galvanic-corrosion/src/routes/img.ts

import { APIUtils, NoBody } from "../apiutils.ts";
import * as BaseImages from "../data/content/baseimages.ts";
import Logging from "@proxnet/undead-logging";
import express from "express";
import * as Images from "./../data/content/images.ts";
import { Image } from "https://deno.land/x/imagescript@1.3.0/mod.ts";
import { Buffer } from "node:buffer";

export const route = APIUtils.createRouter("/img");

const chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890. "
    .split("");
function sanitizeString(input: string) {
    return input.split("").filter((char) => chars.includes(char)).join("");
}

const baseImages = BaseImages.getAllBaseImages();

interface ImageQueryOptions {
    cropSquare?: string;
    width?: string;
    height?: string;
}

route.router.get(
    "*",
    async (
        rq: express.Request<NoBody, NoBody, NoBody, ImageQueryOptions>,
        rs: express.Response,
        nxt: express.NextFunction,
    ) => {
        const filename = sanitizeString(
            rq.path.substring(1, rq.path.length).replaceAll("%20", " "),
        );

        // why does it think it is never reassigned? line 39
        // deno-lint-ignore prefer-const
        let image: Image;
        const imageSource = baseImages.includes(filename)
            ? BaseImages.getBaseImage(filename)
            : await Images.getImage(filename);
        if (imageSource == null) {
            nxt();
            return;
        }
        image = await Image.decode(imageSource);

        let cropSquare: boolean = false;
        if (typeof rq.query.cropSquare == "string") {
            const d = JSON.parse(rq.query.cropSquare);
            if (typeof d == "boolean" && d) cropSquare = true;
        }
        let width: number | null = null;
        if (typeof rq.query.width == "string") {
            const num = parseInt(rq.query.width);
            if (isNaN(num)) width = null;
            else width = num;
        }
        let height: number | null = null;
        if (typeof rq.query.height == "string") {
            const num = parseInt(rq.query.height);
            if (isNaN(num)) height = null;
            else height = num;
        }

        if (cropSquare) {
            if (image.width > image.height) {
                image.crop(
                    Math.round(image.width / 2) - Math.round(image.height / 2),
                    0,
                    image.height,
                    image.height,
                );
            } else {image.crop(
                    0,
                    Math.round(image.height / 2) - Math.round(image.width / 2),
                    image.width,
                    image.width,
                );}
        }
        if (width && height) {
            const targetWidth = width > image.width ? image.width : width;
            const targetHeight = height > image.height ? image.height : height;
            if (image.width > image.height) {
                image.resize(Image.RESIZE_AUTO, height);
                image.crop(
                    Math.round(image.width / 2) - Math.round(targetWidth / 2),
                    0,
                    targetWidth,
                    image.height,
                );
            } else {
                image.resize(width, Image.RESIZE_AUTO);
                image.crop(
                    0,
                    Math.round(image.height / 2) - Math.round(targetHeight / 2),
                    image.width,
                    targetHeight,
                );
            }
        } else if (width) image.resize(width, Image.RESIZE_AUTO);
        else if (height) image.resize(Image.RESIZE_AUTO, height);

        rs.type("png").send(Buffer.from(await image.encode()));
    },
);