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

namespace DevDisciples.Json.Tools;

public static partial class JsonFormatter
{
    public static VisitorContainer Visitors { get; }

    static JsonFormatter()
    {
        Visitors = new();
        Visitors.Register<JsonArray>(PrintArray);
        Visitors.Register<JsonObject>(PrintObject);
        Visitors.Register<JsonString>(PrintString);
        Visitors.Register<JsonNumber>(PrintNumber);
        Visitors.Register<JsonBool>(PrintBool);
        Visitors.Register<JsonNull>(PrintNull);
    }

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

    private static string Format(ISyntaxNode visitee, Context? context = null)
    {
        var ctx = context ?? new();
        Visitors[visitee.GetType()](visitee, ctx);
        return context!.Builder.ToString();
    }

    private static Context ContextFromArgs(object[] args)
    {
        return (args[0] as Context)!;
    }

    private static void PrintArray(object visitee, object[] args)
    {
        var context = ContextFromArgs(args);
        var array = (JsonArray)visitee;

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

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

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

    private static void PrintObject(object visitee, object[] args)
    {
        var context = ContextFromArgs(args);
        var @object = (JsonObject)visitee;

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

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

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

    private static void PrintString(object visitee, object[] args)
    {
        var context = ContextFromArgs(args);
        var @string = (JsonString)visitee;
        context.Builder.Append($"\"{@string.Token.Lexeme}\"");
    }

    private static void PrintNumber(object visitee, object[] args)
    {
        var context = ContextFromArgs(args);
        var number = (JsonNumber)visitee;
        context.Builder.Append($"{number.Value}");
    }

    private static void PrintBool(object visitee, object[] args)
    {
        var context = ContextFromArgs(args);
        var @bool = (JsonBool)visitee;
        context.Builder.Append($"{@bool.Value.ToString().ToLower()}");
    }

    private static void PrintNull(object visitee, object[] args)
    {
        var context = ContextFromArgs(args);
        context.Builder.Append("null");
    }
}