using System.Text.Json;
using Admin.NET.Plugin.AiDOP.Entity.S8;
using Admin.NET.Plugin.AiDOP.Infrastructure.S8;
using Admin.NET.Plugin.AiDOP.Service.S8.Rules.DataAccess;
using Admin.NET.Plugin.AiDOP.Service.S8.Rules.Definitions;
using Microsoft.Extensions.Logging;

namespace Admin.NET.Plugin.AiDOP.Service.S8.Rules;

/// <summary>
/// OUT_OF_RANGE 类规则 evaluator（"测量值越界"）。
/// 三种最小模式：固定上限 / 固定下限 / 行内上下限。
///
/// <para><b>S8-RULE-GOVERNANCE-BATCH1</b>：上下限、容差、测量列、异常类型、去重身份
/// 改由 <see cref="S8RuleDefinition"/> 供给，不再从 params_json 解析
/// （G01 的 single_threshold 兼容协议随 params 解析一并退役 —— 它服务的是"用户在页面里
/// 拼阈值"这个已经取消的能力）。当前仓内**没有任何 OUT_OF_RANGE 规则定义**，
/// 因此本 evaluator 实际不会被执行，这正是期望行为。</para>
/// 判定（任一命中即 HIT）：
///   measured &gt; upperBound + toleranceAbs 且 (measured - upperBound) / |upperBound| &gt; toleranceRatio → ABOVE_UPPER
///   measured &lt; lowerBound - toleranceAbs 且 (lowerBound - measured) / |lowerBound| &gt; toleranceRatio → BELOW_LOWER
/// upperBound / lowerBound 为 0 时 ratio 检查跳过（避免除零）。
/// 不做严重度阶梯、不做 SLA 升级、不做事件触发。
///
/// S8-DATASET-PROVIDER-FOUNDATION-1：取数改由 <see cref="S8MonitoringDataGateway"/> 承担，
/// 判定算法与迁移前逐行一致。
/// </summary>
public class S8OutOfRangeRuleEvaluator : IS8RuleEvaluator, ITransient
{
    public const string RuleTypeCode = "OUT_OF_RANGE";
    public string RuleType => RuleTypeCode;

    private readonly S8MonitoringDataGateway _dataGateway;
    private readonly IS8RuleCatalog _ruleCatalog;
    private readonly ILogger<S8OutOfRangeRuleEvaluator> _logger;

    public S8OutOfRangeRuleEvaluator(
        S8MonitoringDataGateway dataGateway,
        IS8RuleCatalog ruleCatalog,
        ILogger<S8OutOfRangeRuleEvaluator> logger)
    {
        _dataGateway = dataGateway;
        _ruleCatalog = ruleCatalog;
        _logger = logger;
    }

    public async Task<List<S8RuleHit>> EvaluateAsync(
        long tenantId,
        AdoS8WatchRule rule,
        CancellationToken cancellationToken = default)
    {
        // S8-RULE-GOVERNANCE-BATCH1：没有代码定义的规则一律不执行（详见 S8TimeoutRuleEvaluator 同处注释）。
        var effective = ResolveEffective(rule);

        // S8-SQL-EVALUATOR-GUARD-P2-1：每次评估解析 maxRows（env 优先，回退代码默认）。
        var maxRows = S8EvaluatorGuard.ResolveMaxRows(_logger);

        var data = await _dataGateway.LoadAsync(
            tenantId, rule, RuleTypeCode, maxRows, cancellationToken);

        return EvaluateRows(data.RowSet, effective, tenantId, DateTime.Now);
    }

    /// <summary>解析生效规则：定义必须存在、类型必须匹配、OUT_OF_RANGE 语义必须齐备。</summary>
    private S8EffectiveRule ResolveEffective(AdoS8WatchRule rule)
    {
        var definition = _ruleCatalog.TryGet(rule.RuleCode)
            ?? throw new S8RuleEvaluatorException(
                S8RuleCatalog.ReasonNotFound,
                $"规则 {rule.RuleCode} 在当前版本中没有代码定义，不予执行");

        if (!string.Equals(definition.RuleType, RuleTypeCode, StringComparison.Ordinal))
            throw new S8RuleEvaluatorException(
                "rule_type_mismatch",
                $"规则 {rule.RuleCode} 的代码定义类型为 {definition.RuleType}，不能由 OUT_OF_RANGE evaluator 执行");

        if (definition.OutOfRange == null)
            throw new S8RuleEvaluatorException(
                "rule_semantics_missing",
                $"规则 {rule.RuleCode} 的代码定义缺少 OUT_OF_RANGE 判定语义");

        return S8EffectiveRule.Resolve(rule, definition);
    }

    /// <summary>
    /// OUT_OF_RANGE 判定核心：只消费 canonical 行，不接触 SQL / DataTable / 数据源。
    /// 判定算法与迁移前逐行一致；internal 暴露供契约测试直接驱动。
    /// </summary>
    internal static List<S8RuleHit> EvaluateRows(
        S8MonitoringRowSet rowSet,
        S8EffectiveRule effective,
        long tenantId,
        DateTime detectedAt)
    {
        var definition = effective.Definition;
        var semantics = definition.OutOfRange!;
        var parameters = effective.Parameters;
        var rule = effective.Row;

        var hits = new List<S8RuleHit>();
        var exceptionTypeCode = definition.ExceptionTypeCode;
        var sourceObjectType = definition.SourceObjectType;

        var measuredValueColumn = semantics.MeasuredValueColumn;
        var objectCodeColumn = semantics.RelatedObjectCodeColumn;
        var objectIdColumn = semantics.SourceObjectIdColumn;

        foreach (var row in rowSet.Rows)
        {
            var measured = row.GetDecimal(measuredValueColumn);
            if (measured == null) continue;

            // 行内上下限优先；缺失时回退到固定上下限。
            decimal? lower = !string.IsNullOrWhiteSpace(semantics.LowerBoundColumn)
                ? row.GetDecimal(semantics.LowerBoundColumn!) ?? semantics.LowerBound
                : semantics.LowerBound;
            decimal? upper = !string.IsNullOrWhiteSpace(semantics.UpperBoundColumn)
                ? row.GetDecimal(semantics.UpperBoundColumn!) ?? semantics.UpperBound
                : semantics.UpperBound;

            if (lower == null && upper == null) continue; // 无界不命中

            string? direction = null;
            decimal deviation = 0m;
            if (upper != null && measured.Value > upper.Value + semantics.ToleranceAbs)
            {
                var dev = measured.Value - upper.Value;
                if (upper.Value == 0m || dev / Math.Abs(upper.Value) > semantics.ToleranceRatio)
                {
                    direction = "ABOVE_UPPER";
                    deviation = dev;
                }
            }
            if (direction == null && lower != null && measured.Value < lower.Value - semantics.ToleranceAbs)
            {
                var dev = lower.Value - measured.Value;
                if (lower.Value == 0m || dev / Math.Abs(lower.Value) > semantics.ToleranceRatio)
                {
                    direction = "BELOW_LOWER";
                    deviation = dev;
                }
            }
            if (direction == null) continue;

            var relatedObjectCode = row.GetString(objectCodeColumn) ?? string.Empty;
            if (string.IsNullOrWhiteSpace(relatedObjectCode)) continue;

            var sourceObjectId = row.GetString(objectIdColumn) ?? relatedObjectCode;

            var dedupKey = BuildDedupKey(tenantId, definition.RuleCode, sourceObjectType, sourceObjectId);

            hits.Add(new S8RuleHit
            {
                SourceRuleId = rule.Id,
                SourceRuleCode = definition.RuleCode,
                SourceObjectType = sourceObjectType,
                SourceObjectId = sourceObjectId,
                RelatedObjectCode = relatedObjectCode,
                ExceptionTypeCode = exceptionTypeCode,
                SceneCode = definition.SceneCode,
                Severity = parameters.Severity,
                DedupKey = dedupKey,
                SourcePayload = BuildPayload(row, sourceObjectType, sourceObjectId, measured.Value, lower, upper, deviation, direction, exceptionTypeCode),
                DetectedAt = detectedAt,
                Title = BuildTitle(sourceObjectType, sourceObjectId, measured.Value, lower, upper, direction),
                OccurrenceDeptId = row.GetLong(S8CanonicalColumns.OccurrenceDeptId) ?? parameters.DefaultOccurrenceDeptId,
                ResponsibleDeptId = row.GetLong(S8CanonicalColumns.ResponsibleDeptId) ?? parameters.DefaultResponsibleDeptId
            });
        }

        return hits;
    }

    /// <summary>
    /// 构造 dedup_key：<c>T{tenant}:R{ruleCode}:{sourceObjectType}:{sourceObjectId}</c>。
    ///
    /// <para><b>S8-TENANT-ONLY-BATCH5：去掉了 <c>:F{factory}</c> 段。</b>
    /// 租户隔离由首段 <c>T{tenant}</c> 与各查询的 <c>tenant_id</c> 谓词双重保证；
    /// 工厂段既不提供隔离，又让同一个业务对象在不同工厂元数据下被当成两个异常。</para>
    ///
    /// <para>真库证据（迁移前取证）：<c>dwd_supplier_delivery</c> 全表 39854 行 / 4 租户 / 97 个快照，
    /// <c>(tenant_id, stat_date, po_no, po_line)</c> 重复组为 0，跨工厂碰撞组为 0。
    /// 若将来某个规则的 SourceObjectId 在租户内不唯一，唯一性应由该规则的
    /// <b>SourceObjectId contract</b> 负责（例如把工厂编号并进对象标识），
    /// 而不是把工厂重新变回隔离维度。</para>
    ///
    /// internal 暴露供测试。
    /// </summary>
    internal static string BuildDedupKey(long tenantId, string ruleCode, string sourceObjectType, string sourceObjectId) =>
        $"T{tenantId}:R{ruleCode}:{sourceObjectType}:{sourceObjectId}";

    private static string BuildTitle(string sourceObjectType, string sourceObjectId, decimal measured, decimal? lower, decimal? upper, string direction)
    {
        if (direction == "ABOVE_UPPER")
            return $"[超差] {sourceObjectType} {sourceObjectId} 测量值 {measured:0.##} 超过上限 {upper:0.##}";
        return $"[超差] {sourceObjectType} {sourceObjectId} 测量值 {measured:0.##} 低于下限 {lower:0.##}";
    }

    private static string BuildPayload(S8MonitoringRow row, string sourceObjectType, string sourceObjectId,
        decimal measured, decimal? lower, decimal? upper, decimal deviation, string direction, string exceptionTypeCode)
    {
        var payload = new Dictionary<string, object?>(StringComparer.OrdinalIgnoreCase);
        foreach (var kv in row.Values)
            payload[kv.Key] = kv.Value;
        payload["measured_value"] = measured;
        payload["lower_bound"] = lower;
        payload["upper_bound"] = upper;
        payload["deviation"] = deviation;
        payload["direction"] = direction;
        payload["__ruleType"] = RuleTypeCode;
        payload["__sourceObjectType"] = sourceObjectType;
        payload["__sourceObjectId"] = sourceObjectId;
        payload["__exceptionTypeCode"] = exceptionTypeCode;
        return JsonSerializer.Serialize(payload);
    }

}