using MongoDB.Bson;
using MongoDB.Driver;
using MongoDB.Entities;

using PrivaPub.Models.Federation;
using PrivaPub.Models.Group;
using PrivaPub.Models.Post;
using PrivaPub.Models.User;

namespace PrivaPub.Infrastructure.Data
{
	public static class Indexes
	{
		public static async Task Create(CancellationToken token = default)
		{
			await Unique<Post>(p => p.ObjectURI, Builders<Post>.Filter.Type(p => p.ObjectURI, BsonType.String), token);
			await Plain<Post>(token, p => p.GroupUserId, p => p.ID);
			await Plain<Post>(token, p => p.GroupId, p => p.ID);
			await Plain<Post>(token, p => p.ActorURI);

			await Unique<DmPost>(p => p.ObjectURI, Builders<DmPost>.Filter.Type(p => p.ObjectURI, BsonType.String), token);
			await Plain<DmPost>(token, p => p.GroupId, p => p.ID);

			await Unique<ForeignAvatar>(a => a.ActorURI, Builders<ForeignAvatar>.Filter.Type(a => a.ActorURI, BsonType.String), token);
			await Plain<ForeignAvatar>(token, a => a.PublicKeyId);

			await DB.Default.Index<Follower>()
				.Key(f => f.LocalActorId, KeyType.Ascending)
				.Key(f => f.LocalActorKind, KeyType.Ascending)
				.Key(f => f.ActorURI, KeyType.Ascending)
				.Option(o => o.Unique = true)
				.CreateAsync(token);
			await Plain<Follower>(token, f => f.ActorURI);

			await DB.Default.Index<RootToAvatar>()
				.Key(r => r.RootId, KeyType.Ascending)
				.Key(r => r.AvatarId, KeyType.Ascending)
				.Option(o => o.Unique = true)
				.CreateAsync(token);
			await Plain<RootToAvatar>(token, r => r.AvatarId);

			await Unique<ReservedName>(r => r.Name, Builders<ReservedName>.Filter.Type(r => r.Name, BsonType.String), token);
			await Unique<RootUser>(u => u.UserName, Builders<RootUser>.Filter.Type(u => u.UserName, BsonType.String), token);
			await Plain<Avatar>(token, a => a.UserName);
			await Plain<Group>(token, g => g.UserName);
			await Plain<Group>(token, g => g.InvitationCode);

			await Plain<DmGroup>(token, g => g.ParticipantsKey);

			await Plain<Delivery>(token, d => d.DeliveredAt, d => d.AbandonedAt, d => d.NextAttemptAt);
		}

		static async Task Unique<T>(System.Linq.Expressions.Expression<Func<T, object>> key, FilterDefinition<T> partial,
			CancellationToken token) where T : IEntity =>
			await DB.Default.Index<T>()
				.Key(key, KeyType.Ascending)
				.Option(o =>
				{
					o.Unique = true;
					o.PartialFilterExpression = partial;
				})
				.CreateAsync(token);

		static async Task Plain<T>(CancellationToken token, params System.Linq.Expressions.Expression<Func<T, object>>[] keys) where T : IEntity
		{
			var index = DB.Default.Index<T>();
			foreach (var key in keys)
				index.Key(key, KeyType.Ascending);
			await index.CreateAsync(token);
		}
	}
}