import { downloadDir } from "@tauri-apps/api/path";
import { dialog } from "@tauri-apps/api";
import type { File } from "../../../api/models/File";

export class FileHelper {
	/**
	 * Opens a dialog to get a download location for the given file
	 * @param {File} file
	 */
	public static async getFileDownloadLocation(
		file: File,
	): Promise<string | null> {
		let extension = FileHelper.getExtensionForMime(file.mimeType);

		const downloadDirectory = await downloadDir();
		const suggestionPath = downloadDirectory + file.cd + "." + extension;

		return await dialog.save({
			defaultPath: suggestionPath,
			filters: [
				{
					name: file.mimeType,
					extensions: [extension ?? "*"],
				},
				{ name: "All", extensions: ["*"] },
			],
		});
	}

	/**
	 * Parses a mime into its two components
	 * @param {string | undefined} mimeType
	 * @returns {[string, string] | undefined}
	 */
	public static parseMime(
		mimeType: string | undefined,
	): [string, string] | undefined {
		if (!mimeType) {
			return undefined;
		}
		let mimeParts = mimeType.split("/");
		if (mimeParts.length < 2) {
			return undefined;
		}
		const type = mimeParts[0];
		const subtype = mimeParts[1];

		return [type, subtype];
	}

	/**
	 * Returns the extension for a mime type
	 * @param {string} mime
	 * @returns {string | undefined}
	 * @private
	 */
	public static getExtensionForMime(mime: string): string | undefined {
		let parts = mime.split("/");

		if (parts.length === 2) {
			const type = parts[0];
			const subtype = parts[1];
			return FileHelper.convertMimeSubtypeToExtension(subtype);
		}
		return undefined;
	}

	private static convertMimeSubtypeToExtension(subtype: string): string {
		return subtype;
	}
}