using System.Net.Http.Headers;

namespace AnchorCli.Providers;

/// <summary>
/// Interface for extracting token usage from provider responses.
/// </summary>
internal interface ITokenExtractor
{
    /// <summary>
    /// Extracts token usage from response headers and/or body.
    /// Returns (inputTokens, outputTokens) or null if unavailable.
    /// </summary>
    (int inputTokens, int outputTokens)? ExtractTokens(HttpResponseHeaders headers, string? responseBody);

    /// <summary>
    /// Gets the latency from response headers (in ms).
    /// </summary>
    int? ExtractLatency(HttpResponseHeaders headers);

    /// <summary>
    /// Gets the provider name for display purposes.
    /// </summary>
    string ProviderName { get; }
}