#!/bin/sh
# Mirror the latest main-branch build's cozystack-owned component images from the
# CI build registry (OCIR) to the public release registry (GHCR) BY DIGEST — no
# rebuild — and rewrite the baked package tree so the GHCR install closure is
# self-contained on GHCR.
#
# A nightly is a *renamed copy* of what main already built: every image cozystack
# ships is content-addressed, so copying each `<repo>@<digest>` from the source
# registry to the destination registry preserves the digest bit-for-bit. The
# nightly that users install from GHCR is the exact image set built and cached on
# the last push to main — nothing is rebuilt here.
#
# Usage: hack/nightly-mirror.sh <version> <baked-tree-dir> [--dry-run]
#   <version>         dest tag, e.g. 0.0.0-nightly.20260626 (a floating tag is
#                     also moved — see FLOATING)
#   <baked-tree-dir>  the extracted cozystack-packages OCI artifact: a directory
#                     whose layout is <dir>/<group>/<pkg>/values.yaml (apps/,
#                     core/, system/, extra/). This is the digest-vendored tree
#                     main's build baked but never committed.
#   --dry-run         print the skopeo copies and the host rewrite without doing
#                     them
#
# On success the baked tree's values.yaml files have every SRC_REGISTRY image
# host rewritten to DST_REGISTRY (digests untouched). The caller (nightly.yaml)
# then re-pushes that rewritten tree as the GHCR cozystack-packages artifact and
# repackages the cozy-installer chart against it — this script deliberately does
# NOT touch the cozystack-packages artifact itself (it is rebuilt downstream
# from the rewritten content, so a copy here would just be overwritten).
#
# Requires: yq (mikefarah), skopeo, sha256sum, and a login to both registries already done.
set -eu

VERSION="${1:?usage: nightly-mirror.sh <version> <baked-tree-dir> [--dry-run]}"
TREE="${2:?usage: nightly-mirror.sh <version> <baked-tree-dir> [--dry-run]}"
DRY_RUN=0
[ "${3:-}" = "--dry-run" ] && DRY_RUN=1

# Source = the per-CI build registry main pushes to; dest = the public release
# registry nightlies are served from. Defaults mirror hack/common-envs.mk
# (REGISTRY) and the CI workflows; override either for a fork.
SRC_REGISTRY="${SRC_REGISTRY:-iad.ocir.io/idyksih5sir9/cozystack}"
DST_REGISTRY="${DST_REGISTRY:-ghcr.io/cozystack/cozystack}"
# Floating tag moved to this nightly in addition to the pinned <version>.
FLOATING="${FLOATING:-nightly}"

[ -d "$TREE" ] || { echo "baked-tree-dir '$TREE' is not a directory" >&2; exit 1; }
command -v yq >/dev/null     || { echo "yq (mikefarah) is required" >&2; exit 1; }
yq --version 2>&1 | grep -q mikefarah || { echo "yq (mikefarah) is required" >&2; exit 1; }
[ "$DRY_RUN" -eq 1 ] || command -v skopeo >/dev/null || { echo "skopeo is required" >&2; exit 1; }
[ "$DRY_RUN" -eq 1 ] || command -v sha256sum >/dev/null || { echo "sha256sum is required" >&2; exit 1; }

# Ref collection (which files are scanned, and the YAML shapes within them) is
# shared with hack/promote-retag.sh and hack/promote-rewrite-tags.sh — see
# hack/lib/image-refs.sh.
#
# Getting the file set right matters twice over here, and worse than it does
# for the retag. A ref this does not collect is neither mirrored NOR host-
# rewritten (the rewrite below walks the same file list), so the published
# tree keeps pointing at the private CI registry — where a retag miss merely
# leaves an image short of a tag, a mirror miss publishes a nightly whose refs
# a user may not be able to pull at all. That is precisely what happened to
# every ref living in an images/*.tag file or stamped into a template while
# this scanned the depth-2 values.yaml alone.
# shellcheck source=hack/lib/image-refs.sh
. "$(dirname "$0")/lib/image-refs.sh"

collect_refs() { collect_image_refs "$TREE"; }

# Split a "<repo>[:<tag>]@sha256:<digest>" ref into repo and digest, stripping
# the :tag from the LAST path component only so a host :port is preserved.
ref_repo() {
  r="${1%@*}"
  img="${r##*/}"
  if [ "$r" = "$img" ]; then
    printf '%s' "${img%:*}"
  else
    printf '%s/%s' "${r%/*}" "${img%:*}"
  fi
}
ref_digest() { printf '%s' "${1##*@}"; }

copy() {
  _src="$1"; _dst="$2"
  if [ "$DRY_RUN" -eq 1 ]; then
    echo "DRY-RUN skopeo copy --multi-arch all docker://$_src docker://$_dst"
    return 0
  fi
  skopeo copy --multi-arch all "docker://$_src" "docker://$_dst"
}

# Normalize to canonical "<repo>@<digest>", keep only SRC_REGISTRY-owned refs
# (third-party images live in registries this job cannot push to), and drop the
# cozystack-packages artifact — the caller rebuilds it from the rewritten tree,
# so copying it here would only be overwritten downstream. Dedup on real identity.
refs=""
for raw in $(collect_refs); do
  [ -n "$raw" ] || continue
  _repo="$(ref_repo "$raw")"
  case "$_repo" in
    "${SRC_REGISTRY}/cozystack-packages") continue ;;
    "${SRC_REGISTRY}/"*) ;;
    *) continue ;;
  esac
  refs="${refs}${_repo}@$(ref_digest "$raw")
"
done
refs="$(printf '%s' "$refs" | sort -u)"
[ -n "$refs" ] || { echo "No cozystack-owned digest-pinned image refs found under ${SRC_REGISTRY}/ in '${TREE}' — is this the baked main tree?" >&2; exit 1; }

echo "$refs" | while IFS= read -r ref; do
  [ -n "$ref" ] || continue
  src_repo="${ref%@*}"
  digest="${ref##*@}"
  # Swap the source host prefix for the dest host; the path tail is identical.
  dst_repo="${DST_REGISTRY}/${src_repo#"${SRC_REGISTRY}/"}"
  echo "▸ ${src_repo}  ->  ${dst_repo}  ${digest}"
  copy "${src_repo}@${digest}" "${dst_repo}:${VERSION}"
  copy "${src_repo}@${digest}" "${dst_repo}:${FLOATING}"
  # Verify the dest pinned tag resolves to the exact source digest. Hash the raw
  # manifest: without --raw, skopeo resolves a multi-arch index to the host
  # platform's child manifest and reports that digest, which never equals the
  # index digest the tree pins. A failed inspect hashes the empty input and
  # fails the comparison, so the pipe cannot fail open.
  if [ "$DRY_RUN" -eq 0 ]; then
    got="sha256:$(skopeo inspect --raw "docker://${dst_repo}:${VERSION}" 2>/dev/null | sha256sum | cut -d' ' -f1)"
    if [ "$got" != "$digest" ]; then
      echo "::error::${dst_repo}:${VERSION} resolved to '${got}', expected '${digest}'" >&2
      exit 1
    fi
  fi
done

# Rewrite the image host SRC_REGISTRY -> DST_REGISTRY across the whole baked tree,
# digests untouched. Only cozystack-owned refs carry the SRC_REGISTRY prefix, so a
# literal substring replace cannot touch third-party image hosts. Escape the dots
# so sed matches the literal host, not "any character". This also rewrites the
# platformSourceUrl (oci://SRC/cozystack-packages -> oci://DST/cozystack-packages);
# its digest (platformSourceRef) is reset by the caller after the GHCR re-push.
SRC_ESC=$(printf '%s' "$SRC_REGISTRY" | sed -e 's/[].[^$*/\\]/\\&/g')
if [ "$DRY_RUN" -eq 1 ]; then
  # Name the rewrite by intent, not by the `sed -i` idiom the real path stopped
  # using, and report both expressions it applies: the `<host>/` prefix and the
  # bare-host scalar. Naming one expression understates what the run touches.
  echo "DRY-RUN rewrite image host ${SRC_REGISTRY}/ -> ${DST_REGISTRY}/ (and a bare ${SRC_REGISTRY} host scalar -> ${DST_REGISTRY}) over $(image_ref_files "$TREE" | wc -l | tr -d ' ') ref-bearing files under ${TREE}"
else
  # Exactly the files collect_refs scanned, via the same enumeration: the set
  # whose hosts are rewritten must equal the set scanned for images to mirror.
  # Rewriting a file that was not scanned leaves a dangling ref to an image
  # never pushed to DST_REGISTRY; scanning a file that is not rewritten leaves
  # the published tree pointing at the private CI registry. A `find -name
  # values.yaml` at any depth would do the former to vendored chart defaults.
  # The second expression reaches one shape the first cannot: a host that is the
  # *entire* scalar value, with the repository in a sibling key — kubeovn's
  # `global.registry.address`, now that its image is built here rather than in
  # cozystack/kubeovn-chart. There is no trailing slash for `<src>/` to match, so
  # the host survived the rewrite while the image itself was mirrored, publishing
  # a tree that points at the private CI registry. Anchoring on end-of-line means
  # it only fires when SRC_REGISTRY is the complete value: a contiguous
  # `<src>/<repo>@<digest>` ref continues past the host and is left to the first
  # expression, so the two cannot both fire on one reference.
  #
  # Neither expression reaches a host split at any other boundary (`registry:
  # iad.ocir.io` + `repository: idyksih5sir9/cozystack/<name>`), where no key
  # holds SRC_REGISTRY as a whole, so no package may stamp that layout.
  # In-place edit written portably: `sed -i` takes the next argument as the
  # backup suffix on BSD but as a flag on GNU, so `sed -i -e` diverges between
  # them. Route the output through a temp file and copy it back over the original
  # (cat, not mv, keeps the file's inode and permissions). `cat` truncates before
  # it writes, so an interrupt here can leave a half-written file where `mv` would
  # not; that is the lesser evil against `mv` stamping mktemp's 0600 onto every
  # rewritten file in the tree.
  image_ref_files "$TREE" | while IFS= read -r f; do
    # `\{0,1\}` rather than the `\?` optional-quantifier: `\?` is a GNU BRE
    # extension that BSD sed reads as a literal `?`, turning each `["']\?` into
    # "a quote followed by a literal ?". On macOS that makes the whole expression
    # dead -- it matches neither a bare host nor a quoted one, not just the bare
    # case. `\{0,1\}` is POSIX BRE and behaves the same on both.
    tmp_f=$(mktemp)
    sed \
      -e "s|${SRC_ESC}/|${DST_REGISTRY}/|g" \
      -e "s|\(:[[:space:]]*[\"']\{0,1\}\)${SRC_ESC}\([\"']\{0,1\}\)[[:space:]]*$|\1${DST_REGISTRY}\2|" \
      "$f" > "$tmp_f"
    cat "$tmp_f" > "$f"
    rm -f "$tmp_f"
  done
fi

echo "Mirrored cozystack-owned images to ${DST_REGISTRY} (:${VERSION} +:${FLOATING}) and rewrote tree hosts."