using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections.Concurrent;
using System.Reflection;
using Aitex.Core.Util;
using System.Threading.Tasks;
using Aitex.Core.RT.Log;

namespace Aitex.Core.RT.DataCenter
{
    /// <summary>
    /// 
    /// 数据项命名规则：
    /// 
    /// 一般数据项： 模块名.数据项名
    /// 
    /// 设备类型数据项：模块名.设备类型.数据项名 
    /// 
    /// 界面显示设备数据项：模块名.数据项名
    /// 
    /// </summary>
    public class DataManager : ICommonData
    {
        ConcurrentDictionary<string, DataItem<object>> _keyValueMap;
        SortedDictionary<string, Func<object>> _dbRecorderList;
        Func<object, bool> _isSubscriptionAttribute;
        Func<MemberInfo, bool> _hasSubscriptionAttribute;
        object _locker = new object();

        public DataManager()
        {

        }

        public void Initialize()
        {
            _dbRecorderList = new SortedDictionary<string, Func<object>>();
            _keyValueMap = new ConcurrentDictionary<string, DataItem<object>>();
            _isSubscriptionAttribute = attribute => attribute is SubscriptionAttribute;
            _hasSubscriptionAttribute = mi => mi.GetCustomAttributes(false).Any(_isSubscriptionAttribute);

            DATA.InnerDataManager = this;
        }

        public SortedDictionary<string, Func<object>> GetDBRecorderList()
        {
            SortedDictionary<string, Func<object>> result;
            lock (_locker)
            {
                result = new SortedDictionary<string, Func<object>>(_dbRecorderList);
            }
            return result;
        }

        public void Subscribe<T>(T instance, string keyPrefix = null) where T : class
        {
            if (instance == null)
                throw new ArgumentNullException("instance");

            Traverse(instance, keyPrefix);
        }

        public void Subscribe(string key, Func<object> getter, SubscriptionAttribute.FLAG flag)
        {
            if (string.IsNullOrWhiteSpace(key))
                throw new ArgumentNullException("key");
            if (_keyValueMap.ContainsKey(key))
                throw new Exception(string.Format("Duplicated Key:{0}", key));
            if (getter == null)
                throw new ArgumentNullException("getter");

            _keyValueMap.TryAdd(key, new DataItem<object>(getter));

            if (flag != SubscriptionAttribute.FLAG.IgnoreSaveDB)
            {
                lock (_locker)
                {
                    _dbRecorderList[key] = getter;
                }              
            }
        }

        public Dictionary<string, object> Poll(IEnumerable<string> keys)
        {
            Dictionary<string, object> data = new Dictionary<string, object>();

            foreach (string name in keys)
            {
                if (_keyValueMap.ContainsKey(name))
                    data[name] =_keyValueMap[name].Value;
            }

            return data;
        }

        public object Poll(string key)
        {
            return _keyValueMap.ContainsKey(key) ? _keyValueMap[key].Value : null;
        }

        public void Traverse(object instance, string keyPrefix)
        {
            Parallel.ForEach(instance.GetType().GetFields().Where<FieldInfo>(_hasSubscriptionAttribute), fi =>
            {
                string key = Parse(fi);
                key = string.IsNullOrWhiteSpace(keyPrefix) ? key : string.Format("{0}.{1}", keyPrefix, key);
                Subscribe(key, () => fi.GetValue(instance), 0);
            });

            Parallel.ForEach(instance.GetType().GetProperties().Where<PropertyInfo>(_hasSubscriptionAttribute), property =>
            {
                string key = Parse(property);
                key = string.IsNullOrWhiteSpace(keyPrefix) ? key : string.Format("{0}.{1}", keyPrefix, key);
                Subscribe(key, () => property.GetValue(instance, null), 0);
            });
        }

        string Parse(MemberInfo member)
        {
            return _hasSubscriptionAttribute(member) ? (member.GetCustomAttributes(false).First(_isSubscriptionAttribute) as SubscriptionAttribute).Key : null;
        }


        public Dictionary<string, object> PollData(IEnumerable<string> keys)
        {
            Dictionary<string, object> result = new Dictionary<string,object>();
            foreach (string key in keys)
            {
                if (_keyValueMap.ContainsKey(key))
                    result[key] = _keyValueMap[key].Value;
                else
                {
                    //LOG.Error("未定义的DataItem：" + key);
                }
            }

            return result;
        }
    }
}