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;

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

/// <summary>
///     Unit tests for the Phase 6.4 Stream B.5 five-identifier ranked search.
///     Decision #117 identifiers: ZTag / MachineCode / SAPID / EquipmentId / EquipmentUuid.
///     Scoring: exact match = 100, prefix = 50, fuzzy (opt-in) = 20.
///     Tie-break: published generation outranks draft.
/// </summary>
[Trait("Category", "Unit")]
public sealed class EquipmentSearchTests : IDisposable
{
    private readonly OtOpcUaConfigDbContext _db;
    private readonly EquipmentService _svc;

    private const string ClusterId = "cluster-1";
    private const long DraftGenId = 1L;
    private const long PublishedGenId = 2L;

    public EquipmentSearchTests()
    {
        var opts = new DbContextOptionsBuilder<OtOpcUaConfigDbContext>()
            .UseInMemoryDatabase($"eq-search-{Guid.NewGuid():N}")
            .Options;
        _db = new OtOpcUaConfigDbContext(opts);

        // Seed two generations — draft + published — for the same cluster.
        _db.ConfigGenerations.AddRange(
            new ConfigGeneration
            {
                GenerationId = DraftGenId,
                ClusterId = ClusterId,
                Status = GenerationStatus.Draft,
                CreatedBy = "test",
            },
            new ConfigGeneration
            {
                GenerationId = PublishedGenId,
                ClusterId = ClusterId,
                Status = GenerationStatus.Published,
                CreatedBy = "test",
                PublishedAt = DateTime.UtcNow,
                PublishedBy = "test",
            });
        _db.SaveChanges();

        _svc = new EquipmentService(_db);
    }

    public void Dispose() => _db.Dispose();

    // ── Helpers ──────────────────────────────────────────────────────────

    private Equipment AddEquipment(
        long generationId,
        string name,
        string ztag,
        string machineCode = "MC",
        string sapid = "",
        Guid? uuid = null,
        string equipmentId = "")
    {
        var uu = uuid ?? Guid.NewGuid();
        var eq = new Equipment
        {
            EquipmentRowId = Guid.NewGuid(),
            GenerationId = generationId,
            EquipmentId = string.IsNullOrEmpty(equipmentId) ? $"EQ-{uu:N}"[..14] : equipmentId,
            EquipmentUuid = uu,
            DriverInstanceId = "drv",
            UnsLineId = "line-1",
            Name = name,
            MachineCode = machineCode,
            ZTag = ztag,
            SAPID = string.IsNullOrEmpty(sapid) ? null : sapid,
        };
        _db.Equipment.Add(eq);
        _db.SaveChanges();
        return eq;
    }

    // ── Exact-match tests (score 100) ────────────────────────────────────

    [Fact]
    public async Task ExactMatch_ZTag_Returns_Score100()
    {
        AddEquipment(DraftGenId, "Oven-A", ztag: "z-001");

        var hits = await _svc.SearchAsync("z-001", ClusterId, TestContext.Current.CancellationToken);

        hits.Count.ShouldBe(1);
        hits[0].Score.ShouldBe(100);
        hits[0].MatchedField.ShouldBe("ZTag");
        hits[0].Equipment.Name.ShouldBe("Oven-A");
    }

    [Fact]
    public async Task ExactMatch_IsCaseInsensitive()
    {
        AddEquipment(DraftGenId, "Welder-1", ztag: "Z-ABC");

        var hits = await _svc.SearchAsync("z-abc", ClusterId, TestContext.Current.CancellationToken);

        hits.Count.ShouldBe(1);
        hits[0].Score.ShouldBe(100);
    }

    [Fact]
    public async Task ExactMatch_MachineCode_Returns_Score100()
    {
        AddEquipment(DraftGenId, "Wrapper", ztag: "z-2", machineCode: "MC-42");

        var hits = await _svc.SearchAsync("MC-42", ClusterId, TestContext.Current.CancellationToken);

        hits.Count.ShouldBe(1);
        hits[0].Score.ShouldBe(100);
        hits[0].MatchedField.ShouldBe("MachineCode");
    }

    [Fact]
    public async Task ExactMatch_SAPID_Returns_Score100()
    {
        AddEquipment(DraftGenId, "Conveyor", ztag: "z-3", sapid: "SAP-999");

        var hits = await _svc.SearchAsync("SAP-999", ClusterId, TestContext.Current.CancellationToken);

        hits.Count.ShouldBe(1);
        hits[0].Score.ShouldBe(100);
        hits[0].MatchedField.ShouldBe("SAPID");
    }

    [Fact]
    public async Task ExactMatch_EquipmentUuid_Returns_Score100()
    {
        var uu = Guid.NewGuid();
        AddEquipment(DraftGenId, "Robot-A", ztag: "z-4", uuid: uu);

        var hits = await _svc.SearchAsync(uu.ToString(), ClusterId, TestContext.Current.CancellationToken);

        hits.Count.ShouldBe(1);
        hits[0].Score.ShouldBe(100);
        hits[0].MatchedField.ShouldBe("EquipmentUuid");
    }

    // ── Prefix-match tests (score 50) ────────────────────────────────────

    [Fact]
    public async Task PrefixMatch_ZTag_Returns_Score50()
    {
        AddEquipment(DraftGenId, "Press-1", ztag: "z-alpha-001");

        var hits = await _svc.SearchAsync("z-alpha", ClusterId, TestContext.Current.CancellationToken);

        hits.Count.ShouldBe(1);
        hits[0].Score.ShouldBe(50);
        hits[0].MatchedField.ShouldBe("ZTag");
    }

    [Fact]
    public async Task ExactOutranks_Prefix_InResults()
    {
        // exact: z-001 == "z-001" → score 100
        // prefix: z-001x startsWith "z-001" → score 50
        AddEquipment(DraftGenId, "Exact-Hit", ztag: "z-001");
        AddEquipment(DraftGenId, "Prefix-Hit", ztag: "z-001x");

        var hits = await _svc.SearchAsync("z-001", ClusterId, TestContext.Current.CancellationToken);

        hits.Count.ShouldBe(2);
        hits[0].Score.ShouldBe(100);
        hits[0].Equipment.Name.ShouldBe("Exact-Hit");
        hits[1].Score.ShouldBe(50);
        hits[1].Equipment.Name.ShouldBe("Prefix-Hit");
    }

    // ── Fuzzy-match tests (score 20, opt-in) ─────────────────────────────

    [Fact]
    public async Task FuzzyMatch_Disabled_DoesNotReturn_SubstringOnly_Hit()
    {
        AddEquipment(DraftGenId, "SubstrEq", ztag: "prefix-INFIX-suffix");

        var hits = await _svc.SearchAsync("INFIX", ClusterId, TestContext.Current.CancellationToken, allowFuzzy: false);

        hits.ShouldBeEmpty();
    }

    [Fact]
    public async Task FuzzyMatch_Enabled_Returns_Score20()
    {
        AddEquipment(DraftGenId, "SubstrEq", ztag: "prefix-infix-suffix");

        var hits = await _svc.SearchAsync("infix", ClusterId, TestContext.Current.CancellationToken, allowFuzzy: true);

        hits.Count.ShouldBe(1);
        hits[0].Score.ShouldBe(20);
        hits[0].MatchedField.ShouldBe("ZTag");
    }

    // ── Tie-break: published outranks draft ───────────────────────────────

    [Fact]
    public async Task PublishedGeneration_Outranks_Draft_ForEqualScore()
    {
        // Same ZTag prefix "mc-" in both draft + published generation.
        AddEquipment(DraftGenId,     "Draft-Eq",     ztag: "mc-001");
        AddEquipment(PublishedGenId, "Published-Eq", ztag: "mc-002");

        // Both hit prefix match on "mc-" (score 50).
        var hits = await _svc.SearchAsync("mc-", ClusterId, TestContext.Current.CancellationToken);

        hits.Count.ShouldBe(2);
        // Published generation should come first.
        hits[0].IsPublished.ShouldBeTrue();
        hits[1].IsPublished.ShouldBeFalse();
    }

    // ── Empty / no-match ─────────────────────────────────────────────────

    [Fact]
    public async Task EmptyQuery_Returns_EmptyList()
    {
        AddEquipment(DraftGenId, "Irrelevant", ztag: "z-999");

        var hits = await _svc.SearchAsync("   ", ClusterId, TestContext.Current.CancellationToken);

        hits.ShouldBeEmpty();
    }

    [Fact]
    public async Task NoMatch_Returns_EmptyList()
    {
        AddEquipment(DraftGenId, "Irrelevant", ztag: "z-999");

        var hits = await _svc.SearchAsync("xyzzy-unknown", ClusterId, TestContext.Current.CancellationToken);

        hits.ShouldBeEmpty();
    }

    // ── Cross-cluster isolation ───────────────────────────────────────────

    [Fact]
    public async Task Equipment_In_DifferentCluster_NotReturned()
    {
        // Seed a generation in a different cluster.
        _db.ConfigGenerations.Add(new ConfigGeneration
        {
            GenerationId = 99L,
            ClusterId = "cluster-other",
            Status = GenerationStatus.Draft,
            CreatedBy = "test",
        });
        _db.SaveChanges();
        AddEquipment(99L, "OtherEq", ztag: "z-001");

        var hits = await _svc.SearchAsync("z-001", ClusterId, TestContext.Current.CancellationToken);

        hits.ShouldBeEmpty("equipment from another cluster must be invisible");
    }

    // ── MaxResults cap ────────────────────────────────────────────────────

    [Fact]
    public async Task MaxResults_Limits_Output()
    {
        for (var i = 0; i < 10; i++)
            AddEquipment(DraftGenId, $"Eq-{i}", ztag: $"zprefix-{i:D3}");

        var hits = await _svc.SearchAsync("zprefix-", ClusterId, TestContext.Current.CancellationToken, maxResults: 3);

        hits.Count.ShouldBe(3);
    }
}