activate

#!/bin/bash
#
# Activate the Spack environment for developing NESO and set some
# environment variables. This script should be sourced to activate
# the environment. You can then run the "deactivate" function to
# return to your previous setup.
#

NESO_DEV_DIR=$(realpath $(dirname "$BASH_SOURCE"))

deactivate() {
  # Relink build directories
  setup
  # End the monitoring process and any `watch` processes it launched
  if [[ ! -z ${__MONITOR_PROCESS} ]]
  then
      kill $__MONITOR_PROCESS
  fi
  ps -ef | grep "spack find -l neso nektar neso-particles" | grep -v grep | awk '{print $2}' | xargs kill -9

  # Tidy up environment variables
  export I_MPI_FABRICS=$__ORIGINAL_I_MPI_FABRICS
  export SYCL_DEVICE_FILTER=$__ORIGINAL_SYCL_DEVICE_FILTER
  unset __ORIGINAL_I_MPI_FABRICS
  unset __ORIGINAL_SYCL_DEVICE_FILTER
  unset __MONITOR_PROCESS
  unset NESO_DEV_DIR

  # Undeclare all the functions in this file
  unset -f deactivate
  unset -f list-neso-builds
  unset -f list-builds
  unset -f cleanup-deprecated-builds
  unset -f create-link
  unset -f link-nektar-builds
  unset -f link-neso-builds
  unset -f link-neso-particles-builds
  unset -f setup
  unset -f monitor-build-dirs

  spack env deactivate
}

# Get a list of the NESO builds, including both compiler and SYCL
# implementation
list-neso-builds() {
    spack find --format "{compiler.name}-{^sycl.name}/{hash:7}" neso
    return $?
}

# Get a list of the builds of a package (specified as the first
# argument), with the name of the compiler.
list-builds() {
    spack find --format "{compiler.name}/{hash:7}" $1
    return $?
}

# Deletes spack build directories for hashes which are no longer
# installed in the environment. First argument is the package name and
# second is the directory in which to cleanup installs.
cleanup-deprecated-builds() {
    local package="$1"
    local basedir="$2"

    local good_hashes=()
    local h _vals
    for h in $(list-builds "${package}"); do
        IFS="/" read -ra _vals <<<"$h"
        good_hashes+=("${_vals[1]}")
    done

    local f
    for f in "$basedir"/spack-build-???????; do
        if [[ -d "$f" ]]
        then
           local hash="${f:(-7)}"
           if ! [[ " ${good_hashes[*]} " =~ " ${hash} " ]]
           then
              echo "Removing build directory $f"
              rm -Rf "$f" > /dev/null
           fi
        fi   
    done
}

# Creates a link to the specified target (first argument) with the
# specified name (second argument), unless a link to that target with
# that name already exists. It will overwrite links to different
# targets. Also print a message saying what it is doing.
create-link() {
    target="$1"
    link="$2"
    if ! [[ -L "$link" && $(readlink "$link") == "$target" ]]
    then
        echo "    Linking $(realpath -s --relative-to="$(pwd)" "$link") => $target"
        rm -f "$link" > /dev/null
        ln -s "$target" "$link"
    fi
}

# Creates symlinks to the nektar build directories which have
# meaningful names
link-nektar-builds() {
    mkdir -p "${NESO_DEV_DIR}/nektar/builds"
    local build _vals builds
    builds=$(list-builds nektar) # Need to declare builds already or else declaration would overwrite $?
    local list_err=$?
    if [[ $list_err != 0 ]]
    then
        return $list_err
    fi

    for build in $builds; do
        IFS="/" read -ra _vals <<<"$build"
        create-link "../spack-build-${_vals[1]}" "${NESO_DEV_DIR}/nektar/builds/${_vals[0]}"
    done
}

# Creates symlinks to the neso-particles build directories which have
# meaningful names
link-neso-particles-builds() {
    mkdir -p "${NESO_DEV_DIR}/neso-particles/builds"
    local build _vals builds
    builds=$(list-builds neso-particles) # Need to declare builds already or else declaration would overwrite $?
    local list_err=$?
    if [[ $list_err != 0 ]]
    then
        return $list_err
    fi

    for build in $builds; do
        IFS="/" read -ra _vals <<<"$build"
        create-link "../spack-build-${_vals[1]}" "${NESO_DEV_DIR}/neso-particles/builds/${_vals[0]}"
    done
}

# Creates symlinks to the NESO build directories which have
# meaningful names
link-neso-builds() {
    mkdir -p "${NESO_DEV_DIR}/builds"
    local build _vals builds
    builds=$(list-neso-builds) # Need to declare builds already or else declaration would overwrite $?
    list_err=$?
    if [[ $list_err != 0 ]]
    then
        return $list_err
    fi

    for build in ${builds}; do
        IFS="/" read -ra _vals <<<"$build"
        create-link "../spack-build-${_vals[1]}" "${NESO_DEV_DIR}/builds/${_vals[0]}"
    done
}


# Create symlink to the build directories
setup() {
    echo "Checking links to NESO build directories"
    link-neso-builds
    echo "Checking links to Nektar++ build directories"
    link-nektar-builds
    echo "Checking links to NESO-particles build directories"
    link-neso-particles-builds
}

# Monitor for changes which mean the build-directories have been
# changed and then re-link them. It does not delete old ones, as this
# is potentially risky and expensive. That can be done manually with
# the `cleanup` command.
monitor-build-dirs() {
    trap 
    while :
    do
        watch -n10 -g spack find -l neso nektar neso-particles &> /dev/null && setup &> /dev/null
    done
}

# Convenience command to check and delete any build directories no
# longer being used by the environment.
cleanup() {
    cleanup-deprecated-builds neso "${NESO_DEV_DIR}"
    cleanup-deprecated-builds nektar "${NESO_DEV_DIR}/nektar"
    cleanup-deprecated-builds neso-particles "${NESO_DEV_DIR}/neso-particles"
}

spack env activate -p -d ${NESO_DEV_DIR}
setup
( monitor-build-dirs ) & __MONITOR_PROCESS=$!

export __ORIGINAL_I_MPI_FABRICS=$I_MPI_FABRICS
export __ORIGINAL_SYCL_DEVICE_FILTER=$SYCL_DEVICE_FILTER

export I_MPI_FABRICS=shm
export SYCL_DEVICE_FILTER=host