#!/usr/bin/env sh
set -eu

COMPOSE_FILE="${COMPOSE_FILE:-docker-compose.production.yml}"
ENV_FILE="${ENV_FILE:-.env.production}"
BACKUP_DIR="${BACKUP_DIR:-./data/backups}"
RETENTION_DAYS="${BACKUP_RETENTION_DAYS:-14}"
SYNOLOGY_BACKUP_DIR="${SYNOLOGY_BACKUP_DIR:-}"

timestamp="$(date -u +%Y%m%d-%H%M%S)"
postgres_file="postgres-${timestamp}.dump"
config_file="config-${timestamp}.tar.gz"
logs_file="logs-${timestamp}.tar.gz"
manifest_file="backup-${timestamp}.manifest"

mkdir -p "${BACKUP_DIR}"

# If SYNOLOGY_BACKUP_DIR wasn't exported in the shell, read it from ENV_FILE.
if [ -z "${SYNOLOGY_BACKUP_DIR}" ] && [ -f "${ENV_FILE}" ]; then
  SYNOLOGY_BACKUP_DIR="$(
    sed -n 's/^SYNOLOGY_BACKUP_DIR=//p' "${ENV_FILE}" | tail -n 1
  )"
fi

docker compose --env-file "${ENV_FILE}" -f "${COMPOSE_FILE}" exec -T postgres sh -lc \
  "PGPASSWORD=\"\$POSTGRES_PASSWORD\" pg_dump -U \"\$POSTGRES_USER\" -d \"\$POSTGRES_DB\" -Fc" \
  > "${BACKUP_DIR}/${postgres_file}"

cat > "${BACKUP_DIR}/${manifest_file}" <<EOF
created_at_utc=${timestamp}
postgres_dump=${postgres_file}
backup_dir=${BACKUP_DIR}
synology_backup_dir=${SYNOLOGY_BACKUP_DIR}
media_sync_mode=synology-incremental-new-files-only
compose_file=${COMPOSE_FILE}
env_file=${ENV_FILE}
EOF

find "${BACKUP_DIR}" -type f \( \
  -name 'postgres-*.dump' -o \
  -name 'backup-*.manifest' \
\) -mtime +"${RETENTION_DAYS}" -delete

if [ -n "${SYNOLOGY_BACKUP_DIR}" ]; then
  mkdir -p "${SYNOLOGY_BACKUP_DIR}"

  # 1) Always copy the PostgreSQL dump to Synology.
  cp "${BACKUP_DIR}/${postgres_file}" "${SYNOLOGY_BACKUP_DIR}/${postgres_file}"

  # 2) Snapshot deployment config and logs to Synology each run.
  set -- "${ENV_FILE}" "${COMPOSE_FILE}"
  if [ -f deploy/cloudflared/config.yml ]; then
    set -- "$@" deploy/cloudflared/config.yml
  fi
  tar -C . -czf "${SYNOLOGY_BACKUP_DIR}/${config_file}" "$@"

  docker compose --env-file "${ENV_FILE}" -f "${COMPOSE_FILE}" run --rm --no-deps \
    -v "${SYNOLOGY_BACKUP_DIR}:/backup" \
    --entrypoint sh app -lc \
    "if [ -d /app/data/logs ]; then tar -C /app/data/logs -czf /backup/${logs_file} .; else : > /backup/${logs_file}; fi"

  # 3) Sync uploads incrementally to Synology (copy only new files).
  docker compose --env-file "${ENV_FILE}" -f "${COMPOSE_FILE}" run --rm --no-deps \
    -v "${SYNOLOGY_BACKUP_DIR}:/backup" \
    --entrypoint sh app -lc '
      mkdir -p /backup/uploads/documents /backup/uploads/photos;
      if [ -f /app/uploads/homepage.md ] && [ ! -f /backup/uploads/homepage.md ]; then
        cp /app/uploads/homepage.md /backup/uploads/homepage.md;
      fi;
      if [ -d /app/uploads/documents ]; then
        cp -an /app/uploads/documents/. /backup/uploads/documents/;
      fi;
      if [ -d /app/uploads/photos ]; then
        cp -an /app/uploads/photos/. /backup/uploads/photos/;
      fi
    '

  cp "${BACKUP_DIR}/${manifest_file}" "${SYNOLOGY_BACKUP_DIR}/${manifest_file}"

  # Keep rolling dump/config/log/manifest snapshots on Synology.
  find "${SYNOLOGY_BACKUP_DIR}" -maxdepth 1 -type f \( \
    -name 'postgres-*.dump' -o \
    -name 'config-*.tar.gz' -o \
    -name 'logs-*.tar.gz' -o \
    -name 'backup-*.manifest' \
  \) -mtime +"${RETENTION_DAYS}" -delete
fi

echo "Created backup set:"
echo "  ${BACKUP_DIR}/${postgres_file}"
echo "  ${BACKUP_DIR}/${manifest_file}"
if [ -n "${SYNOLOGY_BACKUP_DIR}" ]; then
  echo "Synology artifacts:"
  echo "  ${SYNOLOGY_BACKUP_DIR}/${postgres_file}"
  echo "  ${SYNOLOGY_BACKUP_DIR}/${config_file}"
  echo "  ${SYNOLOGY_BACKUP_DIR}/${logs_file}"
  echo "  ${SYNOLOGY_BACKUP_DIR}/uploads/{homepage.md,documents/,photos/} (incremental)"
  echo "  ${SYNOLOGY_BACKUP_DIR}/${manifest_file}"
else
  echo "SYNOLOGY_BACKUP_DIR not set; skipped Synology copy."
fi