using System;
using System.Collections.Generic;
using System.Linq;
using IPA;
using IPALogger = IPA.Logging.Logger;

namespace Setlist
{
    [Plugin(RuntimeOptions.SingleStartInit)]
    public class Plugin
    {
        internal static Plugin Instance { get; private set; }

        /// <summary>
        /// BSIPA logger (shows in BSIPA console / game logs when verbose).
        /// </summary>
        internal static IPALogger Log { get; private set; }

        [Init]
        public Plugin(IPALogger logger)
        {
            Instance = this;
            Log = logger;
        }

        [OnStart]
        public void OnApplicationStart()
        {
            try
            {
                var playlists = BeatSaberPlaylistsLib.PlaylistManager.DefaultManager.GetAllPlaylists(
                    includeChildren: true,
                    out AggregateException loadErrors);

                if (loadErrors != null)
                {
                    Log.Error(loadErrors.Message);
                    foreach (var inner in loadErrors.InnerExceptions)
                    {
                        Log.Error(inner.ToString());
                    }
                }

                if (playlists == null || playlists.Length == 0)
                {
                    Log.Info("No playlists loaded (or playlist library not initialized yet).");
                    return;
                }

                var entries = new List<(string Title, bool HasSyncUrl, string BeatLeaderGuid)>();
                foreach (var playlist in playlists)
                {
                    var hasSyncUrl = false;
                    string syncUrl = null;
                    if (playlist.TryGetCustomData("syncURL", out var syncObj) && syncObj is string url)
                    {
                        syncUrl = url;
                        hasSyncUrl = !string.IsNullOrWhiteSpace(url);
                    }

                    string blGuid = null;
                    if (hasSyncUrl && BeatLeaderPlaylistOwnership.TryExtractBeatLeaderPlaylistGuid(syncUrl, out var g))
                    {
                        blGuid = g;
                    }

                    entries.Add((playlist.Title, hasSyncUrl, blGuid));
                }

                if (entries.Any(e => e.BeatLeaderGuid != null))
                {
                    BeatLeaderPlaylistOwnership.ScheduleVerifyAndLog(entries, Log);
                }
                else
                {
                    foreach (var e in entries)
                    {
                        Log.Info(FormatPlaylistLogLine(e.Title, e.HasSyncUrl, e.BeatLeaderGuid, ownedGuids: null));
                    }
                }
            }
            catch (Exception ex)
            {
                Log.Error(ex.ToString());
            }
        }

        [OnExit]
        public void OnApplicationQuit()
        {
        }

        internal static string FormatPlaylistLogLine(
            string title,
            bool hasSyncUrl,
            string beatLeaderGuid,
            HashSet<string> ownedGuids)
        {
            string ownerPart;
            if (!hasSyncUrl)
            {
                ownerPart = "beatLeaderOwnerConfirmed=n/a (no sync URL)";
            }
            else if (string.IsNullOrEmpty(beatLeaderGuid))
            {
                ownerPart = "beatLeaderOwnerConfirmed=n/a (sync URL is not a BeatLeader playlist)";
            }
            else if (ownedGuids == null)
            {
                ownerPart = "beatLeaderOwnerConfirmed=unknown (BeatLeader /user/playlists did not succeed; see prior log line)";
            }
            else if (ownedGuids.Contains(beatLeaderGuid))
            {
                ownerPart = "beatLeaderOwnerConfirmed=true";
            }
            else
            {
                ownerPart = "beatLeaderOwnerConfirmed=false";
            }

            return $"Playlist \"{title}\": hasSyncUrl={hasSyncUrl}, {ownerPart}";
        }
    }
}