//File        : fileOps.cpp
//Author      : Andre Long
//Due         : September 21, 2004
//Description : This is program challenge 11 out of chapter 12
//              It will use structures to create records where the user can add new records to a file
//              Display any record in the file
//              Change any record in the file

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

struct inventory
{
   string  description;
   int     quantity;
   float   wholesaleCost;
   float   retailCost;
   string  date;
};
int  countOfRecords(inventory record);
int  menu();
int  add(inventory record, fstream &, int *recordCounter);
void display(inventory record, fstream &, int recordCounter);
void displayAll(inventory record, fstream &, int recordCounter);
void modify(inventory record, fstream &, int recordCounter);


int main()
{
   int choice;
   int recordCounter=0;

   cout<<"Welcome to the company store inventory program"<<"\n";
   cout<<"If the input file does not exists or is not found, the program will create it"<<"\n";
   
   inventory record = {"store item", 0, 0, 0, "01/01/2000"};
   
   recordCounter = countOfRecords(record);
   cout<<"\n";
   cout<<"recordCounter = "<<recordCounter<<"\n";

   fstream inAndOut("inventoryData.txt", ios::in | ios::out | ios::binary);

   if(inAndOut.is_open() ==false)
   {
	   cout<<"was not created";
	   cout<<"\n";
   }
   

   do 
   {
      choice = menu();

	  switch(choice)
      {
         case 0: cout<<"Exiting Program  Good Bye"<<"\n";
		         break;
	     case 1: add(record, inAndOut, &recordCounter);
		         break;
	     case 2: display (record, inAndOut, recordCounter);
		         break;
	     case 3: displayAll (record, inAndOut, recordCounter);
		         break;
	     case 4: modify (record, inAndOut, recordCounter);
	             break;  
      }
   }
   while(choice!=0 || choice <0 || choice >4);

   

   inAndOut.close();
   return 0;
}

int countOfRecords(inventory record)
{
    int recordCounter=0;

    fstream inAndOut("inventoryData.txt", ios::in | ios::out | ios::app| ios::binary);

    if(inAndOut.is_open() ==false)
	{
       cout<<"There was an error reading the data file"<<"\n";
	}
   
	else
	{
       inAndOut.seekg(0 *sizeof(record), ios::beg);
       inAndOut.read(reinterpret_cast<char*>(&record), sizeof(record) );

       while(!inAndOut.eof())
	   {
          recordCounter = recordCounter+1;
	      inAndOut.read(reinterpret_cast<char*>(&record), sizeof(record) );
	   }

	}
	inAndOut.close();
	return recordCounter;
}


int menu()
{
   int choice;

   cout<<"Please make a menu choice for the task you which to accomplish"<<"\n";
   cout<<"\n";
   cout<<"          0: Quit this program"<<"\n";
   cout<<"          1: Add new records to the file"<<"\n";
   cout<<"          2: Display any record in the file"<<"\n";
   cout<<"          3: Display all records in the file"<<"\n";
   cout<<"          4: Change any record in the file"<<"\n";
   cout<<"\n";
   cout<<"\n";
   cout<<"Enter menu choice now   ";
   cin>>choice;
   cout<<"\n";
   
   if (choice <0 || choice > 4)
	   cout<<"You must select a numeric choice from the menu (0, 1, 2, 3, 4)"<<"\n";

   return choice;
}

int add(inventory record, fstream &inAndOut, int *recordCounter)
{
   inAndOut.seekp(0L, ios::end);
   cout<<"Enter the item descripton  ";
   cin.ignore();
   getline(cin, record.description);
   cout<<"\n";
   cout<<"Enter the quantity on hand  ";
   cin>>record.quantity;
   cout<<"\n";
   cout<<"Enter the wholesale cost  ";
   cin>>record.wholesaleCost;
   cout<<"\n";
   cout<<"Enter the retail cost  ";
   cin>>record.retailCost;
   cout<<"\n";
   cout<<"Enter the date added to the inventory  ";
   cin.ignore();
   getline(cin, record.date);
   cout<<"\n";

   inAndOut.write(reinterpret_cast<char*>(&record),sizeof(record));
   *recordCounter = *recordCounter+1;
   
}

void display(inventory record, fstream &inAndOut, int recordCounter)
{
    int recNum;
	cout<<"Which particular file would you like to see?  ";
	   cin>>recNum;
	   cout<<"\n";

	if ( (recNum > (recordCounter-1) ) || (recNum < 0 ))
	{
		cout<<"That record does not exist"<<"\n";
	}
	else
	{

	   

	   inAndOut.seekg(recNum *sizeof(record), ios::beg);
	   inAndOut.read(reinterpret_cast<char*>(&record), sizeof(record));

	   cout<<"For record number  "<<recNum<<"\n";
	   cout<<"Description:  "<<record.description<<"\n";
	   cout<<"Quantity:  "<<record.quantity<<"\n";
	   cout<<"Wholesale Cost:  "<<record.wholesaleCost<<"\n";
	   cout<<"Retail Cost:  "<<record.retailCost<<"\n";
	   cout<<"Date added to inventory:  "<<record.date<<"\n";
	   cout<<"\n";
	}
}

void displayAll(inventory record, fstream &inAndOut,  int recordCounter)
{

   
   for(int i=0; i<recordCounter; i++)
   {
	   
	   inAndOut.seekg(i *sizeof(record), ios::beg);
	   inAndOut.read(reinterpret_cast<char*>(&record), sizeof(record) );
	   cout<<"Record Number: "<<i<<"\n";
	   cout<<"Description:  "<<record.description<<"\n";
	   cout<<"Quantity on hand:  "<<record.quantity<<"\n";
	   cout<<"Wholsale Cost:  "<<record.wholesaleCost<<"\n";
	   cout<<"Retail Cost:  "<<record.retailCost<<"\n";
	   cout<<"Date added to inventory:  "<<record.date<<"\n";
	   cout<<"\n";
	   
   }
}

void modify(inventory record, fstream &inAndOut, int recordCounter)
{
   int recNum;

   cout<<"Which record do you want to edit? ";
   cin>>recNum;

   if ( (recNum > (recordCounter-1) ) || (recNum < 0 ))
   {
      cout<<"That record does not exist and can't be edited! "<<"\n";
   }
   else
   {
       inAndOut.seekg(recNum *sizeof(record), ios::beg);
	   inAndOut.read(reinterpret_cast<char*>(&record), sizeof(record));

	   cout<<"The current item description: "<<record.description<<"\n";
	   cout<<"The current Quantity on hand: "<<record.quantity<<"\n";
	   cout<<"The current Whole Sale Price: "<<record.wholesaleCost<<"\n";
	   cout<<"The current Retail Price:     "<<record.retailCost<<"\n";
	   cout<<"The current date added to inventory: "<<record.date<<"\n";
	   cout<<"\n";
	   cout<<"\n";
	   cout<<"\n";
	   cout<<"The new description for item: ";
	   cin.ignore();
	   getline(cin, record.description);
	   cout<<"\n";
	   cout<<"The new Quantity is: ";
	   cin>>record.quantity;
       cout<<"\n";
	   cout<<"The new Whole Sale Price is: ";
	   cin>>record.wholesaleCost;
	   cout<<"\n";
	   cout<<"The new Retail Price is: ";
	   cin>>record.retailCost;
	   cout<<"\n";
	   cout<<"The new date added to inventory is: ";
	   cin.ignore();
	   getline(cin, record.date);
	   cout<<"\n";
       
       inAndOut.seekp(recNum *sizeof(record), ios::beg);
	   inAndOut.write(reinterpret_cast<char*>(&record),sizeof(record));

   }


}