import { Arc, type Box, Line, Point, type Segment } from '@flatten-js/core';
import { uniqWith } from 'es-toolkit';
import {
	type Shape,
	type SnapPoint,
	SnapPointType,
	type StartAndEndpointEntity,
} from '../App.types';
import type { DrawController } from '../drawControllers/DrawController.ts';
import { getExportColor } from '../helpers/get-export-color';
import { isPointEqual } from '../helpers/is-point-equal';
import { mirrorPointOverAxis } from '../helpers/mirror-point-over-axis.ts';
import { scalePoint } from '../helpers/scale-point';
import { sortPointsOnArc } from '../helpers/sort-points-on-arc';
import { getActiveLayerId, isEntityHighlighted, isEntitySelected } from '../state.ts';
import { type Entity, EntityName, type JsonEntity } from './Entity';
import type { LineEntity } from './LineEntity.ts';

export class ArcEntity implements Entity, StartAndEndpointEntity {
	public id: string = crypto.randomUUID();
	public lineColor = '#fff';
	public lineWidth = 1;
	public lineDash: number[] | undefined = undefined;
	public layerId: string;
	/** 0~1 객체 투명도 (Entity 인터페이스의 선택 항목) */
	public opacity?: number;
	/** GROUP으로 묶인 객체가 공유하는 식별자 */
	public groupId?: string;

	private arc: Arc;

	public static getAngle(centerPoint: Point, pointOnArc: Point): number {
		return new Line(centerPoint, pointOnArc).slope;
	}

	constructor(
		layerId: string,
		centerPoint: Point,
		radius: number,
		startAngle: number,
		endAngle: number,
		counterClockwise = true
	) {
		this.layerId = layerId;
		this.arc = new Arc(centerPoint, radius, startAngle, endAngle, counterClockwise);
	}

	public draw(
		drawController: DrawController,
		parentHighlighted?: boolean,
		parentSelected?: boolean
	): void {
		drawController.setLineStyles(
			parentHighlighted ?? isEntityHighlighted(this),
			parentSelected ?? isEntitySelected(this),
			this.lineColor,
			this.lineWidth,
			this.lineDash
		);
		drawController.drawArc(
			this.arc.center,
			this.arc.r.valueOf(),
			this.arc.startAngle,
			// 끝각 = 시작각 ± 쓸어간 각 — 끝각 0 을 2π 로 바꾸면 시작각이 음수인 호(대칭 뒤)가 온 원으로 그려짐.
			this.arc.startAngle + (this.arc.counterClockwise ? this.arc.sweep : -this.arc.sweep),
			this.arc.counterClockwise
		);
	}

	public move(x: number, y: number) {
		this.arc = this.arc.translate(x, y);
	}

	public scale(scaleOrigin: Point, scaleFactor: number) {
		const center = scalePoint(this.arc.center, scaleOrigin, scaleFactor);
		this.arc = new Arc(
			center,
			this.arc.r.valueOf() * scaleFactor,
			this.arc.startAngle,
			this.arc.endAngle,
			this.arc.counterClockwise
		);
	}

	public rotate(rotateOrigin: Point, angle: number) {
		this.arc = this.arc.rotate(angle, rotateOrigin);
	}

	public mirror(mirrorAxis: LineEntity) {
		const mirroredCenter = mirrorPointOverAxis(this.arc.center, mirrorAxis);
		// 축 각 θ 에 대한 대칭 — 각 α → 2θ − α · 도는 방향 반대.
		const doubleAxisAngle = 2 * mirrorAxis.getAngle();
		this.arc = new Arc(
			mirroredCenter,
			this.arc.r.valueOf(),
			doubleAxisAngle - this.arc.startAngle,
			doubleAxisAngle - this.arc.endAngle,
			!this.arc.counterClockwise
		);
	}

	public clone(): Entity {
		if (this.arc) {
			const { center, r, startAngle, endAngle, counterClockwise } = this.arc;
			// 색 · 층 · 선 꼴은 그대로 — 폴리선 자식도 이 길로 복제됨.
			const copy = new ArcEntity(this.layerId, center, r.valueOf(), startAngle, endAngle, counterClockwise);
			copy.lineColor = this.lineColor;
			copy.lineWidth = this.lineWidth;
			copy.lineDash = this.lineDash;
			copy.opacity = this.opacity;
			return copy;
		}
		return this;
	}

	public intersectsWithBox(box: Box): boolean {
		return this.arc.intersect(box).length > 0;
	}

	public isContainedInBox(box: Box): boolean {
		return box.contains(this.arc);
	}

	public getBoundingBox(): Box {
		return this.arc.box;
	}

	public getShape(): Shape | null {
		return this.arc;
	}

	public getSnapPoints(): SnapPoint[] {
		return [
			{
				point: this.arc.center,
				type: SnapPointType.CircleCenter,
			},
			{
				point: this.arc.start,
				type: SnapPointType.LineEndPoint,
			},
			{
				point: this.arc.end,
				type: SnapPointType.LineEndPoint,
			},
			// TODO add cardinal points if they lay on the arc
			// TODO add tangent points from mouse location to circle
		];
	}

	public getIntersections(entity: Entity): Point[] {
		const otherShape = entity.getShape();
		if (!otherShape) {
			return [];
		}
		return this.arc.intersect(otherShape);
	}

	public getFirstPoint(): Point | null {
		return this.arc.center;
	}

	public distanceTo(shape: Shape): [number, Segment] | null {
		return this.arc.distanceTo(shape);
	}

	public getSvgString(): string | null {
		return (
			this.arc.svg({
				strokeWidth: this.lineWidth,
				stroke: getExportColor(this.lineColor),
			}) || null
		);
	}

	public getType(): EntityName {
		return EntityName.Arc;
	}

	public containsPointOnShape(point: Point): boolean {
		if (!this.arc) {
			return false;
		}
		return this.arc.contains(point);
	}

	public cutAtPoints(pointsOnShape: Point[]): ArcEntity[] {
		const points = uniqWith([this.arc.start, this.arc.end, ...pointsOnShape], isPointEqual);

		const sortedPoints = sortPointsOnArc(points, this.arc.center, this.arc.start);

		const segmentArcs: ArcEntity[] = [];
		for (let i = 0; i < sortedPoints.length - 1; i++) {
			const point1 = sortedPoints[i];
			const point2 = sortedPoints[i + 1];

			const startAngle = ArcEntity.getAngle(this.arc.center, point1);
			const endAngle = ArcEntity.getAngle(this.arc.center, point2);

			const newArc = new ArcEntity(
				getActiveLayerId(),
				this.arc.center,
				Number(this.arc.r),
				startAngle,
				endAngle,
				this.arc.counterClockwise
			);
			newArc.lineColor = this.lineColor;
			newArc.lineWidth = this.lineWidth;
			segmentArcs.push(newArc);
		}
		return segmentArcs;
	}

	public async toJson(): Promise<JsonEntity<ArcJsonData> | null> {
		if (!this.arc) {
			return null;
		}
		return {
			id: this.id,
			type: EntityName.Arc,
			lineColor: this.lineColor,
			lineWidth: this.lineWidth,
			lineDash: this.lineDash,
			layerId: this.layerId,
			shapeData: {
				center: { x: this.arc.center.x, y: this.arc.center.y },
				radius: this.arc.r.valueOf(),
				startAngle: this.arc.startAngle,
				endAngle: this.arc.endAngle,
				counterClockwise: this.arc.counterClockwise,
			},
		};
	}

	public static async fromJson(jsonEntity: JsonEntity<ArcJsonData>): Promise<ArcEntity> {
		if (jsonEntity.type !== EntityName.Arc) {
			throw new Error('Invalid Entity type in JSON');
		}

		if (!jsonEntity.shapeData) {
			throw new Error('Invalid JSON entity of type Arc: missing shapeData');
		}

		const center = new Point(jsonEntity.shapeData.center.x, jsonEntity.shapeData.center.y);
		const radius = jsonEntity.shapeData.radius;
		const startAngle = jsonEntity.shapeData.startAngle;
		const endAngle = jsonEntity.shapeData.endAngle;
		const counterClockwise = jsonEntity.shapeData.counterClockwise;

		const arcEntity = new ArcEntity(
			jsonEntity.layerId || getActiveLayerId(),
			center,
			radius,
			startAngle,
			endAngle,
			counterClockwise
		);
		arcEntity.id = jsonEntity.id;
		arcEntity.lineColor = jsonEntity.lineColor;
		arcEntity.lineWidth = jsonEntity.lineWidth;
		arcEntity.lineDash = jsonEntity.lineDash;
		return arcEntity;
	}

	public getStartPoint(): Point {
		return this.arc.start;
	}

	public getEndPoint(): Point {
		return this.arc.end;
	}
}

export interface ArcJsonData {
	center: { x: number; y: number };
	radius: number;
	startAngle: number;
	endAngle: number;
	counterClockwise: boolean;
}