using System.Collections.Concurrent;
using System.Net.Http.Json;
using System.Text.Json;

public static class AuthHelper
{
    private static readonly ConcurrentDictionary<string, string> TokenCache = new();

    /// <summary>
    /// Logs in as the given user and returns an HttpClient with the JWT
    /// Authorization header pre-configured. Login also returns a refresh token;
    /// integration tests use the access token only.
    /// </summary>
    public static async Task<HttpClient> LoginAsync(
        ApiFixture fixture, string username = "entry1", string password = "password")
    {
        var cacheKey = $"{username}:{password}";

        if (!TokenCache.TryGetValue(cacheKey, out var token))
        {
            var loginClient = fixture.CreateClient();
            var loginResp = await loginClient.PostAsJsonAsync("/api/v1/auth/login",
                new { username, password });

            loginResp.EnsureSuccessStatusCode();

            var body = await loginResp.Content.ReadFromJsonAsync<JsonDocument>();
            token = body!.RootElement.GetProperty("data").GetProperty("token").GetString()!;
            TokenCache[cacheKey] = token;
        }

        var client = fixture.CreateClient();
        client.DefaultRequestHeaders.Authorization =
            new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", token);

        return client;
    }
}