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 Microsoft.Extensions.Logging;

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

/// <summary>
/// R3 OUT_OF_RANGE 类规则 evaluator MVP（"测量值越界"）。
/// 三种最小模式：固定上限 / 固定下限 / 行内上下限；兼容 G01 single_threshold 协议。
/// 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 const string DefaultExceptionTypeCode = "EQUIP_FAULT";

    // S8-WATCH-EXPRESSION-COLUMN-CONTRACT-SHORTAGE-OUTOFRANGE-FIX-1：S8ConfigDraftService.BuildExpression
    // 把 VALUE_RANGE 结果列统一别名为以下 canonical 名（无论源表真实列名为何）。evaluator 优先按 canonical
    // 读取，仅当结果集不含 canonical 列时才回退到 params_json 指定的真实列名（兼容历史/手工规则）。
    // 上下限为行内可选字段、无 canonical 契约，沿用 params 既有逻辑不变。
    private const string CanonicalMeasuredValueColumn = S8CanonicalColumns.MeasuredValue;
    private const string CanonicalSourceObjectIdColumn = S8CanonicalColumns.SourceObjectId;
    private const string CanonicalRelatedObjectCodeColumn = S8CanonicalColumns.RelatedObjectCode;

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

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

    public async Task<List<S8RuleHit>> EvaluateAsync(
        long tenantId,
        long factoryId,
        AdoS8WatchRule rule,
        IReadOnlyList<AdoS8AlertRule> alertRules,
        CancellationToken cancellationToken = default)
    {
        // R5 evaluator 失败语义保护：与 TIMEOUT/SHORTAGE 同形，所有"非命中判定"路径改抛 S8RuleEvaluatorException。
        var accessMode = S8DataAccessMode.Resolve(rule.DataAccessMode);
        var expressionRequired = accessMode == S8DataAccessMode.LegacySql;
        if ((expressionRequired && string.IsNullOrWhiteSpace(rule.Expression))
            || string.IsNullOrWhiteSpace(rule.ParamsJson))
            throw new S8RuleEvaluatorException("rule_not_configured", $"OUT_OF_RANGE 规则 {rule.RuleCode} 缺少 expression 或 params_json");

        S8OutOfRangeParams parameters;
        try { parameters = S8OutOfRangeParams.Parse(rule.ParamsJson!); }
        catch (Exception ex) { throw new S8RuleEvaluatorException("params_parse_failed", $"OUT_OF_RANGE 规则 {rule.RuleCode} params_json 解析失败：{ex.Message}", ex); }

        if (string.IsNullOrWhiteSpace(parameters.MeasuredValueField))
            throw new S8RuleEvaluatorException("params_schema_invalid", $"OUT_OF_RANGE 规则 {rule.RuleCode} params 缺少必填字段 measuredValueField");

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

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

        return EvaluateRows(data.RowSet, parameters, rule, tenantId, factoryId, data.DataSourceId, DateTime.Now);
    }

    /// <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,
        S8OutOfRangeParams parameters,
        AdoS8WatchRule rule,
        long tenantId,
        long factoryId,
        long dataSourceId,
        DateTime detectedAt)
    {
        var hits = new List<S8RuleHit>();
        var exceptionTypeCode = string.IsNullOrWhiteSpace(parameters.ExceptionTypeCode)
            ? DefaultExceptionTypeCode
            : parameters.ExceptionTypeCode!;
        var sourceObjectType = string.IsNullOrWhiteSpace(rule.SourceObjectType)
            ? rule.WatchObjectType
            : rule.SourceObjectType!;

        // 结果列名一次性解析（结果集列在整个结果集内稳定）：canonical 优先，缺失回退 params 真实列名。
        var measuredValueColumn = ResolveResultColumn(rowSet, CanonicalMeasuredValueColumn, parameters.MeasuredValueField);
        var objectCodeColumn = ResolveResultColumn(rowSet, CanonicalRelatedObjectCodeColumn, parameters.ObjectCodeField);
        var objectIdColumn = ResolveResultColumn(rowSet, CanonicalSourceObjectIdColumn, parameters.ObjectIdField);

        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(parameters.LowerBoundField)
                ? row.GetDecimal(parameters.LowerBoundField!) ?? parameters.LowerBound
                : parameters.LowerBound;
            decimal? upper = !string.IsNullOrWhiteSpace(parameters.UpperBoundField)
                ? row.GetDecimal(parameters.UpperBoundField!) ?? parameters.UpperBound
                : parameters.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 + parameters.ToleranceAbs)
            {
                var dev = measured.Value - upper.Value;
                if (upper.Value == 0m || dev / Math.Abs(upper.Value) > parameters.ToleranceRatio)
                {
                    direction = "ABOVE_UPPER";
                    deviation = dev;
                }
            }
            if (direction == null && lower != null && measured.Value < lower.Value - parameters.ToleranceAbs)
            {
                var dev = lower.Value - measured.Value;
                if (lower.Value == 0m || dev / Math.Abs(lower.Value) > parameters.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, factoryId, rule.RuleCode, sourceObjectType, sourceObjectId);

            hits.Add(new S8RuleHit
            {
                SourceRuleId = rule.Id,
                SourceRuleCode = rule.RuleCode,
                SourceObjectType = sourceObjectType,
                SourceObjectId = sourceObjectId,
                RelatedObjectCode = relatedObjectCode,
                ExceptionTypeCode = exceptionTypeCode,
                SceneCode = rule.SceneCode,
                Severity = S8SeverityCode.Normalize(rule.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),
                DataSourceId = dataSourceId,
                OccurrenceDeptId = row.GetLong(S8CanonicalColumns.OccurrenceDeptId),
                ResponsibleDeptId = row.GetLong(S8CanonicalColumns.ResponsibleDeptId)
            });
        }

        return hits;
    }

    /// <summary>R3 OUT_OF_RANGE dedup_key：与 TIMEOUT/SHORTAGE 同形 T{t}:F{f}:R{ruleCode}:{sourceObjectType}:{sourceObjectId}。</summary>
    internal static string BuildDedupKey(long tenantId, long factoryId, string ruleCode, string sourceObjectType, string sourceObjectId) =>
        $"T{tenantId}:F{factoryId}: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);
    }

    /// <summary>
    /// 结果列名解析：BuildExpression 已把 VALUE_RANGE 结果列统一别名为 canonical（measured_value/
    /// source_object_id/related_object_code）。优先返回 canonical 列名；仅当结果集不含 canonical 列时，
    /// 回退到 params_json 指定的真实列名（兼容历史/手工规则）。仅在 canonical 与 params 字段之间二选一，
    /// 不新增无依据兜底字段。
    /// </summary>
    private static string ResolveResultColumn(S8MonitoringRowSet rowSet, string canonicalColumn, string? paramsColumn)
    {
        if (rowSet.HasColumn(canonicalColumn)) return canonicalColumn;
        return string.IsNullOrWhiteSpace(paramsColumn) ? canonicalColumn : paramsColumn!;
    }
}