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>
/// R2 TIMEOUT 类规则 evaluator MVP。
/// params_json 约定（首版最小集合）：
///   { dueAtField, statusField, completedStates[], objectCodeField, objectIdField, graceMinutes, exceptionTypeCode }
/// 判定：dueAt &lt;= now - graceMinutes 且 status 不在 completedStates 内 → HIT。
/// 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，
/// 本类不再直接依赖 DataTable / 数据源 / SQL。判定算法与迁移前逐行一致。
/// </summary>
public class S8TimeoutRuleEvaluator : IS8RuleEvaluator, ITransient
{
    public const string RuleTypeCode = "TIMEOUT";
    public string RuleType => RuleTypeCode;

    // S8-WATCH-EXPRESSION-COLUMN-CONTRACT-FIX-1：S8ConfigDraftService.BuildExpression 统一把结果列
    // 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（兼容历史未别名规则）。
    private const string CanonicalDueAtColumn = S8CanonicalColumns.DueAt;
    private const string CanonicalStatusColumn = S8CanonicalColumns.Status;
    private const string CanonicalSourceObjectIdColumn = S8CanonicalColumns.SourceObjectId;
    private const string CanonicalRelatedObjectCodeColumn = S8CanonicalColumns.RelatedObjectCode;

    private readonly S8MonitoringDataGateway _dataGateway;
    private readonly ILogger<S8TimeoutRuleEvaluator> _logger;

    public S8TimeoutRuleEvaluator(
        S8MonitoringDataGateway dataGateway,
        ILogger<S8TimeoutRuleEvaluator> 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：所有"非命中判定"路径均改为抛出 S8RuleEvaluatorException，
        // 由 SchedulerService 标记 evaluate_failed 并跳过 recovery reconcile，避免对未确认未命中的 rule 误标 recovered_at。
        // LEGACY_SQL 仍要求 expression 存在；STANDARD_DATASET 不依赖 expression。
        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", $"TIMEOUT 规则 {rule.RuleCode} 缺少 expression 或 params_json");

        S8TimeoutParams parameters;
        try { parameters = S8TimeoutParams.Parse(rule.ParamsJson!); }
        catch (Exception ex) { throw new S8RuleEvaluatorException("params_parse_failed", $"TIMEOUT 规则 {rule.RuleCode} params_json 解析失败：{ex.Message}", ex); }

        if (string.IsNullOrWhiteSpace(parameters.DueAtField)
            || string.IsNullOrWhiteSpace(parameters.StatusField)
            || string.IsNullOrWhiteSpace(parameters.ExceptionTypeCode))
            throw new S8RuleEvaluatorException("params_schema_invalid", $"TIMEOUT 规则 {rule.RuleCode} params 缺少必填字段 dueAtField/statusField/exceptionTypeCode");

        // 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>
    /// TIMEOUT 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,
        S8TimeoutParams parameters,
        AdoS8WatchRule rule,
        long tenantId,
        long factoryId,
        long dataSourceId,
        DateTime detectedAt)
    {
        var hits = new List<S8RuleHit>();
        var threshold = detectedAt.AddMinutes(-parameters.GraceMinutes);
        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 statusColumn = ResolveResultColumn(rowSet, CanonicalStatusColumn, parameters.StatusField);
        var dueAtColumn = ResolveResultColumn(rowSet, CanonicalDueAtColumn, parameters.DueAtField);
        var objectCodeColumn = ResolveResultColumn(rowSet, CanonicalRelatedObjectCodeColumn, parameters.ObjectCodeField);
        var objectIdColumn = ResolveResultColumn(rowSet, CanonicalSourceObjectIdColumn, parameters.ObjectIdField);

        foreach (var row in rowSet.Rows)
        {
            var status = row.GetString(statusColumn) ?? string.Empty;
            if (parameters.CompletedStates.Contains(status, StringComparer.OrdinalIgnoreCase))
                continue;

            var due = row.GetDateTime(dueAtColumn);
            if (due == null || due > threshold) 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 = parameters.ExceptionTypeCode!,
                SceneCode = rule.SceneCode,
                Severity = S8SeverityCode.Normalize(rule.Severity),
                DedupKey = dedupKey,
                SourcePayload = BuildPayload(row, sourceObjectType, sourceObjectId, due.Value, status, parameters),
                DetectedAt = detectedAt,
                Title = $"[超时] {sourceObjectType} {sourceObjectId} 已超期至 {due.Value:yyyy-MM-dd HH:mm:ss}（状态 {status}）",
                DataSourceId = dataSourceId,
                OccurrenceDeptId = row.GetLong(S8CanonicalColumns.OccurrenceDeptId),
                ResponsibleDeptId = row.GetLong(S8CanonicalColumns.ResponsibleDeptId)
            });
        }

        return hits;
    }

    /// <summary>构造 R2 dedup_key 稳定字符串：T{tenant}:F{factory}:R{ruleCode}:{sourceObjectType}:{sourceObjectId}。internal 暴露供测试。</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 BuildPayload(S8MonitoringRow row, string sourceObjectType, string sourceObjectId, DateTime dueAt, string status, S8TimeoutParams parameters)
    {
        var payload = new Dictionary<string, object?>(StringComparer.OrdinalIgnoreCase);
        foreach (var kv in row.Values)
            payload[kv.Key] = kv.Value;
        payload["__ruleType"] = RuleTypeCode;
        payload["__sourceObjectType"] = sourceObjectType;
        payload["__sourceObjectId"] = sourceObjectId;
        payload["__dueAt"] = dueAt;
        payload["__status"] = status;
        payload["__graceMinutes"] = parameters.GraceMinutes;
        payload["__exceptionTypeCode"] = parameters.ExceptionTypeCode;
        return JsonSerializer.Serialize(payload);
    }

    /// <summary>
    /// 结果列名解析：BuildExpression 已把结果列统一别名为 canonical（due_at/status/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（兼容历史未别名规则）。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!;
    }
}