!!$ 
!!$              Parallel Sparse BLAS  version 3.1
!!$    (C) Copyright 2006, 2007, 2008, 2009, 2010, 2012, 2013
!!$                       Salvatore Filippone    University of Rome Tor Vergata
!!$                       Alfredo Buttari        CNRS-IRIT, Toulouse
!!$ 
!!$  Redistribution and use in source and binary forms, with or without
!!$  modification, are permitted provided that the following conditions
!!$  are met:
!!$    1. Redistributions of source code must retain the above copyright
!!$       notice, this list of conditions and the following disclaimer.
!!$    2. Redistributions in binary form must reproduce the above copyright
!!$       notice, this list of conditions, and the following disclaimer in the
!!$       documentation and/or other materials provided with the distribution.
!!$    3. The name of the PSBLAS group or the names of its contributors may
!!$       not be used to endorse or promote products derived from this
!!$       software without specific written permission.
!!$ 
!!$  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
!!$  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
!!$  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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!!$ 
!!$  
program maxA_and_lapl_extremums
  use psb_base_mod
  use psb_util_mod
  use psb_eigen_mod
  implicit none

  ! input parameters
  character(len=100) ::  mtrx_file, rhs_file
  character(len=40) :: kmethd, ptype
  real (psb_dpk_) :: precisione,sigma
  integer(psb_ipk_) :: dim_H,start,step

  ! sparse matrices
  type(psb_dspmat_type) :: a, b, aux_a
  type(psb_d_coo_sparse_mat) :: acoo
  
  ! dense matrices
  real(psb_dpk_), allocatable, target ::  aux_b(:,:), d(:)
  real(psb_dpk_), allocatable , save  :: x_col_glob(:), r_col_glob(:)
  real(psb_dpk_), pointer  :: b_col_glob(:)
  type(psb_d_vect_type)    :: b_col, x_col, r_col
  complex(psb_dpk_),allocatable :: eig(:),eigmin(:)


  ! communications data structure
  type(psb_desc_type):: desc_a
  integer(psb_ipk_) :: ictxt, iam, np

  ! solver paramters
  integer(psb_ipk_) :: iter, itmax, ierr, itrace, ircode, ipart,&
       & methd, istopc, irst, nr
  integer(psb_long_int_k_) :: amatsize, descsize, annz, nbytes
  real(psb_dpk_)   :: err, eps,cond

  character(len=5)   :: afmt
  character(len=20)  :: name
  character(len=2)   :: filefmt
  integer(psb_ipk_), parameter :: iunit=12
  integer(psb_ipk_)  :: times=0
  integer(psb_ipk_) :: iparm(20)

  ! other variables 
  integer(psb_ipk_) :: nnzero,nrows,nnz,m_problem
  integer(psb_ipk_) :: i,info,j
  real(psb_dpk_) :: t1, t2, t3, t4
  real(psb_dpk_) :: lambda, lambda2, norm
  integer(psb_ipk_) :: nrhs, n_row, dim, nv, ne
  integer(psb_ipk_), allocatable :: ivg(:), ipv(:)


  call psb_init(ictxt)
  call psb_info(ictxt,iam,np)

  if (iam < 0) then 
    ! This should not happen, but just in case
    call psb_exit(ictxt)
    stop
  endif


  name='power_file'
  if(psb_get_errstatus() /= 0) goto 9999
  info=psb_success_
  call psb_set_errverbosity(2)
  !
  ! Hello world
  !
  if (iam == psb_root_) then 
    write(*,*) 'This is the ',trim(name),' sample program'
    read(psb_inp_unit,*) mtrx_file
    read(psb_inp_unit,*) filefmt
    read(psb_inp_unit,*) ipart
    read(psb_inp_unit,*) precisione
    read(psb_inp_unit,*) dim_H
    read(psb_inp_unit,*) sigma
    read(psb_inp_unit,*) ptype
    read(psb_inp_unit,*) kmethd
    read(psb_inp_unit,*) start
    read(psb_inp_unit,*) step
  end if
  call psb_bcast(ictxt,mtrx_file)
  call psb_bcast(ictxt,filefmt)
  call psb_bcast(ictxt,ipart)
  call psb_bcast(ictxt,precisione)
  call psb_bcast(ictxt,dim_H)
  call psb_bcast(ictxt,sigma)
  call psb_bcast(ictxt,ptype)
  call psb_bcast(ictxt,kmethd)
  call psb_bcast(ictxt,start)
  call psb_bcast(ictxt,step)
  rhs_file = 'NONE'
  afmt     = 'CSR'
  call psb_barrier(ictxt)
  ! read the input matrix to be processed and (possibly) the rhs 
  nrhs = 1

  if (iam==psb_root_) then
    select case(psb_toupper(filefmt)) 
    case ('AD')
      ! call psb_d_adj_read(aux_a,mtrx_file,iunit,info)
      open(iunit, FILE=mtrx_file, STATUS="OLD", ACTION="READ")
      read(iunit, *) nrows , nnzero
      t1 = psb_wtime()
      call acoo%allocate(nrows,nrows,start)
      do i = 1,start
        read(iunit, *) acoo%ia(i),acoo%ja(i)
        acoo%val(i)=1.0
      end do
      call acoo%set_nzeros(start)
      call acoo%fix(info)
      call aux_a%cp_from(acoo)
      call aux_a%cscnv(info,type='csr')

    case default
      info = -1 
      write(psb_err_unit,*) 'Wrong choice for fileformat ', filefmt
    end select
    if (info /= psb_success_) then
      write(psb_err_unit,*) 'Error while reading input matrix '
      call psb_abort(ictxt)
    end if   

    m_problem = aux_a%get_nrows()
    call psb_bcast(ictxt,m_problem)

   ! At this point aux_b may still be unallocated
    if (psb_size(aux_b,dim=1)==m_problem) then
      ! if any rhs were present, broadcast the first one
      write(psb_err_unit,'("Ok, got an rhs ")')
      b_col_glob =>aux_b(:,1)
    else
      call psb_realloc(m_problem,1,aux_b,ircode)
     ! write(psb_err_unit,*) 'Error realloc 1 passed '
      if (ircode /= 0) then
        call psb_errpush(psb_err_alloc_dealloc_,name)
        goto 9999
      endif
      b_col_glob => aux_b(:,1)
      do i=1, m_problem
        b_col_glob(i) = 1.d0
      enddo
    endif
    call psb_bcast(ictxt,b_col_glob(1:m_problem))
  
  else
    !write(psb_err_unit,*) 'avant realloc passed '
    call psb_bcast(ictxt,m_problem)
    call psb_realloc(m_problem,1,aux_b,ircode)
    !write(psb_err_unit,*) 'Error realloc passed '
    if (ircode /= 0) then
      call psb_errpush(psb_err_alloc_dealloc_,name)
      goto 9999
    endif
    b_col_glob =>aux_b(:,1)
    call psb_bcast(ictxt,b_col_glob(1:m_problem))  
  end if
  
  ! switch over different partition types
  if (ipart == 0) then 
    call psb_barrier(ictxt)
    allocate(ivg(m_problem),ipv(np))
    do i=1,m_problem
      call part_block(i,m_problem,np,ipv,nv)
      ivg(i) = ipv(1)
    enddo
    
    call psb_matdist(aux_a, a,ictxt, &
         & desc_a,b_col_glob,b_col,info,fmt=afmt,v=ivg)
      !write(psb_out_unit,*) 'OK matdist 1 ' 
      !write(psb_out_unit,'("nb zeros de a apres dist 1, num proc",i10," , ",i10)')a%get_nzeros(),iam
    
  else if (ipart == 2) then 
    if (iam==psb_root_) then 
      call build_mtpart(aux_a,np)
    endif
    call psb_barrier(ictxt)
    call distr_mtpart(psb_root_,ictxt)
    call getv_mtpart(ivg)
    call psb_matdist(aux_a, a, ictxt, &
         & desc_a,b_col_glob,b_col,info,fmt=afmt,v=ivg)

  else 
    call psb_matdist(aux_a, a,  ictxt, &
         & desc_a,b_col_glob,b_col,info,fmt=afmt,parts=part_block)
  end if

  call psb_barrier(ictxt)
  call psb_d_power_vect(a,x_col,lambda,precisione,iter,500,desc_a,info)
  
  t2 = psb_wtime() - t1
  t1 = psb_wtime()
  call psb_d_laplacian(a,b)
  !    write(psb_out_unit,'("nb zeros de B apres lapl, num proc",i10," , ",i10)')b%get_nzeros(),iam
  call psb_d_arnoldi(b,dim_H,eig,desc_a,ictxt,info)
  
  t3 = psb_wtime()-t1
  t1 = psb_wtime()
  call psb_d_shift_invert(b,dim_H,sigma,eigmin,ptype,kmethd,desc_a,ictxt,iam,info)
  
  call psb_barrier(ictxt)
  t4 = psb_wtime() - t1
  
  if (iam==psb_root_) then 
    open (15, FILE="resultats.dat", position = 'append',ACTION="WRITE")
    write (15,'(i20,F20.6,F20.4)')start,lambda,t2
    write (15,'(F20.6,F20.6,F20.4)')real(eig(dim_H)),real(eig(dim_H-1)),t3
    write (15,'(F20.6,F20.6,F20.4)')real(eigmin(dim_H)),real(eigmin(dim_H-1)),t4
    close(15)
  end if
  call psb_spfree(a, desc_a,info)
  call psb_spfree(aux_a, desc_a,info)
  call psb_spfree(b, desc_a,info)
  call psb_cdfree(desc_a,info)

  nnz=start
  do while (nnz+step <= nnzero)
  ! new acoo is the old one plus 'step' new links of the file
    if (iam==psb_root_) then
      t1 = psb_wtime()
      call acoo%reallocate(nnz+step)
      do j = 1,step
        read(iunit, *) acoo%ia(nnz+j),acoo%ja(nnz+j)
        acoo%val(i)=1.0
      end do
      call acoo%set_nzeros(nnz+step)
      call acoo%fix(info)
      call aux_a%cp_from(acoo)
      call aux_a%cscnv(info,type='csr')
      write(psb_out_unit,'(i10)')aux_a%get_nzeros()
      nnz=nnz+step
    
    !m_problem = aux_a%get_nrows()
    !call psb_bcast(ictxt,m_problem)

   ! At this point aux_b may still be unallocated
    !if (psb_size(aux_b,dim=1)==m_problem) then
      ! if any rhs were present, broadcast the first one
     ! write(psb_err_unit,'("Ok, got an rhs ")')
    !  b_col_glob =>aux_b(:,1)
   ! else
      !call psb_realloc(m_problem,1,aux_b,ircode)
     ! write(psb_err_unit,*) 'Error realloc 1 passed '
      !if (ircode /= 0) then
      !  call psb_errpush(psb_err_alloc_dealloc_,name)
      !  goto 9999
      !endif
      !b_col_glob => aux_b(:,1)
      !do j=1, m_problem
      !  b_col_glob(j) = 1.d0
     ! enddo
    !endif
   ! call psb_bcast(ictxt,b_col_glob(1:m_problem))

  !else
    !write(psb_err_unit,*) 'avant realloc passed '
    !call psb_bcast(ictxt,m_problem)
    !call psb_realloc(m_problem,1,aux_b,ircode)
    !write(psb_err_unit,*) 'Error realloc passed '
    !if (ircode /= 0) then
      !call psb_errpush(psb_err_alloc_dealloc_,name)
      !goto 9999
      !endif
     ! b_col_glob =>aux_b(:,1)
     ! call psb_bcast(ictxt,b_col_glob(1:m_problem))
    end if

    ! switch over different partition types
    if (ipart == 0) then
      write(psb_out_unit,'("on est dans le if",i10)')iam
      call psb_barrier(ictxt)
      write(psb_out_unit,*)"barriere passée"
      do j=1,m_problem
        call part_block(i,m_problem,np,ipv,nv)
        ivg(i) = ipv(1)
      enddo
      call psb_matdist(aux_a, a,ictxt, &
         & desc_a,b_col_glob,b_col,info,fmt=afmt,v=ivg)
     ! write(psb_out_unit,*) 'OK matdist 2 ' 
     ! write(psb_out_unit,'("nb zeros de a apres dist, num proc",i10," , ",i10)')a%get_nzeros(),iam
    
    else if (ipart == 2) then
      if (iam==psb_root_) then
        call build_mtpart(aux_a,np)
      endif
      call psb_barrier(ictxt)
      call distr_mtpart(psb_root_,ictxt)
      call getv_mtpart(ivg)
      call psb_matdist(aux_a, a, ictxt, &
         & desc_a,b_col_glob,b_col,info,fmt=afmt,v=ivg)

    else
      call psb_matdist(aux_a, a,  ictxt, &
         & desc_a,b_col_glob,b_col,info,fmt=afmt,parts=part_block)
    end if

    call psb_barrier(ictxt)
    call psb_d_power_vect(a,x_col,lambda,precisione,iter,500,desc_a,info)

    t2 = psb_wtime() - t1
    t1 = psb_wtime()
    call psb_d_laplacian(a,b)
    call psb_d_arnoldi(b,dim_H,eig,desc_a,ictxt,info)
 
    t3 = psb_wtime()-t1
    t1 = psb_wtime()
    call  psb_d_shift_invert(b,dim_H,sigma,eigmin,ptype,kmethd,desc_a,ictxt,iam,info)

    call psb_barrier(ictxt)
    t4 = psb_wtime() - t1

    if (iam==psb_root_) then
      open (15, FILE="resultats.dat", position = 'append',ACTION="WRITE")
      write (15,'(i20,F20.6,F20.4)')nnz,lambda,t2
      write (15,'(F20.6,F20.6,F20.4)')real(eig(dim_H)),real(eig(dim_H-1)),t3
      write (15,'(F20.6,F20.6,F20.4)')real(eigmin(dim_H)),real(eigmin(dim_H-1)),t4
      close(15)
    end if
    call psb_spfree(a, desc_a,info)
    call psb_spfree(aux_a, desc_a,info)
    call psb_spfree(b, desc_a,info)
    call psb_cdfree(desc_a,info)
  enddo 

  close(iunit)
  call psb_gefree(b_col, desc_a,info)
  call psb_gefree(x_col, desc_a,info)

9999 continue
  if(info /= 0) then
    call psb_error(ictxt)
  end if
  call psb_exit(ictxt)
  stop

end program maxA_and_lapl_extremums