#!/bin/bash

set -e

if [ "mpich" != "serial" ]; then
  update-alternatives \
	--install /usr/bin/h5pcc h5pcc /usr/bin/h5pcc.mpich 10 \
	--slave /usr/bin/h5pfc h5pfc /usr/bin/h5pfc.mpich \
	--slave /usr/share/man/man1/h5pcc.1.gz h5pcc.1.gz /usr/share/man/man1/h5pcc.mpich.1.gz \
	--slave /usr/share/man/man1/h5pfc.1.gz h5pfc.1.gz /usr/share/man/man1/h5pfc.mpich.1.gz
fi
update-alternatives \
	--install /usr/lib/x86_64-linux-gnu/pkgconfig/hdf5.pc hdf5.pc /usr/lib/x86_64-linux-gnu/pkgconfig/hdf5-mpich.pc 10 \

# Install hdf5-mpi.pc as a new slave of the 'mpi' alternatives
# See #953021
# There is no way to simply add a new slave. We must parse the existing
# mpi alternatives, then reinstall the whole related alternative plus the
# wanted --slave part
function read_alt_slaves () {
  # See #973261
  local -n slaves=$1
  set -- $(echo "$2" | sed -n '/Slaves:/{: while;n;s/^ //;T end;p;b while;: end;q}')
  while [ -n "$1" ]; do
    slaves["$1"]="$2"
    shift 2
  done
}

if [ "mpich" != "serial" ]; then
  # Parse existing mpi alternatives
  mpi_alt=$(update-alternatives --query mpi)
  mpi_alt_sig=$(echo "$mpi_alt" | sed '/^$/q')
  mpi_alt_impl=$(echo "$mpi_alt" | sed -n -e '\!^Alternative: /usr/bin/mpicc.mpich!p' -e '0,\!^Alternative: /usr/bin/mpicc.mpich!d' -e '/^$/q' -e 'p')
  mpi_impl_priority=$(echo "$mpi_alt_impl" | sed -n '/^Priority: /{s/Priority: \(.*\)$/\1/;p}')
  declare -A slave_links slave_targets
  read_alt_slaves slave_links "$mpi_alt_sig"
  read_alt_slaves slave_targets "$mpi_alt_impl"
  # At this point:
  # * slave_links holds all the slaves name,link pairs
  # * slave_targets holds all the slaves name,target pairs for our mpi flavor
  # Construct the slaves related part of the update-alternatives command
  current_slaves=
  for key in "${!slave_targets[@]}"; do
    # Do not keep the 'hdf5-mpi.pc' slave for idempotency
    if [ "$key" = "hdf5-mpi.pc" ]; then
      continue
    fi
    current_slaves="$current_slaves --slave ${slave_links[$key]} $key ${slave_targets[$key]}"
  done
  # Re-install the whole alternative plus our 'hdf5-mpi.pc' slave
  update-alternatives --install /usr/bin/mpicc mpi /usr/bin/mpicc.mpich "$mpi_impl_priority" $current_slaves --slave /usr/lib/x86_64-linux-gnu/pkgconfig/hdf5-mpi.pc hdf5-mpi.pc /usr/lib/x86_64-linux-gnu/pkgconfig/hdf5-mpich.pc
  # Corner case:
  # When we have no installed libhdf5-<mpi>-dev for the currently configured mpi alternative
  # we have to provide a dummy hdf5-mpi.pc to enable installing this choice into the hdf5.pc alternatives
  if [ ! -h /usr/lib/x86_64-linux-gnu/pkgconfig/hdf5-mpi.pc ]; then
    ln -s /dev/null /usr/lib/x86_64-linux-gnu/pkgconfig/hdf5-mpi.pc
  fi
  # Install the hdf5-mpi.pc choice into the hdf5.pc alternatives
  update-alternatives --install /usr/lib/x86_64-linux-gnu/pkgconfig/hdf5.pc hdf5.pc /usr/lib/x86_64-linux-gnu/pkgconfig/hdf5-mpi.pc 35
fi



exit 0