using Microsoft.EntityFrameworkCore;
using RadicadeServer.DB;
using RadicadeServer.Extensions;
using RadicadeServer.RecNet.Config;

namespace RadicadeServer.Clubs;

public sealed class PlayerSubscriptionRecord
{
	public long subscriberAccountId { get; set; }
	public long creatorAccountId { get; set; }
	public DateTime createdAt { get; set; } = DateTime.UtcNow;
}

public static class PlayerSubscriptions
{
	private const string ConfigKey = "PlayerSubscriptions";

	private const long PersonalClubIdBase = 1_000_000_000_000L;

	public static long PersonalClubId(long accountId) => accountId > 0 ? PersonalClubIdBase + accountId : 0;

	public static bool IsPersonalClubId(long clubId) => clubId >= PersonalClubIdBase;

	public static long? AccountIdForPersonalClub(long clubId) =>
		IsPersonalClubId(clubId) ? clubId - PersonalClubIdBase : null;

	public static async Task<List<PlayerSubscriptionRecord>> LoadAsync(RecDBContext db)
	{
		var config = await db.ServerConfig.AsNoTracking().FirstOrDefaultAsync(x => x.Key == ConfigKey);
		if (config == null || string.IsNullOrWhiteSpace(config.Value)) return new List<PlayerSubscriptionRecord>();

		try
		{
			return config.Value.FromJson<List<PlayerSubscriptionRecord>>() ?? new List<PlayerSubscriptionRecord>();
		}
		catch
		{
			return new List<PlayerSubscriptionRecord>();
		}
	}

	private static async Task SaveAsync(RecDBContext db, List<PlayerSubscriptionRecord> subscriptions)
	{
		var config = await db.ServerConfig.FirstOrDefaultAsync(x => x.Key == ConfigKey);
		if (config == null)
		{
			config = new ServerConfigVal(ConfigKey, "[]");
			await db.ServerConfig.AddAsync(config);
		}

		config.Value = subscriptions.ToJson();
		await db.SaveChangesAsync();
	}

	public static async Task<bool> SubscribeAsync(RecDBContext db, long subscriberId, long creatorId)
	{
		if (subscriberId <= 0 || creatorId <= 0 || subscriberId == creatorId) return false;

		var subscriptions = await LoadAsync(db);
		if (subscriptions.Any(x => x.subscriberAccountId == subscriberId && x.creatorAccountId == creatorId))
			return true;

		subscriptions.Add(new PlayerSubscriptionRecord
		{
			subscriberAccountId = subscriberId,
			creatorAccountId = creatorId
		});
		await SaveAsync(db, subscriptions);
		return true;
	}

	public static async Task<bool> UnsubscribeAsync(RecDBContext db, long subscriberId, long creatorId)
	{
		var subscriptions = await LoadAsync(db);
		if (subscriptions.RemoveAll(x => x.subscriberAccountId == subscriberId && x.creatorAccountId == creatorId) == 0)
			return false;

		await SaveAsync(db, subscriptions);
		return true;
	}

	public static async Task<List<long>> SubscriptionIdsAsync(RecDBContext db, long accountId) =>
		(await LoadAsync(db))
			.Where(x => x.subscriberAccountId == accountId)
			.Select(x => x.creatorAccountId)
			.Distinct()
			.ToList();

	public static async Task<List<long>> SubscriberIdsAsync(RecDBContext db, long accountId) =>
		(await LoadAsync(db))
			.Where(x => x.creatorAccountId == accountId)
			.Select(x => x.subscriberAccountId)
			.Distinct()
			.ToList();

	public static async Task<int> SubscriberCountAsync(RecDBContext db, long accountId) =>
		(await SubscriberIdsAsync(db, accountId)).Count;

	public static async Task<List<object>> TopCreatorsAsync(RecDBContext db, int limit)
	{
		var creators = (await LoadAsync(db))
			.GroupBy(x => x.creatorAccountId)
			.Select(group => new
			{
				clubId = PersonalClubId(group.Key),
				accountId = group.Key,
				subscriberCount = group.Select(x => x.subscriberAccountId).Distinct().Count()
			})
			.OrderByDescending(creator => creator.subscriberCount)
			.ThenBy(creator => creator.accountId)
			.Take(limit)
			.ToList();

		return creators.Cast<object>().ToList();
	}
}