package com.boman.system.common;

/**
 * @author shiqian
 * @description
 * @date 2021年03月22日 11:42
 **/
public class QueryUtils {

    public static String replaceVariables(String sql, User user) {
        if (user == null) {
            return sql;
        } else if (sql == null) {
            return null;
        } else {
            StringBuilder sb = new StringBuilder();
            int p = 0;

            while (p < sql.length()) {
                int p1 = sql.indexOf("$", p);
                if (p1 > -1) {
                    int p2 = sql.indexOf("$", p1 + 1);
                    if (p2 > -1) {
                        String n = sql.substring(p1, p2 + 1);
                        Object v = user.getAttribute(n);
                        if (v != null) {
                            sb.append(sql.substring(p, p1)).append(v);
                            p = p2 + 1;
                        } else {
                            sb.append(sql.substring(p, p2));
                            p = p2;
                        }
                        continue;
                    }

                    sb.append(sql.substring(p));
                    break;
                }

                sb.append(sql.substring(p));
                break;
            }

            return sb.toString();
        }
    }
}