/** 치수·지시선이 함께 쓰는 조각 만들기 (화살표·치수 문자·직전 치수 기억) */
import { Point } from '@flatten-js/core';
import { getDimArrowSize, getDimDecimals, getDimTextHeight } from '../../commands/dim-settings';
import { ArrowHeadEntity } from '../../entities/ArrowHeadEntity';
import type { Entity } from '../../entities/Entity';
import type { MeasurementEntity } from '../../entities/MeasurementEntity';
import { getActiveLayerId, getActiveLineColor, getScreenCanvasDrawController } from '../../state';
import { textEntity } from '../factories/entity-factory';

/** 화면 px 기준 상수를 도면 단위로 바꾼다 (줌이 달라도 크기가 일정하게 보인다) */
export function worldFactor(): number {
	try {
		return getScreenCanvasDrawController().getScreenScale() || 1;
	} catch {
		return 1;
	}
}

/** tip을 꼭짓점으로 하고 from 방향에서 들어오는 화살표 */
export function arrowHead(tip: Point, from: Point, size = getDimArrowSize()): ArrowHeadEntity {
	const length = size / worldFactor();
	const dx = tip.x - from.x;
	const dy = tip.y - from.y;
	const distance = Math.hypot(dx, dy) || 1;
	const ux = dx / distance;
	const uy = dy / distance;
	const baseX = tip.x - ux * length;
	const baseY = tip.y - uy * length;
	const halfWidth = length * 0.35;

	const head = new ArrowHeadEntity(
		getActiveLayerId(),
		tip,
		new Point(baseX - uy * halfWidth, baseY + ux * halfWidth),
		new Point(baseX + uy * halfWidth, baseY - ux * halfWidth)
	);
	head.lineColor = getActiveLineColor();
	head.fillColor = getActiveLineColor();
	return head;
}

/** 치수 문자 — 설정한 소수 자릿수·문자 높이를 따른다 */
export function dimensionText(value: number, position: Point, prefix = '', suffix = ''): Entity {
	const label = `${prefix}${value.toFixed(getDimDecimals())}${suffix}`;
	return textEntity(label, position, {
		fontSize: getDimTextHeight() / worldFactor(),
		textAlign: 'center',
	});
}

/** 문자 그대로 찍는 주석 (좌표·각도처럼 단위가 다른 값) */
export function annotationText(label: string, position: Point): Entity {
	return textEntity(label, position, {
		fontSize: getDimTextHeight() / worldFactor(),
		textAlign: 'center',
	});
}

/** DIMBASELINE·DIMCONTINUE가 이어 그릴 직전 치수 */
let lastDimension: MeasurementEntity | null = null;

export const rememberDimension = (dimension: MeasurementEntity): void => {
	lastDimension = dimension;
};

export const getLastDimension = (): MeasurementEntity | null => lastDimension;