;HW3: Interactive Database
choice=0
f=''
s=''
x=0.
first=strarr(100)
last=strarr(100)
points=fltarr(100)
year=intarr(100)
syr=['Fr.','So.','Jr.','Sr.']
n=0
while choice ne 10 do begin
print,"***Interactive Database***"
print,'1. Load a file'
print,'2. Save to a file'
print,'3. Create new database'
print,'4. Add a record'
print,'5. Delete a record'
print,'6. Modify a record'
print,'7. Display Records'
print,'8. Sort Records'
print,'9. Search for a Record'
print,'10. Quit'
read,'Enter a choice: ',choice
print,''
CASE choice OF
1: begin
   read,'Enter filename: ',f
   openr,1,f
   n=0
   while NOT EOF(1) do begin
     readf,1,x,y,s
     points[n]=x
     year[n]=y
     s=strcompress(s,/remove_all)
     last[n]=strmid(s,0,strpos(s,','))
     first[n]=strmid(s,strpos(s,',')+1,strlen(s))
     n=n+1 
   endwhile
   close,1
   print,'Loaded '+strcompress(n)+' records.'
end 
2: begin
   read,'Enter filename: ',f
   openw,1,f
   for j=0,n-1 do printf,1,points[j],year[j],'     '+last[j]+', '+first[j]
   close,1
   print,'Save successful.'
end
3: begin
   first=strarr(100)
   last=strarr(100)
   points=fltarr(100)
   year=intarr(100)
   n=0
end
4: begin
   read,'Enter last name: ',s
   last[n]=s
   read,'Enter first name: ',s
   first[n]=s
   read,'Enter scoring average: ',x
   points[n]=x
   read,'Enter year (1-4): ',y
   year[n]=y
   n=n+1
   print,'There are now '+strcompress(n)+' records.'
end
5: begin
   read,'Enter last name: ',s
   d=where(last eq s)
   if d[0] ne -1 then begin
      first[d[0]:n-1]=first[d[0]+1:n]
      last[d[0]:n-1]=last[d[0]+1:n]
      points[d[0]:n-1]=points[d[0]+1:n]
      year[d[0]:n-1]=year[d[0]+1:n]
      n=n-1
   endif else print,'Record not found.'
   print,'There are now '+strcompress(n)+' records.'
end
6: begin
   read,'Enter last name: ',s
   d=where(last eq s)
   if d[0] ne -1 then begin
      read,'Enter new last name: ',s
      last[d[0]]=s
      read,'Enter new first name: ',s
      first[d[0]]=s
      read,'Enter new scoring average: ',x
      points[d[0]]=x
      read,'Enter new year (1-4): ',y
      year[d[0]]=y
   endif else print,'Record not found.'
end
7: begin
     s='                    '
     for j=0,n-1 do begin
	sp=25-strlen(first[j])-strlen(last[j])
        print,first[j]+" "+last[j]+strmid(s,0,sp)+syr[year[j]-1],points[j]
     endfor
   end
8: begin
   print,'***Sort Records***'
   print,'1. Sort by Last Name'
   print,'2. Sort by Year'
   print,'3. Sort by Scoring Average'
   read,'Enter a choice: ',dchoice
   print,''
   CASE dchoice OF
   1: begin
	sname=sort(last[0:n-1])
        last[0:n-1]=last[sname]
	first[0:n-1]=first[sname]
	points[0:n-1]=points[sname]
	year[0:n-1]=year[sname]
      end
   2: if n gt 1 then begin 
	for j=0,n-2 do begin
	   for l=j+1,n-1 do begin
	      if year[l] gt year[j] then begin
		temp=year[j]
		year[j]=year[l]
		year[l]=temp
		temp=points[j]
		points[j]=points[l]
		points[l]=temp
		temp=last[j]
		last[j]=last[l]
		last[l]=temp
		temp=first[j]
		first[j]=first[l]
		first[l]=temp
	      endif
	   endfor
	endfor
      endif
   3: begin
        spts=reverse(sort(points[0:n-1]))
        last[0:n-1]=last[spts]
        first[0:n-1]=first[spts]
        points[0:n-1]=points[spts]
        year[0:n-1]=year[spts]
      end
   else: print,"Invalid Entry."
   endcase
end
9: begin
   read,'Enter last name: ',s
   d=where(last eq s)
   if d[0] ne -1 then begin
        print,first[d[0]]+" "+last[d[0]]+"     "+syr[year[d[0]]-1],points[d[0]]
   endif else print,'Record not found.'
end
10: print,"Goodbye."
else: print,"Invalid entry."
endcase
endwhile
end