#!/usr/bin/env bash
set -x
set -e
set -u
set -o pipefail

verify=false
args="$(getopt -o '' --long verify -- "$@")"
eval "set -- $args"
while true; do
    case "$1" in
        --verify)
            verify=true
            shift
            ;;
        --)
            shift
            break
            ;;
    esac
done

# Ensure the directory for LAST_DEPENDENCIES_HASH exists
mkdir -p /var/lib/zulip

SOURCES_FILE=/etc/apt/sources.list.d/ksplice.list
STAMP_FILE=/etc/apt/sources.list.d/ksplice.list.apt-update-in-progress

ZULIP_SCRIPTS="$(dirname "$(dirname "$0")")"
DEPENDENCIES_HASH=$(sha1sum "$ZULIP_SCRIPTS/setup/"*.asc "$0")
DEPENDENCIES_HASH_FILE="/var/lib/zulip/setup-repositories-state-ksplice"
# Ensure that DEPENDENCIES_HASH_FILE exists before hashing it.
touch "$DEPENDENCIES_HASH_FILE"
LAST_DEPENDENCIES_HASH="$(cat "$DEPENDENCIES_HASH_FILE")"

# First, we only do anything in setup-apt-repo if any of its inputs
# (apt keys, code, etc.)  changed.
if [ "$DEPENDENCIES_HASH" = "$LAST_DEPENDENCIES_HASH" ]; then
    exit 0
elif [ "$verify" == true ]; then
    exit 1
fi

# Ensure that the sources file exists
touch "$SOURCES_FILE"

# Hash it to check if the sources file is changed by the script later.
zulip_source_hash=$(sha1sum "$SOURCES_FILE")

pre_setup_deps=(lsb-release apt-transport-https ca-certificates gnupg wget)
if ! apt-get -dy install "${pre_setup_deps[@]}"; then
    apt-get update
fi
apt-get -y install "${pre_setup_deps[@]}"

SCRIPTS_PATH="$(cd "$(dirname "$(dirname "$0")")" && pwd)"

release=$(lsb_release -sc)
if [[ "$release" =~ ^(buster|bionic|cosmic|disco|eoan|focal|groovy)$ ]]; then
    apt-key add "$SCRIPTS_PATH"/setup/ksplice.asc
    cat >$SOURCES_FILE <<EOF
deb http://www.ksplice.com/apt $release ksplice
deb-src http://www.ksplice.com/apt $release ksplice
EOF
else
    echo "Unsupported release $release."
    exit 1
fi

if [ "$zulip_source_hash" = "$(sha1sum "$SOURCES_FILE")" ] && ! [ -e "$STAMP_FILE" ]; then
    echo "zulip.list file did not change; skipping apt-get update"
else
    # We create this stamp file to ensure `apt-get update` will be run
    # the next time this script is invoked, and each time after, until
    # `apt-get update` finishes successfully.
    touch "$STAMP_FILE"
    apt-get update && rm -f "$STAMP_FILE"
fi

echo "$DEPENDENCIES_HASH" >"$DEPENDENCIES_HASH_FILE"