using ChatBot.Services.Interfaces;

namespace ChatBot.Services.ErrorHandlers
{
    /// <summary>
    /// Error handler for rate limit errors (HTTP 429)
    /// </summary>
    public class RateLimitErrorHandler : IErrorHandler
    {
        private readonly ILogger<RateLimitErrorHandler> _logger;

        public RateLimitErrorHandler(ILogger<RateLimitErrorHandler> logger)
        {
            _logger = logger;
        }

        public bool CanHandle(Exception exception)
        {
            return exception.Message.Contains("429")
                || exception.Message.Contains("Too Many Requests")
                || exception.Message.Contains("rate limit", StringComparison.OrdinalIgnoreCase);
        }

        public async Task<ErrorHandlingResult> HandleAsync(
            Exception exception,
            int attempt,
            string currentModel,
            CancellationToken cancellationToken = default
        )
        {
            _logger.LogWarning(
                exception,
                "Rate limit exceeded on attempt {Attempt} for model {Model}",
                attempt,
                currentModel
            );

            // Apply exponential backoff for rate limiting
            var delay = TimeSpan.FromSeconds(Math.Pow(2, attempt - 1));
            var jitter = TimeSpan.FromMilliseconds(Random.Shared.Next(0, 2000));

            _logger.LogInformation(
                "Rate limit hit, waiting {Delay} before retry",
                delay.Add(jitter)
            );

            await Task.Delay(delay.Add(jitter), cancellationToken);

            return ErrorHandlingResult.Retry();
        }
    }
}