using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.IO;

using System.Data;

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

using NUnit.Framework; // Throws NUnit.Framework.AssertionException

​

//https://stackoverflow.com/questions/76105021/sort-arrays-within-a-json-object-by-date-without-deserializing-the-object

​

    class TestClass

    {

        public static void Test()

        {

            var json = GetJson();

            var text1 = TestOriginal(json);

            Console.WriteLine(text1);

            var text2 = TestImproved(json);

            Assert.AreEqual(text1, text2);

            var text3 = TestDataModel(json);

            Assert.AreEqual(text1, text3);

            int count = 10000;

            var elapsed1 = Time(() => TestOriginal(json), count);

            var elapsed2 = Time(() => TestOriginalWithNoSort(json), count);

            var elapsed3 = Time(() => TestImproved(json), count);

            var elapsed4 = Time(() => TestDataModel(json), count);

            Console.WriteLine("Average time per repetition for {0} reps of original code: {1:0.0000} ms.", count, elapsed1.TotalMilliseconds/((double)count));

            Console.WriteLine("Average time per repetition for {0} reps of original code without sorting: {1:0.0000} ms ({2:0.00}% faster).", count, elapsed2.TotalMilliseconds/((double)count), 100.0*(elapsed1 - elapsed2)/elapsed1);

            Console.WriteLine("Average time per repetition for {0} reps of modified code: {1:0.0000} ms ({2:0.00}% faster).", count, elapsed3.TotalMilliseconds/((double)count), 100.0*(elapsed1 - elapsed3)/elapsed1);

            Console.WriteLine("Average time per repetition for {0} reps of deserialized data model: {1:0.0000} ms ({2:0.00}% faster).", count, elapsed4.TotalMilliseconds/((double)count), 100.0*(elapsed1 - elapsed4)/elapsed1);

        }   

​

        static TimeSpan Time(Action action, int count)

        {

            var stopwatch = new System.Diagnostics.Stopwatch();

            stopwatch.Start();

            try

            {

                for (int i = 0; i < count; i++)

                    action();

            }

            finally

            {

                stopwatch.Stop();

            }

​

            return stopwatch.Elapsed;

        }

        static string TestOriginalWithNoSort(string json)

        {

            var root = JToken.Parse(json);

            var jsonArray = (JArray)root["results"];

            var jsonlBuilder = new StringBuilder();

            var serializer = JsonSerializer.CreateDefault(new JsonSerializerSettings { DateTimeZoneHandling = DateTimeZoneHandling.Utc });

​

            using (var textWriter = new StringWriter(jsonlBuilder))

            using (var jsonWriter = new JsonTextWriter(textWriter) { Formatting = Formatting.None })

            {

                foreach (var obj in jsonArray)

                {

                    var employments = obj.SelectToken("examples");

#if false

                    if (employments.Count() > 1)

                    {

                        var b = employments.ToObject<JArray>().OrderBy(c => c.SelectToken("date").ToObject<DateTime>(serializer)); // ToObject<JArray>() will clone the array

                        var newEmploymentArray = new JArray(b);                                                                    // new JArray(b) will clone the array items again.

                        obj["examples"].Replace(newEmploymentArray);

                    }

#endif

                    obj.WriteTo(jsonWriter);

                    jsonWriter.WriteWhitespace("\n");

                }

            }           

            return jsonlBuilder.ToString();

        }

​

        static string TestOriginal(string json)

        {

            var root = JToken.Parse(json);

            var jsonArray = (JArray)root["results"];

            var jsonlBuilder = new StringBuilder();

            var serializer = JsonSerializer.CreateDefault(new JsonSerializerSettings { DateTimeZoneHandling = DateTimeZoneHandling.Utc });

​

            using (var textWriter = new StringWriter(jsonlBuilder))

            using (var jsonWriter = new JsonTextWriter(textWriter) { Formatting = Formatting.None })

            {

                foreach (var obj in jsonArray)

                {

                    var employments = obj.SelectToken("examples");

                    if (employments.Count() > 1)

                    {

                        var b = employments.ToObject<JArray>().OrderBy(c => c.SelectToken("date").ToObject<DateTime>(serializer)); // ToObject<JArray>() will clone the array

                        var newEmploymentArray = new JArray(b);                                                                    // new JArray(b) will clone the array items again.

                        obj["examples"].Replace(newEmploymentArray);

                    }

                    obj.WriteTo(jsonWriter);

                    jsonWriter.WriteWhitespace("\n");

                }

            }           

            return jsonlBuilder.ToString();

        }

​

        static string TestImproved(string json)

        {

            // Deserialize with DateTimeZoneHandling.Utc.

            // This recogizes all DateTime values automatically and populates then in the JToken hierarchy, thereby avoiding the need to deserialize each one individually

            var settings = new JsonSerializerSettings { 

                DateTimeZoneHandling = DateTimeZoneHandling.Utc, 

                DateParseHandling = DateParseHandling.DateTime 

            };

​

            // Deserialize directly from stream (if reading from file) rather than loading into a string.

            using var textReader = new StringReader(json); // If reading from a file, use a StreamReader and read directly.

            using var jsonReader = new JsonTextReader(textReader);

                var root = JsonSerializer.CreateDefault(settings).Deserialize<JToken>(jsonReader);

            var jsonArray = (JArray)root["results"];

​

            var jsonlBuilder = new StringBuilder();

            using (var textWriter = new StringWriter(jsonlBuilder))  // If writing to a file, use a StreamWriter and write directly.

            using (var jsonWriter = new JsonTextWriter(textWriter) { Formatting = Formatting.None })

            {

                foreach (var obj in jsonArray)

                {

                    var employments = obj is JObject ? obj["examples"] as JArray : null; // Use indexer instead of SelectToken()

                    if (employments.Count > 1) // Use the Count property rather than the LINQ Count() extension method, https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/quality-rules/ca1829

                    {

                        var sortedList = employments

                            .Select(e => (e, date : e["date"].Value<DateTime>())) // Use the indexer and cache the DateTime value

                            .OrderBy(p => p.date).Select(p => p.e)                // And sort by the cached value

                            .ToList();

                        employments.Clear();  // Prevent cloning of JTokens by clearing the array before re-adding the items.

                        foreach (var item in sortedList)

                            employments.Add(item); // Add the existing items rather than creating new items.

                    }

                    obj.WriteTo(jsonWriter);

                    jsonWriter.WriteWhitespace("\n");

                }

            }           

            return jsonlBuilder.ToString();

        }

        public class Example

        {

            public string id { get; set; }

            public DateTime date { get; set; }

        }

​

        public class Group

        {

            public object parent_group { get; set; }

            public string type { get; set; }

        }

​

        public class Result

        {

            public string id { get; set; }

            public List<Group> groups { get; set; } = new ();

            public List<Example> examples { get; set; } = new ();

        }

​

        public class Root

        {

            public List<Result> results { get; set; } = new ();

        }       

        static string TestDataModel(string json)

        {

            var settings = new JsonSerializerSettings { 

                DateTimeZoneHandling = DateTimeZoneHandling.Utc, 

            };

            var serializer = JsonSerializer.CreateDefault(settings);

            // Deserialize directly from stream (if reading from file) rather than loading into a string.

            using var textReader = new StringReader(json); // If reading from a file, use a StreamReader and read directly.

            using var jsonReader = new JsonTextReader(textReader); 

                var root = serializer.Deserialize<Root>(jsonReader);

            var jsonArray = root.results;

            var jsonlBuilder = new StringBuilder();

            using (var textWriter = new StringWriter(jsonlBuilder)) // If writing to a file, use a StreamWriter and write directly.

            using (var jsonWriter = new JsonTextWriter(textWriter) { Formatting = Formatting.None })

            {

                foreach (var obj in jsonArray)

                {

                    if (obj?.examples != null && obj.examples.Count > 0)

                        obj.examples.Sort((x, y) => x.date.CompareTo(y.date));

                    serializer.Serialize(jsonWriter, obj);

                    jsonWriter.WriteWhitespace("\n");

                }

            }           

            return jsonlBuilder.ToString();

        }       

        static string GetJson() =>

            """

            {

              "results": [

                {

                  "id": "abc456",

                  "groups": [

                    {

                      "parent_group": null,

                      "type": "D"

                    },

                    {

                      "parent_group": null,

                      "type": "DEPARTMENT"

                    }

                  ],

                  "examples": [

                    {

                      "id": "e13b1e97-31e3-46e6-9d8f-9776c52e5ce0",

                      "date": "2020-05-10T00:00:00Z"

                    },

                    {

                      "id": "bd31d475-6137-4409-8d17-535f1bf94071",

                      "date": "2021-05-11T00:00:00Z"

                    },

                    {

                      "id": "0e0806ba-56f6-4527-8fd7-7e0061e30783",

                      "date": "2019-05-11T00:00:00Z"

                    },

                  ]

                },

                {

                  "id": "def456",

                  "groups": [

                    {

                      "parent_group": null,

                      "type": "D"

                    },

                    {

                      "parent_group": null,

                      "type": "D"

                    }

                  ],

                  "examples": [

                    {

                      "id": "e13b1e97-31e3-46e6-9d8f-9776c52e5ce0",

                      "date": "2020-05-10T00:00:00Z"

                    },

                    {

                      "id": "bd31d475-6137-4409-8d17-535f1bf94071",

                      "date": "2021-05-11T00:00:00Z"

                    },

                    {

                      "id": "0e0806ba-56f6-4527-8fd7-7e0061e30783",

                      "date": "2019-05-11T00:00:00Z"

                    }

                  ]

                }

              ]

            }

            """;            

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1}), {2}", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , Environment.Version, Environment.OSVersion);

            Console.WriteLine("{0} version: {1}", typeof(JsonSerializer).Namespace, typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​