/*_________________________________________________________________________________

                             S T R E A M   R E A D E R   /   W R I T E R   D E M O
                                                  Traditional Method
                                       Originally Created 4/22/2013 for C#
                                                        Ron Kessler
                                                    C++ 2014 Version
 _________________________________________________________________________________
 Created 1/24/2014
 Last updated 1/24/2014

 FEATURES: 
    1.  Shows how to read/write to a sequential text file
    2.  Lets user create file when program first loads
    3.  Items can be added/removed from list box
    4.  Items in list box can be saved to disk
    5.  Shows how to use Foreach loop with list box items
    6.  Uses structured error handling
 * 7.  I create Stream objects without the new "using" statement
*/
#pragma once

namespace My1UsingStreamsDemo {

	using namespace System;
	using namespace System::ComponentModel;
	using namespace System::Collections;
	using namespace System::Windows::Forms;
	using namespace System::Data;
	using namespace System::Drawing;

	//*********************************
	
	using namespace System::IO;			//be sure to add this
	
	//*********************************

		//**********START OF MY CODE*************

		static String^ diskFile = "inventory.txt";         

        static String^ msgTitle = "Ron's Train Store";

        
        StreamReader^ sr;        //define streamreader here without instaniating
        StreamWriter^ sw;		// streamwriter

#pragma region "Load Event, Reload Button, and Reload Method"
	private: System::Void Form1_Load(System::Object^  sender, System::EventArgs^  e) 
			 
			 {
					DoReload();
			 
			 }

	private: System::Void btnReload_Click(System::Object^  sender, System::EventArgs^  e) 
		 
		    {
	            DoReload();
			}

	 private: System::Void DoReload()

        {
                       
            //---if file does not exist lets create it for them if they want to.
            if (File::Exists(diskFile) == false)
            {
               if (MessageBox::Show("Cannot locate inventory file. Shall I create it?", msgTitle, 
                MessageBoxButtons::YesNo, MessageBoxIcon::Question) ==System::Windows::Forms::DialogResult::Yes)
                                   
                    File::Create(diskFile);
                else
                    txtNewItem->Focus();      //or you could exit here:  this.close();
               
            }
            else
            {
                try
                {
                    lstItems->Items->Clear();              //no duplicates
                    sr = gcnew StreamReader(diskFile);

                    {
                        while (sr->Peek() != -1)
                        {
                            String^ dataFromFile = sr->ReadLine();
                            lstItems->Items->Add(dataFromFile);

                        }

                    }
                }
                catch (Exception^ e)
                {

                    MessageBox::Show("An error occurred while reading...." + e->Message,
                        msgTitle, MessageBoxButtons::OK, MessageBoxIcon::Error);
                    this->Close();
                }
                finally
                {
                    sr->Close();         //make sure to always close the reader
                   
                
                }
            }
             
        }
#pragma endregion


#pragma region "Add new Item & Delete Item"

	private: System::Void btnAdd_Click(System::Object^  sender, System::EventArgs^  e) 
		 {

					String^ myNewItem = txtNewItem->Text->Trim();
					lstItems->Items->Add(myNewItem);

		 }
	private: System::Void btnDelete_Click(System::Object^  sender, System::EventArgs^  e) 
		 
		 {
			
            if (MessageBox::Show("Are you sure you want to delete " + lstItems->SelectedItem + "?", msgTitle,
                  MessageBoxButtons::YesNo, MessageBoxIcon::Question) == System::Windows::Forms::DialogResult::Yes)
                    
                lstItems->Items->Remove(lstItems->SelectedItem);
            else
                txtNewItem->Focus();
			 
			 
		 }
#pragma endregion	

	
#pragma region "Save Data to Disk"
		    
    private: System::Void btnSave_Click(System::Object^  sender, System::EventArgs^  e) 

        {
			     try
            {
                sw = gcnew StreamWriter(diskFile, false);   //false means do not append data!

                    for each (String^ myItem in lstItems->Items)
                    {
                        sw->WriteLine(myItem);
                    }
                MessageBox::Show("Your data has been updated.",
                    msgTitle, MessageBoxButtons::OK, MessageBoxIcon::Information);
            }

            catch (Exception^ ex)
            {
                MessageBox::Show("I could not save your changes." + ex->Message,
                    msgTitle, MessageBoxButtons::OK, MessageBoxIcon::Error);

            }
            finally
            {
                    sw->Close();             //always do this
                              
            }

        }

#pragma endregion

#pragma region "Clear & Exit"

private: System::Void btnClear_Click(System::Object^  sender, System::EventArgs^  e) 
		 
		 {
			lstItems->Items->Clear();
			txtNewItem->Clear();
			 
		 }
	
private: System::Void btnExit_Click(System::Object^  sender, System::EventArgs^  e) {

			this->Close();
		 }

#pragma endregion

};
}