// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System;
using System.Collections.Generic;
using Microsoft.AspNetCore.JsonPatch.Operations;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json.Serialization;
 
namespace Microsoft.AspNetCore.JsonPatch.Converters;
 
public class JsonPatchDocumentConverter : JsonConverter
{
    internal static DefaultContractResolver DefaultContractResolver { get; } = new();
 
    public override bool CanConvert(Type objectType)
    {
        return true;
    }
 
    public override object ReadJson(JsonReader reader, Type objectType, object existingValue,
        JsonSerializer serializer)
    {
        if (objectType != typeof(JsonPatchDocument))
        {
            throw new ArgumentException(Resources.FormatParameterMustMatchType(nameof(objectType), "JsonPatchDocument"), nameof(objectType));
        }
 
        try
        {
            if (reader.TokenType == JsonToken.Null)
            {
                return null;
            }
 
            // load jObject
            var jObject = JArray.Load(reader);
 
            // Create target object for Json => list of operations
            var targetOperations = new List<Operation>();
 
            // Create a new reader for this jObject, and set all properties
            // to match the original reader.
            var jObjectReader = jObject.CreateReader();
            jObjectReader.Culture = reader.Culture;
            jObjectReader.DateParseHandling = reader.DateParseHandling;
            jObjectReader.DateTimeZoneHandling = reader.DateTimeZoneHandling;
            jObjectReader.FloatParseHandling = reader.FloatParseHandling;
 
            // Populate the object properties
            serializer.Populate(jObjectReader, targetOperations);
 
            // container target: the JsonPatchDocument.
            var container = new JsonPatchDocument(targetOperations, DefaultContractResolver);
 
            return container;
        }
        catch (Exception ex)
        {
            throw new JsonSerializationException(Resources.InvalidJsonPatchDocument, ex);
        }
    }
 
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        if (value is IJsonPatchDocument jsonPatchDoc)
        {
            var lst = jsonPatchDoc.GetOperations();
 
            // write out the operations, no envelope
            serializer.Serialize(writer, lst);
        }
    }
}