import re
from flask import jsonify

def sanitize_search_term(term):
    if not term:
        return ''
    term = re.sub(r'[%_\\]', '', term)
    term = term.strip()
    return term[:100]

def build_search_conditions(fields, search_term):
    sanitized = sanitize_search_term(search_term)
    if not sanitized:
        return '', []
    conditions = ' AND (' + ' OR '.join(f'{f} LIKE ?' for f in fields) + ')'
    values = [f'%{sanitized}%'] * len(fields)
    return conditions, values

def error_response(message, status_code=400):
    return jsonify({'success': False, 'error': message}), status_code

def success_response(message='操作成功', data=None):
    response = {'success': True, 'message': message}
    if data is not None:
        response['data'] = data
    return jsonify(response)