import type * as Flatten from '@flatten-js/core';
import { type Box, Point, Polygon, Relations, type Segment, Vector } from '@flatten-js/core';
import { type Shape, type SnapPoint, SnapPointType } from '../App.types';
import { DEFAULT_TEXT_OPTIONS, type DrawController } from '../drawControllers/DrawController.ts';
import { twoPointBoxToPolygon } from '../helpers/box-to-polygon';
import { getExportColor } from '../helpers/get-export-color';
import { mirrorAngleOverAxis } from '../helpers/mirror-angle-over-axis.ts';
import { mirrorPointOverAxis } from '../helpers/mirror-point-over-axis.ts';
import { polygonToSegments } from '../helpers/polygon-to-segments';
import { scalePoint } from '../helpers/scale-point';
import { getActiveLayerId, isEntityHighlighted, isEntitySelected } from '../state.ts';
import { type Entity, EntityName, type JsonEntity } from './Entity';
import type { LineEntity } from './LineEntity.ts';

export class ImageEntity implements Entity {
	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 imageElement: HTMLImageElement;
	private polygon: Polygon;
	private angle: number;
	/**
	 * JSON에서 받은 그림 주소 원본. `imageElement.currentSrc`는 브라우저가 절대 URL로
	 * 바꿔 놓아, 도각의 자리표시자(`{{회사로고}}`)가 저장 한 번에
	 * `http://…/b07-cad/%7B%7B회사로고%7D%7D`로 굳는다(2026-09-02 실측 — 회사 도각이
	 * 그렇게 손상됐다). 원본을 들고 있다가 그대로 돌려준다.
	 */
	private sourceData: string | null = null;
	/** 저장값(그림 주소 또는 자리표 토큰). */
	public getSourceData(): string | null {
		return this.sourceData;
	}

	/** 자리표인가 — `{{회사로고}}` 처럼 토큰을 들고 있는 그림. */
	public isPlaceholder(): boolean {
		return (this.sourceData ?? '').includes('{{');
	}

	/** 도각 편집에서만 쓰는 보여 주기용 그림. 저장값(sourceData)은 토큰 그대로 둔다. */
	public setPreviewImage(dataUrl: string): void {
		const image = new Image();
		image.src = dataUrl;
		this.imageElement = image;
	}

	constructor(
		layerId: string,
		imgData: HTMLImageElement,
		startPointOrPolygon?: Point | Polygon,
		endPointOrAngle?: Point | number,
		angle = 0
	) {
		this.layerId = layerId;
		this.imageElement = imgData;
		if (startPointOrPolygon instanceof Polygon) {
			this.polygon = startPointOrPolygon as Polygon;
		} else {
			this.polygon = twoPointBoxToPolygon(startPointOrPolygon as Point, endPointOrAngle as Point);
		}
		if (endPointOrAngle instanceof Point) {
			this.angle = angle;
		} else {
			this.angle = endPointOrAngle as number;
		}
	}

	public draw(
		drawController: DrawController,
		parentHighlighted?: boolean,
		parentSelected?: boolean
	): void {
		const highlighted = parentHighlighted ?? isEntityHighlighted(this);
		const selected = parentSelected ?? isEntitySelected(this);
		drawController.setLineStyles(
			highlighted,
			selected,
			this.lineColor,
			this.lineWidth,
			this.lineDash
		);
		// 자리표(`{{회사로고}}` 등)는 그림이 없어 화면에 아무것도 안 보였다 — 도각 편집에서
		// 무엇을 어디에 놓았는지 알 수 없어, 자리표일 때는 테두리와 이름을 늘 그린다
		// (2026-09-06). 출력 때는 서버가 값으로 바꾸거나 엔티티째 빼므로 산출물에 안 실린다.
		const placeholder = this.isPlaceholder() && !this.imageElement.src;
		// 그 밖의 그림은 **집었을 때만** 테두리를 그린다. 늘 그리면 도각의 로고 자리에 흰
		// 사각형이 남고, 출력·내보내기가 같은 draw()를 타므로 산출물에도 실린다(2026-09-02).
		if (highlighted || selected || placeholder) {
			for (const edge of polygonToSegments(this.polygon)) {
				drawController.drawLine(edge.start, edge.end);
			}
		}

		if (placeholder) {
			// 아직 보여 줄 그림이 없으면 이름표만 남긴다.
			drawController.drawText(this.sourceData ?? '', this.polygon.box.center, {
				...DEFAULT_TEXT_OPTIONS,
				textAlign: 'center',
				fontSize: Math.max(this.polygon.box.height / 4, 2),
				textColor: this.lineColor,
			});
			return; // 그림이 없으니 그릴 것도 없다
		}

		// 칸 안에 **비율을 지켜** 넣는다 (2026-09-06 사용자 지시) — 칸을 늘렸다고 그림이
		// 늘어나면 로고·서명이 찌그러진다. 남는 자리는 비운다(가운데 맞춤).
		const boxWidth = this.polygon.box.width;
		const boxHeight = this.polygon.box.height;
		const naturalWidth = this.imageElement.naturalWidth || boxWidth;
		const naturalHeight = this.imageElement.naturalHeight || boxHeight;
		const fit = Math.min(boxWidth / naturalWidth, boxHeight / naturalHeight);
		const width = naturalWidth * fit;
		const height = naturalHeight * fit;

		// Draw image
		drawController.drawImage(
			this.imageElement,
			this.polygon.box.xmin + (boxWidth - width) / 2,
			this.polygon.box.ymin + (boxHeight - height) / 2,
			width,
			height,
			this.angle
		);
	}

	/** 자리표 칸 크기(mm)를 바꾼다. 가운데는 그대로 두고 네 귀만 다시 잡는다. */
	public setBoxSize(width: number, height: number): void {
		const center = this.polygon.box.center;
		const halfWidth = Math.max(width, 1) / 2;
		const halfHeight = Math.max(height, 1) / 2;
		this.polygon = twoPointBoxToPolygon(
			new Point(center.x - halfWidth, center.y - halfHeight),
			new Point(center.x + halfWidth, center.y + halfHeight)
		);
	}

	/** 마주 보는 두 모서리로 칸을 다시 잡는다 — 마우스로 끌어 크기를 바꿀 때 쓴다. */
	public setBoxFromCorners(a: Point, b: Point): void {
		this.polygon = twoPointBoxToPolygon(
			new Point(Math.min(a.x, b.x), Math.min(a.y, b.y)),
			new Point(Math.max(a.x, b.x), Math.max(a.y, b.y))
		);
	}

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

	public scale(scaleOrigin: Point, scaleFactor: number) {
		const center = this.polygon.box.center;
		const newCenter = scalePoint(center, scaleOrigin, scaleFactor);
		this.polygon = this.polygon.translate(
			new Vector(newCenter.x - center.x, newCenter.y - center.y)
		);
	}

	public rotate(rotateOrigin: Point, angle: number) {
		this.polygon = this.polygon.rotate(angle, rotateOrigin);
		this.angle += angle; // Need to keep track of the angle for drawing the image
	}

	public mirror(mirrorAxis: LineEntity) {
		const mirroredVertices = this.polygon.vertices.map((p) => mirrorPointOverAxis(p, mirrorAxis));
		const mirroredAngle = mirrorAngleOverAxis(this.angle, mirrorAxis);
		// TODO mirror image pixels
		// this.imageElement = new HTMLImageElement(
		//     this.imageElement.
		// )
		this.polygon = new Polygon(mirroredVertices);
		this.angle = mirroredAngle;
	}

	public clone(): ImageEntity {
		const clonedImage = document.createElement('img');
		clonedImage.src = this.imageElement.src;
		const cloned = new ImageEntity(getActiveLayerId(), clonedImage, this.polygon.clone());
		cloned.sourceData = this.sourceData;
		return cloned;
	}

	// TODO add destroy method to cleanup this.imageElement.src

	public intersectsWithBox(selectionBox: Box): boolean {
		return Relations.relate(this.polygon, selectionBox).B2B.length > 0;
	}

	public isContainedInBox(selectionBox: Box): boolean {
		return selectionBox.contains(this.polygon);
	}

	public distanceTo(shape: Shape): [number, Segment] | null {
		const distanceInfos: [number, Segment][] = polygonToSegments(this.polygon).map((segment) =>
			segment.distanceTo(shape)
		);
		let shortestDistanceInfo: [number, Segment | null] = [Number.MAX_SAFE_INTEGER, null];
		for (const distanceInfo of distanceInfos) {
			if (distanceInfo[0] < shortestDistanceInfo[0]) {
				shortestDistanceInfo = distanceInfo;
			}
		}
		return shortestDistanceInfo as [number, Segment];
	}

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

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

	public getSnapPoints(): SnapPoint[] {
		const corners = this.polygon.vertices;
		const edges = polygonToSegments(this.polygon);
		return [
			{
				point: corners[0],
				type: SnapPointType.LineEndPoint,
			},
			{
				point: corners[1],
				type: SnapPointType.LineEndPoint,
			},
			{
				point: corners[2],
				type: SnapPointType.LineEndPoint,
			},
			{
				point: corners[3],
				type: SnapPointType.LineEndPoint,
			},
			{
				point: edges[0].middle(),
				type: SnapPointType.LineMidPoint,
			},
			{
				point: edges[1].middle(),
				type: SnapPointType.LineMidPoint,
			},
			{
				point: edges[2].middle(),
				type: SnapPointType.LineMidPoint,
			},
			{
				point: edges[3].middle(),
				type: SnapPointType.LineMidPoint,
			},
		];
	}

	public getIntersections(entity: Entity): Point[] {
		const otherShape = entity.getShape();
		if (!otherShape) {
			return [];
		}
		return polygonToSegments(this.polygon).flatMap((segment) => {
			return segment.intersect(otherShape);
		});
	}

	public getFirstPoint(): Point | null {
		return this.polygon?.vertices[0] || null;
	}

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

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

	public containsPointOnShape(point: Flatten.Point): boolean {
		return polygonToSegments(this.polygon).some((segment) => segment.contains(point));
	}

	public async toJson(): Promise<JsonEntity<ImageJsonData> | null> {
		return {
			id: this.id,
			type: EntityName.Image,
			lineColor: this.lineColor,
			lineWidth: this.lineWidth,
			lineDash: this.lineDash,
			layerId: this.layerId,
			shapeData: {
				points: this.polygon.vertices.map((vertex) => ({
					x: vertex.x,
					y: vertex.y,
				})),
				imageData: this.sourceData ?? this.imageElement.currentSrc,
			},
		};
	}

	public static async fromJson(jsonEntity: JsonEntity<ImageJsonData>): Promise<ImageEntity> {
		if (!jsonEntity.shapeData) {
			throw new Error('Invalid JSON entity of type Image: missing shapeData');
		}
		const rectangle = new Polygon(
			jsonEntity.shapeData.points.map((point) => new Point(point.x, point.y))
		);
		const image = new Image();
		// 자리표시자는 주소가 아니다 — 그대로 넣으면 404 요청이 나가고 그림이 'broken'
		// 상태가 된다. 그 상태의 그림을 그리려 하면 캔버스가 예외를 던져 렌더 루프가
		// 끊기고 **이후 모든 도면이 백지**로 남았다(2026-09-02 실측). 자리만 남긴다.
		if (!jsonEntity.shapeData.imageData.includes('{{')) {
			image.src = jsonEntity.shapeData.imageData;
		}
		const rectangleEntity = new ImageEntity(
			jsonEntity.layerId || getActiveLayerId(),
			image,
			rectangle
		);
		rectangleEntity.id = jsonEntity.id;
		rectangleEntity.lineColor = jsonEntity.lineColor;
		rectangleEntity.lineWidth = jsonEntity.lineWidth;
		rectangleEntity.lineDash = jsonEntity.lineDash;
		rectangleEntity.sourceData = jsonEntity.shapeData.imageData;
		return rectangleEntity;
	}
}

export interface ImageJsonData {
	points: { x: number; y: number }[];
	imageData: string;
}