namespace LaaProduction.Data.SQL
{
    using LaaProduction.Data.SQL.Interfaces;
    
    using System;
    using System.Data.SqlClient;

    public class SQLReader : ISQLReader, IDisposable
    {
        private readonly SqlDataReader sqlDataReader;

        private SQLReader(SqlDataReader sqlDataReader) 
            => this.sqlDataReader = sqlDataReader;

        public void Dispose()
        {
            this.sqlDataReader.Close();
            this.sqlDataReader.Dispose();
        }

        public T GetValue<T>(int index)
        {
            if (!this.sqlDataReader.IsDBNull(index))
            {
                var value = this.sqlDataReader.GetValue(index);
                var type = Nullable.GetUnderlyingType(typeof(T));

                if (type is null)
                {
                    type = typeof(T);
                }

                try
                {
                    value = Convert.ChangeType(value, type);
                }
                catch (Exception)
                {
                    // TODO:
                }

                if (value is T _value)
                {
                    return _value;
                }
            }

            return default(T);
        }

        public T GetValue<T>(string column)
        {
            var table = this.sqlDataReader.GetSchemaTable();

            if (table?.Columns?.Contains(column) == true)
            {
                var index = this.sqlDataReader.GetOrdinal(column);

                return this.GetValue<T>(index);
            }

            return default(T);
        }

        internal bool Read() 
            => this.sqlDataReader.Read();

        public static implicit operator SQLReader(SqlDataReader sqlDataReader)
            => new SQLReader(sqlDataReader);
    }
}