#!/usr/bin/env bash
# Generate a package changelog for a freshly built image and publish it as a
# Gitea release (instead of committing JSON files under changelogs/).
#
# Usage: release.sh <image> <distro> <buildid> <packages-file>
#
# The full package list is attached to each release as
#   packages-<image>-<distro>.txt
# and the previous release's asset is used as the diff baseline.
set -euo pipefail

if [[ $# -lt 4 ]]; then
  echo "Usage: $0 <image> <distro> <buildid> <packages-file>" >&2
  exit 1
fi

IMAGE="$1"
DISTRO="$2"
BUILDID="$3"
PACKAGES_FILE="$4"

GITEA_URL="${GITEA_URL:-https://git.plabble.org}"
GITEA_REPO="${GITEA_REPO:-Misthios/bootc-images}"
TOKEN="${RELEASE_TOKEN:-${GITHUB_TOKEN:-}}"

[[ -n "${TOKEN}" ]] || { echo "RELEASE_TOKEN (or GITHUB_TOKEN) is required" >&2; exit 1; }
[[ -f "${PACKAGES_FILE}" ]] || { echo "Missing package list: ${PACKAGES_FILE}" >&2; exit 1; }

API="${GITEA_URL%/}/api/v1/repos/${GITEA_REPO}"
RELEASE_TAG="${IMAGE}-${DISTRO}.${BUILDID}"
ASSET_NAME="packages-${IMAGE}-${DISTRO}.txt"
RELEASE_TITLE="${IMAGE} ${DISTRO} ${BUILDID}"

WORK="$(mktemp -d)"
trap 'rm -rf "${WORK}"' EXIT

# Idempotency: never create the same release twice (e.g. a re-run).
if curl -fsSL -H "Authorization: token ${TOKEN}" \
     "${API}/releases/tags/${RELEASE_TAG}" >/dev/null 2>&1; then
  echo "Release ${RELEASE_TAG} already exists; nothing to do."
  exit 0
fi

# --- package list from the build -------------------------------------------
echo "Using package list ${PACKAGES_FILE} ..."
cp "${PACKAGES_FILE}" "${WORK}/packages-current.txt"

# --- previous package list from the last release ---------------------------
# Walk the release list (newest first) until we find the newest release for
# this image/distro.
prev_release_id=""
page=1
while :; do
  page_json="$(curl -fsSL -H "Authorization: token ${TOKEN}" \
    "${API}/releases?limit=50&page=${page}")"
  [[ "$(jq 'length' <<< "${page_json}")" -eq 0 ]] && break
  prev_release_id="$(jq -r --arg prefix "${IMAGE}-${DISTRO}." \
    '.[] | select(.tag_name | startswith($prefix)) | .id' <<< "${page_json}" \
    | head -n1)"
  [[ -n "${prev_release_id}" ]] && break
  page=$((page + 1))
  [[ "${page}" -gt 20 ]] && break
done

if [[ -n "${prev_release_id}" ]]; then
  asset_url="$(curl -fsSL -H "Authorization: token ${TOKEN}" \
    "${API}/releases/${prev_release_id}" \
    | jq -r --arg name "${ASSET_NAME}" \
        '.assets[] | select(.name == $name) | .browser_download_url' \
    | head -n1)"
  if [[ -n "${asset_url}" && "${asset_url}" != "null" ]]; then
    curl -fsSL -H "Authorization: token ${TOKEN}" "${asset_url}" \
      -o "${WORK}/packages-previous.txt" || true
  fi
fi
# First ever build: baseline against itself so nothing shows up as removed.
[[ -f "${WORK}/packages-previous.txt" ]] \
  || cp "${WORK}/packages-current.txt" "${WORK}/packages-previous.txt"

# --- diff -------------------------------------------------------------------
CUR_NAMES="$(mktemp)"
PREV_NAMES="$(mktemp)"
cut -d' ' -f1 "${WORK}/packages-current.txt" | sort > "${CUR_NAMES}"
cut -d' ' -f1 "${WORK}/packages-previous.txt" | sort > "${PREV_NAMES}"

added_names="$(comm -13 "${PREV_NAMES}" "${CUR_NAMES}" || true)"
removed_names="$(comm -23 "${PREV_NAMES}" "${CUR_NAMES}" || true)"
common_names="$(comm -12 "${PREV_NAMES}" "${CUR_NAMES}" || true)"

ver_of() { awk -v p="$1" '$1 == p {print $2}' "$2"; }

added=()
while read -r n; do
  [[ -z "${n}" ]] && continue
  added+=("${n} $(ver_of "${n}" "${WORK}/packages-current.txt")")
done <<< "${added_names}"

removed=()
while read -r n; do
  [[ -z "${n}" ]] && continue
  removed+=("${n} $(ver_of "${n}" "${WORK}/packages-previous.txt")")
done <<< "${removed_names}"

updated=()
while read -r n; do
  [[ -z "${n}" ]] && continue
  old="$(ver_of "${n}" "${WORK}/packages-previous.txt")"
  new="$(ver_of "${n}" "${WORK}/packages-current.txt")"
  [[ -z "${old}" || -z "${new}" ]] && continue
  [[ "${old}" != "${new}" ]] && updated+=("${n} ${old} -> ${new}")
done <<< "${common_names}"

{
  echo "Automated build of \`${IMAGE}\` \`${DISTRO}\` (\`${BUILDID}\`)."
  echo
  echo "- Added: ${#added[@]}"
  echo "- Removed: ${#removed[@]}"
  echo "- Updated: ${#updated[@]}"
  echo
  if (( ${#added[@]} )); then
    echo "### Added"
    printf -- '- %s\n' "${added[@]}"
    echo
  fi
  if (( ${#removed[@]} )); then
    echo "### Removed"
    printf -- '- %s\n' "${removed[@]}"
    echo
  fi
  if (( ${#updated[@]} )); then
    echo "### Updated"
    printf -- '- %s\n' "${updated[@]}"
    echo
  fi
} > "${WORK}/changelog.md"

# --- create the release -----------------------------------------------------
echo "Creating release ${RELEASE_TAG} ..."
payload="$(jq -n \
  --arg tag "${RELEASE_TAG}" \
  --arg name "${RELEASE_TITLE}" \
  --arg body "$(cat "${WORK}/changelog.md")" \
  '{tag_name: $tag, name: $name, body: $body, draft: false, prerelease: false}')"

response="$(curl -fsSL -X POST \
  -H "Authorization: token ${TOKEN}" \
  -H "Content-Type: application/json" \
  -d "${payload}" \
  "${API}/releases")"
release_id="$(jq -r '.id' <<< "${response}")"

echo "Uploading ${ASSET_NAME} ..."
curl -fsSL -X POST \
  -H "Authorization: token ${TOKEN}" \
  -F "attachment=@${WORK}/packages-current.txt" \
  "${API}/releases/${release_id}/assets?name=${ASSET_NAME}"

echo "Published release ${RELEASE_TAG}."

# --- prune older releases (and their assets/tags) for this image/distro -----
echo "Pruning older ${IMAGE} ${DISTRO} releases ..."
old_releases=""
page=1
while :; do
  page_json="$(curl -fsSL -H "Authorization: token ${TOKEN}" \
    "${API}/releases?limit=50&page=${page}")"
  [[ "$(jq 'length' <<< "${page_json}")" -eq 0 ]] && break
  old_releases+="$(jq -r --arg prefix "${IMAGE}-${DISTRO}." --arg keep "${release_id}" \
    '.[] | select(.tag_name | startswith($prefix)) | select((.id | tostring) != $keep) | "\(.id)\t\(.tag_name)"' \
    <<< "${page_json}")"$'\n'
  page=$((page + 1))
  [[ "${page}" -gt 20 ]] && break
done

while IFS=$'\t' read -r old_id old_tag; do
  [[ -z "${old_id}" ]] && continue
  echo "  removing release ${old_tag}"
  curl -fsSL -X DELETE -H "Authorization: token ${TOKEN}" \
    "${API}/releases/${old_id}" >/dev/null || true
  curl -fsSL -X DELETE -H "Authorization: token ${TOKEN}" \
    "${API}/tags/${old_tag}" >/dev/null || true
done <<< "${old_releases}"

echo "Done."