using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;

namespace EyeRisk.Tools
{
    public class DbHandler
    {
        private SqlConnection _conn;

        private static DbHandler instance = null;
        private static readonly object padlock = new object();

        private DbHandler()
        {
            _conn = new SqlConnection(Startup.connectionString);
        }

        public static DbHandler Instance
        {
            get
            {
                lock (padlock)
                {
                    if (instance == null)
                    {
                        instance = new DbHandler();
                    }
                    return instance;
                }
            }
        }


        public void Close()
        {
            _conn.Close();
        }


        public DbHandler OpenConnection()
        {
            _conn.Open();
            return this;
        }

        public SqlCommand setCommand(string ps)
        {
            SqlCommand cmd = new SqlCommand(ps, _conn);
            cmd.CommandType = CommandType.StoredProcedure;
            return cmd;
        }

        public static DataTable getDataTable<T>(T model) where T : new()
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("ColumnName");
            dt.Columns.Add("ColumnValue");
            //System.Reflection.MemberInfo info = typeof(T);
            foreach (var attr in typeof(T).GetProperties())
            {

                dt.Rows.Add(attr.Name, typeof(T).GetProperty(attr.Name).GetValue(model));
            }

            return dt;
        }

        public static SqlParameter[] getParamsFromModel<T>(T model) where T : new()
        {
            List<SqlParameter> parameters = new List<SqlParameter>();
            for (int i = 0; i < typeof(T).GetProperties().Count(); i++)
            {
                if (!(typeof(T).GetProperties()[i].SetMethod is null) && typeof(T).GetProperties()[i].SetMethod.IsPublic)
                {
                    parameters.Add(new SqlParameter(
                    typeof(T).GetProperties()[i].Name, typeof(T).GetProperty(typeof(T).GetProperties()[i].Name).GetValue(model)));
                }
            }

            return parameters.ToArray();
        }

    }
}