day22.ts

type Prettify<T> = { [K in keyof T]: Prettify<T[K]> }
type Trim<
	T extends string,
	U extends string = ' ' | '\t' | '\n' | ',',
> = T extends `${infer F}${U}` | `${U}${infer F}` ? Trim<F> : T

type Parse<T extends string, _Trimmed extends string = Trim<T>> = Prettify<
	_Trimmed extends `{${infer U}}`
		? ParseObjectContent<U>
		: _Trimmed extends `[${infer U}]`
			? ParseArrayContent<U>
			: _Trimmed extends `${infer P extends number | boolean | null}`
				? P
				: ParseString<_Trimmed>
>

type EscapeCharMap = { r: '\r'; n: '\n'; b: '\b'; f: '\f' }
type HandleEscapeChar<
	T extends string,
	_Res extends string = '',
> = T extends `${infer F}\\${infer Char extends keyof EscapeCharMap}${infer R}`
	? HandleEscapeChar<R, `${_Res}${F}${EscapeCharMap[Char]}`>
	: `${_Res}${T}`
type ParseString<T extends string> = T extends `"${infer U}"`
	? HandleEscapeChar<U>
	: T

type ParseArrayContent<
	T extends string,
	_Acc extends any[] = [],
	_Trimmed extends string = Trim<T>,
> = _Trimmed extends `{${infer F}}${infer R}`
	? ParseArrayContent<R, [..._Acc, ParseObjectContent<F>]>
	: _Trimmed extends `${infer F},${infer R}`
		? ParseArrayContent<R, [..._Acc, Parse<F>]>
		: Parse<_Trimmed> extends ''
			? _Acc
			: [..._Acc, Parse<_Trimmed>]

type ParseObjectContent<
	T extends string,
	_Acc extends Record<PropertyKey, any> = {},
	_Trimmed extends string = Trim<T>,
> = _Trimmed extends `${infer K}:${infer V}`
	? Trim<V> extends `[${infer V}]${infer R}`
		? ParseObjectContent<
				R,
				_Acc & {
					[Key in K as ParseString<Key>]: ParseArrayContent<V>
				}
			>
		: V extends `${infer V},${infer R}`
			? ParseObjectContent<
					R,
					_Acc & { [Key in K as ParseString<Key>]: Parse<V> }
				>
			: _Acc & {
					[Key in K as ParseString<Key>]: Parse<V>
				}
	: _Acc