using System.Net.Http.Headers;

namespace AnchorCli.Providers;

/// <summary>
/// Token extractor for OpenRouter responses.
/// </summary>
internal sealed class OpenRouterTokenExtractor : ITokenExtractor
{
    public string ProviderName => "OpenRouter";

    public (int inputTokens, int outputTokens)? ExtractTokens(HttpResponseHeaders headers, string? responseBody)
    {
        // OpenRouter provides x-total-tokens header
        if (headers.TryGetValues("x-total-tokens", out var values))
        {
            // Note: OpenRouter only provides total tokens, not split
            // We'll estimate split based on typical ratios if needed
            if (long.TryParse(values.FirstOrDefault(), out var total))
            {
                // For now, return total as output (placeholder until we have better splitting)
                // In practice, you'd need to track input separately from the request
                return (0, (int)total);
            }
        }

        return null;
    }

    public int? ExtractLatency(HttpResponseHeaders headers)
    {
        if (headers.TryGetValues("x-response-timing", out var values))
        {
            if (int.TryParse(values.FirstOrDefault(), out var latency))
            {
                return latency;
            }
        }

        return null;
    }
}