# Goals stdlib Fedora module.
# Copyright (C) 2020 Richard W.M. Jones
# Copyright (C) 2020 Red Hat Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

# Goals for dealing with Fedora builds.

# For these to work you must set up your environment in
# a particular way as described below:
#
# %fedora-dir:
# Points to a directory containing Fedora packages checked out
# of dist git.  You must use the fedpkg clone -B command to
# create separate branches.
#
# %fedora-branch:   Working branch, eg. "rawhide".
# %fedora-tag:      Build tag, eg. "f32-build".
#
# %fedora-rebuild-name:
# Magic string that identifies this rebuild.  This is used to
# detect if a rebuild has been attempted before in this run.
# eg. "Perl 5.99 rebuild"
#
# %fedora-source-packages:
# List of source packages that will be rebuilt.
#
# %fedora-ignored:
# List of source packages which will be ignored.  These are treated
# as if they have been rebuilt.
#
# %fedora-blocked:
# List of packages which are blocked.  Any dependent packages are
# also blocked. XXX NOT IMPLEMENTED

# Check if the source package has been built in Koji.

predicate is-koji-built (pkg) = {
    cd %fedora-dir/%pkg/%fedora-branch
    specfile=%pkg.spec

    # Packages which are ignored are treated as if they were rebuilt already.
    for p in %fedora-ignored; do
        if [ %pkg = "$p" ]; then exit 0; fi
    done

    # If the specfile doesn't have the magic string then the
    # package definitely needs to be rebuilt.
    grep -sq %fedora-rebuild-name $specfile || exit 99

    # Else we must check Koji itself.
    # Koji sends some messages to stderr.
    nvr=$(fedpkg verrel)
    buildinfo=$(koji buildinfo $nvr 2>&1 ||:)

    # No build at all, needs rebuild.
    echo "$buildinfo" | grep -sq "No such build" && exit 99

    # Existing build, find out what state it is in.
    state=$(echo "$buildinfo" | grep ^State: | awk '{print $2}')
    taskid=$(echo "$buildinfo" | grep ^Task: | awk '{print $2}')

    case "$state" in
    COMPLETE)
        # Complete so we don't need to rebuild.
        exit 0 ;;
    FAILED)
        # Failed builds must be examined and fixed manually.
        exit 1 ;;
    BUILDING)
        # Cancel the build, we will resubmit it.
        koji cancel $taskid ||:
        exit 99 ;;
    CANCELED|DELETED)
        # Do a rebuild.
        exit 99 ;;
    esac
    # Don't know what happened there, so fail.
    exit 1
}

# Rebuild a Fedora package.  This rebuilds any dependencies first.

goal fedora-rebuild (pkg) =
is-koji-built ("%pkg") :
        wrap ("is-koji-built", fedora-source-dependencies (pkg)) {
    cd %fedora-dir/%pkg/%fedora-branch
    specfile=%pkg.spec

    # We have to wait for the dependencies to become available
    # before we can start the new build.
    for p in %<; do
        nvr=$(koji --quiet latest-build %fedora-tag $p | awk '{print $1}')
        while ! koji wait-repo --timeout=10000 %fedora-tag --build=$nvr; do sleep 1m; done
    done

    # Make sure the local directory is up to date.
    # This should also fail if there are local changes, which
    # would need to be corrected/integrated by hand.
    git pull

    # If we're not building for Rawhide then we must use the rightmost
    # (-r) flag so there's an upgrade path to Rawhide.
    rightmost=
    if test %fedora-branch != "rawhide"; then rightmost=-r; fi

    # If the specfile doesn't have the magic string then add
    # that now.
    if ! grep -sq %fedora-rebuild-name $specfile; then
        rpmdev-bumpspec -c "- "%fedora-rebuild-name $rightmost *.spec
    else
        rpmdev-bumpspec -c "- Bump release and rebuild." $rightmost *.spec
    fi

    # Commit and push the change.
    fedpkg commit -c
    fedpkg push

    # Do the Koji build in the side tag.
    fedpkg build --target %fedora-tag
}

# Get the source package names for a particular package.
# Note this is not merely the BuildRequires, since those are
# the binary packages.  Also this will only find packages
# which are in the list of fedora-source-packages.
pure function fedora-source-dependencies (pkg) returning strings = @{
    echo Calculating dependencies of %pkg >&2

    specfile=%fedora-dir/%pkg/%fedora-branch/%pkg.spec

    # We will require the mapping of all source packages to the
    # list of binary packages they build, so work this out in advance.
    declare -A bin2src
    for p in %fedora-source-packages; do
        p_specfile=%fedora-dir/$p/%fedora-branch/$p.spec
        p_depcache=%fedora-dir/$p/%fedora-branch/.depcache
        if ! test -f "$p_depcache" || test "$p_specfile" -nt "$p_depcache";
        then
            rm -f $p_depcache
            for b in $(rpmspec -q --provides $p_specfile 2>/dev/null | awk '{print $1}'); do
                echo "bin2src['$b']='$p'" >> $p_depcache
            done
        fi
        source $p_depcache
    done

    for b in $(rpmspec -q --buildrequires $specfile 2>/dev/null |
               awk '{print $1}'); do
        # Find the source package that produces these binary requirements.
        echo ${bin2src[$b]}
    done | grep -v '^$' | sort -u
}