#!/bin/bash
set -e

do_update_alternatives(){
    # skip update if program doesn't exist
    command -v update-alternatives >/dev/null || return 0
    local altscore now
    now=$(date -u +%s)          # Number of seconds since 1 Jan 1970

    # The reason for this approach rather than using the build number
    # is to allow for jobs from different builds. In one build job the
    # job number might be at 1200, whilst in a release job the number
    # may be only 1. This approach assums that if you install a build
    # with a different semantic version then the highest is the
    # desired one, but if you install two with the same semver then
    # the newest is the desired version.

    # Build up a score. It needs to fit in 32 bits
    altscore=$((@VERSION_MAJOR@ - 3))
    altscore=$((altscore * 14 + @VERSION_MINOR@)) # Allow up to 14 minor
    altscore=$((altscore * 14 + @VERSION_PATCH@)) # Allow up to 14 patch

    # So far if the version is less than 9 we have a number (altscore)
    # that is less than 1175.  2**31/1175 is about 1.8 million. So
    # multiply altscore by 1,000,000 and add in a factor of how many
    # minutes have passed from an arbitary point in time (1,600,000,000
    # seconds after 1 Jan 1970 or Sep 13 12:26:40 2020) on the
    # basis that no one is going to be installing a new version more
    # often than every minute. This does get things wrong if a million
    # minutes pass and you are downgrading, but the chances of someone
    # waiting almost 2 years between installing a version and the
    # previous patch level is small.


    altscore=$((altscore*1000000+(now-1600000000)/60))

    # Update the /opt/rocm symlink
    # For custom location installation of rpm package, /opt/rocm symlink is not required
    # TBD: For custom location installation of deb package.
    if [[ ${ID_LIKE:-$ID} == "debian" ]] || [[ "$RPM_INSTALL_PREFIX0" == "/opt/rocm-"* ]] ; then
        update-alternatives --install "/opt/rocm" "rocm" "@CPACK_PACKAGING_INSTALL_PREFIX@" "$altscore"
    fi

    for loc in "/usr/share/modules/modulefiles" "/usr/local/Modules/modulefiles" "/usr/share/Modules/modulefiles" "/usr/share/Modules/3.2.10/modulefiles"
    do
       if [ -d "$loc" ]
       then
           mkdir -p "$loc/rocm"
           if [[ ${ID_LIKE:-$ID} == "debian" ]] ; then
               update-alternatives --install "$loc/rocm/@ROCM_VERSION@" "rocmmod@ROCM_VERSION@" "@CPACK_PACKAGING_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@/rocmmod" "$altscore"
           else
               update-alternatives --install "$loc/rocm/@ROCM_VERSION@" "rocmmod@ROCM_VERSION@" "$RPM_INSTALL_PREFIX0/@CMAKE_INSTALL_LIBDIR@/rocmmod" "$altscore"
           fi
           break;
       fi
    done
    true
}

if [ -e /etc/os-release ] && source /etc/os-release && [[ ${ID_LIKE:-$ID} == "debian" ]]
then
    case "$1" in
       (configure)
       do_update_alternatives
       ;;
       (abort-upgrade|abort-remove|abort-deconfigure)
           echo "$1"
       ;;
       (*)
          exit 0
       ;;
    esac
else
    do_update_alternatives
fi