using System.Data;
using System.Threading;
using System.Threading.Tasks;
using GB5Shared.Connection;
using GB5Shared.DTO.Framework.Login;
using Microsoft.Data.SqlClient;

namespace AdminDAL.CustomCode.BulkInsert
{
    public class BulkInsertService : IBulkInsertService
    {
        private readonly IApplicationConnection _appConnection;

        public BulkInsertService(IApplicationConnection appConnection) => _appConnection = appConnection;

        public async Task InsertAsync(
            string destinationTable,
            DataTable data,
            LoginDTO login,
            CancellationToken ct = default)
        {
            if (data.Rows.Count == 0) return;

            string connStr = await _appConnection.DBConnectionStringCached(login);

            await using var connection = new SqlConnection(connStr);
            await connection.OpenAsync(ct).ConfigureAwait(false);

            using var bulkCopy = new SqlBulkCopy(connection)
            {
                DestinationTableName = destinationTable,
                BatchSize            = 5000,
                BulkCopyTimeout      = 300
            };

            foreach (DataColumn col in data.Columns)
                bulkCopy.ColumnMappings.Add(col.ColumnName, col.ColumnName);

            await bulkCopy.WriteToServerAsync(data, ct).ConfigureAwait(false);
        }
    }
}