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

COMPOSE_FILE="${COMPOSE_FILE:-docker-compose.production.yml}"
ENV_FILE="${ENV_FILE:-.env.production}"
BACKUP_DIR="${BACKUP_DIR:-${DATABASE_BACKUP_DIR:-./data/backups}}"
APP_DATA_BACKUP_DIR="${APP_DATA_BACKUP_DIR:-${BACKUP_DIR}/data}"
UPLOADS_BACKUP_DIR="${UPLOADS_BACKUP_DIR:-${BACKUP_DIR}/uploads}"
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

use_compose_backup=0
if command -v docker >/dev/null 2>&1 && [ -S /var/run/docker.sock ] && [ -f "${COMPOSE_FILE}" ]; then
  use_compose_backup=1
fi

if [ "${use_compose_backup}" -eq 1 ]; then
  docker compose --env-file "${ENV_FILE}" -f "${COMPOSE_FILE}" exec -T postgres sh -lc \
    "PGPASSWORD=\"\$POSTGRES_PASSWORD\" pg_dump -U \"\$POSTGRES_USER\" -d \"\$POSTGRES_DB\" -Fc" \
    > "${BACKUP_DIR}/${postgres_file}"
else
  : "${POSTGRES_HOST:=postgres}"
  : "${POSTGRES_PORT:=5432}"
  if [ -z "${POSTGRES_DB:-}" ] || [ -z "${POSTGRES_USER:-}" ] || [ -z "${POSTGRES_PASSWORD:-}" ]; then
    echo "POSTGRES_DB, POSTGRES_USER, and POSTGRES_PASSWORD must be set for in-container backup mode." >&2
    exit 1
  fi
  if ! command -v pg_dump >/dev/null 2>&1; then
    echo "pg_dump is not installed in this environment." >&2
    exit 1
  fi
  PGPASSWORD="${POSTGRES_PASSWORD}" pg_dump \
    -h "${POSTGRES_HOST}" \
    -p "${POSTGRES_PORT}" \
    -U "${POSTGRES_USER}" \
    -d "${POSTGRES_DB}" \
    -Fc \
    > "${BACKUP_DIR}/${postgres_file}"
fi

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

# Always keep a rolling incremental mirror of uploaded files in BACKUP_DIR.
mkdir -p "${APP_DATA_BACKUP_DIR}"
if [ -d /app/data ]; then
  cp -a /app/data/. "${APP_DATA_BACKUP_DIR}/"
fi

mkdir -p "${UPLOADS_BACKUP_DIR}/documents" "${UPLOADS_BACKUP_DIR}/photos"
if [ -f /app/uploads/homepage.md ] && [ ! -f "${UPLOADS_BACKUP_DIR}/homepage.md" ]; then
  cp /app/uploads/homepage.md "${UPLOADS_BACKUP_DIR}/homepage.md"
fi
if [ -d /app/uploads/documents ]; then
  cp -an /app/uploads/documents/. "${UPLOADS_BACKUP_DIR}/documents/"
fi
if [ -d /app/uploads/photos ]; then
  cp -an /app/uploads/photos/. "${UPLOADS_BACKUP_DIR}/photos/"
fi

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 --
  [ -f "${ENV_FILE}" ] && set -- "$@" "${ENV_FILE}"
  [ -f "${COMPOSE_FILE}" ] && set -- "$@" "${COMPOSE_FILE}"
  [ -f deploy/cloudflared/config.yml ] && set -- "$@" deploy/cloudflared/config.yml
  if [ "$#" -gt 0 ]; then
    tar -C . -czf "${SYNOLOGY_BACKUP_DIR}/${config_file}" "$@"
  else
    : > "${SYNOLOGY_BACKUP_DIR}/${config_file}"
  fi

  if [ "${use_compose_backup}" -eq 1 ]; then
    docker compose --env-file "${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"

  else
    if [ -d /app/data/logs ]; then
      tar -C /app/data/logs -czf "${SYNOLOGY_BACKUP_DIR}/${logs_file}" .
    else
      : > "${SYNOLOGY_BACKUP_DIR}/${logs_file}"
    fi

    mkdir -p "${SYNOLOGY_BACKUP_DIR}/uploads"
    cp -an "${UPLOADS_BACKUP_DIR}/." "${SYNOLOGY_BACKUP_DIR}/uploads/"
  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}"
echo "  ${APP_DATA_BACKUP_DIR}/ (incremental app data mirror)"
echo "  ${UPLOADS_BACKUP_DIR}/ (incremental uploads mirror)"
if [ -n "${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/ (copied from local incremental mirror)"
  echo "  ${SYNOLOGY_BACKUP_DIR}/${manifest_file}"
else
  echo "SYNOLOGY_BACKUP_DIR not set; skipped Synology copy."
fi