src/reflex/scanners.ts

// @ts-expect-error
import * as us from "unscan";
import fetch from "node-fetch";
import { writeFileSync } from "fs";
import generateFileName from "../utils/temp/generateFileName.js";
import Tesseract from "node-tesseract-ocr";
import type Discord from "discord.js";

interface NSFWSchema {
    nsfw: boolean;
}
interface MalwareSchema {
    safe: boolean;
}

export async function testNSFW(link: string): Promise<NSFWSchema> {
    const p = await saveAttachment(link);
    const result = await us.nsfw.file(p);
    return { nsfw: result.nsfw ?? false };
}

export async function testMalware(link: string): Promise<MalwareSchema> {
    const p = await saveAttachment(link);
    const result = await us.malware.file(p);
    return { safe: result.safe ?? true };
}

export async function saveAttachment(link: string): Promise<string> {
    const image = (await (await fetch(link)).buffer()).toString("base64");
    const fileName = generateFileName(link.split("/").pop()!.split(".").pop()!);
    writeFileSync(fileName, image, "base64");
    return fileName;
}

const defaultLinkTestResult: { safe: boolean; tags: string[] } = {
    safe: true,
    tags: []
};
export async function testLink(
    link: string
): Promise<{ safe: boolean; tags: string[] }> {
    const scanned: { safe?: boolean; tags?: string[] } | undefined =
        await us.link.scan(link);
    if (scanned === undefined) return defaultLinkTestResult;
    return {
        safe: scanned.safe ?? defaultLinkTestResult.safe,
        tags: scanned.tags ?? defaultLinkTestResult.tags
    };
}

const linkTypes = {
    PHISHING: "Links designed to trick users into clicking on them.",
    DATING: "Dating sites.",
    TRACKERS: "Websites that store or track personal information.",
    ADVERTISEMENTS: "Websites only for ads.",
    FACEBOOK:
        "Facebook pages. (Facebook has a number of dangerous trackers. Read more on /privacy)",
    AMP: "AMP pages. (AMP is a technology that allows websites to be served by Google. Read more on /privacy)",
    "FACEBOOK TRACKERS": "Websites that include trackers from Facebook.",
    "IP GRABBERS":
        "Websites that store your IP address, which shows your approximate location.",
    PORN: "Websites that include pornography.",
    GAMBLING: "Gambling sites, often scams.",
    MALWARE:
        "Websites which download files designed to break or slow down your device.",
    PIRACY: "Sites which include illegally downloaded material.",
    RANSOMWARE:
        "Websites which download a program that can steal your data and make you pay to get it back.",
    REDIRECTS: "Sites like bit.ly which could redirect to a malicious site.",
    SCAMS: "Sites which are designed to trick you into doing something.",
    TORRENT: "Websites that download torrent files.",
    HATE: "Websites that spread hate towards groups or individuals.",
    JUNK: "Websites that are designed to make you waste time."
};
export { linkTypes };

export async function LinkCheck(message: Discord.Message): Promise<string[]> {
    const links =
        message.content.match(
            /https?:\/\/(www\.)?[-a-zA-Z0-9@:%._+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_+.~#?&//=]*)/gi
        ) ?? [];
    const detections: { tags: string[]; safe: boolean }[] = [];
    const promises: Promise<void>[] = links.map(async (element) => {
        let returned;
        try {
            if (
                element.match(
                    /https?:\/\/[a-zA-Z]+\.?discord(app)?\.(com|net)\/?/
                )
            )
                return; // Also matches discord.net, not enough of a bug
            returned = await testLink(element);
        } catch {
            detections.push({ tags: [], safe: true });
            return;
        }
        detections.push({ tags: returned.tags, safe: returned.safe });
    });
    await Promise.all(promises);
    const detectionsTypes = detections
        .map((element) => {
            const type = Object.keys(linkTypes).find((type) =>
                element.tags.includes(type)
            );
            if (type) return type;
            // if (!element.safe) return "UNSAFE"
            return undefined;
        })
        .filter((element) => element !== undefined);
    return detectionsTypes as string[];
}

export async function NSFWCheck(element: string): Promise<boolean> {
    try {
        const test = await testNSFW(element);
        return test.nsfw;
    } catch {
        return false;
    }
}

export async function SizeCheck(element: {
    height: number | null;
    width: number | null;
}): Promise<boolean> {
    if (element.height === null || element.width === null) return true;
    if (element.height < 20 || element.width < 20) return false;
    return true;
}

export async function MalwareCheck(element: string): Promise<boolean> {
    try {
        return (await testMalware(element)).safe;
    } catch {
        return true;
    }
}

export function TestString(
    string: string,
    soft: string[],
    strict: string[]
): object | null {
    for (const word of strict) {
        if (string.toLowerCase().includes(word)) {
            return { word: word, type: "strict" };
        }
    }
    for (const word of soft) {
        for (const word2 of string.match(/[a-z]+/gi) ?? []) {
            if (word2 === word) {
                return { word: word, type: "strict" };
            }
        }
    }
    return null;
}

export async function TestImage(url: string): Promise<string | null> {
    const text = await Tesseract.recognize(url, {
        lang: "eng",
        oem: 1,
        psm: 3
    });
    return text;
}