#!/usr/bin/env bash
set -euo pipefail

# [DEF:scripts.build_offline_docker_bundle:Module]
# @PURPOSE: Build and export an offline Docker bundle for enterprise-clean releases.
# [/DEF:scripts.build_offline_docker_bundle:Module]

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "${SCRIPT_DIR}/.." && pwd)"
DIST_ROOT="${PROJECT_ROOT}/dist/docker"

TAG="${1:-v1.0.0-rc2}"
POSTGRES_IMAGE="${POSTGRES_IMAGE:-postgres:16-alpine}"
BACKEND_IMAGE="ss-tools-backend:${TAG}"
FRONTEND_IMAGE="ss-tools-frontend:${TAG}"

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

get_repo_digest() {
  local digest
  digest="$(docker image inspect --format '{{join .RepoDigests ","}}' "$1" 2>/dev/null || true)"
  if [[ -n "${digest}" && "${digest}" != "<no value>" ]]; then
    printf '%s' "${digest}"
  else
    printf '%s' "unavailable"
  fi
}

mkdir -p "${DIST_ROOT}"

cd "${PROJECT_ROOT}"

echo "[offline-bundle] building backend image ${BACKEND_IMAGE}"
docker build -f docker/backend.Dockerfile -t "${BACKEND_IMAGE}" .

echo "[offline-bundle] building frontend image ${FRONTEND_IMAGE}"
docker build -f docker/frontend.Dockerfile -t "${FRONTEND_IMAGE}" .

echo "[offline-bundle] pulling postgres image ${POSTGRES_IMAGE}"
docker pull "${POSTGRES_IMAGE}"

echo "[offline-bundle] exporting tar archives"
docker save -o "${DIST_ROOT}/backend.${TAG}.tar" "${BACKEND_IMAGE}"
docker save -o "${DIST_ROOT}/frontend.${TAG}.tar" "${FRONTEND_IMAGE}"
docker save -o "${DIST_ROOT}/postgres.${TAG}.tar" "${POSTGRES_IMAGE}"

echo "[offline-bundle] calculating checksums"
(
  cd "${DIST_ROOT}"
  sha256sum "backend.${TAG}.tar" "frontend.${TAG}.tar" "postgres.${TAG}.tar" > "sha256sums.${TAG}.txt"
)

BACKEND_IMAGE_ID="$(get_image_id "${BACKEND_IMAGE}")"
FRONTEND_IMAGE_ID="$(get_image_id "${FRONTEND_IMAGE}")"
POSTGRES_IMAGE_ID="$(get_image_id "${POSTGRES_IMAGE}")"

BACKEND_REPO_DIGEST="$(get_repo_digest "${BACKEND_IMAGE}")"
FRONTEND_REPO_DIGEST="$(get_repo_digest "${FRONTEND_IMAGE}")"
POSTGRES_REPO_DIGEST="$(get_repo_digest "${POSTGRES_IMAGE}")"

cat > "${DIST_ROOT}/manifest.${TAG}.txt" <<EOF
release_tag=${TAG}
backend_image=${BACKEND_IMAGE}
backend_image_id=${BACKEND_IMAGE_ID}
backend_repo_digest=${BACKEND_REPO_DIGEST}
frontend_image=${FRONTEND_IMAGE}
frontend_image_id=${FRONTEND_IMAGE_ID}
frontend_repo_digest=${FRONTEND_REPO_DIGEST}
postgres_image=${POSTGRES_IMAGE}
postgres_image_id=${POSTGRES_IMAGE_ID}
postgres_repo_digest=${POSTGRES_REPO_DIGEST}
compose_file=docker-compose.enterprise-clean.yml
env_template=.env.enterprise-clean.example
env_bootstrap_fields=INITIAL_ADMIN_CREATE,INITIAL_ADMIN_USERNAME,INITIAL_ADMIN_PASSWORD,INITIAL_ADMIN_EMAIL
checksums_file=sha256sums.${TAG}.txt
generated_at_utc=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
EOF

cat > "${DIST_ROOT}/manifest.${TAG}.json" <<EOF
{
  "release_tag": "${TAG}",
  "images": [
    {
      "role": "backend",
      "image": "${BACKEND_IMAGE}",
      "image_id": "${BACKEND_IMAGE_ID}",
      "repo_digest": "${BACKEND_REPO_DIGEST}",
      "archive": "backend.${TAG}.tar"
    },
    {
      "role": "frontend",
      "image": "${FRONTEND_IMAGE}",
      "image_id": "${FRONTEND_IMAGE_ID}",
      "repo_digest": "${FRONTEND_REPO_DIGEST}",
      "archive": "frontend.${TAG}.tar"
    },
    {
      "role": "postgres",
      "image": "${POSTGRES_IMAGE}",
      "image_id": "${POSTGRES_IMAGE_ID}",
      "repo_digest": "${POSTGRES_REPO_DIGEST}",
      "archive": "postgres.${TAG}.tar"
    }
  ],
  "compose_file": "docker-compose.enterprise-clean.yml",
  "env_template": ".env.enterprise-clean.example",
  "env_bootstrap_fields": [
    "INITIAL_ADMIN_CREATE",
    "INITIAL_ADMIN_USERNAME",
    "INITIAL_ADMIN_PASSWORD",
    "INITIAL_ADMIN_EMAIL"
  ],
  "checksums_file": "sha256sums.${TAG}.txt"
}
EOF

cp "${PROJECT_ROOT}/docker-compose.enterprise-clean.yml" "${DIST_ROOT}/docker-compose.enterprise-clean.yml"
cp "${PROJECT_ROOT}/.env.enterprise-clean.example" "${DIST_ROOT}/.env.enterprise-clean.example"

echo "[offline-bundle] bundle created in ${DIST_ROOT}"
echo "[offline-bundle] next step:"
echo "  docker load -i ${DIST_ROOT}/backend.${TAG}.tar"
echo "  docker load -i ${DIST_ROOT}/frontend.${TAG}.tar"
echo "  docker load -i ${DIST_ROOT}/postgres.${TAG}.tar"