#!/usr/bin/env sh

set -eu

COMMAND="${1:-help}"
ENV_FILE="${ENV_FILE:-.env}"
BACKUP_ROOT="${BACKUP_ROOT:-backups}"
RETENTION_DAYS="${RETENTION_DAYS:-14}"
TIMESTAMP="${BACKUP_TIMESTAMP:-$(date +%Y%m%d_%H%M%S)}"

log() {
  printf '[backup] %s\n' "$*"
}

fail() {
  printf '[backup] %s\n' "$*" >&2
  exit 1
}

require_command() {
  command -v "$1" >/dev/null 2>&1 || fail "Required command not found: $1"
}

has_command() {
  command -v "$1" >/dev/null 2>&1
}

load_env() {
  [ -f "$ENV_FILE" ] || fail "Env file not found: $ENV_FILE"

  case "$ENV_FILE" in
    */*) env_path="$ENV_FILE" ;;
    *) env_path="./$ENV_FILE" ;;
  esac

  set -a
  # shellcheck disable=SC1090
  . "$env_path"
  set +a

  : "${DB_HOST:?DB_HOST is required in $ENV_FILE}"
  : "${DB_PORT:=3306}"
  : "${DB_USER:?DB_USER is required in $ENV_FILE}"
  : "${DB_PASS:?DB_PASS is required in $ENV_FILE}"
  : "${DB_NAME:?DB_NAME is required in $ENV_FILE}"
}

db_dump() {
  require_command gzip
  load_env

  mkdir -p "$BACKUP_ROOT/db"
  output_path="$BACKUP_ROOT/db/${DB_NAME}_${TIMESTAMP}.sql.gz"

  log "Creating DB dump: $output_path"

  if has_command mysqldump; then
    MYSQL_PWD="$DB_PASS" mysqldump \
      --host="$DB_HOST" \
      --port="$DB_PORT" \
      --user="$DB_USER" \
      --single-transaction \
      --quick \
      --routines \
      --triggers \
      "$DB_NAME" | gzip > "$output_path"
  elif has_command docker; then
    docker exec itam-backend sh -lc "MYSQL_PWD=\"$DB_PASS\" exec mysqldump --host=\"$DB_HOST\" --port=\"$DB_PORT\" --user=\"$DB_USER\" --single-transaction --quick --routines --triggers \"$DB_NAME\"" | gzip > "$output_path"
  else
    fail "Required command not found: mysqldump (and docker fallback unavailable)"
  fi

  log "DB dump completed: $output_path"
}

files_backup() {
  require_command tar
  mkdir -p "$BACKUP_ROOT/files"

  archive_path="$BACKUP_ROOT/files/runtime_${TIMESTAMP}.tar.gz"
  set --

  [ -f "$ENV_FILE" ] && set -- "$@" "$ENV_FILE"
  [ -d "uploads" ] && set -- "$@" "uploads"
  [ -f "map_config.json" ] && set -- "$@" "map_config.json"

  [ "$#" -gt 0 ] || fail "No runtime files found to archive"

  log "Creating runtime archive: $archive_path"
  tar -czf "$archive_path" "$@"
  log "Runtime archive completed: $archive_path"
}

cleanup_backups() {
  require_command find
  [ -d "$BACKUP_ROOT" ] || {
    log "Backup root does not exist, skipping cleanup: $BACKUP_ROOT"
    return 0
  }

  log "Deleting backup files older than ${RETENTION_DAYS} days from $BACKUP_ROOT"
  find "$BACKUP_ROOT" -type f -mtime "+$RETENTION_DAYS" -print -delete
}

case "$COMMAND" in
  db)
    db_dump
    ;;
  files)
    files_backup
    ;;
  full)
    db_dump
    files_backup
    ;;
  cleanup)
    cleanup_backups
    ;;
  help|--help|-h)
    log "Commands: db | files | full | cleanup"
    ;;
  *)
    fail "Unknown command: $COMMAND"
    ;;
esac