using System.Globalization;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
using ZB.MOM.WW.OtOpcUa.Driver.Sql.Contracts;

namespace ZB.MOM.WW.OtOpcUa.Driver.Sql.Tests;

/// <summary>
///     The authored <c>write</c> block (lmxopcua#781 item 2): Update (default) / Insert / Upsert / Procedure, the
///     timestamp stamp, the parser's refusals, every dialect's statement, the routine catalog gate, constraint-failure
///     status mapping, and — over SQLite — the end-to-end Insert / Upsert / stamp paths.
/// </summary>
public sealed class SqlWriteModeTests
{
    private static readonly DateTime Now = new(2026, 11, 9, 12, 0, 0, DateTimeKind.Utc);

    private const string KvBase =
        "\"model\":\"KeyValue\",\"table\":\"plant.sp\",\"keyColumn\":\"tag\",\"keyValue\":\"L1\",\"valueColumn\":\"val\"";

    private static string Kv(string write, string extra = "") =>
        "{" + KvBase + extra + ",\"writable\":true,\"write\":" + write + "}";

    private static SqlTagDefinition Parse(string json)
    {
        SqlEquipmentTagParser.TryParse(json, "T", out var def).ShouldBeTrue();
        return def;
    }

    // ---- parse ----

    [Fact]
    public void NoWriteBlock_isTheDefaultUpdate()
    {
        var def = Parse("{" + KvBase + ",\"writable\":true}");
        def.Write.ShouldBeNull();
        def.EffectiveWrite.ShouldBe(SqlWriteSpec.Default);
    }

    [Theory]
    [InlineData("Update", SqlWriteMode.Update)]
    [InlineData("insert", SqlWriteMode.Insert)]
    [InlineData("UPSERT", SqlWriteMode.Upsert)]
    public void Mode_parses_caseInsensitively(string mode, SqlWriteMode expected)
        => Parse(Kv($$"""{"mode":"{{mode}}"}""")).Write!.Mode.ShouldBe(expected);

    [Fact]
    public void ModeAbsent_inABlock_isUpdate_andStampIsRead()
    {
        var w = Parse(Kv("""{"stampTimestamp":true}""", ",\"timestampColumn\":\"ts\"")).Write!;
        w.Mode.ShouldBe(SqlWriteMode.Update);
        w.StampTimestamp.ShouldBeTrue();
    }

    [Fact]
    public void Procedure_parsesNames_stripsAMarkerPrefix_andDefaultsTheValueParam()
    {
        var w = Parse(Kv("""{"mode":"Procedure","procedure":"dbo.SetSp","keyParam":"@TagName","timestampParam":":ts"}""")).Write!;
        w.ShouldBe(new SqlWriteSpec(SqlWriteMode.Procedure, false, "dbo.SetSp", "value", "TagName", "ts"));
    }

    [Fact]
    public void Procedure_isTheOneModeAQueryTagMayWrite()
    {
        const string query = """{"model":"Query","query":"q","column":"c","rowKey":{"column":"line","value":"L1"},"writable":true,"write":""";
        Parse(query + """{"mode":"Procedure","procedure":"p","keyParam":"line"}}""").Write!.KeyParameter.ShouldBe("line");
        SqlEquipmentTagParser.TryParse(query + """{"mode":"Update"}}""", "T", out _).ShouldBeFalse();
        SqlEquipmentTagParser.TryParse(query + """{"mode":"Insert"}}""", "T", out _).ShouldBeFalse();
    }

    [Theory]
    [InlineData("[]", "must be a JSON object")]
    [InlineData("""{"mode":"Merge"}""", "'write.mode' must be one of")]
    [InlineData("""{"mode":1}""", "'write.mode' must be one of")]
    [InlineData("""{"mode":"Update","stampTimestmp":true}""", "unknown key 'stampTimestmp'")]
    [InlineData("""{"stampTimestamp":"yes"}""", "must be a JSON boolean")]
    [InlineData("""{"stampTimestamp":true}""", "no timestamp column")]
    [InlineData("""{"mode":"Update","procedure":"p"}""", "applies only to mode Procedure")]
    [InlineData("""{"mode":"Procedure"}""", "needs 'write.procedure'")]
    [InlineData("""{"mode":"Procedure","procedure":"  "}""", "needs 'write.procedure'")]
    [InlineData("""{"mode":"Procedure","procedure":"db.dbo.p"}""", "'schema.procedure' only")]
    [InlineData("""{"mode":"Procedure","procedure":"p","valueParam":"v; DROP"}""", "plain parameter name")]
    [InlineData("""{"mode":"Procedure","procedure":"p","keyParam":"1abc"}""", "plain parameter name")]
    [InlineData("""{"mode":"Procedure","procedure":"p","keyParam":5}""", "must be a string")]
    [InlineData("""{"mode":"Procedure","procedure":"p","keyParam":"Value"}""", "same procedure parameter")]
    [InlineData("""{"mode":"Procedure","procedure":"p","stampTimestamp":true}""", "does not apply to mode Procedure")]
    public void MalformedBlocks_refuseTheTag_andInspectGivesTheParsersReason(string write, string reason)
    {
        var json = Kv(write);
        SqlEquipmentTagParser.TryParse(json, "T", out _).ShouldBeFalse();
        SqlEquipmentTagParser.TryParseDetailed(json, "T", out _, out var writeError).ShouldBeFalse();
        writeError.ShouldNotBeNull().ShouldContain(reason);
        SqlTagDefinitionFactory.DescribeWriteBlock(json).ShouldNotBeNull().ShouldContain(reason);
        SqlTagDefinitionFactory.Inspect(json).ShouldHaveSingleItem().ShouldContain(reason);
    }

    [Fact]
    public void UpdateAndUpsert_needARowKey_butInsertAppendsToANewestRowTag()
    {
        static string Newest(string mode) =>
            $$$"""{"model":"WideRow","table":"t","columnName":"c","rowSelector":{"topByTimestamp":"ts"},"writable":true,"write":{"mode":"{{{mode}}}","stampTimestamp":true}}""";
        SqlTagDefinitionFactory.DescribeWriteBlock(Newest("Update")).ShouldNotBeNull().ShouldContain("needs a row key");
        SqlTagDefinitionFactory.DescribeWriteBlock(Newest("Upsert")).ShouldNotBeNull().ShouldContain("needs a row key");
        SqlTagDefinitionFactory.DescribeWriteBlock(Newest("Insert")).ShouldBeNull();   // positive control
    }

    [Fact]
    public void KeyParam_onAModelWithNoKey_isRefused()
        => SqlTagDefinitionFactory.DescribeWriteBlock(
                """{"model":"Query","query":"q","column":"c","write":{"mode":"Procedure","procedure":"p","keyParam":"k"}}""")
            .ShouldNotBeNull().ShouldContain("no key to bind");

    [Fact]
    public void DescribeWriteBlock_isQuiet_forAValidBlock_noBlock_orABlobBrokenElsewhere()
    {
        SqlTagDefinitionFactory.DescribeWriteBlock(Kv("""{"mode":"Upsert"}""")).ShouldBeNull();
        SqlTagDefinitionFactory.DescribeWriteBlock("{" + KvBase + "}").ShouldBeNull();
        // The tag's own fields are what fail (no table) — Inspect reports that, not the write block.
        SqlTagDefinitionFactory.DescribeWriteBlock("""{"model":"KeyValue","write":{"mode":"Nope"}}""").ShouldBeNull();
    }

    // ---- shared support table ----

    [Theory]
    [InlineData(SqlProvider.Odbc, SqlWriteMode.Update, true)]
    [InlineData(SqlProvider.Odbc, SqlWriteMode.Insert, true)]
    [InlineData(SqlProvider.Odbc, SqlWriteMode.Upsert, false)]
    [InlineData(SqlProvider.Odbc, SqlWriteMode.Procedure, false)]
    [InlineData(SqlProvider.SqlServer, SqlWriteMode.Upsert, true)]
    [InlineData(SqlProvider.Oracle, SqlWriteMode.Procedure, true)]
    public void SupportTable(SqlProvider provider, SqlWriteMode mode, bool supported)
        => SqlWriteSupport.IsSupported(provider, mode).ShouldBe(supported);

    /// <summary>
    ///     The shared table (deploy's verdict) and each real dialect's statements (runtime's) must agree: a mode the
    ///     table says is served has a statement, and one it refuses has none — so deploy can never accept a mode the
    ///     driver then refuses, or refuse one it would serve.
    /// </summary>
    [Fact]
    public void EveryRealDialect_buildsAStatement_exactlyForTheModesTheSharedTableServes()
    {
        foreach (var provider in Enum.GetValues<SqlProvider>())
        {
            var dialect = SqlDialects.TryCreate(provider).ShouldNotBeNull();
            dialect.SupportsWriteMode(SqlWriteMode.Upsert).ShouldBe(SqlWriteSupport.IsSupported(provider, SqlWriteMode.Upsert));
            (dialect.UpsertSql("t", "k", "m", [("v", "n")]) is not null)
                .ShouldBe(SqlWriteSupport.IsSupported(provider, SqlWriteMode.Upsert), provider.ToString());
            (dialect.ProcedureCallSql("p", [("value", "m")]) is not null && dialect.ListRoutinesSql is not null)
                .ShouldBe(SqlWriteSupport.IsSupported(provider, SqlWriteMode.Procedure), provider.ToString());
        }
    }

    // ---- planner: per mode, per dialect ----

    private static SqlTagDefinition KvTag(SqlWriteSpec? write, string? ts = null) =>
        new("A", SqlTagModel.KeyValue, "plant.sp", KeyColumn: "tag", KeyValue: "L1", ValueColumn: "val",
            TimestampColumn: ts, Writable: true, Write: write);

    private static SqlWritePlan Plan(SqlTagDefinition tag, ISqlDialect dialect, object? value = null)
    {
        SqlWritePlanner.TryPlan(tag, value ?? 5.5, dialect, Now, out var plan).ShouldBe(SqlStatusCodes.Good);
        return plan!;
    }

    [Fact]
    public void Update_withStamp_setsValueThenStamp_thenTheKey_inMarkerOrder()
    {
        var plan = Plan(KvTag(new SqlWriteSpec(SqlWriteMode.Update, StampTimestamp: true), ts: "ts"), new OdbcDialect());

        plan.SqlText.ShouldBe("UPDATE \"plant\".\"sp\" SET \"val\" = ?, \"ts\" = ? WHERE \"tag\" = ?");
        plan.Parameters.ShouldBe([5.5, Now, "L1"]);
        plan.Mode.ShouldBe(SqlWriteMode.Update);
    }

    [Fact]
    public void Update_withoutStamp_isByteIdenticalToTheOriginalStatement()
        => Plan(KvTag(null, ts: "ts"), new SqlServerDialect()).SqlText
            .ShouldBe("UPDATE [plant].[sp] SET [val] = @v WHERE [tag] = @k");

    [Fact]
    public void Insert_keyValue_insertsKeyValueAndStamp_inColumnOrder()
    {
        var plan = Plan(KvTag(new SqlWriteSpec(SqlWriteMode.Insert, StampTimestamp: true), ts: "ts"), new OdbcDialect());

        plan.SqlText.ShouldBe("INSERT INTO \"plant\".\"sp\" (\"tag\", \"val\", \"ts\") VALUES (?, ?, ?)");
        plan.Parameters.ShouldBe(["L1", 5.5, Now]);
    }

    [Fact]
    public void Insert_onANewestRowTag_appendsTheValueAndItsOrderingColumn_withNoKey()
    {
        var tag = new SqlTagDefinition("A", SqlTagModel.WideRow, "hist", ColumnName: "temp",
            RowSelectorTopByTimestamp: "sample_ts", Writable: true, Write: new SqlWriteSpec(SqlWriteMode.Insert, true));

        var plan = Plan(tag, new SqlServerDialect());

        plan.SqlText.ShouldBe("INSERT INTO [hist] ([temp], [sample_ts]) VALUES (@v, @t)");
        plan.ParameterBindNames.ShouldBe(["@v", "@t"]);
    }

    [Fact]
    public void Upsert_sqlServer_isAHoldlockMerge()
    {
        var plan = Plan(KvTag(new SqlWriteSpec(SqlWriteMode.Upsert, true), ts: "ts"), new SqlServerDialect());

        plan.SqlText.ShouldBe(
            "MERGE INTO [plant].[sp] WITH (HOLDLOCK) AS tgt USING (SELECT 1 AS one) AS src ON tgt.[tag] = @k " +
            "WHEN MATCHED THEN UPDATE SET [val] = @v, [ts] = @t " +
            "WHEN NOT MATCHED THEN INSERT ([tag], [val], [ts]) VALUES (@k, @v, @t);");
        plan.ParameterBindNames.ShouldBe(["@k", "@v", "@t"]);
        plan.Parameters.ShouldBe(["L1", 5.5, Now]);
        plan.MaxRowsAffected.ShouldBe(1);
    }

    [Fact]
    public void Upsert_postgres_isInsertOnConflict()
        => Plan(KvTag(new SqlWriteSpec(SqlWriteMode.Upsert)), new PostgresDialect()).SqlText.ShouldBe(
            "INSERT INTO \"plant\".\"sp\" (\"tag\", \"val\") VALUES (@k, @v) ON CONFLICT (\"tag\") DO UPDATE SET \"val\" = EXCLUDED.\"val\"");

    [Fact]
    public void Upsert_mySql_isOnDuplicateKeyUpdate_andAllowsTwoRows()
    {
        var plan = Plan(KvTag(new SqlWriteSpec(SqlWriteMode.Upsert)), new MySqlDialect());

        plan.SqlText.ShouldBe("INSERT INTO `plant`.`sp` (`tag`, `val`) VALUES (@k, @v) ON DUPLICATE KEY UPDATE `val` = @v");
        plan.MaxRowsAffected.ShouldBe(2);
    }

    [Fact]
    public void Upsert_oracle_isAMergeFromDual_withNamespacedBinds()
    {
        var plan = Plan(KvTag(new SqlWriteSpec(SqlWriteMode.Upsert)), new OracleDialect());

        plan.SqlText.ShouldBe(
            "MERGE INTO \"plant\".\"sp\" tgt USING (SELECT 1 AS one FROM dual) src ON (tgt.\"tag\" = :p_k) " +
            "WHEN MATCHED THEN UPDATE SET tgt.\"val\" = :p_v WHEN NOT MATCHED THEN INSERT (\"tag\", \"val\") VALUES (:p_k, :p_v)");
        plan.ParameterBindNames.ShouldBe(["p_k", "p_v"]);
    }

    [Fact]
    public void Upsert_andProcedure_onOdbc_areNotSupported()
    {
        SqlWritePlanner.TryPlan(KvTag(new SqlWriteSpec(SqlWriteMode.Upsert)), 1.0, new OdbcDialect(), Now, out _)
            .ShouldBe(SqlStatusCodes.BadNotSupported);
        SqlWritePlanner.TryPlan(KvTag(new SqlWriteSpec(SqlWriteMode.Procedure, Procedure: "p", ValueParameter: "value")),
            1.0, new OdbcDialect(), Now, out _).ShouldBe(SqlStatusCodes.BadNotSupported);
    }

    private static SqlTagDefinition ProcTag(string? key = "TagName", string? ts = "Ts") =>
        KvTag(new SqlWriteSpec(SqlWriteMode.Procedure, false, "dbo.SetSp", "Value", key, ts));

    [Theory]
    [InlineData(SqlProvider.SqlServer, "EXEC [dbo].[SetSp] @Value = @v, @TagName = @k, @Ts = @t")]
    [InlineData(SqlProvider.Postgres, "CALL \"dbo\".\"SetSp\"(Value => @v, TagName => @k, Ts => @t)")]
    [InlineData(SqlProvider.MySql, "CALL `dbo`.`SetSp`(@v, @k, @t)")]
    [InlineData(SqlProvider.Oracle, "BEGIN \"dbo\".\"SetSp\"(Value => :p_v, TagName => :p_k, Ts => :p_t); END;")]
    public void Procedure_callsByName_orPositionallyOnMySql_valueKeyStampInThatOrder(SqlProvider provider, string sql)
    {
        var plan = Plan(ProcTag(), SqlDialects.TryCreate(provider)!);

        plan.SqlText.ShouldBe(sql);
        plan.Parameters.ShouldBe([5.5, "L1", Now]);
        plan.Mode.ShouldBe(SqlWriteMode.Procedure);
    }

    [Fact]
    public void Procedure_bindsOnlyWhatTheBlockNames()
    {
        var plan = Plan(ProcTag(key: null, ts: null), new SqlServerDialect());

        plan.SqlText.ShouldBe("EXEC [dbo].[SetSp] @Value = @v");
        plan.Parameters.ShouldBe([5.5]);
    }

    [Fact]
    public void AHostileValue_isBound_inEveryMode()
    {
        const string hostile = "x'); DROP TABLE sp; --";
        foreach (var write in new[]
                 {
                     new SqlWriteSpec(SqlWriteMode.Insert), new SqlWriteSpec(SqlWriteMode.Upsert),
                     new SqlWriteSpec(SqlWriteMode.Procedure, false, "p", "value"),
                 })
        {
            var plan = Plan(KvTag(write) with { DeclaredType = DriverDataType.String }, new SqlServerDialect(), hostile);
            plan.SqlText.ShouldNotContain("DROP");
            plan.Parameters.ShouldContain(hostile);
        }
    }

    // ---- catalog gate: the procedure is an identifier like any other ----

    private static SqlCatalog Catalog(params string[] procedures) => new(
        "dbo", ["dbo"],
        new Dictionary<string, IReadOnlyList<string>>(StringComparer.Ordinal) { ["dbo"] = ["sp"] },
        new Dictionary<string, IReadOnlyList<string>>(StringComparer.Ordinal) { ["dbo.sp"] = ["tag", "val"] },
        new Dictionary<string, IReadOnlyList<string>>(StringComparer.Ordinal) { ["dbo"] = procedures });

    private static SqlTagDefinition GateTag(string procedure) =>
        new("A", SqlTagModel.KeyValue, "sp", KeyColumn: "tag", KeyValue: "L1", ValueColumn: "val", Writable: true,
            Write: new SqlWriteSpec(SqlWriteMode.Procedure, false, procedure, "value"));

    [Fact]
    public void Gate_resolvesTheProcedure_toTheCatalogSpelling()
    {
        var result = SqlCatalogGate.Apply([GateTag("setsp")], Catalog("SetSp"), new SqlServerDialect());

        result.Rejected.ShouldBeEmpty();
        result.Accepted.ShouldHaveSingleItem().Write!.Procedure.ShouldBe("dbo.SetSp");
    }

    [Fact]
    public void Gate_rejectsAnUnknownProcedure_byField()
    {
        var result = SqlCatalogGate.Apply([GateTag("Nope")], Catalog("SetSp"), new SqlServerDialect());

        result.Accepted.ShouldBeEmpty();
        var rejection = result.Rejected.ShouldHaveSingleItem();
        rejection.Field.ShouldBe(SqlCatalogGate.ProcedureField);
        rejection.Reason.ShouldContain("'Nope' does not exist");
    }

    [Fact]
    public void Gate_checksAQueryTagsProcedure_too()
    {
        var query = new SqlTagDefinition("Q", SqlTagModel.Query, string.Empty, ColumnName: "c", QueryName: "q",
            Writable: true, Write: new SqlWriteSpec(SqlWriteMode.Procedure, false, "Missing", "value"));

        SqlCatalogGate.Apply([query], Catalog("SetSp"), new SqlServerDialect()).Rejected.ShouldHaveSingleItem();
        SqlCatalogGate.Apply([query with { Write = query.Write! with { Procedure = "SetSp" } }], Catalog("SetSp"),
            new SqlServerDialect()).Accepted.ShouldHaveSingleItem().Write!.Procedure.ShouldBe("dbo.SetSp");
    }

    [Fact]
    public void Gate_refusesAProcedure_onADialectWithNoRoutineCatalog()
        => SqlCatalogGate.Apply([GateTag("SetSp")], Catalog("SetSp"), new OdbcDialect())
            .Rejected.ShouldHaveSingleItem().Reason.ShouldContain("no stored-procedure catalog");

    // ---- failure classification → status ----

    [Theory]
    [InlineData("23505", SqlWriteFailure.UniqueViolation)]
    [InlineData("23502", SqlWriteFailure.IntegrityViolation)]
    [InlineData("23000", SqlWriteFailure.IntegrityViolation)]
    [InlineData("22003", SqlWriteFailure.DataException)]
    [InlineData("42501", SqlWriteFailure.Other)]   // insufficient privilege stays a communication error
    [InlineData(null, SqlWriteFailure.Other)]
    public void SqlState_classification(string? sqlState, SqlWriteFailure expected)
        => SqlWriteFailures.FromSqlState(sqlState).ShouldBe(expected);

    [Theory]
    [InlineData(SqlWriteFailure.UniqueViolation, 0x809F0000u)]       // BadEntryExists
    [InlineData(SqlWriteFailure.IntegrityViolation, 0x803C0000u)]    // BadOutOfRange
    [InlineData(SqlWriteFailure.DataException, 0x803C0000u)]
    [InlineData(SqlWriteFailure.Other, 0x80050000u)]                 // BadCommunicationError
    public void Failure_mapsToTheDocumentedStatus(SqlWriteFailure failure, uint status)
        => SqlDriver.MapWriteFailure(failure).ShouldBe(status);

    [Fact]
    public void AnUnrelatedException_isNeverAConstraint_onAnyDialect()
    {
        foreach (var provider in Enum.GetValues<SqlProvider>())
            SqlDialects.TryCreate(provider)!.ClassifyWriteFailure(new InvalidOperationException()).ShouldBe(SqlWriteFailure.Other);
    }

    // ---- end to end over SQLite ----

    private const string Setpoints = "Setpoints";

    private static SqlitePollFixture SetpointFixture()
    {
        var fixture = new SqlitePollFixture();
        fixture.Execute($"CREATE TABLE {Setpoints} (tag TEXT NOT NULL PRIMARY KEY, sp REAL NOT NULL, ts TEXT NULL)");
        fixture.Execute($"INSERT INTO {Setpoints} VALUES ('Present', 1.0, NULL)");
        return fixture;
    }

    private static string SpTag(string key, string write) => $$$"""
        {"model":"KeyValue","table":"{{{Setpoints}}}","keyColumn":"tag","keyValue":"{{{key}}}","valueColumn":"sp",
         "timestampColumn":"ts","type":"Float64","writable":true,"write":{{{write}}}}
        """;

    [Fact]
    public async Task Insert_addsANewRow_andASecondInsertOfTheKey_isBadEntryExists()
    {
        using var fixture = SetpointFixture();
        await using var driver = await StartAsync(fixture, Entry("New", SpTag("New", """{"mode":"Insert"}""")));

        (await WriteAsync(driver, "New", 7.5)).ShouldBe(SqlStatusCodes.Good);
        Scalar(fixture, "SELECT sp FROM Setpoints WHERE tag = 'New'").ShouldBe(7.5);

        (await WriteAsync(driver, "New", 8.5)).ShouldBe(SqlStatusCodes.BadEntryExists);
        Scalar(fixture, "SELECT sp FROM Setpoints WHERE tag = 'New'").ShouldBe(7.5);
    }

    [Fact]
    public async Task Insert_violatingNotNull_isBadOutOfRange_andCommitsNothing()
    {
        using var fixture = SetpointFixture();
        await using var driver = await StartAsync(fixture, Entry("New", SpTag("New", """{"mode":"Insert"}""")));

        (await WriteAsync(driver, "New", null)).ShouldBe(SqlStatusCodes.BadOutOfRange);
        Scalar(fixture, "SELECT COUNT(*) FROM Setpoints").ShouldBe(1.0);
    }

    [Fact]
    public async Task Upsert_insertsAnAbsentKey_andUpdatesAPresentOne()
    {
        using var fixture = SetpointFixture();
        await using var driver = await StartAsync(fixture,
            Entry("Absent", SpTag("Absent", """{"mode":"Upsert"}""")),
            Entry("Present", SpTag("Present", """{"mode":"Upsert"}""")));

        (await WriteAsync(driver, "Absent", 3.0)).ShouldBe(SqlStatusCodes.Good);
        (await WriteAsync(driver, "Present", 4.0)).ShouldBe(SqlStatusCodes.Good);

        Scalar(fixture, "SELECT sp FROM Setpoints WHERE tag = 'Absent'").ShouldBe(3.0);
        Scalar(fixture, "SELECT sp FROM Setpoints WHERE tag = 'Present'").ShouldBe(4.0);
        Scalar(fixture, "SELECT COUNT(*) FROM Setpoints").ShouldBe(2.0);
    }

    /// <summary>The same absent key under the default Update is BadNoData and inserts nothing — the back-compat pin.</summary>
    [Fact]
    public async Task Update_toAnAbsentKey_isStillBadNoData()
    {
        using var fixture = SetpointFixture();
        await using var driver = await StartAsync(fixture, Entry("Absent", SpTag("Absent", """{"mode":"Update"}""")));

        (await WriteAsync(driver, "Absent", 3.0)).ShouldBe(SqlStatusCodes.BadNoData);
        Scalar(fixture, "SELECT COUNT(*) FROM Setpoints").ShouldBe(1.0);
    }

    [Fact]
    public async Task StampTimestamp_setsTheTimestampColumn_toTheWriteTime_andWithoutItTheColumnIsUntouched()
    {
        using var fixture = SetpointFixture();
        await using var driver = await StartAsync(fixture,
            Entry("Stamped", SpTag("Present", """{"mode":"Update","stampTimestamp":true}""")));

        var before = DateTime.UtcNow.AddSeconds(-1);
        (await WriteAsync(driver, "Stamped", 9.0)).ShouldBe(SqlStatusCodes.Good);

        using var command = fixture.Connection.CreateCommand();
        command.CommandText = "SELECT ts FROM Setpoints WHERE tag = 'Present'";
        var stamped = DateTime.Parse((string)command.ExecuteScalar()!, CultureInfo.InvariantCulture,
            DateTimeStyles.AdjustToUniversal | DateTimeStyles.AssumeUniversal);
        stamped.ShouldBeGreaterThan(before);
        stamped.ShouldBeLessThan(DateTime.UtcNow.AddSeconds(1));
    }

    [Fact]
    public async Task Procedure_onADialectWithNoRoutineCatalog_isRejectedByTheGate_notExecuted()
    {
        using var fixture = SetpointFixture();
        await using var driver = await StartAsync(fixture,
            Entry("Proc", SpTag("Present", """{"mode":"Procedure","procedure":"SetSp"}""")));

        (await WriteAsync(driver, "Proc", 2.0)).ShouldBe(SqlStatusCodes.BadNodeIdUnknown);
        Scalar(fixture, "SELECT sp FROM Setpoints WHERE tag = 'Present'").ShouldBe(1.0);
    }

    [Fact]
    public async Task Discover_advertisesOperate_forAnInsertOnANewestRowTag()
    {
        using var fixture = SetpointFixture();
        await using var driver = await StartAsync(fixture, Entry("Append", $$$"""
            {"model":"WideRow","table":"{{{SqlitePollFixture.WideRowTable}}}","columnName":"oven_temp",
             "rowSelector":{"topByTimestamp":"sample_ts"},"writable":true,"write":{"mode":"Insert","stampTimestamp":true}}
            """));

        var builder = new Capture();
        await driver.DiscoverAsync(builder, CancellationToken.None);
        builder.Classes["Append"].ShouldBe(SecurityClassification.Operate);
    }

    // ---- helpers ----

    private static RawTagEntry Entry(string rawPath, string json) => new(rawPath, json, WriteIdempotent: false);

    private static async Task<uint> WriteAsync(SqlDriver driver, string reference, object? value)
        => (await ((IWritable)driver).WriteAsync([new WriteRequest(reference, value)], CancellationToken.None))
            .ShouldHaveSingleItem().StatusCode;

    private static double Scalar(SqlitePollFixture fixture, string sql)
    {
        using var command = fixture.Connection.CreateCommand();
        command.CommandText = sql;
        return Convert.ToDouble(command.ExecuteScalar(), CultureInfo.InvariantCulture);
    }

    private static async Task<SqlDriver> StartAsync(SqlitePollFixture fixture, params RawTagEntry[] tags)
    {
        var driver = new SqlDriver(
            new SqlDriverOptions
            {
                RawTags = tags,
                OperationTimeout = TimeSpan.FromSeconds(15),
                CommandTimeout = TimeSpan.FromSeconds(10),
                AllowWrites = true,
            },
            "sql-write-modes", new SqliteDialect(), fixture.ConnectionString, fixture.Factory);
        await driver.InitializeAsync("{}", CancellationToken.None);
        return driver;
    }

    private sealed class Capture : IAddressSpaceBuilder
    {
        public Dictionary<string, SecurityClassification> Classes { get; } = [];

        public IAddressSpaceBuilder Folder(string browseName, string displayName) => this;

        public IVariableHandle Variable(string browseName, string displayName, DriverAttributeInfo attributeInfo)
        {
            Classes[attributeInfo.FullName] = attributeInfo.SecurityClass;
            return new Handle(attributeInfo.FullName);
        }

        public void AddProperty(string browseName, DriverDataType dataType, object? value) { }

        private sealed class Handle(string fullReference) : IVariableHandle
        {
            public string FullReference => fullReference;

            public IAlarmConditionSink MarkAsAlarmCondition(AlarmConditionInfo info) => new Sink();

            private sealed class Sink : IAlarmConditionSink
            {
                public void OnTransition(AlarmEventArgs args) { }
            }
        }
    }
}