ");
        Assert.Equal(2, changes.Count);
        Assert.Equal(("RightMESReceiver.MoveInFlag", 1, "MESReceiver_022.MoveInFlag"), (changes[0].CanonicalName, changes[0].ConnectionId, changes[0].Override));
        Assert.Equal(("RightMESReceiver.ScanStateCmd", 1, "MESReceiver_022.ScanStateCmd"), (changes[1].CanonicalName, changes[1].ConnectionId, changes[1].Override));
    }

    [Fact]
    public void ApplyObject_NestedTail_KeepsNesting()
    {
        var g = Assert.Single(BindingGroupBuilder.Build(new[] { Row("LeftReactorSide.LeakTest.DeltaVac", "DeltaVac", 1, null) }));
        var c = Assert.Single(BindingGroupBuilder.ApplyObject(g, 1, "Left_002"));
        Assert.Equal("Left_002.LeakTest.DeltaVac", c.Override);
    }

    [Fact]
    public void ApplyObject_EmptyObject_ClearsOverrides_KeepsConnection()
    {
        var g = Assert.Single(BindingGroupBuilder.Build(new[] { Row("M.A", "A", 1, "Obj.A") }));
        var c = Assert.Single(BindingGroupBuilder.ApplyObject(g, 2, ""));
        Assert.Null(c.Override);
        Assert.Equal(2, c.ConnectionId);
    }

    // ── Review fixes 2026-08-20 ──

    [Fact]
    public void ApplyObject_NullConnection_KeepsEachMembersCurrentConnection()
    {
        // A header reading "— mixed —"/"— none —" (0) must not unbind the group:
        // Save is an upsert, so a removal could never persist anyway.
        var g = Assert.Single(BindingGroupBuilder.Build(new[]
        {
            Row("M.A", "A", 1, "Old.A"),
            Row("M.B", "B", 2, "Old.B"),
            Row("M.C", "C", null, null),
        }));
        var changes = BindingGroupBuilder.ApplyObject(g, connectionId: null, objectPath: "New");
        Assert.Equal(new int?[] { 1, 2, null }, changes.Select(c => c.ConnectionId));
        Assert.All(changes, c => Assert.StartsWith("New.", c.Override!));
    }

    [Fact]
    public void InferredObject_MixedWhenSomeMembersStillOnBareDefault()
    {
        // M.B has no override and its default ("B") is not "<prefix>.B" — the gate
        // will reject it, so the group must read mixed rather than unified on "O".
        var rows = new[] { Row("M.A", "A", 1, "O.A"), Row("M.B", "B", 1, null) };
        var g = Assert.Single(BindingGroupBuilder.Build(rows));
        Assert.Null(g.InferredObject);
        Assert.True(g.IsObjectMixed);
    }

    [Fact]
    public void InferredObject_UsesEffectiveReference_DefaultThatCarriesPrefixIsNotMixed()
    {
        var rows = new[] { Row("M.A", "A", 1, "O.A"), Row("M.B", "B", 1, null) with { DefaultReference = "O.B" } };
        var g = Assert.Single(BindingGroupBuilder.Build(rows));
        Assert.Equal("O", g.InferredObject);
        Assert.False(g.IsObjectMixed);
    }

    [Fact]
    public void InferredObject_NoOverrides_InfersFromDefaultsWhenTheyShareAPrefix()
    {
        var rows = new[] { Row("A", "Z28061.A", 1, null), Row("B", "Z28061.B", 1, null) };
        var g = Assert.Single(BindingGroupBuilder.Build(rows));
        Assert.Equal("Z28061", g.InferredObject);
        Assert.False(g.IsObjectMixed);
    }

    [Fact]
    public void IsUnbound_WhenConnectionIdIsNotAKnownConnection()
    {
        var rows = new[] { Row("M.A", "A", 99, "O.A") };
        var g = Assert.Single(BindingGroupBuilder.Build(rows, knownConnectionIds: new[] { 1, 2 }));
        Assert.Equal(1, g.UnboundCount);
        Assert.Equal(BindingConnectionState.None, g.ConnectionState);
    }
}