#include<stdio.h>
#include<conio.h>
#include<dos.h>
#include<stdlib.h>
#include<string.h>
#define NUM_REC 100
#define NAME 100
#define AUTHOR 50
#define REF 20
typedef struct {
			char name[NAME];   //book name
			char author[AUTHOR];  //author
			char ref[REF];     //reference no.
			} BOOK;

int showchoices(void);
void listall(BOOK *, int);
void showhead(void);
void save(BOOK *, char *, int);
int load(BOOK *, char *, int);
void add(BOOK *, int *);
int find(BOOK *, char *, int, char);

void main(int argc, char *argv[])
{
BOOK bk[NUM_REC];
int bc=0;
char ch;
char *filename;
clrscr();
if(!argv[1])
	{
	do	{
	printf("\nEnter Choice: New session (N) or Update file (U) :  ");
	ch=getche();
	}while(ch!='u'&&ch!='U' && ch!='n'&&ch!='N');
	if(ch=='u' || ch=='U')
		{
		printf("Enter FILENAME: ");
		scanf("%12s",filename);
		}
	} //end if
else
	{
	ch='u';
	filename=argv[1];
	}

if(ch=='n' || ch=='N')
	{
	printf("\nEnter FILENAME: ");
	scanf("%11s",filename);
	bc=load(bk, filename, 0); //filename not given as
	}  // end if      new file is to be made
if(ch=='u' || ch=='U')
	{
	bc=load(bk, filename, 1);
	}
int cha;
showchoices:
clrscr();
printf("File %s is open...\n",filename);
cha=showchoices();
if(cha==0)	//save &exit
	{
	printf("\nSave? [yn]");
	if(cha=getch()=='y' || cha=='Y')
		{ save(bk, filename, bc); }
	}

else if(cha==1)	//save & continue
	{
	save(bk, filename, bc);
	goto showchoices;
	}

else if(cha==2)  //find in DB
	{
	char jz;
	char *tofind;
	do{
	  printf("Enter the search pattern (in "
			"LOWERCASE please!)"
			" \nName or Author: ");
	  jz=getche();
	  } while(jz!='a' && jz!='n');
	printf("\nEnter the Text String to Find"
		  "\n(Part strings OK):  ");
	fflush(stdin);
	gets(tofind);
	cha=find(bk, tofind, bc, jz);
	if(cha==-1) puts("NOT FOUND");
	else
		{
		printf("Required Record found at posn. %d\n",cha+1);
		puts("\nRecord is: ");
		printf("\nBook Name : %s",bk[cha].name);
		printf("\nAuthor    : %s",bk[cha].author);
		printf("\nReference # %s",bk[cha].ref);
		}

	cha=getch();
	goto showchoices;
	}

else if(cha==3)  //list all
	{
	listall(bk, bc);
	goto showchoices;
	}

else if(cha==4)
	{
	add(bk, &bc);
	goto showchoices;
	}

else	{
	putch(7);
	goto showchoices;
	}
}  //----end main()

int load(BOOK *b, char *fn, int fc)
{
int i=0;
if(fc!=0) {
FILE*stream=fopen(fn,"rt");
if(!stream)
	{
	puts("Error on input file");
	exit(0);
	}
while(!feof(stream))
	{
	fscanf(stream," %[^\n]",(b+i)->name);
	fscanf(stream," %[^\n]",(b+i)->author);
	fscanf(stream," %[^\n]",(b+i)->ref);
	i++;
	}
} //end the if(fn!="no file") if st.; NOT the fn()
else {
while(1)
	{
	add(b, &i);
	printf("Hit ESC to stop, or ENTER to add more records");
	if(getch()==27) break;
	fflush(stdin);
	}
} //end ELSE
return i-1;
}

void save(BOOK *b,char *fn, int records)
{
char yn;
do	{
	printf("\nOld Filename is: %s. ",fn);
	printf("Enter NEW file name? [yn]");
	yn=getche();
	} while(yn!='Y' && yn!='y' && yn!='N' && yn!='n');
if(yn=='y' || yn=='Y')
	{
	printf("Enter FILENAME: ");
	gets(fn);
	}
FILE*fp=fopen(fn,"wt");
for(int i=0;i<records;i++)
	{
	fputs((b+i)->name,fp); fputc('\n',fp);
	fputs((b+i)->author,fp); fputc('\n',fp);
	fputs((b+i)->ref,fp); fputc('\n',fp);
	}
fclose(fp);
}

int showchoices(void)
{
printf("0: save and exit\n");
printf("1: save only\n");
printf("2: find in DB\n");
printf("3: list all\n");
printf("4: add to DB\n");
printf("Enter Choice:  ");
int ch;
ch=getche();
ch-=48;
return ch;
}
	/* */
void showhead(void)
{
printf("BOOK NAME");
gotoxy(45,1);
printf("AUTHOR");
gotoxy(65,1);
printf("REF#");
}

void listall(BOOK *b, int records)
{
int bn;
for(bn=0;bn<records;bn++)
	{
	if(bn%20==0)
		{
		clrscr();
		showhead();
		}
	gotoxy(1,(bn%20+2));
	printf("%s",b[bn].name);
	gotoxy(45,(bn%20 + 2));
	printf("%s",b[bn].author);
	gotoxy(65,(bn%20+2));
	printf("%s",b[bn].ref);
	}
bn=getch();
}

void add(BOOK *b, int *i)
{
fflush(stdin);
printf("\n\nEnter NAME of book: ");
gets((b + *i)->name);
fflush(stdin);
printf("Enter the name of AUTHOR: ");
gets((b + *i)->author);
fflush(stdin);
printf("Enter the REFERENCE No. of book: ");
gets((b + *i)->ref);
*i+=1;
}

int find(BOOK *b, char *tofind, int max, char f)
{
int l=strlen(tofind);
for(int i=0;i<max;i++)
	{
	char *buff;
	for(int j=0;j<l;j++)
		{
		if(f=='n') *buff=(b+i)->name[j];
		else if(f=='a') *buff=(b+i)->author[j];
		buff++;
		}  *buff='\0';
		buff-=l;
	if(!stricmp(tofind, buff)) return i;
	}
return -1;
}