using Jellyfin.Plugin.Vanguard.Configuration;
using Microsoft.Extensions.Logging;

namespace Jellyfin.Plugin.Vanguard.Services;

/// <summary>Folder name (streamer / submitter) -> Discord member, via the config map or Authentik.</summary>
public sealed class IdentityResolver
{
    private static readonly TimeSpan MemberTtl = TimeSpan.FromHours(6);
    private static readonly TimeSpan IdentityTtl = TimeSpan.FromHours(24);

    private readonly DiscordClient _discord;
    private readonly AuthentikClient _authentik;
    private readonly EventStore _store;
    private readonly ILogger<IdentityResolver> _log;

    public IdentityResolver(DiscordClient discord, AuthentikClient authentik, EventStore store, ILogger<IdentityResolver> log)
    { _discord = discord; _authentik = authentik; _store = store; _log = log; }

    private static PluginConfiguration Cfg => Plugin.Instance?.Configuration ?? new PluginConfiguration();

    public async Task<DiscordMember?> ResolveFolderAsync(string folderName, CancellationToken ct)
    {
        var cfg = Cfg;
        if (string.IsNullOrWhiteSpace(cfg.DiscordBotToken) || string.IsNullOrWhiteSpace(cfg.DiscordGuildId)) return null;

        if (!_store.TryGetCachedIdentity(folderName, IdentityTtl, out var discordId))
        {
            discordId = await LookupDiscordIdAsync(cfg, folderName, ct).ConfigureAwait(false);
            _store.CacheIdentity(folderName, discordId);
        }
        if (discordId is null) return null;

        var cached = _store.GetCachedMember(discordId, MemberTtl);
        if (cached is not null) return cached;
        var m = await _discord.GetGuildMemberAsync(cfg.DiscordBotToken, cfg.DiscordGuildId, discordId, ct).ConfigureAwait(false);
        if (m is not null) _store.CacheMember(m);
        return m;
    }

    private async Task<string?> LookupDiscordIdAsync(PluginConfiguration cfg, string folder, CancellationToken ct)
    {
        string authentikUser = folder;
        foreach (var raw in (cfg.FolderIdentityMap ?? string.Empty).Split('\n'))
        {
            var line = raw.Trim();
            var eq = line.IndexOf('=');
            if (eq <= 0 || !line[..eq].Trim().Equals(folder, StringComparison.OrdinalIgnoreCase)) continue;
            var val = line[(eq + 1)..].Trim();
            if (val.StartsWith("authentik:", StringComparison.OrdinalIgnoreCase)) { authentikUser = val["authentik:".Length..].Trim(); break; }
            if (val.All(char.IsDigit) && val.Length >= 15) return val;            // a Discord snowflake
        }
        var id = await _authentik.GetDiscordIdForUsernameAsync(cfg.AuthentikUrl, cfg.AuthentikApiToken, authentikUser, ct).ConfigureAwait(false);
        if (id is null) _log.LogInformation("No Discord identity for folder {Folder} (authentik user {User})", folder, authentikUser);
        return id;
    }
}