using Microsoft.EntityFrameworkCore;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.AdminUI.Uns;
using ZB.MOM.WW.OtOpcUa.Configuration.Entities;
using ZB.MOM.WW.OtOpcUa.Configuration.Enums;

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

/// <summary>
/// Verifies the save-time equipment-relative-path guard on <see cref="UnsTreeService"/>: when a
/// VirtualTag binds a script that uses the reserved <c>{{equip}}</c> token, the owning equipment
/// must have a derivable tag base (≥1 driver tag, all sharing one object prefix). Otherwise the
/// create/update is rejected with an error naming the equipment and the unresolvable token.
/// </summary>
/// <remarks>
/// Reuses the shared <see cref="UnsTreeTestDb"/> InMemory fixture pattern: a uniquely-named
/// InMemory database seeded with an area→line→equipment path plus a script, with driver tags
/// added per-test so the base-derivation outcome is what each case isolates.
/// </remarks>
[Trait("Category", "Unit")]
public sealed class VirtualTagEquipTokenValidationTests
{
    private const string EquipBaseScript = "return ctx.GetTag(\"{{equip}}.X\");";
    private const string PlainScript = "return ctx.GetTag(\"TestMachine_001.X\");";

    private static (UnsTreeService Service, string DbName) Fresh()
    {
        var dbName = $"uns-equiptoken-{Guid.NewGuid():N}";
        return (new UnsTreeService(UnsTreeTestDb.Factory(dbName)), dbName);
    }

    /// <summary>
    /// Seeds an area→line→equipment path (equipment id <c>EQ-1</c>) plus one script whose source is
    /// <paramref name="scriptSource"/>, and optionally a driver tag whose <c>TagConfig</c> carries the
    /// supplied <c>FullName</c> so the equipment has a derivable base.
    /// </summary>
    private static void Seed(string dbName, string scriptSource, string? tagFullName)
    {
        using var db = UnsTreeTestDb.CreateNamed(dbName);
        db.UnsAreas.Add(new UnsArea { UnsAreaId = "AREA-1", ClusterId = "MAIN", Name = "a" });
        db.UnsLines.Add(new UnsLine { UnsLineId = "LINE-1", UnsAreaId = "AREA-1", Name = "l" });
        db.Equipment.Add(new Equipment
        {
            EquipmentId = "EQ-1",
            EquipmentUuid = Guid.NewGuid(),
            UnsLineId = "LINE-1",
            Name = "TestMachine_001",
            MachineCode = "machine_001",
        });
        db.Scripts.Add(new Script
        {
            ScriptId = "SCRIPT-1",
            Name = "compute",
            SourceCode = scriptSource,
            SourceHash = "hash-1",
            Language = "CSharp",
        });
        if (tagFullName is not null)
        {
            db.Tags.Add(new Tag
            {
                TagId = "TAG-1",
                DriverInstanceId = "DRV-1",
                EquipmentId = "EQ-1",
                Name = "x",
                DataType = "Float",
                AccessLevel = TagAccessLevel.Read,
                TagConfig = $"{{\"FullName\":\"{tagFullName}\"}}",
            });
        }
        db.SaveChanges();
    }

    private static VirtualTagInput Input(string virtualTagId = "VTAG-1", string name = "computed") =>
        new(virtualTagId, name, DataType: "Double", ScriptId: "SCRIPT-1",
            ChangeTriggered: true, TimerIntervalMs: null, Historize: false, Enabled: true);

    /// <summary>Seeds an existing VirtualTag and returns its RowVersion (for update-path tests).</summary>
    private static byte[] SeedVirtualTagAndRowVersion(string dbName)
    {
        using var db = UnsTreeTestDb.CreateNamed(dbName);
        db.VirtualTags.Add(new VirtualTag
        {
            VirtualTagId = "VTAG-1",
            EquipmentId = "EQ-1",
            Name = "computed",
            DataType = "Double",
            ScriptId = "SCRIPT-1",
        });
        db.SaveChanges();
        return db.VirtualTags.Single(v => v.VirtualTagId == "VTAG-1").RowVersion;
    }

    // ----- Create -----

    /// <summary>{{equip}} script + a driver tag whose FullName gives a base → create succeeds.</summary>
    [Fact]
    public async Task Create_equip_token_with_derivable_base_succeeds()
    {
        var (service, dbName) = Fresh();
        Seed(dbName, EquipBaseScript, tagFullName: "TestMachine_001.X");

        var result = await service.CreateVirtualTagAsync("EQ-1", Input());

        result.Ok.ShouldBeTrue();
        result.Error.ShouldBeNull();
    }

    /// <summary>{{equip}} script + no driver tags → create rejected, error names equipment + token.</summary>
    [Fact]
    public async Task Create_equip_token_without_base_rejected()
    {
        var (service, dbName) = Fresh();
        Seed(dbName, EquipBaseScript, tagFullName: null);

        var result = await service.CreateVirtualTagAsync("EQ-1", Input());

        result.Ok.ShouldBeFalse();
        result.Error.ShouldNotBeNull();
        result.Error.ShouldContain("EQ-1");
        result.Error.ShouldContain("{{equip}}");

        using var db = UnsTreeTestDb.CreateNamed(dbName);
        db.VirtualTags.Any(v => v.VirtualTagId == "VTAG-1").ShouldBeFalse();
    }

    /// <summary>A script with no {{equip}} token → create succeeds regardless of tags.</summary>
    [Fact]
    public async Task Create_no_equip_token_succeeds_without_tags()
    {
        var (service, dbName) = Fresh();
        Seed(dbName, PlainScript, tagFullName: null);

        var result = await service.CreateVirtualTagAsync("EQ-1", Input());

        result.Ok.ShouldBeTrue();
        result.Error.ShouldBeNull();
    }

    /// <summary>
    /// {{equip}} script + TWO driver tags whose FullNames have DIFFERENT object prefixes
    /// (no single base can be derived) → create rejected, error names equipment + token.
    /// </summary>
    [Fact]
    public async Task Create_equip_token_with_divergent_prefixes_rejected()
    {
        var (service, dbName) = Fresh();
        Seed(dbName, EquipBaseScript, tagFullName: "TestMachine_001.X");
        using (var db = UnsTreeTestDb.CreateNamed(dbName))
        {
            db.Tags.Add(new Tag
            {
                TagId = "TAG-2",
                DriverInstanceId = "DRV-1",
                EquipmentId = "EQ-1",
                Name = "y",
                DataType = "Float",
                AccessLevel = TagAccessLevel.Read,
                TagConfig = "{\"FullName\":\"DelmiaReceiver_001.Y\"}",
            });
            db.SaveChanges();
        }

        var result = await service.CreateVirtualTagAsync("EQ-1", Input());

        result.Ok.ShouldBeFalse();
        result.Error.ShouldNotBeNull();
        result.Error.ShouldContain("EQ-1");
        result.Error.ShouldContain("{{equip}}");

        using var verifyDb = UnsTreeTestDb.CreateNamed(dbName);
        verifyDb.VirtualTags.Any(v => v.VirtualTagId == "VTAG-1").ShouldBeFalse();
    }

    // ----- Update -----

    /// <summary>{{equip}} script + a derivable base → update succeeds.</summary>
    [Fact]
    public async Task Update_equip_token_with_derivable_base_succeeds()
    {
        var (service, dbName) = Fresh();
        Seed(dbName, EquipBaseScript, tagFullName: "TestMachine_001.X");
        var rv = SeedVirtualTagAndRowVersion(dbName);

        var result = await service.UpdateVirtualTagAsync("VTAG-1", Input(name: "renamed"), rv);

        result.Ok.ShouldBeTrue();
        result.Error.ShouldBeNull();
    }

    /// <summary>{{equip}} script + no driver tags → update rejected, error names equipment + token.</summary>
    [Fact]
    public async Task Update_equip_token_without_base_rejected()
    {
        var (service, dbName) = Fresh();
        Seed(dbName, EquipBaseScript, tagFullName: null);
        var rv = SeedVirtualTagAndRowVersion(dbName);

        var result = await service.UpdateVirtualTagAsync("VTAG-1", Input(name: "renamed"), rv);

        result.Ok.ShouldBeFalse();
        result.Error.ShouldNotBeNull();
        result.Error.ShouldContain("EQ-1");
        result.Error.ShouldContain("{{equip}}");

        using var db = UnsTreeTestDb.CreateNamed(dbName);
        db.VirtualTags.Single(v => v.VirtualTagId == "VTAG-1").Name.ShouldBe("computed");
    }

    /// <summary>A script with no {{equip}} token → update succeeds regardless of tags.</summary>
    [Fact]
    public async Task Update_no_equip_token_succeeds_without_tags()
    {
        var (service, dbName) = Fresh();
        Seed(dbName, PlainScript, tagFullName: null);
        var rv = SeedVirtualTagAndRowVersion(dbName);

        var result = await service.UpdateVirtualTagAsync("VTAG-1", Input(name: "renamed"), rv);

        result.Ok.ShouldBeTrue();
        result.Error.ShouldBeNull();
    }
}
