using System;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Globalization;
using System.Windows.Forms;

namespace ServerExplorer.UI
{
    public partial class FrmExec : Form
    {
        #region Declarations

        private readonly string _cnxString;

        #endregion

        #region Form life cycle

        public FrmExec(string cnxString)
        {
            InitializeComponent();

            _cnxString = cnxString;
        }

        #endregion

        #region Events

        private void btnExec_Click(object sender, EventArgs e)
        {
            try
            {
                DataTable dt = Exec();
                dgvDatos.DataSource = dt;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void btnGenInserts_Click(object sender, EventArgs e)
        {
            try
            {
                // Obtener el nombre de la tabla destino
                string destTable = Microsoft.VisualBasic.Interaction.InputBox("Nombre de la tabla destino", "tabla destino", String.Empty,
                    Top + (Height / 2), Left + (Width / 2));

                DataTable dt = GenerarInserts(destTable);
                dgvDatos.DataSource = dt;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void dgvDatos_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
        {
            if (e.DesiredType == typeof(Image))
            {
                if (e.Value is DBNull || (e.Value is byte[] && ((byte[])e.Value).Length <= 0))
                {
                    e.Value = new Bitmap(1, 1);
                }
            }
        }

        #endregion

        #region Private methods

        private DataTable Exec()
        {
            // Establecer conexion
            var cnx = new SqlConnection(_cnxString);

            // Obtener resultado en un datatable.
            var da = new SqlDataAdapter(txtCommand.Text, cnx);
            var dt = new DataTable();
            cnx.Open();
            da.Fill(dt);
            cnx.Close();

            return dt;
        }

        private DataTable GenerarInserts(string destTable)
        {
            var nfi = new NumberFormatInfo { NumberDecimalSeparator = "." };

            DataTable dataTable = Exec();

            // Preparar la datatable destino
            var destDataTable = new DataTable();
            destDataTable.Columns.Add("Comando", typeof(String));

            // Recorrer la tabla de datos
            foreach (DataRow dr in dataTable.Rows)
            {
                string strColumns = String.Empty;
                string strValues = String.Empty;
                foreach (DataColumn dc in dataTable.Columns)
                {
                    // El nombre de la columna
                    if (strColumns != String.Empty)
                        strColumns += ", ";
                    strColumns += "[" + dc.ColumnName + "]";

                    // El valor de la columna
                    if (strValues != String.Empty)
                        strValues += ", ";
                    object valor = dr[dc];
                    if (valor == DBNull.Value || valor == null)
                    {
                        // NULOS
                        strValues += "NULL";
                    }
                    else
                    {
                        string type = dc.DataType.Name.ToLower();
                        if (type == "string")
                        {
                            // Cadenas
                            strValues += "'" + ((string)valor).Replace("'", "''") + "'";
                        }
                        else if (type == "decimal")
                        {
                            // Decimales
                            strValues += ((decimal)valor).ToString(nfi);
                        }
                        else if (type == "bit" || type == "bool" || type == "boolean")
                        {
                            // Booleanos
                            strValues += ((bool)valor) ? "1" : "0";
                        }
                        else if (type == "byte[]" )
                        {
                            // Arrays de bytes (imagenes, archivos etc)
                            strValues += "0x" + BitConverter.ToString(((byte[])valor)).Replace("-", "");
                        }
                        else
                        {
                            // Otros
                            strValues += valor.ToString();
                        }

                    }
                }

                // Insertar fila a la datatable destino
                destDataTable.Rows.Add(
                    new object[] { 
                        String.Format("INSERT INTO {0} ({1}) VALUES ({2})",
                            destTable, strColumns, strValues)
                    });
            }

            return destDataTable;
        }


        #endregion
    }
}