using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using MongoDB.Bson;
using MongoDB.Driver;

namespace BuildFeed.Model
{
    public partial class BuildRepository
    {
        public async Task<BuildVersion[]> SelectAllVersions(int limit = -1, int skip = 0)
        {
            var query = _buildCollection.Aggregate()
                .Group(new BsonDocument("_id",
                    new BsonDocument
                    {
                        new BsonElement(nameof(BuildVersion.Major), $"${nameof(Build.MajorVersion)}"),
                        new BsonElement(nameof(BuildVersion.Minor), $"${nameof(Build.MinorVersion)}")
                    }))
                .Sort(new BsonDocument
                {
                    new BsonElement($"_id.{nameof(BuildVersion.Major)}", -1),
                    new BsonElement($"_id.{nameof(BuildVersion.Minor)}", -1)
                })
                .Skip(skip);

            if (limit > 0)
            {
                query = query.Limit(limit);
            }

            var grouping = await query.ToListAsync();

            return (from g in grouping
                select new BuildVersion
                {
                    Major = (uint)g["_id"].AsBsonDocument[nameof(BuildVersion.Major)].AsInt32,
                    Minor = (uint)g["_id"].AsBsonDocument[nameof(BuildVersion.Minor)].AsInt32
                }).ToArray();
        }

        public async Task<long> SelectAllVersionsCount()
        {
            var query = await _buildCollection.Aggregate()
                .Group(new BsonDocument("_id",
                    new BsonDocument
                    {
                        new BsonElement(nameof(BuildVersion.Major), $"${nameof(Build.MajorVersion)}"),
                        new BsonElement(nameof(BuildVersion.Minor), $"${nameof(Build.MinorVersion)}")
                    }))
                .ToListAsync();
            return query.Count;
        }

        public async Task<List<Build>> SelectVersion(uint major, uint minor, int limit = -1, int skip = 0)
        {
            var query = _buildCollection.Find(new BsonDocument
                {
                    new BsonElement(nameof(Build.MajorVersion), major),
                    new BsonElement(nameof(Build.MinorVersion), minor)
                })
                .Sort(sortByOrder)
                .Skip(skip);

            if (limit > 0)
            {
                query = query.Limit(limit);
            }

            return await query.ToListAsync();
        }

        public async Task<long> SelectVersionCount(uint major, uint minor) => await _buildCollection.CountAsync(
            new BsonDocument
            {
                new BsonElement(nameof(Build.MajorVersion), major),
                new BsonElement(nameof(Build.MinorVersion), minor)
            });
    }
}