summaryrefslogtreecommitdiff
path: root/src/SMAPI.Toolkit/Serialization/JsonHelper.cs
blob: 7d1804e521de7f00f318180bcba22826fc133086 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
using StardewModdingAPI.Toolkit.Serialization.Converters;

namespace StardewModdingAPI.Toolkit.Serialization
{
    /// <summary>Encapsulates SMAPI's JSON file parsing.</summary>
    public class JsonHelper
    {
        /*********
        ** Accessors
        *********/
        /// <summary>The JSON settings to use when serializing and deserializing files.</summary>
        public JsonSerializerSettings JsonSettings { get; } = new()
        {
            Formatting = Formatting.Indented,
            ObjectCreationHandling = ObjectCreationHandling.Replace, // avoid issue where default ICollection<T> values are duplicated each time the config is loaded
            Converters = new List<JsonConverter>
            {
                new SemanticVersionConverter(),
                new StringEnumConverter()
            }
        };


        /*********
        ** Public methods
        *********/
        /// <summary>Read a JSON file.</summary>
        /// <typeparam name="TModel">The model type.</typeparam>
        /// <param name="fullPath">The absolute file path.</param>
        /// <param name="result">The parsed content model.</param>
        /// <returns>Returns false if the file doesn't exist, else true.</returns>
        /// <exception cref="ArgumentException">The given <paramref name="fullPath"/> is empty or invalid.</exception>
        /// <exception cref="JsonReaderException">The file contains invalid JSON.</exception>
        public bool ReadJsonFileIfExists<TModel>(string fullPath, [NotNullWhen(true)] out TModel? result)
        {
            // validate
            if (string.IsNullOrWhiteSpace(fullPath))
                throw new ArgumentException("The file path is empty or invalid.", nameof(fullPath));

            // read file
            string json;
            try
            {
                json = File.ReadAllText(fullPath);
            }
            catch (Exception ex) when (ex is DirectoryNotFoundException or FileNotFoundException)
            {
                result = default;
                return false;
            }

            // deserialize model
            try
            {
                result = this.Deserialize<TModel>(json);
                return result != null;
            }
            catch (Exception ex)
            {
                string error = $"Can't parse JSON file at {fullPath}.";

                if (ex is JsonReaderException)
                {
                    error += " This doesn't seem to be valid JSON.";
                    if (json.Contains("“") || json.Contains("”"))
                        error += " Found curly quotes in the text; note that only straight quotes are allowed in JSON.";
                }
                error += $"\nTechnical details: {ex.Message}";
                throw new JsonReaderException(error);
            }
        }

        /// <summary>Save to a JSON file.</summary>
        /// <typeparam name="TModel">The model type.</typeparam>
        /// <param name="fullPath">The absolute file path.</param>
        /// <param name="model">The model to save.</param>
        /// <exception cref="InvalidOperationException">The given path is empty or invalid.</exception>
        public void WriteJsonFile<TModel>(string fullPath, TModel model)
            where TModel : class
        {
            // validate
            if (string.IsNullOrWhiteSpace(fullPath))
                throw new ArgumentException("The file path is empty or invalid.", nameof(fullPath));

            // create directory if needed
            string dir = Path.GetDirectoryName(fullPath)!;
            if (dir == null)
                throw new ArgumentException("The file path is invalid.", nameof(fullPath));
            if (!Directory.Exists(dir))
                Directory.CreateDirectory(dir);

            // write file
            string json = this.Serialize(model);
            File.WriteAllText(fullPath, json);
        }

        /// <summary>Deserialize JSON text if possible.</summary>
        /// <typeparam name="TModel">The model type.</typeparam>
        /// <param name="json">The raw JSON text.</param>
        public TModel Deserialize<TModel>(string json)
        {
            try
            {
                return JsonConvert.DeserializeObject<TModel>(json, this.JsonSettings)
                    ?? throw new InvalidOperationException($"Couldn't deserialize model type '{typeof(TModel)}' from empty or null JSON.");
            }
            catch (JsonReaderException)
            {
                // try replacing curly quotes
                if (json.Contains("“") || json.Contains("”"))
                {
                    try
                    {
                        return JsonConvert.DeserializeObject<TModel>(json.Replace('“', '"').Replace('”', '"'), this.JsonSettings)
                            ?? throw new InvalidOperationException($"Couldn't deserialize model type '{typeof(TModel)}' from empty or null JSON.");
                    }
                    catch { /* rethrow original error */ }
                }

                throw;
            }
        }

        /// <summary>Serialize a model to JSON text.</summary>
        /// <typeparam name="TModel">The model type.</typeparam>
        /// <param name="model">The model to serialize.</param>
        /// <param name="formatting">The formatting to apply.</param>
        public string Serialize<TModel>(TModel model, Formatting formatting = Formatting.Indented)
        {
            return JsonConvert.SerializeObject(model, formatting, this.JsonSettings);
        }

        /// <summary>Get a low-level JSON serializer matching the <see cref="JsonSettings"/>.</summary>
        public JsonSerializer GetSerializer()
        {
            return JsonSerializer.CreateDefault(this.JsonSettings);
        }
    }
}