from flask import flash, redirect, url_for
from pymysql.cursors import Cursor

def verify_user(cursor:Cursor, id:str, password:str) -> str:
    # 检查已有用户
        sql = """
        SELECT COUNT(*) FROM passengers \
        WHERE ID = %s;
        """
        try:
            cursor.execute(sql, (id,))
            id_exist = cursor.fetchall()[0][0]
        except Exception as e:
            flash("数据库异常，查询失败")
            print(e)
            return redirect(url_for('signup'))
        if (id_exist == 0):
            return "NO_USER"
        
        # 检查密码
        sql = """
        SELECT `Password` FROM passengers \
        WHERE ID = %s;
        """
        try:
            cursor.execute(sql, (id,))
            record_password = cursor.fetchall()[0][0]
        except Exception as e:
            flash("数据库异常，查询失败")
            print(e)
            return redirect(url_for('modify'))
        if (record_password != password):
            return "WRONG_PASSWORD"
        
        return "USER_VERIFIED"