using System.Text.Json;
using RadicadeServer.DB;

namespace RadicadeServer.RecNet.Keepsakes;

public sealed class KeepsakeRoomConfig
{
	public const string FileName = "keepsake-rooms.json";

	public const string AllRoomsToken = "*";

	public const long DefaultRoomListId = 1;

	public const int DefaultRoomLimit = 10;

	public const long DefaultEventId = 1;

	public const string DefaultEventName = "Science Core";

	public IReadOnlySet<long> RoomIds { get; init; } = new HashSet<long>();

	public bool AllRooms { get; init; }

	public long RoomListId { get; init; } = DefaultRoomListId;

	public int RoomLimit { get; init; } = DefaultRoomLimit;

	public long EventId { get; init; } = DefaultEventId;

	public string EventName { get; init; } = DefaultEventName;

	public bool EventEnabled { get; init; } = true;

	public bool Any => AllRooms || RoomIds.Count > 0;

	public bool IsKeepsakeRoom(long roomId) => AllRooms || RoomIds.Contains(roomId);

	public long[] AdvertisedRooms(long roomId)
		=> RoomIds.Count == 0 ? new[] { roomId } : RoomIds.OrderBy(id => id).ToArray();

	public long[] ConfiguredRooms => RoomIds.OrderBy(id => id).ToArray();

	public object[] RoomListEntries(long[] rooms)
		=> new object[]
		{
			new
			{
				KeepsakeRoomListId = RoomListId,
				ProgressionEventId = EventId,
				UnlockItemAvatarItemId = (int?)null,
				UnlockItemGiftDropId = (int?)null,
				UnlockItemLockDurationTicks = (long?)null,
				RoomUnlockStartOffsetTicks = 0L,
				RoomUnlockIntervalTicks = TimeSpan.TicksPerDay,
				RoomUnlockBatchSize = Math.Max(rooms.Length, 1),
				RoomType = 0,
				KeepsakeRoomLimit = RoomLimit,
				KeepsakeRooms = rooms.Select((id, order) => new
				{
					KeepsakeRoomId = id, RoomId = id, KeepsakeRoomListId = RoomListId,
					Type = 0, Order = order
				}).ToArray(),
			}
		};

	public static KeepsakeRoomConfig? Override { get; set; }

	public static KeepsakeRoomConfig Current => Override ?? Load();

	public static KeepsakeRoomConfig Load()
		=> Parse(
			ReadConfigFile(),
			Environment.GetEnvironmentVariable("RADICADE_KEEPSAKE_ROOMS"),
			Environment.GetEnvironmentVariable("RADICADE_KEEPSAKE_ROOM_LIST_ID"),
			Environment.GetEnvironmentVariable("RADICADE_KEEPSAKE_ROOM_LIMIT"),
			Environment.GetEnvironmentVariable("RADICADE_KEEPSAKE_EVENT_ID"),
			Environment.GetEnvironmentVariable("RADICADE_KEEPSAKE_EVENT_NAME"));

	public static IEnumerable<string> CandidatePaths()
		=> DBConfig.AvatarCatalogDirectories()
			.Select(directory => Path.Join(directory, FileName))
			.Distinct(StringComparer.OrdinalIgnoreCase);

	private static string? ReadConfigFile()
	{
		foreach (var path in CandidatePaths())
		{
			try
			{
				if (File.Exists(path)) return File.ReadAllText(path);
			}
			catch (IOException)
			{
			}
			catch (UnauthorizedAccessException)
			{
			}
		}

		return null;
	}

	public static KeepsakeRoomConfig Parse(
		string? json,
		string? rooms = null,
		string? roomListId = null,
		string? roomLimit = null,
		string? eventIdText = null,
		string? eventNameText = null)
	{
		var allRooms = false;
		var ids = new HashSet<long>();
		var listId = DefaultRoomListId;
		var limit = DefaultRoomLimit;
		var eventId = DefaultEventId;
		var eventName = DefaultEventName;
		var eventEnabled = true;

		if (!string.IsNullOrWhiteSpace(json))
		{
			try
			{
				using var document = JsonDocument.Parse(json);
				var root = document.RootElement;

				if (root.ValueKind == JsonValueKind.Array) AddIds(root, ids);
				else if (root.ValueKind == JsonValueKind.Object)
				{
					foreach (var property in root.EnumerateObject())
					{
						switch (property.Name.ToLowerInvariant())
						{
							case "allrooms":
								allRooms = IsTrue(property.Value);
								break;
							case "roomids" or "rooms" or "keepsakerooms":
								AddIds(property.Value, ids);
								break;
							case "roomlistid" or "keepsakeroomlistid":
								listId = ReadLong(property.Value) ?? listId;
								break;
							case "roomlimit" or "keepsakeroomlimit":
								if (ReadLong(property.Value) is > 0 and <= int.MaxValue and var configuredLimit)
									limit = (int)configuredLimit;
								break;
							case "eventenabled":
								eventEnabled = IsTrue(property.Value);
								break;
							case "eventid" or "progressioneventid":
								eventId = ReadLong(property.Value) ?? eventId;
								break;
							case "eventname" or "progressioneventname":
								var name = property.Value.ValueKind == JsonValueKind.String ? property.Value.GetString() : null;
								if (!string.IsNullOrWhiteSpace(name)) eventName = name!.Trim();
								break;
						}
					}
				}
			}
			catch (JsonException)
			{
			}
		}

		if (!string.IsNullOrWhiteSpace(rooms))
		{
			ids.Clear();
			var text = rooms.Trim();
			allRooms = text == AllRoomsToken;
			if (!allRooms) AddIdsFromText(text, ids);
		}

		if (long.TryParse(roomListId, out var parsedListId)) listId = parsedListId;
		if (int.TryParse(roomLimit, out var parsedLimit) && parsedLimit > 0) limit = parsedLimit;
		if (long.TryParse(eventIdText, out var parsedEventId)) eventId = parsedEventId;
		if (!string.IsNullOrWhiteSpace(eventNameText)) eventName = eventNameText.Trim();

		return new KeepsakeRoomConfig
		{
			RoomIds = ids,
			AllRooms = allRooms,
			RoomListId = listId,
			RoomLimit = limit,
			EventId = eventId,
			EventName = eventName,
			EventEnabled = eventEnabled,
		};
	}

	private static void AddIds(JsonElement element, HashSet<long> ids)
	{
		switch (element.ValueKind)
		{
			case JsonValueKind.Array:
				foreach (var item in element.EnumerateArray())
				{
					if (ReadLong(item) is { } id) ids.Add(id);
				}
				break;
			case JsonValueKind.String:
				AddIdsFromText(element.GetString(), ids);
				break;
			default:
				if (ReadLong(element) is { } single) ids.Add(single);
				break;
		}
	}

	private static void AddIdsFromText(string? text, HashSet<long> ids)
	{
		if (string.IsNullOrWhiteSpace(text)) return;

		foreach (var part in text.Split(new[] { ',', ';', ' ', '\t', '\r', '\n' }, StringSplitOptions.RemoveEmptyEntries))
		{
			if (long.TryParse(part, out var id)) ids.Add(id);
		}
	}

	private static long? ReadLong(JsonElement element) => element.ValueKind switch
	{
		JsonValueKind.Number when element.TryGetInt64(out var number) => number,
		JsonValueKind.String when long.TryParse(element.GetString(), out var parsed) => parsed,
		_ => null,
	};

	private static bool IsTrue(JsonElement element) => element.ValueKind switch
	{
		JsonValueKind.True => true,
		JsonValueKind.False => false,
		JsonValueKind.Number when element.TryGetInt64(out var number) => number != 0,
		JsonValueKind.String => string.Equals(element.GetString()?.Trim(), "true", StringComparison.OrdinalIgnoreCase)
			|| element.GetString()?.Trim() == "1",
		_ => false,
	};
}