using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace Questionable.Model.Common.Converter;

public abstract class EnumConverter<T> : JsonConverter<T> where T : Enum
{
	private readonly ReadOnlyDictionary<T, string> _enumToString;

	private readonly ReadOnlyDictionary<string, T> _stringToEnum;

	protected EnumConverter(IReadOnlyDictionary<T, string> values)
	{
		_enumToString = ((values is IDictionary<T, string> dictionary) ? new ReadOnlyDictionary<T, string>(dictionary) : new ReadOnlyDictionary<T, string>(values.ToDictionary<KeyValuePair<T, string>, T, string>((KeyValuePair<T, string> x) => x.Key, (KeyValuePair<T, string> x) => x.Value)));
		_stringToEnum = new ReadOnlyDictionary<string, T>(_enumToString.ToDictionary<KeyValuePair<T, string>, string, T>((KeyValuePair<T, string> x) => x.Value, (KeyValuePair<T, string> x) => x.Key));
	}

	public override T? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
	{
		if (reader.TokenType != JsonTokenType.String)
		{
			throw new JsonException();
		}
		string text = reader.GetString();
		if (text == null)
		{
			throw new JsonException();
		}
		if (!_stringToEnum.TryGetValue(text, out var value))
		{
			throw new JsonException();
		}
		return value;
	}

	public override void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions options)
	{
		writer.WriteStringValue(_enumToString[value]);
	}
}