#!/usr/bin/env bash
#
# Purge the entire BunnyCDN pull zone.
#
# `purge_cdn_cache.sh` purges the five index files by URL, which is right after
# a normal update: new packages arrive at new URLs, so only the index is stale.
#
# A rebuild is different. It replaces an object *in place*: a package whose
# build failed was published as its CRAN source, and the rebuilt binary takes
# exactly the same URL. The zone caches tarballs for ~370 days
# (`cache_expiration_time` in cdn.tf), so without a purge every client keeps
# receiving the source tarball for up to a year, and nothing about it looks
# wrong from the outside.
#
# Purging per URL would mean one API call per replaced package -- ~13.5k per
# arch against a rate-limited endpoint, where a single missed call leaves a
# silently stale package. One zone purge is a single call regardless of how many
# objects were replaced. The cost is a cold cache for everything else, which is
# why this is not used by the daily update path.
#
# All hostnames on the zone (cran.devxy.io, cran.allianceswisspass.devxy.io,
# cran.rpkgs.com) share pull zone 3857050, so one purge covers all of them.
#
# Usage:
#   purge_cdn_zone.sh <BUNNYNET_API_KEY> <pull_zone_id>
#
set -euo pipefail

if (($# < 2)); then
  echo "usage: $0 <api_key> <pull_zone_id>" >&2
  exit 2
fi

api_key="$1"
zone_id="$2"

echo "Purging BunnyCDN pull zone ${zone_id}"

status=$(
  curl -sS -o /tmp/purge_zone_response.txt -w '%{http_code}' -X POST \
    -H "AccessKey: ${api_key}" \
    -H "Content-Length: 0" \
    "https://api.bunny.net/pullzone/${zone_id}/purgeCache"
)

if [[ "${status}" != "200" && "${status}" != "204" ]]; then
  echo "Purge of pull zone ${zone_id} failed with HTTP ${status}:" >&2
  cat /tmp/purge_zone_response.txt >&2
  exit 1
fi

echo "Purged pull zone ${zone_id} (HTTP ${status})"