import * as matrix from 'zrender/src/core/matrix';

function createTransform(zoom) {
	let transform = matrix.create();
	transform = matrix.scale(matrix.create(), transform, [zoom.scaleRate, zoom.scaleRate]);
	transform = matrix.translate(matrix.create(), transform, [-zoom.offsetX, -zoom.offsetY]);
	return transform;
}

function createBoundingRect(view) {
	const rect = view.getBoundingRect();
	const scale = view.scale[0];
	const offsetX = view.position[0];
	const offsetY = view.position[1];
	rect.width = rect.width * scale;
	rect.height = rect.height * scale;
	rect.x = rect.x * scale + offsetX;
	rect.y = rect.y * scale + offsetY;
	return rect;
}

class ZoomHandle {
	constructor(painter, zr) {
		this.$painter = painter;
		this.$zr = zr;

		this.rect = { x: 0, y: 0, width: this.$zr.getWidth(), height: this.$zr.getHeight() };
		this.transform = createTransform({ scale: 1, offsetX: 0, offsetY: 0 });
	}

	checkVisible(view) {
		return createBoundingRect(view).intersect(this.rect);
	}

	revisibleView(view) {
		if (this.checkVisible(view)) {
			view.show();
		} else {
			view.hide();
		}
		view.dirty();
	}

	// 视图进行缩放/平移
	transformView(view) {
		if (view) {
			view.transform = this.transform;
			view.decomposeTransform();
			this.revisibleView(view);
		}

		return view;
	}

	// 处理所有视图缩放/平移
	transformAll() {
		const parentLevel = this.$painter.getParentLevel();
		if (parentLevel) {
			parentLevel.eachChild((level) => {
				level.eachChild((view) => {
					this.transformView(view);
				});
			});
		}
	}

	// 重新计算显示图形
	revisibleAll() {
		const parentLevel = this.$painter.getParentLevel();
		if (parentLevel) {
			parentLevel.eachChild((level) => {
				level.eachChild((view) => {
					this.revisibleView(view);
				});
			});
		}
	}

	// 更新偏移量
	updateTransform(zoom) {
		this.transform = createTransform(zoom);
		this.transformAll();
	}
}

export default ZoomHandle;