using System.Diagnostics;
using System.Diagnostics.Metrics;
using Microsoft.Extensions.Logging;

namespace CellularManagement.Infrastructure.Monitoring;

public class WebSocketMetrics
{
    private readonly ILogger<WebSocketMetrics> _logger;
    private readonly Meter _meter;
    private readonly Counter<int> _connectionsCounter;
    private readonly Counter<int> _messagesCounter;
    private readonly Histogram<double> _messageLatency;
    private readonly Histogram<double> _messageSize;
    private readonly Counter<int> _errorsCounter;

    public WebSocketMetrics(ILogger<WebSocketMetrics> logger)
    {
        _logger = logger;
        _meter = new Meter("CellularManagement.WebSocket", "1.0.0");

        _connectionsCounter = _meter.CreateCounter<int>("websocket.connections", "个", "活跃连接数");
        _messagesCounter = _meter.CreateCounter<int>("websocket.messages", "个", "消息处理数");
        _messageLatency = _meter.CreateHistogram<double>("websocket.message.latency", "ms", "消息处理延迟");
        _messageSize = _meter.CreateHistogram<double>("websocket.message.size", "bytes", "消息大小");
        _errorsCounter = _meter.CreateCounter<int>("websocket.errors", "个", "错误数");
    }

    public void ConnectionEstablished()
    {
        _connectionsCounter.Add(1);
        _logger.LogInformation("WebSocket connection established");
    }

    public void ConnectionClosed()
    {
        _connectionsCounter.Add(-1);
        _logger.LogInformation("WebSocket connection closed");
    }

    public void MessageReceived(int size)
    {
        _messagesCounter.Add(1);
        _messageSize.Record(size);
        _logger.LogDebug("WebSocket message received, size: {Size} bytes", size);
    }

    public void MessageProcessed(TimeSpan latency)
    {
        _messageLatency.Record(latency.TotalMilliseconds);
        _logger.LogDebug("WebSocket message processed, latency: {Latency}ms", latency.TotalMilliseconds);
    }

    public void ErrorOccurred(string errorType)
    {
        _errorsCounter.Add(1);
        _logger.LogError("WebSocket error occurred: {ErrorType}", errorType);
    }

    public void RecordGauge(string name, double value)
    {
        var gauge = _meter.CreateObservableGauge<double>($"websocket.{name}", () => value);
        _logger.LogDebug("WebSocket gauge recorded: {Name} = {Value}", name, value);
    }
}