#!/usr/bin/env bash
# SPDX-License-Identifier: MIT
# Run in a Fedora build environment with the application's dependencies.
set -euo pipefail
if (( $# != 2 )); then
    printf 'Usage: %s OLD_RPM NEW_RPM\n' "$0" >&2
    exit 2
fi
old_rpm=$(realpath "$1")
new_rpm=$(realpath "$2")
work=$(mktemp -d)
trap 'rm -rf -- "$work"' EXIT
mkdir -p "$work/root" "$work/runtime"
export XDG_CONFIG_HOME="$work/config" XDG_CACHE_HOME="$work/cache"
export XDG_DATA_HOME="$work/data" XDG_DATA_DIRS="$work/root/usr/share:/usr/share"
export XDG_RUNTIME_DIR="$work/runtime"
export QT_QPA_PLATFORM=offscreen QT_QUICK_BACKEND=software
unset QML_DISABLE_DISK_CACHE QML_FORCE_DISK_CACHE QML_DISK_CACHE_PATH QML_DISK_CACHE

launch_settings() {
    if timeout 3s dbus-run-session -- "$work/root/usr/bin/plasma-panel-actions" --settings > "$work/launch.log" 2>&1; then
        printf 'Settings exited before the test timeout.\n' >&2
        cat "$work/launch.log" >&2
        exit 1
    else
        status=$?
        if (( status != 124 )); then
            cat "$work/launch.log" >&2
            exit "$status"
        fi
    fi
}

cache_for() {
    for file in "$XDG_CACHE_HOME"/plasma-panel-actions/qmlcache/*.qmlc; do
        [[ -f $file ]] || continue
        if strings -el "$file" | grep -Fx "file://$1" > /dev/null; then
            printf '%s\n' "$file"
            return
        fi
    done
    printf 'No QML cache was generated for %s\n' "$1" >&2
    return 1
}

rpm2cpio "$old_rpm" | (cd "$work/root" && cpio -idm --quiet)
launch_settings
old_ui="$work/root/usr/share/plasma-panel-actions/ConfigGeneral.qml"
old_cache=$(cache_for "$old_ui")
old_checksum=$(sha256sum "$old_cache")

# Extract over the same location and keep the old cache intact. Changing
# the staging directory would hide the cache-collision regression.
rpm2cpio "$new_rpm" | (cd "$work/root" && cpio -idmu --quiet)
new_ui="$work/root$(rpm -qpl "$new_rpm" | grep '/ConfigGeneral.qml$')"
[[ $(stat -c %Y "$old_ui") == "$(stat -c %Y "$new_ui")" ]]
launch_settings
new_cache=$(cache_for "$new_ui")
[[ $new_cache != "$old_cache" ]]
[[ $(sha256sum "$old_cache") == "$old_checksum" ]]
strings -el "$new_cache" | grep -Fx twinFormLayouts > /dev/null
printf 'PASS: updated settings loaded with identical source timestamps and the old cache intact.\n'