/** 명령 입력 해석 — 숫자 · 좌표 · 극좌표 · 각도 고정 꼴 */
import { Point } from '@flatten-js/core';
import {
	type AbsolutePointInputEvent,
	ActorEvent,
	type NumberInputEvent,
	type RelativePointInputEvent,
} from '../tools/tool.types.ts';

/** 부호 있는 실수 한 개 — `-5` · `.5` · `1.5` */
const SIGNED = '(-?(?:[0-9]+(?:[.][0-9]+)?|[.][0-9]+))';
export const NUMBER_REGEXP = new RegExp(`^${SIGNED}$`);
export const ABSOLUTE_POINT_REGEXP = new RegExp(`^${SIGNED}[ ]*,[ ]*${SIGNED}$`);
export const RELATIVE_POINT_REGEXP = new RegExp(`^@${SIGNED}[ ]*,[ ]*${SIGNED}$`);
/** 극좌표 — 거리<각도(도). `@`가 붙으면 직전 점 기준 */
export const ABSOLUTE_POLAR_REGEXP = new RegExp(`^${SIGNED}[ ]*<[ ]*${SIGNED}$`);
export const RELATIVE_POLAR_REGEXP = new RegExp(`^@${SIGNED}[ ]*<[ ]*${SIGNED}$`);
/** 각도 고정 — `<30` (다음 한 점만 그 방향) */
export const ANGLE_LOCK_REGEXP = new RegExp(`^<[ ]*${SIGNED}$`);

/** 거리·각도(도)를 x·y 변위로 바꾼다 — 각도 = 동쪽 0° 반시계 + */
export function polarToPoint(distance: number, degrees: number): Point {
	const radians = (degrees * Math.PI) / 180;
	return new Point(distance * Math.cos(radians), distance * Math.sin(radians));
}

export type PointTextEvent = NumberInputEvent | AbsolutePointInputEvent | RelativePointInputEvent;

/** 친 글 → 점 · 거리 사건(숫자 · `x,y` · `@x,y` · `@d<a` · `d<a`) · 아니면 null · 커서는 숫자일 때만 읽음 */
export function parsePointText(text: string, cursor: () => Point): PointTextEvent | null {
	const num = (value: string) => Number.parseFloat(value);
	let match = NUMBER_REGEXP.exec(text);
	if (match) {
		return { type: ActorEvent.NUMBER_INPUT, value: num(match[1]), worldMouseLocation: cursor() };
	}
	match = ABSOLUTE_POINT_REGEXP.exec(text);
	if (match) {
		return {
			type: ActorEvent.ABSOLUTE_POINT_INPUT,
			value: new Point(num(match[1]), num(match[2])),
		};
	}
	match = RELATIVE_POINT_REGEXP.exec(text);
	if (match) {
		return {
			type: ActorEvent.RELATIVE_POINT_INPUT,
			value: new Point(num(match[1]), num(match[2])),
		};
	}
	match = RELATIVE_POLAR_REGEXP.exec(text);
	if (match) {
		return {
			type: ActorEvent.RELATIVE_POINT_INPUT,
			value: polarToPoint(num(match[1]), num(match[2])),
		};
	}
	match = ABSOLUTE_POLAR_REGEXP.exec(text);
	if (match) {
		return {
			type: ActorEvent.ABSOLUTE_POINT_INPUT,
			value: polarToPoint(num(match[1]), num(match[2])),
		};
	}
	return null;
}