#!/usr/bin/env bash
# Build candidate app (+events) and pi-agent images once for a commit.
# Writes .doc/test-reports/assets/promotion-receipts/<sha>.images.json
#
# Usage:
#   ./scripts/candidate-images-build.sh [--commit SHA] [--force]
set -euo pipefail

ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
cd "${ROOT}"

COMMIT=""
FORCE=0
while [[ $# -gt 0 ]]; do
  case "$1" in
    --commit) COMMIT="${2:-}"; shift 2 ;;
    --force) FORCE=1; shift ;;
    -h|--help)
      sed -n '2,8p' "$0" | sed 's/^# \{0,1\}//'
      exit 0
      ;;
    *) echo "unknown arg: $1" >&2; exit 1 ;;
  esac
done

if [[ -z "${COMMIT}" ]]; then
  COMMIT="$(git rev-parse HEAD)"
fi
COMMIT="$(git rev-parse --verify "${COMMIT}^{commit}")"
python3 "${ROOT}/scripts/agentctl.py" guard build --commit "${COMMIT}"
SHORT="${COMMIT:0:12}"
RECEIPT_DIR="${ROOT}/.doc/test-reports/assets/promotion-receipts"
OUT="${RECEIPT_DIR}/${COMMIT}.images.json"
mkdir -p "${RECEIPT_DIR}"

if [[ -f "${OUT}" && "${FORCE}" -ne 1 ]]; then
  echo "images.json already exists (immutable): ${OUT}" >&2
  echo "hint: use --force to rebuild local fixtures" >&2
  python3 - "${OUT}" "${COMMIT}" <<'CHECK_MANIFEST'
import json, sys
with open(sys.argv[1], encoding="utf-8") as source:
    manifest = json.load(source)
if manifest.get("commit") != sys.argv[2]:
    raise SystemExit("candidate manifest commit mismatch")
for field in ("image_ids", "image_digests", "tags"):
    if not isinstance(manifest.get(field), dict) or not all(manifest[field].get(k) for k in ("app", "events", "pi-agent")):
        raise SystemExit("incomplete candidate manifest")
CHECK_MANIFEST
  cat "${OUT}"
  exit 0
fi

# Docker reads an immutable export of the requested commit, never the mutable
# checkout or the nightly evidence generated after checkout.
BUILD_CONTEXT="$(mktemp -d "${TMPDIR:-/tmp}/agent-image-context.XXXXXX")"
trap 'rm -rf -- "${BUILD_CONTEXT}"' EXIT
trap 'exit 130' INT
trap 'exit 143' TERM
trap 'exit 129' HUP
git archive --format=tar "${COMMIT}" | tar -xf - -C "${BUILD_CONTEXT}"
SOURCE_TREE="$(git rev-parse "${COMMIT}^{tree}")"

APP_TAG="shuimu-agent-app:candidate-${SHORT}"
EVENTS_TAG="shuimu-agent-events:candidate-${SHORT}"
PI_TAG="shuimu-pi-agent:candidate-${SHORT}"

echo "==> building app/events image ${APP_TAG}..."
docker build -f "${BUILD_CONTEXT}/deploy/app/Dockerfile" -t "${APP_TAG}" "${BUILD_CONTEXT}"
# events binary lives in the same image
docker tag "${APP_TAG}" "${EVENTS_TAG}"

echo "==> building pi-agent image ${PI_TAG}..."
docker build -f "${BUILD_CONTEXT}/deploy/pi-agent/Dockerfile" -t "${PI_TAG}" "${BUILD_CONTEXT}"

image_id() {
  docker inspect --format '{{.Id}}' "$1"
}

repo_digest_or_id() {
  local name="$1"
  local repo
  repo="$(docker inspect --format '{{index .RepoDigests 0}}' "${name}" 2>/dev/null || true)"
  if [[ -n "${repo}" && "${repo}" != "<no value>" ]]; then
    printf '%s' "${repo}"
  else
    image_id "${name}"
  fi
}

APP_ID="$(image_id "${APP_TAG}")"
EVENTS_ID="$(image_id "${EVENTS_TAG}")"
PI_ID="$(image_id "${PI_TAG}")"
APP_DIGEST="$(repo_digest_or_id "${APP_TAG}")"
EVENTS_DIGEST="$(repo_digest_or_id "${EVENTS_TAG}")"
PI_DIGEST="$(repo_digest_or_id "${PI_TAG}")"

RECORDED_AT="$(date -u +%Y-%m-%dT%H:%M:%SZ)"
export COMMIT SHORT RECORDED_AT APP_TAG EVENTS_TAG PI_TAG SOURCE_TREE
export APP_ID EVENTS_ID PI_ID APP_DIGEST EVENTS_DIGEST PI_DIGEST OUT

python3 -c '
import json, os, tempfile
payload = {
    "commit": os.environ["COMMIT"],
    "source_tree": os.environ["SOURCE_TREE"],
    "source_context": "git-archive",
    "recorded_at": os.environ["RECORDED_AT"],
    "tags": {
        "app": os.environ["APP_TAG"],
        "events": os.environ["EVENTS_TAG"],
        "pi-agent": os.environ["PI_TAG"],
    },
    "image_ids": {
        "app": os.environ["APP_ID"],
        "events": os.environ["EVENTS_ID"],
        "pi-agent": os.environ["PI_ID"],
    },
    "image_digests": {
        "app": os.environ["APP_DIGEST"],
        "events": os.environ["EVENTS_DIGEST"],
        "pi-agent": os.environ["PI_DIGEST"],
    },
}
out = os.environ["OUT"]
fd, temporary = tempfile.mkstemp(prefix=".candidate-images-", dir=os.path.dirname(out))
try:
    with os.fdopen(fd, "w", encoding="utf-8") as f:
        json.dump(payload, f, indent=2, ensure_ascii=False)
        f.write("\n")
        f.flush()
        os.fsync(f.fileno())
    os.replace(temporary, out)
    directory = os.open(os.path.dirname(out), os.O_DIRECTORY)
    try:
        os.fsync(directory)
    finally:
        os.close(directory)
finally:
    if os.path.exists(temporary):
        os.unlink(temporary)
print(os.environ["OUT"])
'

echo "wrote candidate images manifest: ${OUT}"
echo "app=${APP_DIGEST}"
echo "events=${EVENTS_DIGEST}"
echo "pi-agent=${PI_DIGEST}"