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

APP_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
BACKUP_ROOT="${BACKUP_ROOT:-$APP_DIR/backups}"
DB_NAME="${DB_NAME:-EMI_SOCIAL}"
MONGO_IMAGE="${MONGO_BACKUP_IMAGE:-mongo:7}"
KEEP_ARCHIVES="${KEEP_ARCHIVES:-12}"

timestamp="$(date -u +%Y%m%dT%H%M%SZ)"
dump_name="emi_social_${timestamp}"
archive_path="$BACKUP_ROOT/${dump_name}.tar.gz"

mkdir -p "$BACKUP_ROOT"

docker run --rm \
  --user "$(id -u):$(id -g)" \
  --env-file "$APP_DIR/.env" \
  -e DB_NAME="$DB_NAME" \
  -e DUMP_NAME="$dump_name" \
  -v "$BACKUP_ROOT:/backup" \
  "$MONGO_IMAGE" \
  bash -lc '
    set -euo pipefail
    : "${MONGO_URL:?MONGO_URL is missing}"

    uri="$MONGO_URL"
    uri="${uri/\/myFirstDatabase?/\/${DB_NAME}?}"
    uri="${uri/\/myFirstDatabase$/\/${DB_NAME}}"

    mongodump --uri "$uri" --db "$DB_NAME" --out "/backup/$DUMP_NAME"
  '

tar -czf "$archive_path" -C "$BACKUP_ROOT" "$dump_name"
rm -rf "$BACKUP_ROOT/$dump_name"

find "$BACKUP_ROOT" -maxdepth 1 -name 'emi_social_*.tar.gz' -type f \
  -printf '%T@ %p\n' \
  | sort -rn \
  | awk -v keep="$KEEP_ARCHIVES" 'NR > keep { print $2 }' \
  | xargs -r rm -f

echo "Created MongoDB backup: $archive_path"