using AZKiServer.Models;

using MongoDB.Bson;
using MongoDB.Bson.Serialization.Attributes;
using MongoDB.Driver;

using System.Collections.Frozen;

namespace AZKiServer.Services;

public class MediaService(IMongoDatabase db)
{
	public readonly IMongoCollection<MediaEntry> _entries = db.GetCollection<MediaEntry>("media");

	[BsonIgnoreExtraElements]
	private record class MediaInfo(string Filepath, int Version);
	public async Task<FrozenDictionary<string, int>> GetExistingFilePathsAsync(CancellationToken cancellationToken = default)
	{
		var files = await _entries.Find("{}").As<MediaInfo>().ToListAsync(cancellationToken);
		if (files.Count == 0)
			return FrozenDictionary<string, int>.Empty;
		return files.ToFrozenDictionary(m => m.Filepath, m => m.Version);
	}

	public async Task AddMediaBulkAsync(List<MediaEntry> entries, CancellationToken cancellationToken = default)
	{
		await _entries.InsertManyAsync(entries, cancellationToken: cancellationToken);
	}

	public async Task<List<MediaEntry>> GetEntriesInRangeAsync(MediaType mediaType, DateTime from, DateTime to, CancellationToken cancellationToken = default)
	{
		var filter = Builders<MediaEntry>.Filter
			.And([
					Builders<MediaEntry>.Filter.BitsAnySet(m => m.Type, (long)mediaType),
					Builders<MediaEntry>.Filter.Gte(m => m.Date, from),
					Builders<MediaEntry>.Filter.Lte(m => m.Date, to),
				]);

		return await _entries.Find(filter).ToListAsync(cancellationToken);
	}

	public async Task DeleteAllEntriesAsync(IEnumerable<ObjectId> ids, CancellationToken cancellationToken = default)
	{
		await _entries.DeleteManyAsync(e => ids.Contains(e.Id), cancellationToken);
	}

	public async Task DeleteAllEntriesAsync(IEnumerable<string> paths, CancellationToken cancellationToken = default)
	{
		await _entries.DeleteManyAsync(e => paths.Contains(e.Filepath), cancellationToken);
	}

#if DEBUG
	public async Task DeleteAllEntriesAsync(CancellationToken cancellationToken = default) {
		await _entries.DeleteManyAsync("{}", cancellationToken);
	}
#endif

	public class IndexCreation : BackgroundService
	{
		protected override Task ExecuteAsync(CancellationToken stoppingToken)
		{
			throw new NotImplementedException();
		}
	}


}