using Admin.NET.Plugin.AiDOP.DataPlatform.Executors;
using Admin.NET.Plugin.AiDOP.Entity.DataPlatform;
using Microsoft.Extensions.Logging;
using SqlSugar;

namespace Admin.NET.Plugin.AiDOP.DataPlatform.S0Dim;

/// <summary>
/// 单个 S0 维度的物化：source → staging → dim，FULL REPLACE 语义。
///
/// 时序与事务边界：
/// <code>
/// [0] 前置校验（只读）：mdp_entity 配置与 definition 一致 + 源侧业务键无重复 + 数据量未超单页
/// [1] source_count（只读，按租户）
/// ── 阶段 I：staging（非事务，可重跑）
/// [2] purge 本租户+本源系统+本源表 分区
/// [3] FULL pull（源侧/写入侧双重租户过滤）
/// [4] staging_count（本批四段谓词）
/// ── 阶段 II：闸门
/// [5] stg_count != source_count → 本维度 FAILED，**dim 不动**（保持上一轮完整快照）
/// ── 阶段 III：dim（单事务）
/// [6] DELETE tenant 行 + INSERT（无 ON DUPLICATE KEY）+ 事务内阻断级对账 → 任一失败整体回滚
/// </code>
///
/// 失败时 dim 永远停在**上一轮的完整快照**，不会半新半旧。
/// </summary>
public sealed class S0DimMaterializer : ITransient
{
    private readonly ISqlSugarClient _db;
    private readonly MdpSourcePullDispatcher _pullDispatcher;
    private readonly S0DimStagingPurge _purge;
    private readonly S0DimReconciler _reconciler;
    private readonly ILogger<S0DimMaterializer> _logger;

    /// <summary>构造。</summary>
    public S0DimMaterializer(
        ISqlSugarClient db,
        MdpSourcePullDispatcher pullDispatcher,
        S0DimStagingPurge purge,
        S0DimReconciler reconciler,
        ILogger<S0DimMaterializer> logger)
    {
        _db = db;
        _pullDispatcher = pullDispatcher;
        _purge = purge;
        _reconciler = reconciler;
        _logger = logger;
    }

    /// <summary>物化一个维度。</summary>
    public async Task<S0DimMaterializeResult> RunAsync(
        S0DimDefinition def, long tenantId, string batchId, CancellationToken ct = default)
    {
        def.Validate();
        if (tenantId <= 0) throw new InvalidOperationException($"[{def.Key}] 拒绝无效租户：{tenantId}");
        if (string.IsNullOrWhiteSpace(batchId)) throw new InvalidOperationException($"[{def.Key}] batchId 不得为空");

        var result = new S0DimMaterializeResult { Key = def.Key, TenantId = tenantId, BatchId = batchId };
        var ps = new List<SugarParameter>
        {
            new("@TenantId", tenantId),
            new("@SourceSystem", def.SourceSystem),
            new("@SourceTable", def.SourceTable),
            new("@BatchId", batchId)
        };

        try
        {
            // [0] 前置校验：配置漂移与源侧数据质量，全部在动任何数据之前
            var batchSize = await AssertEntityContractAsync(def, ct);
            var sourceCount = await _db.Ado.GetIntAsync(S0DimSqlBuilder.BuildSourceCountSql(def), ps);
            await AssertNoSourceDuplicateAsync(def, tenantId, sourceCount, batchSize, ps);

            // [2] purge：三段谓词精确到本租户 + 本源系统 + 本源表
            result.StagingPurged = await _purge.PurgeAsync(def, tenantId, ct);

            // [3] FULL pull
            //     租户三重防护：① MdpDbPullExecutor 对含租户列的源表加 WHERE tenant_id=@scopeTenantId；
            //     ② MdpStagingWriter 对 tenantValue != ctx.TenantId 的行直接跳过；
            //     ③ RequireMatchingSourceTenant=true → 源行无租户时不拿 ctx 兜底，直接跳过（绝不落 0）
            var pullCtx = new MdpPullContext
            {
                TenantId = tenantId,
                BatchId = batchId,
                FullRefresh = true,
                RequireMatchingSourceTenant = true
            };
            var pull = await _pullDispatcher.PullAllByEntityCodeAsync(def.EntityCode, pullCtx, ct);
            result.SourcePulled = pull.RowsPulled;
            result.StagingWritten = pull.RowsWritten;

            // [4][5] 闸门：本批 staging 必须与源侧行数完全一致，否则不碰 dim
            var stagingCount = await _db.Ado.GetIntAsync(S0DimSqlBuilder.BuildStagingCountSql(def), ps);
            if (stagingCount != sourceCount)
                throw new InvalidOperationException(
                    $"[{def.Key}] 贴源闸门未通过：source_count={sourceCount} 本批 stg_count={stagingCount}（dim 未改动）");

            // [6] dim 单事务：DELETE 本租户 → INSERT → 事务内阻断级对账
            result.DimRows = await MdpStdFullReplace.ReplaceAsync(
                _db, def.DimTable, tenantId, extraWhere: null,
                insertScopedAsync: async () =>
                {
                    var now = DateTime.Now;
                    var insertPs = new List<SugarParameter>(ps) { new("@Now", now) };
                    var rows = await _db.Ado.ExecuteCommandAsync(S0DimSqlBuilder.BuildInsertSql(def), insertPs);
                    result.Reconcile = await _reconciler.AssertBlockingAsync(def, tenantId, batchId, ct);
                    return rows;
                },
                ct);

            result.Status = "SUCCESS";
            _logger.LogInformation(
                "[S0Dim] {Key} tenant={Tenant} batch={Batch} purged={Purged} pulled={Pulled} stg={Stg} dim={Dim}",
                def.Key, tenantId, batchId, result.StagingPurged, result.SourcePulled, stagingCount, result.DimRows);
        }
        catch (OperationCanceledException)
        {
            // 取消不是本维度的「失败」：吞掉它会把客户端断开记成 FAILED，
            // 且外层 RefreshAsync 的 ct.ThrowIfCancellationRequested() 会在下一轮抛出，
            // 导致 CompleteRunLogAsync 永不执行、run log 永久停在 RUNNING。
            // 事务侧无需担心：异常已在 MdpStdFullReplace 的 catch 中回滚，dim 未改动。
            throw;
        }
        catch (Exception ex)
        {
            result.Status = "FAILED";
            result.Error = ex.Message;
            _logger.LogError(ex, "[S0Dim] {Key} tenant={Tenant} batch={Batch} 物化失败（dim 未改动）",
                def.Key, tenantId, batchId);
        }

        return result;
    }

    /// <summary>
    /// 断言 <c>mdp_entity</c> 的运行时配置与 definition 完全一致，返回 batch_size。
    /// 这一步把「配置漂移」变成显式失败 —— 否则 <c>PullAll</c> 可能悄悄拉到别的表 / 别的源。
    /// </summary>
    private async Task<int> AssertEntityContractAsync(S0DimDefinition def, CancellationToken ct)
    {
        var entity = await _db.Queryable<MdpEntity>()
            .Where(x => x.EntityCode == def.EntityCode)
            .FirstAsync(ct)
            ?? throw new InvalidOperationException($"[{def.Key}] mdp_entity 未登记：{def.EntityCode}（migration 未执行？）");

        if (entity.Status != 1)
            throw new InvalidOperationException($"[{def.Key}] mdp_entity.{def.EntityCode} 已停用（status={entity.Status}）");

        var source = await _db.Queryable<MdpSource>().Where(x => x.Id == entity.SourceId).FirstAsync(ct)
            ?? throw new InvalidOperationException($"[{def.Key}] mdp_source id={entity.SourceId} 不存在");

        void Expect(string what, string? actual, string expected)
        {
            if (!string.Equals(actual, expected, StringComparison.Ordinal))
                throw new InvalidOperationException($"[{def.Key}] mdp_entity 配置漂移：{what} 实际='{actual}' 期望='{expected}'");
        }

        Expect("source_code", source.SourceCode, def.SourceSystem);
        Expect("source_table_name", entity.SourceTableName, def.SourceTable);
        Expect("target_table_name", entity.TargetTableName, def.StagingTable);
        Expect("biz_key_expr", entity.BizKeyExpr, string.Join(",", def.SourceBizKeyColumns));

        // ── 执行器选路的三个开关：不查会被静默改道 ──
        // MdpSourcePullDispatcher 按
        //   !IsNullOrWhiteSpace(entity.SourceApiPath) || source.SourceType == "API" → _apiExecutor
        //   source.SourceType == "FILE_EXCEL"                                       → Excel 分支
        // 选择执行器。上面那几条 Expect 全部**照样通过**，但拉取已不再是「本库 SELECT」。
        // 比较口径与 dispatcher 一致（OrdinalIgnoreCase），否则大小写差异会造成假通过。
        if (!string.IsNullOrWhiteSpace(entity.SourceApiPath))
            throw new InvalidOperationException(
                $"[{def.Key}] mdp_entity.source_api_path 必须为空，实际='{entity.SourceApiPath}'：" +
                "非空会让 MdpSourcePullDispatcher 改走 API 执行器，绕开本库 DB 拉取契约");
        if (!string.Equals(source.SourceType, "DB", StringComparison.OrdinalIgnoreCase))
            throw new InvalidOperationException(
                $"[{def.Key}] mdp_source.source_type 必须为 DB，实际='{source.SourceType}'");
        if (!string.Equals(source.DbType, "MySQL", StringComparison.OrdinalIgnoreCase))
            throw new InvalidOperationException(
                $"[{def.Key}] mdp_source.db_type 必须为 MySQL，实际='{source.DbType}'");

        // 本阶段只做 FULL：留了 incr_column 会让 BuildSelectSql 生成 "col > @cursor"，
        // 使源侧水位为 NULL 的行（如 DepartmentMaster 的 UATDEMO/未分配）永久不可达
        if (!string.Equals(entity.SyncMode, "FULL", StringComparison.OrdinalIgnoreCase))
            throw new InvalidOperationException($"[{def.Key}] sync_mode 必须为 FULL，实际='{entity.SyncMode}'");
        if (!string.IsNullOrWhiteSpace(entity.IncrColumn))
            throw new InvalidOperationException($"[{def.Key}] incr_column 必须为空（FULL 语义），实际='{entity.IncrColumn}'");

        return entity.BatchSize > 0 ? entity.BatchSize : 1000;
    }

    /// <summary>
    /// 源侧业务键重复探针 + 单页容量检查。两者都在 purge 之前，失败时**任何数据都未被触碰**。
    /// </summary>
    private async Task AssertNoSourceDuplicateAsync(
        S0DimDefinition def, long tenantId, int sourceCount, int batchSize, List<SugarParameter> ps)
    {
        // 分页依赖 MdpDbPullExecutor 无 incr_column 时的 "ORDER BY 1"（按第 1 个物理列），
        // 而 LocationMaster 的第 1 列是 Capacity（非唯一）→ 一旦真的翻页，OFFSET 结果不稳定。
        // 因此要求单页装得下；超出时显式失败并提示调大 mdp_entity.batch_size。
        if (sourceCount >= batchSize)
            throw new InvalidOperationException(
                $"[{def.Key}] 源行数 {sourceCount} 已达单页容量 {batchSize}：" +
                "通用执行器在无 incr_column 时按 'ORDER BY 1' 分页，对本表非稳定序，请调大 mdp_entity.batch_size");

        var q = await _db.Ado.SqlQueryAsync<SourceBizKeyProbe>(
            S0DimSqlBuilder.BuildBizKeyQualitySql(S0DimSqlBuilder.SourceBizKeySetSql(def)), ps);
        var probe = q.FirstOrDefault();
        if (probe is null) return;

        if (probe.Blank_Cnt > 0)
            throw new InvalidOperationException(
                $"[{def.Key}] tenant={tenantId} 源侧有 {probe.Blank_Cnt} 行业务键为空，拒绝物化");

        if (probe.Total != probe.Distinct_Cnt)
            throw new InvalidOperationException(
                $"[{def.Key}] tenant={tenantId} 源侧业务键重复（total={probe.Total} distinct={probe.Distinct_Cnt}）：" +
                "主数据唯一性已被破坏，transform 显式失败 —— 不做 first-wins / last-wins 静默取舍");
    }

    private sealed class SourceBizKeyProbe
    {
        public int Total { get; set; }
        public int Distinct_Cnt { get; set; }
        public int Blank_Cnt { get; set; }
    }
}