/*
Written by: D_S (Alex Cottner)
Date Finished: 2/6/2006
Description: Program controles database of students
*/

#include <iostream.h>
#include <conio.h>
#include <dos.h>
#include <fstream.h>
#include <string.h>



struct student
{
	char f_name[25];
	char l_name[25];
	long int id;
	char gender;
	float gpa;
};

void intro ();
void open_file(int &, student []);
void view (int, student []);
void add (int &, student []);
void del (int &, student []);
void sort (int, student []);
void swap (int, student []);
void alpha (char []);
void search (int&, student []);
void find (int, student []);
int compare (char [], int, char []);
void update (int, student []);
void write (int, student []);


void main ()
{
student list[100];
int menu=0, num_students;

intro ();

open_file (num_students, list);

while (menu<6)
{
   clrscr ();
   cout << "\n\t1) View Students";
   cout << "\n\t2) Add A Student";
   cout << "\n\t3) Delete A Student";
   cout << "\n\t4) Search For A Student";
   cout << "\n\t5) Update Student Information";
   cout << "\n\t6) Exit Program";

   cout << "\n\n\tWhat would you like to do?";
   cin >> menu;

   switch (menu)
   {
      case 1: clrscr (); view (num_students, list); break;
      case 2: clrscr (); add (num_students, list); break;
      case 3: clrscr (); del (num_students, list); break;
      case 4: clrscr (); find (num_students, list); break;
      case 5: clrscr (); update (num_students, list); break;
   }

} // menu loop

write (num_students, list);
} // end main



// simple introduction
void intro ()
{
// sets screan colors
textcolor(WHITE);
clrscr();

gotoxy (0,10);
cout << "\n\tStudent Editor\n";
cout << "\n\n\tVersion .10\n";
delay(2000);

cout << "\n\n\n\tProgram stores meaningless infromation on students.\n";
cout << "\n\n\tPress any key to continue.";

getch ();
clrscr();
} // end of intro



void open_file (int &num, student list[])
{

ifstream file;

file.open("c:\\student.x",ios::in);

// gets number of students
file >> num;

// gets student information
for (int i=0; i<num; i++)
{
   file >> list[i].l_name;
   file >> list[i].f_name;
   file >> list[i].id;
   file >> list[i].gender;
   file >> list[i].gpa;
}

file.close();
}



void view (int num, student list[])
{
cout << "Listing student names and information.\n";

// lists students line by line
for (int i=0; i<num; i++)
{
   cout << list[i].l_name << ", ";
   cout << list[i].f_name << "\t";
   cout << list[i].id << "\t";
   cout << list[i].gender << "\t";
   cout << list[i].gpa << "\n";

   // keeps screan from overflowing
   if ((i%58==0)&&(i!=0))
   {
      cout << "Screan paused for viewing.\n";
      cout << "Press any key to continue listing students.\n";
      getch ();
      clrscr ();
      cout << "Listing student names and information.\n";
   } // end if statement for breaks
} // end listing for loop

cout << "End of student list.\n";
cout << "Press any key to return to main menu.";
getch ();
} // end view students function


// retrieves student information from user
void add (int &num, student list[])
{
cout << "\n\tStudent's last name:\n\t";
cin >> list[num].l_name;
alpha(list[num].l_name);

cout << "\n\tStudent's first name:\n\t";
cin >> list[num].f_name;
alpha (list[num].f_name);

cout << "\n\tStudent's ID number:\n\t";
cin >> list[num].id;

cout << "\n\tStudent's gender:\n\t";
cin >> list[num].gender;
if (list[num].gender>90)
   list[num].gender-=32;

cout << "\n\tStudent's current GPA:\n\t";
cin >> list[num].gpa;

num++;

sort (num, list);
cout << "\n\n\n\tStudent information collected.";
cout << "\n\tPress any key to return to the main menu.";

getch ();
}



void del (int &num, student list[])
{
char name[25];
int array_num;

cout << "\n\n\tEnter the last name of the student you wish to delete:\n\t";
cin >> name;
alpha (name);

// finds student to delete
for (int i=0; i<num; i++)
{
   if (strcmp(name, list[i].l_name)==0)
      array_num=i;
}

// copies last students info over deleted students then sorts
strcpy(list[array_num].f_name, list[num-1].f_name);
strcpy(list[array_num].l_name, list[num-1].l_name);
list[array_num].id=list[num-1].id;
list[array_num].gender=list[num-1].gender;
list[array_num].gpa=list[num-1].gpa;

num--;
sort (num, list);

cout << "\n\n\n\tStudent deleted.";
cout << "\n\tPress any key to continue.";
getch ();
} // delete student function



void sort (int num, student list[])
{
int change;

do {
   change=0;

   for (int i=0; i+1<num; i++)
   {
      if (strcmp(list[i].l_name, list[i+1].l_name)>0)
      {
	 swap (i, list); // switches students
	 change=1; // flag for bubble sort
      }

   }// end for loop

   num--;
}while (change>0);

} // end sort function


// very long and tedious but very simple swap functions
void swap (int num, student list[])
{
student temp;

strcpy (temp.f_name, list[num].f_name);
strcpy (temp.l_name, list[num].l_name);
temp.id=list[num].id;
temp.gender=list[num].gender;
temp.gpa=list[num].gpa;

strcpy (list[num].f_name, list[num+1].f_name);
strcpy (list[num].l_name, list[num+1].l_name);
list[num].id=list[num+1].id;
list[num].gender=list[num+1].gender;
list[num].gpa=list[num+1].gpa;

strcpy (list[num+1].f_name, temp.f_name);
strcpy (list[num+1].l_name, temp.l_name);
list[num+1].id=temp.id;
list[num+1].gender=temp.gender;
list[num+1].gpa=temp.gpa;
} // end swap function


// makes all characters uppercase by moving them down the ascii table
void alpha (char word[])
{
for (int i=0; word[i]!='\0'; i++)
{
   if (word[i]>=95)
      word[i]-=32;
}

} // end alpha function


// search function used by the other functions
void search (int &i, student list[])
{
char name[25];
int flag=0;

cout << "\n\tEnter the last name of the student.\n\t";
cin >> name;
alpha (name);

for (i=0; flag<1; i++)
{
   if (strcmp(name, list[i].l_name)==0)
      flag=1;
}
} // end search function


// fancy ass find function used by the user
void find (int num, student list [])
{
char ltz[25];
int let=0;

do{
   cout << "\n\tEnter the start of the persons first or last name.\n\t";
   for (int x=0; x<let; x++)
      cout << ltz[x];

   ltz[let]=getch();
   let++;

   alpha (ltz);

   clrscr ();

   if ((ltz[let-1]==8)&&(let>1))
      let-=2;

   for (int i=0; i<num; i++)
   {
      if (((compare (ltz, let, list[i].l_name)>0)||(compare (ltz, let, list[i].f_name)>0))&&let>0)
      {
	 cout << "\n\t";
	 cout << list[i].l_name << ", ";
	 cout << list[i].f_name << "\t";
	 cout << list[i].id << "\t";
	 cout << list[i].gender << "\t";
	 cout << list[i].gpa;
      } // end cout if statement
   } // end for loop to run through student list

   cout << "\n\n\tEnter a 6 to return to the main menu.";
} while (ltz[let-1]!='6');
} // end fancy ass find function



int compare (char word[], int size, char temp[])
{
// compares the words one letter at a time until something is uneven
for (int i=0; temp[i]==word[i]; i++)
{
}

if (i>=size)
   return 1;
else
   return 0;
} // end compare function



// updates previous student information
void update (int num, student list [])
{
unsigned int choice;
search (num, list);
num--;
do{
clrscr ();

// displays student info for user
cout << "\n\t";
cout << list[num].l_name << ", ";
cout << list[num].f_name << "\t";
cout << list[num].id << "\t";
cout << list[num].gender << "\t";
cout << list[num].gpa << "\n";

cout << "\n\t1. Last name";
cout << "\n\t2. First name";
cout << "\n\t3. ID Number";
cout << "\n\t4. Gender";
cout << "\n\t5. GPA";
cout << "\n\t6. Exit";

cout << "\n\n\tWhat would you like to change?\t";
cin >> choice;
switch (choice)
{
   case 1:
      cout << "\n\n\tEnter the new last name.\n\t";
      cin >> list[num].l_name;
      alpha (list[num].l_name);
      break;
   case 2:
      cout<< "\n\n\tEnter the new first name.\n\t";
      cin >> list[num].f_name;
      alpha (list[num].f_name);
      break;
   case 3:
      cout << "\n\n\tEnter the new ID number.\n\t";
      cin >> list[num].id;
      break;
   case 4:
      cout << "\n\n\tEnter the new Gender.\n\t";
      cin >> list[num].gender;
      if (list[num].gender<95)
	 list[num].gender-=32;
      break;
   case 5:
      cout << "\n\n\tEnter the new GPA.\n\t";
      cin >> list[num].gpa;
      break;
   }// end switch statement

}while(choice<6);
} // end update function


// writes data to file once user is done
void write (int num, student list [])
{
ofstream file;

file.open("c:\\student.x",ios::out);
file << num <<'\n';

for (int i=0; i<num; i++)
{
   file << list[i].l_name <<'\t';
   file << list[i].f_name <<'\t';
   file << list[i].id <<'\t';
   file << list[i].gender <<'\t';
   file << list[i].gpa <<'\n';
}

file.close();
} // end write file function