using decePubClient.Extensions;
using decePubClient.Models;
using decePubClient.Models.Mastodon;

namespace decePubClient.Services
{
	/// <summary>How a post reached PrivaPub (/api/privapub/v1/statuses/{id}/provenance), read on demand and kept for the session.</summary>
	public class ProvenanceService(IHttpService httpService)
	{
		readonly Dictionary<string, Provenance> provenances = [];

		public Provenance Known(string statusId) => statusId is not null ? provenances.GetValueOrDefault(statusId) : null;

		/// <summary>The post's provenance, or null when PrivaPub has none to show.</summary>
		public async Task<Provenance> Get(string statusId, CancellationToken cancellationToken = default)
		{
			if (Known(statusId) is { } known)
				return known;

			using var response = await httpService.GetAnon(APIs.PrivaPub.GET_M_Provenance(statusId), cancellationToken: cancellationToken);
			if (!response.IsSuccessStatusCode)
				return null;

			var provenance = await response.MastodonReadFromJsonAsync<Provenance>(cancellationToken);
			if (provenance is not null)
				provenances[statusId] = provenance;
			return provenance;
		}
	}
}