#include<stdio.

h>
#include<conio.h>
#include<stdlib.h>

void input();
void writefile();
void search();
void output();

struct date{
int month;
int day;
int year;
};

struct account {
int number;
char name[100];
int acct_no;
float mobile_no;
char street[100];
char city[100];
char acct_type;
float oldbalance;
float newbalance;
float payment;
struct date lastpayment;
}customer;
int tl,sl,ts;
void main()
{
int i,n;
char ch;
clrscr();

_setcursortype(_NOCURSOR);
printf(" CUSTOMER BILLING SYSTEM:\n\n");
printf("===============================\n");
printf("\n1: to add account on list\n");
printf("2: to search customer account\n");
printf("3: exit\n");
printf("\n================================\n");
do{
printf("\nselect what do you want to do?");
ch=getche();
}while(ch<='0' || ch>'3');
switch(ch){
case '1':
clrscr();
printf("\nhow many customer accounts?");
scanf("%d",&n);
for(i=0;i<n;i++){
input();
if(customer.payment>0)

customer.acct_type=(customer.payment<0.1*customer.oldbalance)? 'O': 'D';

else
customer.acct_type=(customer.oldbalance>0)?'D' : 'C';
 customer.newbalance=customer.oldbalance -
customer.payment;
writefile();
}
main();
case '2':
clrscr();
printf("search by what?\n");
printf("\n1 --- search by customer number\n");
printf("2 --- search by customer name\n");
search();
ch=getche();
main();
case '3':
clrscr();
delay(700);
textcolor(RED);
gotoxy(25,25);
cprintf("\nA PROJECT BY BIDUR & SUJAN");
delay(1500);
exit(1);
}
}

void input()
{
FILE *fp=fopen("bidur.dat","rb");
fseek (fp,0,SEEK_END);
tl=ftell(fp);
 sl=sizeof(customer);
ts=tl/sl;
fseek(fp,(ts-1)*sl,SEEK_SET);
fread(&customer,sizeof(customer),1,fp);
printf("\ncustomer no:%d\n",++customer.number);
fclose(fp);
printf(" Account number:");
scanf("%d",&customer.acct_no);
printf("\n Name:");
scanf("%s",customer.name);
printf("\n mobile no:");
scanf("%f",&customer.mobile_no);
printf(" Street:");
scanf("%s",customer.street);
printf(" City:");
scanf("%s",customer.city);
printf(" Previous balance:");
scanf("%f",&customer.oldbalance);
printf(" Current payment:");
scanf("%f",&customer.payment);
printf(" Payment date(mm/dd/yyyy):");
scanf("%d/%d/
%d",&customer.lastpayment.month,&customer.lastpayment.day,&customer.lastpayment.year
);
return;
}

void writefile()
{
FILE *fp;
 fp=fopen("bidur.dat","ab");
fwrite(&customer,sizeof(customer),1,fp);
fclose(fp);
return;
}

void search()
{
char ch;
char nam[100];
int n,i,m=1;
FILE *fp;
fp=fopen("bidur.dat","rb");
do{
printf("\nenter your choice:");
ch=getche();
}while(ch!='1' && ch!='2');
switch(ch){
case '1':
fseek(fp,0,SEEK_END);
tl=ftell(fp);
sl=sizeof(customer);
ts=tl/sl;
do{
printf("\nchoose customer number:");
scanf("%d",&n);
if(n<=0 || n>ts)
printf("\nenter correct\n");
else{
 fseek(fp,(n-1)*sl,SEEK_SET);
fread(&customer,sl,1,fp);
output();
}
printf("\n\nagain?(y/n)");
ch=getche();
}while(ch=='y');
fclose(fp);
break;
case '2':
fseek(fp,0,SEEK_END);
tl=ftell(fp);
sl=sizeof(customer);
ts=tl/sl;
fseek(fp,(ts-1)*sl,SEEK_SET);
fread(&customer,sizeof(customer),1,fp);
n=customer.number;

do{
printf("\nenter the name:");
scanf("%s",nam);
fseek(fp,0,SEEK_SET);
for(i=1;i<=n;i++)
{
fread(&customer,sizeof(customer),1,fp);
if(strcmp(customer.name,nam)==0)
{
output();
m=0;
 break;
}
}
if(m!=0)
printf("\n\ndoesn't exist\n");
printf("\nanother?(y/n)");
ch=getche();
}while(ch=='y');
fclose(fp);
}
return;
}

void output()
{
printf("\n\n Customer no :%d\n",customer.number);
printf(" Name :%s\n",customer.name);
printf(" Mobile no :%.f\n",customer.mobile_no);
printf(" Account number :%d\n",customer.acct_no);
printf(" Street :%s\n",customer.street);
printf(" City :%s\n",customer.city);
printf(" Old balance :%.2f\n",customer.oldbalance);
printf(" Current payment:%.2f\n",customer.payment);
printf(" New balance :%.2f\n",customer.newbalance);
printf(" Payment date :%d/%d/
%d\n\n",customer.lastpayment.month,customer.lastpayment.day,customer.lastpayment.year);
printf(" Account status :");
textcolor(128+RED);
switch(customer.acct_type)
{
case 'C':
cprintf("CURRENT\n\n");
break;
case 'O':
cprintf("OVERDUE\n\n");
break;
case 'D':
cprintf("DELINQUENT\n\n");
break;
default:
cprintf("ERROR\\n\n");
}
textcolor(WHITE);
return;
}