Function upload

frontend/src/utility-functions/files.ts:36–81

(
	accept: string,
	textOrData: "text" | "data" | "both",
	multiple = false,
)

export async function upload(accept: string, textOrData: "both"): Promise<UploadResult<{ text: string; data: Uint8Array }>>;
export async function upload(accept: string, textOrData: "data", multiple: true): Promise<UploadResult<Uint8Array>[]>;
export async function upload(
	accept: string,
	textOrData: "text" | "data" | "both",
	multiple = false,
): Promise<UploadResult<string | Uint8Array | { text: string; data: Uint8Array }> | UploadResult<Uint8Array>[]> {
	return new Promise((resolve) => {
		const element = document.createElement("input");
		element.type = "file";
		element.accept = accept;
		element.multiple = multiple;

		element.addEventListener(
			"change",
			async () => {
				if (!element.files?.length) return;

				// The `multiple: true` overload constrains `textOrData` to "data", so we know each file produces a Uint8Array
				if (multiple) {
					const results = await Promise.all(
						Array.from(element.files).map(async (file) => ({
							filename: file.name,
							type: file.type,
							content: new Uint8Array(await file.arrayBuffer()),
						})),
					);
					resolve(results);
					return;
				}

				const file = element.files[0];
				const content =
					textOrData === "text"
						? await file.text()
						: textOrData === "data"
							? new Uint8Array(await file.arrayBuffer())
							: { text: await file.text(), data: new Uint8Array(await file.arrayBuffer()) };
				resolve({ filename: file.name, type: file.type, content });
			},
			{ capture: false, once: true },
		);

		element.click();

		// Once `element` goes out of scope, it has no references so it gets garbage collected along with its event listener, so `removeEventListener` is not needed
	});
}
export type UploadResult<T> = { filename: string; type: string; content: T };

export async function pasteFile(item: DataTransferItem, editor: EditorWrapper, mouse?: [number, number], insertParentId?: bigint, insertIndex?: number) {