update

#!/usr/bin/env nix-shell
#!nix-shell -i bash -p bash nix curl jq --pure
# vim: filetype=sh
set -euo pipefail

banner() {
    echo
    echo "--- $*"
    echo
}


update() {
    local versions="$1"
    local package="$2"
    echo "Versions file: $versions"
    echo "Package to update: $package"
    local owner=$(cat $versions | jq -r ".[\"$package\"].owner")
    local repo=$(cat $versions | jq -r ".[\"$package\"].repo")
    local branch=$(cat $versions | jq -r ".[\"$package\"].branch")
    local rev=$(cat $versions | jq -r ".[\"$package\"].rev")
    local sha256=$(cat $versions | jq -r ".[\"$package\"].sha256")

    echo "Owner: $owner"
    echo "Repository: $repo"
    echo "Branch: $branch"


    case "$PREFETCH_ONLY" in
        TRUE)
        local new_rev=$rev
        echo "Using existing revision"
        ;;
        FALSE)
        local new_rev=$(curl -sfL \
            https://api.github.com/repos/$owner/$repo/git/refs/heads/$branch \
            | jq -r .object.sha)
        echo "Fetching latest revision on branch $branch"
        ;;
    esac
    echo "The following revision will be used:"
    echo "  $new_rev"

    local url=https://github.com/$owner/$repo/archive/$new_rev.tar.gz
    local new_sha256=$(nix-prefetch-url --unpack "$url")

    echo "The following url will be used:"
    echo "  $url"

    echo "The following sha256 will be used:"
    echo "  $new_sha256"

    res=$(cat $versions \
        | jq -rM ".[\"$package\"].rev = \"$new_rev\"" \
        | jq -rM ".[\"$package\"].sha256 = \"$new_sha256\""
        )

    echo "New versions file:"
    echo "$res"

    echo "$res" > $versions
}

ROOT="$( cd "$( dirname "${BASH_SOURCE[0]}" )"/.. >/dev/null && pwd )"
VERSIONS_DEF="$ROOT/nix/versions.json"
PACKAGES_DEF="$(cat $VERSIONS_DEF | jq -r 'keys | .[]')"

VERSIONS="$VERSIONS_DEF"
echo "Using versions file ${VERSIONS}"

PREFETCH_ONLY="FALSE"
PACKAGES=""


while [[ $# -gt 0 ]]
do
key="$1"

case $key in
    --prefetch)
    PREFETCH_ONLY="TRUE"
    shift
    ;;
    *)
    PACKAGES="$key $PACKAGES"
    shift # past value
    ;;
esac
done

if [ -z "$PACKAGES" ];
then
    PACKAGES="$PACKAGES_DEF"
fi

echo "Using packages:"
for p in $PACKAGES; do echo " - $p"; done

for p in $PACKAGES; do
    banner "$p"
    update "$VERSIONS" "$p"
done