using Admin.NET.Plugin.AiDOP.Entity.S8;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using SqlSugar;

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

/// <summary>
/// 扫描疑似卡死的 ActiveFlow 异常，并输出可检索告警。
/// 当前只做发现，不做自动恢复。
/// </summary>
public class S8ActiveFlowWatchService : ITransient
{
    public const string AlertChannel = "s8-active-flow-stuck";

    private readonly SqlSugarRepository<AdoS8Exception> _exceptionRep;
    private readonly SqlSugarRepository<AdoS8NotificationLog> _notificationLogRep;
    private readonly S8NotificationService _notificationService;
    private readonly S8ActiveFlowWatchOptions _options;
    private readonly ILogger<S8ActiveFlowWatchService> _logger;

    public S8ActiveFlowWatchService(
        SqlSugarRepository<AdoS8Exception> exceptionRep,
        SqlSugarRepository<AdoS8NotificationLog> notificationLogRep,
        S8NotificationService notificationService,
        IOptions<S8ActiveFlowWatchOptions> options,
        ILogger<S8ActiveFlowWatchService> logger)
    {
        _exceptionRep = exceptionRep;
        _notificationLogRep = notificationLogRep;
        _notificationService = notificationService;
        _options = options.Value;
        _logger = logger;
    }

    public async Task<int> ScanAsync(CancellationToken cancellationToken = default)
    {
        if (!_options.Enabled)
            return 0;

        var now = DateTime.Now;
        var thresholdHours = _options.ThresholdHours > 0 ? _options.ThresholdHours : 4;
        var cooldownMinutes = _options.AlertCooldownMinutes > 0 ? _options.AlertCooldownMinutes : 60;
        var batchSize = _options.BatchSize > 0 ? _options.BatchSize : 100;
        var staleBefore = now.AddHours(-thresholdHours);
        var alertedAfter = now.AddMinutes(-cooldownMinutes);

        var staleExceptions = await _exceptionRep.AsQueryable()
            .Where(x => !x.IsDeleted && x.ActiveFlowInstanceId.HasValue &&
                        SqlFunc.IsNull(x.UpdatedAt, x.CreatedAt) < staleBefore)
            .OrderBy(x => x.UpdatedAt, OrderByType.Asc)
            .OrderBy(x => x.Id, OrderByType.Asc)
            .Take(batchSize)
            .ToListAsync();

        if (staleExceptions.Count == 0)
            return 0;

        var exceptionIds = staleExceptions.Select(x => x.Id).ToHashSet();
        var recentAlertLogs = await _notificationLogRep.AsQueryable()
            .Where(x => x.Channel == AlertChannel && x.CreatedAt >= alertedAfter && x.ExceptionId != null)
            .ToListAsync();

        var alertedIds = recentAlertLogs
            .Where(x => x.ExceptionId.HasValue && exceptionIds.Contains(x.ExceptionId.Value))
            .Select(x => x.ExceptionId!.Value)
            .ToHashSet();

        var alertCount = 0;
        foreach (var item in staleExceptions.Where(x => !alertedIds.Contains(x.Id)))
        {
            cancellationToken.ThrowIfCancellationRequested();

            var lastTouchedAt = item.UpdatedAt ?? item.CreatedAt;
            var payload = new
            {
                type = "S8_ACTIVE_FLOW_STUCK",
                message = "S8 异常存在进行中的审批实例，但已超过阈值未更新，请人工检查审批流状态与回调链路",
                exceptionId = item.Id,
                exceptionCode = item.ExceptionCode,
                title = item.Title,
                status = item.Status,
                activeFlowInstanceId = item.ActiveFlowInstanceId,
                activeFlowBizType = item.ActiveFlowBizType,
                tenantId = item.TenantId,
                factoryId = item.FactoryId,
                lastTouchedAt,
                thresholdHours,
                detectedAt = now
            };

            try
            {
                await _notificationService.SendAsync(item.TenantId, item.FactoryId, item.Id, AlertChannel, payload);
                _logger.LogWarning(
                    "S8 ActiveFlow 疑似卡死: ExceptionId={ExceptionId}, Code={ExceptionCode}, Status={Status}, FlowInstanceId={FlowInstanceId}, LastTouchedAt={LastTouchedAt}, ThresholdHours={ThresholdHours}",
                    item.Id,
                    item.ExceptionCode,
                    item.Status,
                    item.ActiveFlowInstanceId,
                    lastTouchedAt,
                    thresholdHours);
                alertCount++;
            }
            catch (Exception ex)
            {
                _logger.LogError(
                    ex,
                    "S8 ActiveFlow 卡死告警写入失败: ExceptionId={ExceptionId}, Code={ExceptionCode}, FlowInstanceId={FlowInstanceId}",
                    item.Id,
                    item.ExceptionCode,
                    item.ActiveFlowInstanceId);
            }
        }

        if (alertCount > 0)
        {
            _logger.LogInformation(
                "S8 ActiveFlow 卡死扫描完成，本轮新增告警 {AlertCount} 条，候选 {CandidateCount} 条",
                alertCount,
                staleExceptions.Count);
        }

        return alertCount;
    }
}