jtr/DevDisciples.Json.Tools/JsonFormatter.cs

using DevDisciples.Json.Parser;
using DevDisciples.Json.Parser.Syntax;
using DevDisciples.Parsing;

namespace DevDisciples.Json.Tools;

public static partial class JsonFormatter
{
    private static VisitorContainer<IJsonSyntax, Context> Visitors { get; } = new();

    static JsonFormatter()
    {
        Visitors.Register<JsonArraySyntax>(PrintArray);
        Visitors.Register<JsonObjectSyntax>(PrintObject);
        Visitors.Register<JsonStringSyntax>(PrintString);
        Visitors.Register<JsonNumberSyntax>(PrintNumber);
        Visitors.Register<JsonBoolSyntax>(PrintBool);
        Visitors.Register<JsonNullSyntax>(PrintNull);
    }

    public static string Format(string source, Context? context)
    {
        var node = JsonParser.Parse("<source>", source);
        return Format(node, context);
    }

    public static string Format(IJsonSyntax visitee, Context? context = null)
    {
        context ??= new();
        Visitors[visitee.GetType()](visitee, context);
        return context.Builder.ToString();
    }

    private static void PrintArray(IJsonSyntax visitee, Context context)
    {
        var array = (JsonArraySyntax)visitee;

        context.Builder.Append($"[{context.NewLine}");
        context.IncrementDepth();

        for (var i = 0; i < array.Elements.Length; i++)
        {
            var node = array.Elements[i];
            context.Builder.Append(context.Indent);
            Visitors[node.GetType()](node, context);
            if (i < array.Elements.Length - 1) context.Builder.Append($",{context.NewLine}");
        }

        context.DecrementDepth();
        context.Builder.Append($"{context.NewLine}{context.Indent}]");
    }

    private static void PrintObject(IJsonSyntax visitee, Context context)
    {
        var @object = (JsonObjectSyntax)visitee;

        context.Builder.Append($"{{{context.NewLine}");
        context.IncrementDepth();

        var count = @object.Properties.Length;
        for (var i = 0; i < count; i++)
        {
            var property = @object.Properties.ElementAt(i);
            context.Builder.Append($"{context.Indent}\"{property.Key.Lexeme}\":{context.Space}");
            Visitors[property.Value.GetType()](property.Value, context);
            if (i < count - 1) context.Builder.Append($",{context.NewLine}");
        }

        context.DecrementDepth();
        context.Builder.Append($"{context.NewLine}{context.Indent}}}");
    }

    private static void PrintString(IJsonSyntax visitee, Context context)
    {
        var @string = (JsonStringSyntax)visitee;
        context.Builder.Append($"\"{@string.Token.Lexeme}\"");
    }

    private static void PrintNumber(IJsonSyntax visitee, Context context)
    {
        var number = (JsonNumberSyntax)visitee;
        context.Builder.Append($"{number.Value}");
    }

    private static void PrintBool(IJsonSyntax visitee, Context context)
    {
        var @bool = (JsonBoolSyntax)visitee;
        context.Builder.Append($"{@bool.Value.ToString().ToLower()}");
    }

    private static void PrintNull(IJsonSyntax visitee, Context context)
    {
        context.Builder.Append("null");
    }
}