#!/usr/bin/bash
# Is a newer Quine Linux available, or downloaded and waiting for a restart?
# Writes the answer to /run/quine-linux/update-status.json, which Kickoff's
# update bar reads (quine-global-labs/plasma-desktop). Run as root by
# quine-update-check.service: bootc needs root.
#
#   state: "staged"    an update is downloaded; it applies at the next boot
#          "available" the registry has a newer image than the running one
#          "current"   neither
#   new:   the staged or available image's version and build time
#   error: why the registry check failed, if it did (state then falls back
#          to what bootc already knew)
set -euo pipefail

out_dir=/run/quine-linux
out="$out_dir/update-status.json"
mkdir -p "$out_dir"

# Fetches the image's manifest and config only, not its layers, and records
# what it found as the booted entry's cachedUpdate.
error=""
if ! check_output=$(bootc upgrade --check 2>&1); then
  error=$(tail -n 1 <<<"$check_output")
fi

bootc status --json | jq --arg error "$error" --arg checked "$(date -Is)" '
  .status as $s
  | ($s.booted.image.imageDigest // null) as $booted
  | ($s.staged.image // null) as $staged
  | ($s.booted.cachedUpdate // null) as $cached
  | {
      checked: $checked,
      error: (if $error == "" then null else $error end),
      current: {version: $s.booted.image.version, timestamp: $s.booted.image.timestamp},
      state: (
        if $staged != null and $staged.imageDigest != $booted then "staged"
        elif $cached != null and $cached.imageDigest != $booted then "available"
        else "current" end),
      new: (
        if $staged != null and $staged.imageDigest != $booted then $staged
        elif $cached != null and $cached.imageDigest != $booted then $cached
        else null end
        | if . == null then null else {version, timestamp} end)
    }' >"$out.tmp"
chmod 0644 "$out.tmp"
mv "$out.tmp" "$out"
jq -c '{state, new, error}' "$out"