sample

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Models;
using Newtonsoft.Json.Linq;

namespace Repositories
{
    public class JsonRepository
    {

        public IEnumerable<string> GetAllData(string source)
        {
            var files = Directory.GetFiles(source, "*.json", SearchOption.AllDirectories);

            List<string> datas = new List<string>();
            foreach (var file in files)
            {
                string data = File.ReadAllText(file);
                datas.Add(data);
            }

            return datas;
        }

        public IEnumerable<Meal> ParseJsonToMealObject(string data)
        {
            var jObj = JObject.Parse(data);

            var dayTime = jObj["calendar"]["dateToDayId"]
                .Select(x => (JProperty) x)
                .Select(p => new KeyValuePair<string, string>(p.Value.ToString(), p.Name.ToString()));

            Dictionary<string, string> myDict = dayTime.ToDictionary(x => x.Key, x => x.Value);


            var meals = jObj["calendar"]["daysWithDetails"]
                .Select(x => (JProperty) x)
                .SelectMany(p => (JToken) p.Value["details"]["mealsWithDetails"])
                .SelectMany(m => (JProperty) m)
                .Select(q => q["meal"])
                .Select(w => new Meal()
                {
                    userId = w["userId"].ToString(),
                    day = myDict[w["dayId"].ToString()]
                });
            return meals;
        }

        public Dictionary<string, int> GetMealPerUser(IEnumerable<Meal> meals, string startDate, string endDate)
        {
            DateTime startDateTime = DateTime.Parse(startDate);
            DateTime endDateTime = DateTime.Parse(endDate);

            Dictionary<string, int> mealCount = new Dictionary<string, int>();

            //Console.WriteLine(mealCount[10]);
            foreach (var s in meals)
            {
                DateTime tmpDate = DateTime.Parse(s.day);
                if (tmpDate >= startDateTime && tmpDate <= endDateTime)
                {
                    if (!mealCount.ContainsKey(s.userId))
                    {
                        mealCount.Add(s.userId, 0);
                    }

                    mealCount[s.userId]++;
                }
                // Console.WriteLine(s.day + "  " + s.userId);
            }

            return mealCount;
        }
    }
}