using Admin.NET.Plugin.AiDOP.Entity.S8;
using Admin.NET.Plugin.AiDOP.Service.S8.Rules;
using Admin.NET.Plugin.AiDOP.Service.S8.Rules.DataAccess;
using Admin.NET.Plugin.AiDOP.Service.S8.Rules.DataAccess.Providers;
using Microsoft.Extensions.Logging.Abstractions;
using Xunit;

namespace Admin.NET.Test.S8;

/// <summary>
/// S8-RULE01-PURCHASE-DELIVERY-A：PURCHASE_DELIVERY 的取数作用域、canonical 映射与 TIMEOUT 判定契约。
/// 锁定项与失败后果：
///
///   A. 作用域只能按 tenant   → Phase 1 拍板：Security Boundary = Tenant。若有人日后往 SQL 里补回
///                              factory_id 过滤，规则会恒返 0 行且不报错（dwd_supplier_delivery.factory_id
///                              是写死的常量 1，与 S8 侧真实 SysOrg.Id 永不相等）——静默失效，最难发现。
///   B. 快照按 tenant 各自收敛 → 用全局 MAX(stat_date) 会让落后一天的租户整租户静默丢数据。
///   C. 身份稳定且唯一         → source_object_id 进 DedupKey，格式一变历史异常与新异常直接断代。
///   D. DedupKey 预算守卫      → 预算比 source_object_id 列宽（64）更紧；落在预算与列宽之间的键
///                              会过得了列校验、卡在 DedupKey 上，数据库静默截断会把两个 PO Line 折叠成一条异常。
///   E. due_at 双分支          → need_date 为 NULL 时回落 due_date；两者实测 18/36 行不同，不是等价列。
///   F. 判定归 evaluator       → Provider 不滤 status，"逾期但已完成不命中"必须由 evaluator 判出来。
///   G. STANDARD 绝不回落      → 取数失败偷偷执行 rule.Expression 会让迁移失败被静默隐藏：
///                              规则看起来在正常跑，实际跑的还是旧 SQL。
///
/// 不接 DB、不接 DI、不触发任何真实规则。SQL 在真实库上的行为已由实施前的只读核验覆盖
/// （4 租户身份唯一、跨租户交集 0、外层走 idx_stat_date），本文件锁定的是结构契约。
/// </summary>
public class S8PurchaseDeliveryProviderMappingTests
{
    private const string PurchaseDelivery = S8BusinessDatasetDefinitions.PurchaseDeliveryCode;
    private const string RuleCode = "RULE_S4_PURCHASE_DELIVERY_DATE_DELAY";

    private static S8MonitoringDataRequest Request(
        long tenantId = 838257186181189, long factoryId = 838257186320453) => new()
    {
        TenantId = tenantId,
        FactoryId = factoryId,
        DatasetCode = PurchaseDelivery,
        RuleCode = RuleCode,
        RuleType = "TIMEOUT"
    };

    private static AdoS8WatchRule NewRule() => new()
    {
        Id = 900101,
        RuleCode = RuleCode,
        SceneCode = "S4",
        WatchObjectType = "PURCHASE_ORDER_LINE",
        SourceObjectType = "PURCHASE_ORDER_LINE",
        Severity = "SERIOUS",
        RuleType = "TIMEOUT",
        DataAccessMode = S8DataAccessMode.StandardDataset,
        DatasetCode = PurchaseDelivery
    };

    private static S8TimeoutParams Params() => S8TimeoutParams.Parse(
        """
        {"dueAtField":"due_at","statusField":"status",
         "completedStates":["COMPLETED","CLOSED","CANCELLED"],
         "objectCodeField":"related_object_code","objectIdField":"source_object_id",
         "graceMinutes":0,"exceptionTypeCode":"PURCHASE_DELIVERY_ABNORMAL"}
        """);

    /// <summary>真实 DWD 行样本（取自 UAT 租户 2026-09-05 快照）。</summary>
    private static S8PurchaseDeliveryDataProvider.PurchaseDeliveryRow Row(
        string poNo, string poLine, DateTime? needDate, DateTime? dueDate, string status,
        string supplierName = "珩睿", string supplierCode = "10003232") => new()
    {
        SourceObjectId = $"{poNo}#{poLine}",
        RelatedObjectCode = poNo,
        RelatedObjectName = string.IsNullOrEmpty(supplierName) ? supplierCode : supplierName,
        DueAt = needDate ?? dueDate,
        Status = status,
        DueAtSource = needDate == null ? "due_date" : "need_date",
        PoNo = poNo,
        PoLine = poLine,
        PoType = "po",
        SupplierCode = supplierCode,
        SupplierName = supplierName,
        ItemCode = "ITM-001",
        ItemName = "物料",
        OrderQty = 3000m,
        RemainingQty = 3000m,
        NeedDate = needDate,
        DueDate = dueDate,
        RiskLevel = "HIGH",
        StatDate = new DateTime(2026, 9, 5)
    };

    private static S8MonitoringRowSet RowSet(params S8PurchaseDeliveryDataProvider.PurchaseDeliveryRow[] rows) =>
        S8MonitoringRowSet.FromRows(
            rows.Select(r => S8MonitoringRow.FromValues(S8PurchaseDeliveryDataProvider.ToCanonicalValues(r))));

    // ============================================================
    // A/B. 作用域与快照收敛（SQL 结构契约）
    // ============================================================

    [Fact]
    public void T4_Sql_FiltersByTenant_InBothOuterQueryAndSnapshotSubquery()
    {
        // 外层与快照子查询都必须带租户，否则会拿到别的租户的最新快照日期。
        var sql = S8PurchaseDeliveryDataProvider.Sql;

        Assert.Contains("d.tenant_id = @TenantId", sql);
        Assert.Contains("x.tenant_id = @TenantId", sql);
    }

    [Fact]
    public void T5_Sql_DoesNotUseFactoryAsDatasetFilter()
    {
        // Phase 1 拍板：Factory 是业务上下文，不是本数据集的过滤条件。
        // 这条断言是防回归的主锁——补回 factory 过滤会让规则恒返 0 行且不报任何错。
        Assert.DoesNotContain("factory_id", S8PurchaseDeliveryDataProvider.Sql);
    }

    [Fact]
    public void T5b_FactoryId_DoesNotAlterQuery_ButTenantIdDoes()
    {
        // 同一租户下换工厂：SQL 与唯一参数都不受影响（工厂根本不进 SQL）。
        // 换租户：参数随之改变。二者共同证明"隔离维度只有租户"。
        var sameTenantOtherFactory = Request(factoryId: 999_999_999);
        var otherTenant = Request(tenantId: 838257212780613);

        Assert.Equal(Request().TenantId, sameTenantOtherFactory.TenantId);
        Assert.NotEqual(Request().TenantId, otherTenant.TenantId);
        // 工厂不在 SQL 中，因此不可能成为取数差异的来源。
        Assert.DoesNotContain("@FactoryId", S8PurchaseDeliveryDataProvider.Sql);
    }

    [Fact]
    public void T6_Sql_ConvergesSnapshot_PerTenantLatest_NotGlobalMax()
    {
        var sql = S8PurchaseDeliveryDataProvider.Sql;

        // 反向索引扫描而非聚合：大租户上实测 143ms → 2.7ms。
        Assert.Contains("ORDER BY x.stat_date DESC", sql);
        Assert.Contains("LIMIT 1", sql);
        Assert.DoesNotContain("MAX(", sql);
    }

    [Fact]
    public void Sql_ExcludesDegenerateIdentity_AndDoesNotFilterOnBusinessState()
    {
        var sql = S8PurchaseDeliveryDataProvider.Sql;

        // 身份任一段为空会产生退化的 "#"，必须排除。
        Assert.Contains("d.po_no <> ''", sql);
        Assert.Contains("d.po_line <> ''", sql);

        // 判定归 evaluator：Provider 不得按状态或不可信的 remaining_qty 预筛。
        Assert.DoesNotContain("remaining_qty >", sql);
        Assert.DoesNotContain("delivery_status <>", sql);
        Assert.DoesNotContain("delivery_status !=", sql);
    }

    [Fact]
    public async Task LoadAsync_ValidatesScope_BeforeTouchingDatabase()
    {
        // 故意注入 null 数据库：若作用域校验不是第一步，这里会得到 NullReferenceException。
        var provider = new S8PurchaseDeliveryDataProvider(
            null, NullLogger<S8PurchaseDeliveryDataProvider>.Instance);

        var ex = await Assert.ThrowsAsync<S8RuleEvaluatorException>(() =>
            provider.LoadAsync(Request(tenantId: 0)));
        Assert.Equal("dataset_scope_invalid", ex.Reason);

        var ex2 = await Assert.ThrowsAsync<S8RuleEvaluatorException>(() =>
            provider.LoadAsync(Request(factoryId: 0)));
        Assert.Equal("dataset_scope_invalid", ex2.Reason);
    }

    // ============================================================
    // C/D. 身份与 DedupKey 预算
    // ============================================================

    [Fact]
    public void T7_Identity_IsStableComposite_UniquePerLine()
    {
        var line3 = Row("PO202608260002", "3", new DateTime(2026, 8, 17, 4, 33, 7), new DateTime(2026, 9, 10), "DELAYED");
        var line4 = Row("PO202608260002", "4", new DateTime(2026, 8, 17), new DateTime(2026, 9, 10), "DELAYED");

        var v3 = S8PurchaseDeliveryDataProvider.ToCanonicalValues(line3);
        var v4 = S8PurchaseDeliveryDataProvider.ToCanonicalValues(line4);

        Assert.Equal("PO202608260002#3", v3[S8CanonicalColumns.SourceObjectId]);
        Assert.Equal("PO202608260002", v3[S8CanonicalColumns.RelatedObjectCode]);
        // 同单不同行必须是不同对象，否则同一采购单只会产出一条异常。
        Assert.NotEqual(v3[S8CanonicalColumns.SourceObjectId], v4[S8CanonicalColumns.SourceObjectId]);
    }

    [Fact]
    public void T7b_Identity_IsInvariantAcrossSnapshots()
    {
        // 身份只由 po_no + po_line 决定，与 stat_date 无关；否则每天换一次身份，
        // 昨天的异常今天会被判恢复、并新建一条。
        var day1 = Row("PO202608260002", "3", new DateTime(2026, 8, 17), new DateTime(2026, 9, 10), "DELAYED");
        var day2 = Row("PO202608260002", "3", new DateTime(2026, 8, 17), new DateTime(2026, 9, 10), "DELAYED");
        day2.StatDate = new DateTime(2026, 9, 6);

        Assert.Equal(
            S8PurchaseDeliveryDataProvider.ToCanonicalValues(day1)[S8CanonicalColumns.SourceObjectId],
            S8PurchaseDeliveryDataProvider.ToCanonicalValues(day2)[S8CanonicalColumns.SourceObjectId]);
    }

    [Fact]
    public void T7c_DedupKey_StaysWithinColumnLimit_ForRealWorstCase()
    {
        // 实测该租户最长 source_object_id 为 16 字符；此处按真实规则编码与作用域算完整 DedupKey。
        var key = S8TimeoutRuleEvaluator.BuildDedupKey(
            838257186181189, 838257186320453, RuleCode, "PURCHASE_ORDER_LINE", "PO202608260002#4");

        Assert.True(key.Length <= S8PurchaseDeliveryDataProvider.DedupKeyMaxLength,
            $"DedupKey 长度 {key.Length} 超过 {S8PurchaseDeliveryDataProvider.DedupKeyMaxLength}：{key}");
    }

    [Fact]
    public void T7d_Budget_IsTighterThanSourceObjectIdColumnWidth()
    {
        // 关键认知：预算（128 − 前缀）比 source_object_id 的列宽 64 更紧。
        // 落在预算与 64 之间的键会过得了列校验、卡在 DedupKey 上。
        var budget = S8PurchaseDeliveryDataProvider.ResolveSourceObjectIdBudget(Request());

        Assert.True(budget > 0);
        Assert.True(budget < 64, $"预期预算紧于列宽 64，实际 {budget}");

        // 预算 + 前缀必须正好等于上限，证明算式与 BuildDedupKey 的格式一致。
        var probe = new string('x', budget);
        var key = S8TimeoutRuleEvaluator.BuildDedupKey(
            Request().TenantId, Request().FactoryId, RuleCode, "PURCHASE_ORDER_LINE", probe);
        Assert.Equal(S8PurchaseDeliveryDataProvider.DedupKeyMaxLength, key.Length);
    }

    [Fact]
    public void T7e_Budget_ShrinksWhenRuleCodeGrows()
    {
        // 预算按 request 现算而非写死；换更长的规则编码必须自动收紧。
        var longRule = new S8MonitoringDataRequest
        {
            TenantId = Request().TenantId,
            FactoryId = Request().FactoryId,
            DatasetCode = PurchaseDelivery,
            RuleCode = RuleCode + "_MUCH_LONGER_SUFFIX",
            RuleType = "TIMEOUT"
        };

        Assert.True(
            S8PurchaseDeliveryDataProvider.ResolveSourceObjectIdBudget(longRule)
            < S8PurchaseDeliveryDataProvider.ResolveSourceObjectIdBudget(Request()));
    }

    // ============================================================
    // E. Canonical 映射
    // ============================================================

    [Fact]
    public void T8_Canonical_Mapping_IsComplete_WhenNeedDatePresent()
    {
        var values = S8PurchaseDeliveryDataProvider.ToCanonicalValues(
            Row("PO202608260002", "3", new DateTime(2026, 8, 17, 4, 33, 7), new DateTime(2026, 9, 10), "DELAYED"));

        Assert.Equal("PO202608260002#3", values[S8CanonicalColumns.SourceObjectId]);
        Assert.Equal("PO202608260002", values[S8CanonicalColumns.RelatedObjectCode]);
        Assert.Equal(new DateTime(2026, 8, 17, 4, 33, 7), values[S8CanonicalColumns.DueAt]);
        Assert.Equal("DELAYED", values[S8CanonicalColumns.Status]);
        Assert.Equal("need_date", values["due_at_source"]);
    }

    [Fact]
    public void T8b_DueAt_FallsBackToDueDate_WhenNeedDateIsNull()
    {
        // 真实样本 PW202608280001#1：need_date 为 NULL，是唯一能验回落分支的行。
        var values = S8PurchaseDeliveryDataProvider.ToCanonicalValues(
            Row("PW202608280001", "1", null, new DateTime(2026, 8, 29), "DELAYED", supplierName: "怡祥"));

        Assert.Equal(new DateTime(2026, 8, 29), values[S8CanonicalColumns.DueAt]);
        // due_at 是两种业务日期的混合，必须逐行自证用的是哪个基准。
        Assert.Equal("due_date", values["due_at_source"]);
    }

    [Fact]
    public void T8c_Canonical_DoesNotFabricateBusinessJudgements()
    {
        // Provider 不得构造 is_delivery_complete / is_active_obligation / severity ——
        // 上一轮数据契约审计已判这三项 NOT_PROVEN，凭空构造等于把中台缺口埋进 S8。
        var values = S8PurchaseDeliveryDataProvider.ToCanonicalValues(
            Row("PO202608260002", "1", new DateTime(2026, 8, 17), new DateTime(2026, 9, 10), "COMPLETED"));

        Assert.DoesNotContain("is_delivery_complete", values.Keys);
        Assert.DoesNotContain("is_active_obligation", values.Keys);
        Assert.DoesNotContain("severity", values.Keys);
    }

    // ============================================================
    // F. TIMEOUT 判定（由 evaluator 判，不由 Provider 预筛）
    // ============================================================

    [Fact]
    public void T9_Timeout_Hits_WhenOverdueAndNotCompleted()
    {
        var rowSet = RowSet(Row("PO202608260002", "3",
            new DateTime(2026, 8, 17, 4, 33, 7), new DateTime(2026, 9, 10), "DELAYED"));

        var hits = S8TimeoutRuleEvaluator.EvaluateRows(
            rowSet, Params(), NewRule(), 838257186181189, 838257186320453, 0, new DateTime(2026, 9, 5));

        var hit = Assert.Single(hits);
        Assert.Equal("PO202608260002#3", hit.SourceObjectId);
        Assert.Equal("PO202608260002", hit.RelatedObjectCode);
        Assert.Equal("PURCHASE_ORDER_LINE", hit.SourceObjectType);
    }

    [Fact]
    public void T10_Timeout_NoHit_WhenNotYetDue()
    {
        // 真实样本 PO202608280001#1：due 2026-09-17，状态 OPEN。
        var rowSet = RowSet(Row("PO202608280001", "1",
            new DateTime(2026, 9, 17), new DateTime(2026, 8, 9), "OPEN", supplierName: "怡祥"));

        var hits = S8TimeoutRuleEvaluator.EvaluateRows(
            rowSet, Params(), NewRule(), 838257186181189, 838257186320453, 0, new DateTime(2026, 9, 5));

        Assert.Empty(hits);
    }

    [Fact]
    public void T11_Timeout_NoHit_WhenOverdueButCompleted()
    {
        // 真实样本 PO202608260002#1：已逾期但 COMPLETED。
        // 这一条必须由 evaluator 判出来 —— 若 Provider 在 SQL 里滤掉已完成行，
        // 本测试会"通过"但测的是过滤而非判定，且该行不在 hits 里会被误判为恢复。
        var rowSet = RowSet(Row("PO202608260002", "1",
            new DateTime(2026, 8, 17, 4, 33, 7), new DateTime(2026, 9, 10), "COMPLETED"));

        var hits = S8TimeoutRuleEvaluator.EvaluateRows(
            rowSet, Params(), NewRule(), 838257186181189, 838257186320453, 0, new DateTime(2026, 9, 5));

        Assert.Empty(hits);
    }

    [Fact]
    public void T11b_Timeout_NoHit_ForClosedAndCancelled()
    {
        // dwd_supplier_delivery 有三个写入方，词表不一致：批量转换产 COMPLETED/DELAYED/OPEN，
        // 增量写入方产 CANCELLED/CLOSED/PARTIAL。当前库中后两值 0 行，这是零行为变更的安全余量。
        var rowSet = RowSet(
            Row("PO-CLOSED", "1", new DateTime(2026, 8, 1), null, "CLOSED"),
            Row("PO-CANCELLED", "1", new DateTime(2026, 8, 1), null, "CANCELLED"));

        var hits = S8TimeoutRuleEvaluator.EvaluateRows(
            rowSet, Params(), NewRule(), 838257186181189, 838257186320453, 0, new DateTime(2026, 9, 5));

        Assert.Empty(hits);
    }

    [Fact]
    public void T11c_Timeout_Hits_ForPartial_BecausePartialIsNotTerminal()
    {
        // PARTIAL 刻意不列入 completedStates：部分收货不是终态，仍需继续监控。
        var rowSet = RowSet(Row("PO-PARTIAL", "1", new DateTime(2026, 8, 1), null, "PARTIAL"));

        var hits = S8TimeoutRuleEvaluator.EvaluateRows(
            rowSet, Params(), NewRule(), 838257186181189, 838257186320453, 0, new DateTime(2026, 9, 5));

        Assert.Single(hits);
    }

    [Fact]
    public void T13_Recovery_Contract_HitSetShrinksWhenStatusBecomesCompleted()
    {
        // 恢复判定的输入是"本轮 hits 的 dedup_key 集合"（见 ReconcileRecoveriesForRuleAsync）。
        // 这里证明：同一对象在状态转为 COMPLETED 后不再出现在 hits 中，
        // 从而进入恢复候选。真实 recovered_at 写入属运行态，由 Batch B 验证。
        var before = RowSet(Row("PO202608260002", "2",
            new DateTime(2026, 8, 17, 4, 33, 7), new DateTime(2026, 9, 10), "DELAYED"));
        var after = RowSet(Row("PO202608260002", "2",
            new DateTime(2026, 8, 17, 4, 33, 7), new DateTime(2026, 9, 10), "COMPLETED"));

        var hitsBefore = S8TimeoutRuleEvaluator.EvaluateRows(
            before, Params(), NewRule(), 838257186181189, 838257186320453, 0, new DateTime(2026, 9, 5));
        var hitsAfter = S8TimeoutRuleEvaluator.EvaluateRows(
            after, Params(), NewRule(), 838257186181189, 838257186320453, 0, new DateTime(2026, 9, 5));

        var dedupKey = Assert.Single(hitsBefore).DedupKey;
        Assert.Empty(hitsAfter);
        Assert.DoesNotContain(dedupKey, hitsAfter.Select(h => h.DedupKey));
    }

    [Fact]
    public void T14_Hit_CarriesExceptionTypeAndDiagnosticPayload()
    {
        var rowSet = RowSet(Row("PO202608260002", "3",
            new DateTime(2026, 8, 17, 4, 33, 7), new DateTime(2026, 9, 10), "DELAYED"));

        var hit = Assert.Single(S8TimeoutRuleEvaluator.EvaluateRows(
            rowSet, Params(), NewRule(), 838257186181189, 838257186320453, 0, new DateTime(2026, 9, 5)));

        Assert.Equal("PURCHASE_DELIVERY_ABNORMAL", hit.ExceptionTypeCode);
        Assert.Equal("PURCHASE_ORDER_LINE", hit.SourceObjectType);
        Assert.Equal("PO202608260002#3", hit.SourceObjectId);
        Assert.Equal("T838257186181189:F838257186320453:RRULE_S4_PURCHASE_DELIVERY_DATE_DELAY:PURCHASE_ORDER_LINE:PO202608260002#3",
            hit.DedupKey);

        // 诊断列必须随 payload 落盘：remaining_qty 供后续数据治理观察，
        // due_at_source 用于追溯每行实际使用了 need_date 还是 due_date。
        Assert.Contains("remaining_qty", hit.SourcePayload);
        Assert.Contains("due_at_source", hit.SourcePayload);
        Assert.Contains("stat_date", hit.SourcePayload);
    }

    // ============================================================
    // G. STANDARD_DATASET 绝不回落 Legacy
    // ============================================================

    [Fact]
    public async Task T12_StandardDataset_NeverFallsBackToLegacySql()
    {
        var legacy = new SpyLegacy();
        var gateway = new S8MonitoringDataGateway(
            legacy,
            new S8MonitoringDataProviderRegistry(new IS8MonitoringDataProvider[] { new EmptyPurchaseDeliveryProvider() }),
            new S8DatasetCatalog(new IS8DatasetDefinitionSource[] { new S8BusinessDatasetDefinitions() }),
            NullLogger<S8MonitoringDataGateway>.Instance);

        var rule = NewRule();
        // 历史遗留字段里即使躺着可执行 SQL，STANDARD_DATASET 路径也绝不能碰它。
        rule.Expression = "DROP TABLE ado_s8_exception; SELECT SHOULD_NEVER_RUN";
        rule.DataSourceId = 99;

        var result = await gateway.LoadAsync(838257186181189, 838257186320453, rule, "TIMEOUT", 60, 1000);

        Assert.Equal(S8DataAccessMode.StandardDataset, result.DataAccessMode);
        Assert.Equal(0, legacy.CallCount);
        Assert.Null(legacy.LastExpression);
    }

    [Fact]
    public async Task T12b_ProviderFailure_SurfacesAsQueryFailed_WithoutLegacyFallback()
    {
        var legacy = new SpyLegacy();
        var gateway = new S8MonitoringDataGateway(
            legacy,
            new S8MonitoringDataProviderRegistry(new IS8MonitoringDataProvider[] { new ThrowingPurchaseDeliveryProvider() }),
            new S8DatasetCatalog(new IS8DatasetDefinitionSource[] { new S8BusinessDatasetDefinitions() }),
            NullLogger<S8MonitoringDataGateway>.Instance);

        var rule = NewRule();
        rule.Expression = "SELECT SHOULD_NEVER_RUN";

        var ex = await Assert.ThrowsAsync<S8RuleEvaluatorException>(() =>
            gateway.LoadAsync(838257186181189, 838257186320453, rule, "TIMEOUT", 60, 1000));

        Assert.Equal(S8DatasetReasonCode.QueryFailed, ex.Reason);
        Assert.Equal(0, legacy.CallCount);   // ← 本测试的核心断言
    }

    private sealed class SpyLegacy : IS8LegacySqlDataProvider
    {
        public int CallCount { get; private set; }
        public string LastExpression { get; private set; }

        public Task<S8MonitoringDataResult> LoadAsync(
            long tenantId, long factoryId, AdoS8WatchRule rule, string ruleType,
            int timeoutSeconds, CancellationToken cancellationToken = default)
        {
            CallCount++;
            LastExpression = rule.Expression;
            return Task.FromResult(new S8MonitoringDataResult { RowSet = S8MonitoringRowSet.Empty });
        }
    }

    private sealed class EmptyPurchaseDeliveryProvider : IS8MonitoringDataProvider
    {
        public string DatasetCode => PurchaseDelivery;
        public S8DatasetCapabilities Capabilities => S8BusinessDatasetDefinitions.PurchaseDeliveryCapabilities;

        public Task<S8MonitoringRowSet> LoadAsync(
            S8MonitoringDataRequest request, CancellationToken cancellationToken = default)
        {
            request.EnsureValid();
            return Task.FromResult(S8MonitoringRowSet.Empty);
        }
    }

    private sealed class ThrowingPurchaseDeliveryProvider : IS8MonitoringDataProvider
    {
        public string DatasetCode => PurchaseDelivery;
        public S8DatasetCapabilities Capabilities => S8BusinessDatasetDefinitions.PurchaseDeliveryCapabilities;

        public Task<S8MonitoringRowSet> LoadAsync(
            S8MonitoringDataRequest request, CancellationToken cancellationToken = default) =>
            throw new InvalidOperationException("dwd unavailable");
    }
}