#!/usr/bin/env bash
# aptly-mirror-refresh — periodic content refresh for mirrors declared in
# state.yaml: fetch the mirror, snapshot it, switch every publish target that
# references it, then prune old snapshots. Intended to be run by an external
# scheduler (cron, a Compose --profile, a k8s CronJob you wire up yourself —
# this chart does not ship one, see docs/versioning.md "Nicht im Scope").
#
# Only touches mirrors listed in --mirrors (or all mirrors in state.yaml if
# omitted). Safe to run concurrently with aptly-reconcile against the same
# instance (both go through the REST API); NOT safe to run two instances of
# this script concurrently against the same mirror, since both would try to
# update+snapshot it at once — use your scheduler's concurrency policy
# (Gitea/k8s CronJob: concurrencyPolicy=Forbid) to prevent that.
#
# Env:
#   APTLY_STATE_FILE          path to state.yaml (required)
#   APTLY_MIRRORS             comma-separated mirror names to refresh (default: all)
#   APTLY_KEEP_SNAPSHOTS      how many historical snapshots to retain per mirror (default: 5)
#   APTLY_SNAPSHOT_PREFIX     snapshot name template prefix (default: mirror name)
#   plus lib/common.sh's APTLY_URL / auth vars
set -euo pipefail

SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
# shellcheck source=rootfs/usr/local/bin/lib/common.sh
source "${SCRIPT_DIR}/lib/common.sh"
require_cmd curl jq yq date

: "${APTLY_STATE_FILE:?APTLY_STATE_FILE must point at a state.yaml}"
KEEP="${APTLY_KEEP_SNAPSHOTS:-5}"
STATE_JSON="$(yq -o=json '.' "$APTLY_STATE_FILE")"
STAMP="$(date -u +%Y%m%dT%H%M%SZ)"

wanted_mirrors=()
if [[ -n "${APTLY_MIRRORS:-}" ]]; then
  IFS=',' read -ra wanted_mirrors <<< "$APTLY_MIRRORS"
fi

wants() {
  local name="$1"
  [[ "${#wanted_mirrors[@]}" -eq 0 ]] && return 0
  for m in "${wanted_mirrors[@]}"; do [[ "$m" == "$name" ]] && return 0; done
  return 1
}

api_ready
failures=0

mirror_count="$(jq '(.mirrors // []) | length' <<<"$STATE_JSON")"
for ((i=0; i<mirror_count; i++)); do
  m="$(jq ".mirrors[$i]" <<<"$STATE_JSON")"
  name="$(jq -r '.name' <<<"$m")"
  wants "$name" || continue

  log "updating mirror '${name}'"
  resp="$(api PUT "/api/mirrors/${name}" -H 'Content-Type: application/json' -d '{"ForceUpdate": true}')" \
    || { warn "mirror update failed for ${name}"; failures=$((failures+1)); continue; }
  task_id="$(jq -r '.ID // empty' <<<"$resp")"
  if ! wait_task "$task_id"; then
    warn "mirror update task failed for ${name}, skipping snapshot/publish"
    failures=$((failures+1))
    continue
  fi

  snap_name="${name}-${STAMP}"
  log "snapshotting '${name}' -> '${snap_name}'"
  resp="$(api POST "/api/mirrors/${name}/snapshots" -H 'Content-Type: application/json' \
    -d "$(jq -n --arg n "$snap_name" '{Name: $n}')")" \
    || { warn "snapshot failed for ${name}"; failures=$((failures+1)); continue; }

  # Switch every publish target in state.yaml whose sources reference this mirror's snapshots.
  publish_count="$(jq '(.publish // []) | length' <<<"$STATE_JSON")"
  for ((j=0; j<publish_count; j++)); do
    p="$(jq ".publish[$j]" <<<"$STATE_JSON")"
    kind="$(jq -r '.sourceKind // "local"' <<<"$p")"
    [[ "$kind" == "snapshot" ]] || continue
    refs_mirror="$(jq --arg m "$name" '[.sources[] | select(.name | startswith($m + "-"))] | length > 0' <<<"$p")"
    [[ "$refs_mirror" == "true" ]] || continue

    prefix="$(jq -r '.prefix // ""' <<<"$p")"
    dist="$(jq -r '.distribution' <<<"$p")"
    escaped_prefix="$(api_prefix "$prefix")"
    component="$(jq -r '.sources[0].component // "main"' <<<"$p")"

    log "switching publish prefix='${prefix}' distribution='${dist}' -> snapshot '${snap_name}'"
    resp="$(api PUT "/api/publish/${escaped_prefix}/${dist}" -H 'Content-Type: application/json' \
      -d "$(jq -n --arg n "$snap_name" --arg c "$component" '{Snapshots: [{Name: $n, Component: $c}]}')")" \
      || { warn "publish switch failed for ${prefix}/${dist}"; failures=$((failures+1)); continue; }
    task_id="$(jq -r '.ID // empty' <<<"$resp")"
    wait_task "$task_id" || { warn "publish switch task failed for ${prefix}/${dist}"; failures=$((failures+1)); }
  done

  # Prune old snapshots for this mirror beyond APTLY_KEEP_SNAPSHOTS, oldest first.
  all_snaps="$(api GET "/api/snapshots" | jq -r --arg m "$name" \
    '[.[] | select(.Name | startswith($m + "-"))] | sort_by(.CreatedAt) | .[].Name')"
  total="$(wc -l <<<"$all_snaps" | tr -d ' ')"
  to_prune=$(( total > KEEP ? total - KEEP : 0 ))
  if [[ "$to_prune" -gt 0 ]]; then
    log "pruning ${to_prune} old snapshot(s) for '${name}' (keeping ${KEEP})"
    head -n "$to_prune" <<<"$all_snaps" | while IFS= read -r s; do
      [[ -z "$s" ]] && continue
      api DELETE "/api/snapshots/${s}" >/dev/null 2>&1 \
        || warn "could not drop snapshot ${s} (likely still referenced by a publish — will retry next run)"
    done
  fi
done

if [[ "$failures" -gt 0 ]]; then
  die "${failures} mirror(s) failed to refresh — see warnings above"
fi
log "mirror refresh complete"