*------------------------------------------------------------------------
*     RECONG  Gen Target & HMS reconstruction  
*    -======-
*
*     HMS reconstruction including the effects of vertical beam offsets
*     and the Gen target magnetic field
*     - reads the data from a PAW/hbook ntuple written by hms.f
*     - writtes the results to a new PAW/hbook ntuple file
*     
*     written by Markus Muehlbauer
*------------------------------------------------------------------------
      IMPLICIT NONE

      REAL       pi180
      PARAMETER (pi180 = 3.141592653/180.)
      
      INTEGER   nwpawc,icycle,istat
      PARAMETER (nwpawc = 1000000)
      REAL      paw(nwpawc)
      COMMON    /pawc/paw 

      CHARACTER*8 tags(17)  
      REAL        event(17),param(20)
      CHARACTER   name1*80,name2*80,name3*80 
      CHARACTER   filename1*80,filename2*80
       
      DATA tags/'x0','dx0dz','y0','dy0dz','z0','delta0', 
     +          'x', 'dxdz', 'y', 'dydz', 'z',  
     +          'x1','dx1dz','y1','dy1dz','z1','delta1'/

       
      ! other variables
      REAL      tht_e,tht_B,E,x,y
      INTEGER   i,j,cnt
       
 10   FORMAT (X,A,$)
 20   FORMAT (A)

      PRINT *,'RECON  - struct simulated Gen data'
      PRINT *,'=====    (including the Gen target effects)'    
      PRINT *
      
      PRINT *
      PRINT 10,'Enter the name of the event file:            '
      READ (5,20) filename1
      PRINT 10,'Enter the name of the reconstruction matrix: '
      READ (5,20) filename2

      ! init HBOOK
      CALL hlimit(nwpawc)
 
      ! open the data ntuple file  
      name1 = filename1(:INDEX(filename1,' ')-1)//'.hbook'
      print *, 'Opening the event data file '//name1(:index(name1,' '))
      CALL hropen(20,'Input',name1,' ',4096,istat)
      CALL hcdir ('//Input',' ')
      CALL hrin  (0,999999,0)
      ! get the parameters
      CALL hunpak (1,param,' ',20)
      tht_e = param(2)
      tht_B = param(3)
      E     = param(4) - param(5)
      
      ! and prepare for the access of the data n-tuple
      CALL hgnpar(20,'MAIN')
      CALL hnoent(20,cnt)
 
      ! read the transport and field matrices
      name1 = 'fwd_maps.dat'
      name2 = filename2(:INDEX(filename2,' ')-1)//'.map'
      name3 = 'field_map.dat'
      print *,'Reading the transport ('//
     >         name1(:index(name1,' ')-1)//')'
      print *,'            reconstruction ('//
     >         name2(:index(name2,' ')-1)//')'
      print *,'            and field ('//
     >         name3(:index(name3,' ')-1)//') maps'  
      CALL genInitRecon (name2,name3,tht_B,name1,9,tht_e,E)
           
      ! open the data ntuple file  
      name1 = filename1(:INDEX(filename1,' ')-1)//'.hbook'
      print *, 'Reading the event data '//name1(:index(name1,' '))
       
      ! open the reconstructed data ntuple file
      name1 = filename1(:INDEX(filename1,' ')-1)//'_'//
     >        filename2(:INDEX(filename2,' ')-1)//'.hbook'
      print *, 'Writing the reconstructed data '
     >          //name1(:index(name1,' '))
      CALL hropen(21,'Output',name1,'NX',4096,istat)
      CALL hcdir ('//Output',' ')
   
      CALL hbookn(30,'Reconstructed Events',17,'//Output',4096,tags)
      
      tht_e = tht_e*pi180
      
      DO i=1,cnt
        CALL hcdir ('//Input',' ')
        CALL hgnf  (20,i,event,j)
        
	! calculate beam coordinates
	x = event(1)
 	y = cos(tht_e)*event(3) - sin(tht_e)*event(5) 
       
        ! reconstruct target coordinates 
        CALL genRecon (event(7),x,y,event(12))
	
!	print *,event(3),event(5),event(14),event(16)
!	print *,cos(tht_e),sin(tht_e)
! 	print *,cos(tht_e)*event(3) - sin(tht_e)*event(5), 
!     >          cos(tht_e)*event(5) + sin(tht_e)*event(3) 
!	print *,cos(tht_e)*event(14) - sin(tht_e)*event(16), 
!     >          cos(tht_e)*event(16) + sin(tht_e)*event(14) 
 	
        CALL hcdir ('//Output',' ')
        CALL hfn   (30,event)
      ENDDO
       
      CALL hdelet(10)
      CALL hdelet(20)
      CALL hrout(0,ICYCLE,' ')
      CALL hrend('Output')
      CALL hrend('Input')         
      
      STOP
      END