using Microsoft.Extensions.Diagnostics.HealthChecks;
using MongoDB.Driver;
using MongoDB.Bson;
using System.Diagnostics;

namespace BCards.Web.HealthChecks;

public class MongoDbHealthCheck : IHealthCheck
{
    private readonly IMongoDatabase _database;
    private readonly ILogger<MongoDbHealthCheck> _logger;

    public MongoDbHealthCheck(IMongoDatabase database, ILogger<MongoDbHealthCheck> logger)
    {
        _database = database;
        _logger = logger;
    }

    public async Task<HealthCheckResult> CheckHealthAsync(
        HealthCheckContext context,
        CancellationToken cancellationToken = default)
    {
        var stopwatch = Stopwatch.StartNew();
        
        try
        {
            // Executa ping no MongoDB
            var command = new BsonDocument("ping", 1);
            await _database.RunCommandAsync<BsonDocument>(command, cancellationToken: cancellationToken);
            
            stopwatch.Stop();
            var duration = stopwatch.ElapsedMilliseconds;

            _logger.LogInformation("MongoDB health check completed successfully in {Duration}ms", duration);

            var data = new Dictionary<string, object>
            {
                { "status", "healthy" },
                { "duration", $"{duration}ms" },
                { "database", _database.DatabaseNamespace.DatabaseName },
                { "connection_state", "connected" },
                { "latency", duration }
            };

            // Status baseado na latência
            if (duration > 5000) // > 5s
                return HealthCheckResult.Unhealthy($"MongoDB response time too high: {duration}ms", data: data);
            
            if (duration > 2000) // > 2s
                return HealthCheckResult.Degraded($"MongoDB response time elevated: {duration}ms", data: data);

            return HealthCheckResult.Healthy($"MongoDB is responsive ({duration}ms)", data: data);
        }
        catch (Exception ex)
        {
            stopwatch.Stop();
            var duration = stopwatch.ElapsedMilliseconds;

            _logger.LogError(ex, "MongoDB health check failed after {Duration}ms", duration);

            var data = new Dictionary<string, object>
            {
                { "status", "unhealthy" },
                { "duration", $"{duration}ms" },
                { "database", _database.DatabaseNamespace.DatabaseName },
                { "connection_state", "disconnected" },
                { "error", ex.Message }
            };

            return HealthCheckResult.Unhealthy($"MongoDB connection failed: {ex.Message}", ex, data);
        }
    }
}