import type { ImageContent, ImageContentView } from "../content/image"

export interface CroppedImage {
	zoom: number
	/** X coordinate of the crop rect on the original image */
	x: number
	/** Y coordinate of the crop rect on the original image */
	y: number

	/** The width of the crop rect over the original image */
	cropWidth: number
	/** The height of the crop rect over the original image */
	cropHeight: number

	/** Final (user defined via W input) width of the image */
	width: number
	/** Final (user defined via H input) height of the image */
	height: number
}

export function buildCropURL(args: {
	origin: ImageContent["origin"]
	croppedImage: CroppedImage
}): string {
	const { origin, croppedImage } = args
	const { x, y, width, height, cropHeight, cropWidth } = croppedImage

	const url = new URL(origin.url)

	const hasResize = origin.height !== height || origin.width !== width

	const hasCrop = x !== 0 || y !== 0 || cropHeight !== origin.height || cropWidth !== origin.width

	if (hasCrop) {
		const crop = [x, y, cropWidth, cropHeight].map(Math.round).join(",")

		url.searchParams.set("rect", crop)
		url.searchParams.set("w", width.toString())
		url.searchParams.set("h", height.toString())
	}

	if (hasResize) {
		url.searchParams.set("w", width.toString())
		url.searchParams.set("h", height.toString())
	}

	return url.toString()
}

export function getCroppedImage({ contentView }: { contentView: ImageContentView }): CroppedImage {
	const {
		edit: {
			crop: { x, y },
			zoom,
		},
		width,
		height,
		origin: { width: originWidth, height: originHeight },
	} = contentView

	let cropWidth
	let cropHeight
	const originAspect = originWidth / originHeight
	const cropAspect = width / height
	if (cropAspect >= originAspect) {
		// crop and origin image would be the same width if zoom was equal to 1
		cropWidth = originWidth / zoom
		cropHeight = cropWidth / cropAspect
	} else {
		// crop and origin image would be the same height if zoom was equal to 1
		cropHeight = originHeight / zoom
		cropWidth = cropHeight * cropAspect
	}

	return {
		x,
		y,
		width,
		height,
		zoom,
		cropWidth,
		cropHeight,
	}
}