using System;
using System.Collections.Generic;
using System.IO;
using System.Xml;

namespace CB.Config
{
    public class DataProviderConfig
    {
        //修改DJP2016-05-24,修改拼接方式，避免出现 debugconfig\DataPrivoder.config
        // private static string configPath = AppDomain.CurrentDomain.BaseDirectory +"Config\\DataPrivoder.config"
        private static string configPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Config\\DataPrivoder.config");
        
        private static long _version = 0;
        private static List<DataProviderConfigInfo> _configList = null;
        private static object lockObject = new object();

        static DataProviderConfig()
        {
            LoadConfig();
        }

        public static void LoadConfig()
        {
            lock (lockObject)
            {
                if (!File.Exists(configPath))
                { throw new Exception("未找到数据访问层配置文件[/Config/DataPrivoder.config]"); }

                XmlDocument doc = new XmlDocument();
                try
                { doc.Load(configPath); }
                catch
                { throw new Exception("数据访问层配置文件[/Config/DataPrivoder.config]配置有误，请核查！"); }

                string default_privoder = "", default_connect = "";

                #region 数据访问层接口配置
                XmlNode node = doc.SelectSingleNode("DataPrivoderConfig/DbProviders");
                if (null == node)
                { throw new Exception("数据访问层配置文件[/Config/DataPrivoder.config]未配置DataPrivoderConfig/DbProviders节点"); }

                XmlAttribute attr = node.Attributes["Provider"];
                if (null != attr)
                    default_privoder = attr.Value;

                Dictionary<string, string> DbProviderDic = new Dictionary<string, string>();
                var nodeList = node.SelectNodes("DbProvider");
                if (null != nodeList && 0 < nodeList.Count)
                {
                    foreach (XmlNode item in nodeList)
                    {
                        DbProviderDic.Add(item.Attributes["name"].Value, item.Attributes["Provider"].Value);
                    }
                }
                if (string.IsNullOrEmpty(default_privoder) && 0 >= DbProviderDic.Keys.Count)
                    throw new Exception("数据访问层配置文件[/Config/DataPrivoder.config]未配置DataPrivoderConfig/DbProviders节点");
                #endregion

                #region 数据库连接字符串
                node = doc.SelectSingleNode("DataPrivoderConfig/ConnectStrings");
                if (null == node)
                { throw new Exception("数据访问层配置文件[/Config/DataPrivoder.config]未配置DataPrivoderConfig/ConnectStrings节点"); }

                attr = node.Attributes["ConnectString"];
                if (null != attr)
                    default_connect = attr.Value;

                Dictionary<string, string> ConnectStringDic = new Dictionary<string, string>();
                nodeList = node.SelectNodes("ConnectString");
                if (null != nodeList && 0 < nodeList.Count)
                {
                    foreach (XmlNode item in nodeList)
                    {
                        ConnectStringDic.Add(item.Attributes["name"].Value, item.Attributes["ConnectString"].Value);
                    }
                }

                if (string.IsNullOrEmpty(default_connect) && 0 >= ConnectStringDic.Keys.Count)
                    throw new Exception("数据访问层配置文件[/Config/DataPrivoder.config]未配置DataPrivoderConfig/ConnectStrings节点");
                #endregion

                nodeList = doc.SelectNodes("DataPrivoderConfig/objects/object");
                if (null != nodeList && 0 < nodeList.Count)
                {
                    var configList = new List<DataProviderConfigInfo>();
                    XmlAttributeCollection attrArray;
                    foreach (XmlNode item in nodeList)
                    {
                        attrArray = item.Attributes;
                        var config = new DataProviderConfigInfo()
                        {
                            InterfaceId = attrArray["id"].Value,
                            TypeName = attrArray["typeName"].Value
                        };
                        config.ConnectStringName = null == attrArray["ConnectStringName"] || !ConnectStringDic.ContainsKey(attrArray["ConnectStringName"].Value) ?
                            default_connect : ConnectStringDic[attrArray["ConnectStringName"].Value];
                        config.DbProviderName = null == attrArray["DbProviderName"] || !DbProviderDic.ContainsKey(attrArray["DbProviderName"].Value) ?
                            default_privoder : DbProviderDic[attrArray["DbProviderName"].Value];
                        configList.Add(config);
                    }
                    _configList = configList;
                }

                _version = File.GetLastWriteTime(configPath).Ticks;
            }
        }

        public static DataProviderConfigInfo GetConfig(string interfaceId)
        {
            if (null == _configList || 0 >= _configList.Count)
            {
                LoadConfig();
            }

            if (_version != File.GetLastWriteTime(configPath).Ticks)
            {
                LoadConfig();
            }

            foreach (var item in _configList)
            {
                if (item.InterfaceId == interfaceId)
                {
                    return item;
                }
            }

            return null;
        }
    }
}