using System.Linq;
using Couchbase;
using System;
using System.Collections.Generic;
using Enyim.Caching.Memcached;

namespace Sony.Filtr.DistributedCaching
{
    public class DistributedCacheHandler
    {
        const int GroupCount = 50;
        private readonly string _cachePrefix;
        private readonly ICouchbaseClient _couchbaseClient;
        private Object _stubObj = new Object();

        //TODO: NEED TO FIX THIS CLASS TO USE CACHE
        public DistributedCacheHandler(string cachePrefix)
        {
            _cachePrefix = cachePrefix;
        }
        
        //public DistributedCacheHandler(string cachePrefix, ICouchbaseClient couchbaseClient)
        //{
        //    _cachePrefix = cachePrefix;
        //    _couchbaseClient = couchbaseClient;
        //}


        public object Get(string key)
        {
            //var obj = _couchbaseClient.Get(GetKey(key));

            //return obj;
            return _stubObj;
        }

        public IDictionary<string, object> Get(IEnumerable<string> keys)
        {
            //var objs = _couchbaseClient.ExecuteGet(keys.Select(GetKey));

            //return objs.ToDictionary(k => k.Key.Replace(_cachePrefix, string.Empty), v => v.Value.Value);

            return null;
        }

        public List<T> GetList<T>(string key)
        {
            //try
            //{
            //    var obj = _couchbaseClient.Get(GetKey(key));
            //    if (obj is ToLargeObject)
            //    {
            //        return GetCacheListItems<T>(key, (ToLargeObject)obj, GroupCount);
            //    }
            //}
            //catch (Exception)
            //{
            //    return null;
            //}
            return null;
        }

        private List<T> GetCacheListItems<T>(string key, ToLargeObject obj, int groupCount)
        {
            //var itemCount = obj.Count;
            //List<T> items = new List<T>(itemCount);
            //var numGroups = (itemCount / groupCount);
            //var keys = Enumerable.Range(0, numGroups + 1).Select(i => GetToLongKey(key, i)).ToList();
            //var gets = _couchbaseClient.ExecuteGet(keys);
            //foreach (var localKey in keys)
            //{
            //    if (!gets.ContainsKey(localKey))
            //        return null; //If we can't fetch an individual group we can't recreate the entire array so we fail and consider it a miss
            //    if (!gets[localKey].HasValue)
            //        return null; //If we can't fetch an individual group we can't recreate the entire array so we fail and consider it a miss
            //    var localList = gets[localKey].Value as IList<T>;
            //    if (localList == null)
            //        return null; //If we can't fetch an individual group we can't recreate the entire array so we fail and consider it a miss
            //    items.AddRange(localList);
            //}

            //return items;
            return null;
        }

        public void PutList<T>(string key, IList<T> list, DateTime? expiresAt = null)
        {
            //if (expiresAt.HasValue)
            //    _couchbaseClient.Store(StoreMode.Set, GetKey(key), new ToLargeObject(list.Count), expiresAt.Value);
            //else
            //    _couchbaseClient.Store(StoreMode.Set, GetKey(key), new ToLargeObject(list.Count));

            //var defaultGroupCount = GroupCount;
            //PutListItems(key, list, defaultGroupCount, expiresAt);
        }

        public void PutSpecial<T>(string key, IList<T> list, DateTime? expiresAt = null, int groupCount = GroupCount)
        {
            //var cacheItem = new CacheItemTooLargeObject(list.Count) { GroupCount = groupCount, UtcCacheTime = DateTime.UtcNow };
            //if (expiresAt.HasValue)
            //    _couchbaseClient.Store(StoreMode.Set, GetKey(key), cacheItem, expiresAt.Value);
            //else
            //    _couchbaseClient.Store(StoreMode.Set, GetKey(key), cacheItem);

            //PutListItems(key, list, groupCount, expiresAt);
        }

        public SpecialListCacheItem<T> GetSpecialList<T>(string key)
        {
            //var obj = _couchbaseClient.Get(GetKey(key)) as CacheItemTooLargeObject;
            //if (obj != null)
            //{
            //    var items = GetCacheListItems<T>(key, obj, obj.GroupCount);
            //    if (items == null)
            //        return null;

            //    return new SpecialListCacheItem<T>()
            //    {
            //        UtcCacheTime = obj.UtcCacheTime,
            //        Items = items,
            //    };
            //}

            return null;
        }



        private void PutListItems<T>(string key, IList<T> list, int groupCount, DateTime? expiresAt)
        {
            //for (int i = 0; i <= (list.Count / groupCount); i++)
            //{
            //    var startIndex = i * groupCount;
            //    var endIndex = (i + 1) * groupCount;
            //    IList<T> tempList = new List<T>(groupCount);
            //    for (var j = startIndex; j < endIndex; j++)
            //    {
            //        if (j < list.Count)
            //            tempList.Add(list[j]);
            //    }

            //    if (expiresAt.HasValue)
            //        _couchbaseClient.Store(StoreMode.Set, GetToLongKey(key, i), tempList, expiresAt.Value);
            //    else
            //        _couchbaseClient.Store(StoreMode.Set, GetToLongKey(key, i), tempList);
            //}
        }

        public void Put(string key, object value)
        {
            //_couchbaseClient.Store(StoreMode.Set, GetKey(key), value);
        }

        private string GetToLongKey(string key, int count)
        {
            return _cachePrefix + "Range:" + key + "|" + count;
        }

        public void Put(string key, object value, DateTime expiresAt)
        {
            //_couchbaseClient.Store(StoreMode.Set, GetKey(key), value, expiresAt);
        }

        public void Remove(string key)
        {
           // _couchbaseClient.Remove(GetKey(key));
        }

        private string GetKey(string key)
        {
            return _cachePrefix + key;
        }
    }
}