#
#Write a Script for Simple Database Management System Operation. 
#Database File Contains Following Fields. 
#EMP_NO  
#EMP_NAME 
#EMP_ADDRESS  
#EMP_AGE 
#EMP_GENDER   
#EMP_DESIGNATION 
#EMP_BASIC_SALARY  
# 
#Provide Menu Driven Facility For 
# 
#VIEW RECORD BASED ON QUERY 
#ADD RECORD   
#DELETE RECORD 
#MODIFY RECORD. 
#COUNT TOTAL NUMBER OF RECORDS   
#EXIT 
#
 
clear
################################ FUNCTION DECLARATIONS ############################
getTotalRecords()
{
    total=`cat $dbfile | wc -l`
	echo "Total records :"$total	
}
viewAllRecords()
{
	total=`cat $dbfile | wc -l`
	echo "Total records :"$total
	if [ $total -gt 0 ]
	then
		i=1
		while [ $i -le $total ]
		do
		echo "===================================="
			echo "Employee - "$i
			echo "============="
			record=`cat $dbfile | head -$i | tail -1`
			emp_no=`echo $record | cut -d "|" -f1`
			emp_name=`echo $record | cut -d "|" -f2`
			emp_add=`echo $record | cut -d "|" -f3`
			emp_age=`echo $record | cut -d "|" -f4`
			emp_gen=`echo $record | cut -d "|" -f5`
			emp_desg=`echo $record | cut -d "|" -f6`
			emp_sal=`echo $record | cut -d "|" -f7`
			echo "Employee No. :" $emp_no
			echo "Employee Name :" $emp_name
			echo "Employee Address :" $emp_add
			echo "Employee Age :" $emp_age
			echo "Employee Gender :" $emp_gen
			echo "Employee Designation :" $emp_desg
			echo "Employee salary :" $emp_sal
			i=`expr $i + 1`			
		echo "===================================="
		done
 
	fi
}
addRecord()
{
		echo "===================================="
		echo "	  ENTER EMPLOYEE INFORMATION"	
		echo "===================================="
		echo -n "Enter employee no. :"
		read no
		echo -n "Enter employee name :"	
		read name
		echo -n "Enter employee address :"	
		read add
		echo -n "Enter employee age :"	
		read age
		echo -n "Enter employee gender :"	
		read gen
		echo -n "Enter employee designation :"	
		read desc
		echo -n "Enter employee salary :"	
		read sal
		record="$no|$name|$add|$age|$gen|$desc|$sal"
		echo $record >> $dbfile
		echo "Employee information added successfully."
}
getEmployeeInformation()
{
		echo "===================================="
		echo "	   FIND EMPLOYEE INFORMATION"	
		echo "===================================="
		echo -n "Enter employee no. :"
		read no
		total=`cat $dbfile | grep -cwi $no`
		if [ $total -gt 0 ]
		then
			record=`cat $dbfile | grep -wi $no`
			emp_no=`echo $record | cut -d "|" -f1`
			emp_name=`echo $record | cut -d "|" -f2`
			emp_add=`echo $record | cut -d "|" -f3`
			emp_age=`echo $record | cut -d "|" -f4`
			emp_gen=`echo $record | cut -d "|" -f5`
			emp_desg=`echo $record | cut -d "|" -f6`
			emp_sal=`echo $record | cut -d "|" -f7`
			echo "Employee No. :" $emp_no
			echo "Employee Name :" $emp_name
			echo "Employee Address :" $emp_add
			echo "Employee Age :" $emp_age
			echo "Employee Gender :" $emp_gen
			echo "Employee Designation :" $emp_desc
			echo "Employee salary :" $emp_sal
		elif [ $total -eq 0 ]
		then
			echo "No record found for this id"
		fi
}
deleteEmployee()
{
		echo "===================================="
		echo "	   DELETE EMPLOYEE INFORMATION"	
		echo "===================================="
		echo -n "Enter employee no. :"
		read no
		total=`cat $dbfile | grep -cwi $no`
		if [ $total -gt 0 ]
		then
			totalrecords=`cat $dbfile | wc -l`
			i=1
			while [ $i -le $totalrecords ]
			do
				record=`cat $dbfile | head -$i | tail -1`
				findrecord=`echo $record | grep -wci $no`
				if [ $findrecord -eq 0 ]
				then
					echo "$record" >> "tempdata"
				fi
				i=`expr $i + 1`			
			done
			mv "tempdata" "data"
			echo "Employee with id $no deleted."
		elif [ $total -eq 0 ]
		then
			echo "No record found for this id"
		fi	
}
modifyRecord()
{
	echo "===================================="
	echo "	   MODIFY EMPLOYEE INFORMATION"	
	echo "===================================="
	echo -n "Enter employee no. :"
	read no
	total=`cat $dbfile | grep -cwi $no`
	if [ $total -gt 0 ]
	then
		record=`cat $dbfile | grep -wi $no`
		echo "================================================="
		echo "	   ENTER EMPLOYEE INFORMATION FOR ID : $no"	
		echo "================================================="
		echo -n "Enter employee name :"	
		read name
		echo -n "Enter employee address :"	
		read add
		echo -n "Enter employee age :"	
		read age
		echo -n "Enter employee gender :"	
		read gen
		echo -n "Enter employee designation :"	
		read desc
		echo -n "Enter employee salary :"	
		read sal	
		updatedrecord="$no|$name|$add|$age|$gen|$desc|$sal"
		#updates=$(`cat $dbfile` | sed s/$record/$updatedrecord/g)
		totalrecords=`cat $dbfile | wc -l`
		i=1
		while [ $i -le $totalrecords ]
		do
			record=`cat $dbfile | head -$i | tail -1`
			findrecord=`echo $record | grep -wci $no`
			if [ $findrecord -eq 0 ]
			then
				echo "$record" >> "tempdata"
			else
				echo "$updatedrecord" >> "tempdata"				
			fi
			i=`expr $i + 1`			
		done
		mv "tempdata" "data"
		echo "Record updated successfully"
	else
		echo "Record with this id not found"
	fi			
}
############################ END OF FUNCTION DECLARATIONS #########################
dbfile="data"
 
echo "===== AVAILABLE CHOICES ====="
echo "1 - All records display"
echo "2 - Add record"
echo "3 - View record"
echo "4 - Delete record"
echo "5 - Modify record"
echo "6 - Count total records"
echo "E - Exit"
echo "=============================="
echo -n "Enter your choice :"
read choice
case $choice in
"1")
viewAllRecords
;;
"2")
addRecord
;;
"3")
getEmployeeInformation
;;
"4")
deleteEmployee	
;;
"5")
modifyRecord
;;
"6")
getTotalRecords
;;
[eE])
	exit
;;
*)
	echo "Invalid choice"
;;
esac