using JiShe.CollectBus.Common;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using System.Diagnostics;
using System.Threading.Channels;
using Volo.Abp.DependencyInjection;

namespace JiShe.CollectBus.DataChannels
{
    /// <summary>
    /// 数据通道管理服务
    /// </summary>
    public class DataChannelManageService : IDataChannelManageService, ITransientDependency
    {
        private readonly ILogger<DataChannelManageService> _logger;
        private readonly IoTDBSessionPoolProvider _dbProvider;
        private readonly IProducerService _producerService;
        private readonly KafkaOptionConfig _kafkaOptions;
        private readonly ServerApplicationOptions _applicationOptions;  

        public DataChannelManageService(
            ILogger<DataChannelManageService> logger,
            IoTDBSessionPoolProvider dbProvider, 
            IProducerService producerService,
            IOptions<KafkaOptionConfig> kafkaOptions,
            IOptions<ServerApplicationOptions> applicationOptions)
        {
            _logger = logger;
            _dbProvider = dbProvider; 
            _producerService = producerService;
            _kafkaOptions = kafkaOptions.Value;
            _applicationOptions = applicationOptions.Value;  
        }

        /// <summary>
        /// 定时任务数据通道写入
        /// </summary>
        /// <returns></returns>
        public async Task ScheduledMeterTaskWriterAsync(ChannelWriter<ValueTuple<string, List<MeterReadingTelemetryPacketInfo>>> _telemetryPacketInfoWriter, ValueTuple<string, List<MeterReadingTelemetryPacketInfo>> dataItems)
        {
            await _telemetryPacketInfoWriter.WriteAsync(dataItems);
        }
        /// <summary>
        /// 定时任务数据入库和Kafka推送通道
        /// </summary>
        public async Task ScheduledMeterTaskReadingAsync(
            ChannelReader<ValueTuple<string, List<MeterReadingTelemetryPacketInfo>>> telemetryPacketInfoReader)
        {
            const int BatchSize = 50000;
            const int EmptyWaitMilliseconds = 50;
            var timeout = TimeSpan.FromMilliseconds(50);
            var timer = Stopwatch.StartNew();
            long timeoutMilliseconds = 0;
            var metadata = await _dbProvider.GetMetadata<MeterReadingTelemetryPacketInfo>();
            var timeoutStopwatch = Stopwatch.StartNew();

            try
            {
                while (true)
                {
                    var batch = new List<ValueTuple<string, List<MeterReadingTelemetryPacketInfo>>>();
                    var canRead = telemetryPacketInfoReader.Count;
                    if (canRead <= 0)
                    {
                        if (timeoutMilliseconds > 0)
                        {
                            _logger.LogError($"{nameof(ScheduledMeterTaskReadingAsync)} 任务数据通道处理数据耗时{timeoutMilliseconds}毫秒");
                        }
                        timeoutMilliseconds = 0;
                        //无消息时短等待50毫秒
                        await Task.Delay(EmptyWaitMilliseconds);
                        continue;
                    }

                    timer.Restart();
                    timeoutStopwatch.Restart();

                    try
                    {
                        // 异步批量读取数据
                        while (batch != null && batch.Count < BatchSize && timeoutStopwatch.Elapsed <= timeout)
                        {
                            try
                            {
                                if (telemetryPacketInfoReader.TryRead(out var dataItem))
                                {
                                    batch.Add(dataItem);
                                }
                            }
                            catch (Exception)
                            {
                                throw;
                            }
                        }
                    }
                    catch (Exception)
                    {
                        throw;
                    }
                     

                    if (batch.Count == 0)
                    {
                        await Task.Delay(EmptyWaitMilliseconds);
                        continue;
                    }

                    // 按TopicName分组处理
                    var topicGroups = new Dictionary<string, List<MeterReadingTelemetryPacketInfo>>();
                    foreach (var (topicName, records) in batch)
                    {
                        if (!topicGroups.TryGetValue(topicName, out var list))
                        {
                            list = new List<MeterReadingTelemetryPacketInfo>();
                            topicGroups[topicName] = list;
                        }
                        list.AddRange(records);
                    }

                    // 处理每个分组
                    foreach (var (topicName, records) in topicGroups)
                    {
                        try
                        {
                            // 批量写入数据库
                            await _dbProvider.GetSessionPool(true).BatchInsertAsync(metadata, records);

                            // 限流推送Kafka
                            await DeviceGroupBalanceControl.ProcessWithThrottleAsync(
                                items: records,
                                deviceIdSelector: data => data.DeviceId,
                                processor: async (data, groupIndex) =>
                                    await KafkaProducerIssuedMessageAction(topicName, data, groupIndex)
                            );
                        }
                        catch (Exception ex)
                        {
                            _logger.LogError(ex, "数据通道处理主题 {TopicName} 数据时发生异常", topicName);
                        }
                    }

                    batch.Clear();
                    timer.Stop();

                    timeoutStopwatch.Stop();
                    timeoutMilliseconds = timeoutMilliseconds + timer.ElapsedMilliseconds;
                }
            }
            catch (Exception ex)
            {
                _logger.LogCritical(ex, "定时任务处理发生致命错误");
                throw;
            }
        }

        /// <summary>
        /// Kafka推送消息(增加重试机制和参数校验)
        /// </summary>
        protected async Task KafkaProducerIssuedMessageAction<T>(
            string topicName,
            T taskRecord,
            int partition) where T : class
        {
            if (string.IsNullOrWhiteSpace(topicName) || taskRecord == null)
            {
                throw new Exception($"{nameof(KafkaProducerIssuedMessageAction)} 推送消息失败，参数异常,-101");
            }

            const int maxRetries = 3;//重试次数
            for (int retry = 0; retry < maxRetries; retry++)
            {
                try
                {
                    await _producerService.ProduceAsync(topicName, taskRecord, partition);
                    return;
                }
                catch (Exception ex)
                {
                    _logger.LogWarning(ex, "Kafka推送{topicName}主题分区{partition}重试中({Retry}/{MaxRetries})", topicName, partition, retry + 1, maxRetries);
                    if (retry == maxRetries - 1) throw;
                    await Task.Delay(1000 * (retry + 1));
                }
            }
        } 
    }
}