import { type App, type TFile } from "obsidian";

interface CompressOptions {
	width?: number;
	height?: number;
	maintainAspectRatio?: boolean;
	quality?: number;
}

export async function compressImage(
	app: App,
	file: TFile,
	options: CompressOptions
) {
	const img = await new Promise<HTMLImageElement>((resolve) => {
		const img = new Image();
		img.src = app.vault.getResourcePath(file);
		img.onload = () => {
			resolve(img);
		};
	});

	const canvas = document.createElement("canvas");
	const ctx = canvas.getContext("2d")!;

	const quality = options.quality ?? 1;
	let height = options.height;
	let width = options.width;

	if (!width && !height) {
		width = img.width;
		height = img.height;
	} else if (!width && height) {
		width = height * (img.width / img.height);
	} else if (!height && width) {
		height = width * (img.height / img.width);
	}

	if (options.maintainAspectRatio) {
		const aspectRatio = img.width / img.height;

		if (options.height)
			if (width! > height!) {
				height = width! / aspectRatio;
			} else {
				width = height! * aspectRatio;
			}
	}

	console.log(width, height);

	canvas.width = width!;
	canvas.height = height!;

	ctx.drawImage(img, 0, 0, width!, height!);

	const blob = await new Promise<Blob>((resolve, reject) => {
		canvas.toBlob(
			(blob) => {
				if (blob) {
					resolve(blob);
				} else {
					reject(new Error("Failed to compress image"));
				}
			},
			"image/jpeg",
			quality
		);
	});

	return app.vault.modifyBinary(file, await blob.arrayBuffer());
}