using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Configuration;

namespace AutoUpdater.Lib
{
    public static class ConfigHelper
    {
        /// <summary>
        /// 依据连接串名字connectionName返回数据连接字符串  
        /// </summary>
        /// <param name="ConfigFilePath">配置文件</param>
        /// <param name="connectionName">ConnectionStrings连接名</param>
        /// <returns></returns>
        public static string GetConnectionStringsConfig(string ConfigFilePath, string connectionName)
        {
            //指定config文件读取
            ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap
            {
                ExeConfigFilename = ConfigFilePath
            };
            Configuration _Configuration = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);
            string connectionString = _Configuration.ConnectionStrings.ConnectionStrings[connectionName].ConnectionString;
            return connectionString;
        }

        ///<summary> 
        ///更新连接字符串  
        ///</summary> 
        ///<param name="newName">连接字符串名称</param> 
        ///<param name="newConString">连接字符串内容</param> 
        ///<param name="newProviderName">数据提供程序名称</param> 
        public static void UpdateConnectionStringsConfig(string ConfigFilePath, string newName, string newConString, string newProviderName)
        {
            //指定config文件读取
            ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap
            {
                ExeConfigFilename = ConfigFilePath
            };
            Configuration _Configuration = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);
            
            bool exist = false; //记录该连接串是否已经存在  
                                //如果要更改的连接串已经存在  
            if (_Configuration.ConnectionStrings.ConnectionStrings[newName] != null)
            {
                exist = true;
            }
            // 如果连接串已存在，首先删除它  
            if (exist)
            {
                _Configuration.ConnectionStrings.ConnectionStrings.Remove(newName);
            }
            //新建一个连接字符串实例  
            ConnectionStringSettings mySettings =
                new ConnectionStringSettings(newName, newConString, newProviderName);
            // 将新的连接串添加到配置文件中.  
            _Configuration.ConnectionStrings.ConnectionStrings.Add(mySettings);
            // 保存对配置文件所作的更改  
            _Configuration.Save(ConfigurationSaveMode.Modified);
            // 强制重新载入配置文件的ConnectionStrings配置节  
            ConfigurationManager.RefreshSection("ConnectionStrings");
        }

        ///<summary> 
        ///返回*.exe.config文件中appSettings配置节的value项  
        ///</summary> 
        ///<param name="strKey"></param> 
        ///<returns></returns> 
        public static string GetAppConfig(string ConfigFilePath, string Key)
        {

            ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap
            {
                ExeConfigFilename = ConfigFilePath
            };
            Configuration _Configuration = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);
            if (_Configuration.AppSettings.Settings[Key] == null)
            {
                return "";
            }
            else
            {
                return _Configuration.AppSettings.Settings[Key].Value;
            }
        }

        ///<summary>  
        ///在*.exe.config文件中appSettings配置节增加一对键值对  
        ///</summary>  
        ///<param name="newKey"></param>  
        ///<param name="newValue"></param>  
        public static void UpdateAppConfig(string ConfigFilePath, string Key, string Value)
        {
            ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap
            {
                ExeConfigFilename = ConfigFilePath
            };
            Configuration _Configuration = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);
            if (_Configuration.AppSettings.Settings[Key] == null)
            {
                _Configuration.AppSettings.Settings.Add(Key, Value);
            }
            else
            {
                _Configuration.AppSettings.Settings[Key].Value = Value;
            }
            _Configuration.Save();
            ConfigurationManager.RefreshSection("appSettings");
        }
    }
}