namespace StellaOps.Microservice;

/// <summary>
/// Abstraction for HTTP-style header collection.
/// </summary>
public interface IHeaderCollection : IEnumerable<KeyValuePair<string, string>>
{
    /// <summary>
    /// Gets a header value by key.
    /// </summary>
    /// <param name="key">The header key (case-insensitive).</param>
    /// <returns>The header value, or null if not found.</returns>
    string? this[string key] { get; }

    /// <summary>
    /// Gets all values for a header key.
    /// </summary>
    /// <param name="key">The header key (case-insensitive).</param>
    /// <returns>All values for the key.</returns>
    IEnumerable<string> GetValues(string key);

    /// <summary>
    /// Tries to get a header value.
    /// </summary>
    /// <param name="key">The header key.</param>
    /// <param name="value">The header value if found.</param>
    /// <returns>True if the header was found.</returns>
    bool TryGetValue(string key, out string? value);

    /// <summary>
    /// Checks if a header exists.
    /// </summary>
    /// <param name="key">The header key.</param>
    /// <returns>True if the header exists.</returns>
    bool ContainsKey(string key);
}