import { createWriteStream } from "fs";
import { join, dirname } from "path";
import Busboy from "busboy";
import mkdirp from "mkdirp";

function formData(
    contType: string,
    options: busboy.BusboyConfig & {
        abortOnLimit?: boolean;
        tmpDir?: string;
        onFile?: (
            fieldname: string,
            file: NodeJS.ReadableStream,
            filename: string,
            encoding: string,
            mimetype: string
        ) => string;
        onField?: (fieldname: string, value: any) => void; // eslint-disable-line @typescript-eslint/no-explicit-any
        filename?: (oldName: string) => string;
    } = {}
) {
    console.log("Enter form data");
    options.headers = {
        "content-type": contType,
    };

    return new Promise((resolve, reject) => {
        const busb = new Busboy(options);
        const ret = {};

        this.bodyStream().pipe(busb);

        busb.on("limit", () => {
            if (options.abortOnLimit) {
                reject(Error("limit"));
            }
        });

        busb.on("file", function (fieldname, file, filename, encoding, mimetype) {
            const value: { filePath: string | undefined; filename: string; encoding: string; mimetype: string } = {
                filename,
                encoding,
                mimetype,
                filePath: undefined,
            };

            if (typeof options.tmpDir === "string") {
                if (typeof options.filename === "function") filename = options.filename(filename);
                const fileToSave = join(options.tmpDir, filename);
                mkdirp(dirname(fileToSave));

                file.pipe(createWriteStream(fileToSave));
                value.filePath = fileToSave;
            }
            if (typeof options.onFile === "function") {
                value.filePath = options.onFile(fieldname, file, filename, encoding, mimetype) || value.filePath;
            }

            setRetValue(ret, fieldname, value);
        });

        busb.on("field", function (fieldname, value) {
            if (typeof options.onField === "function") options.onField(fieldname, value);

            setRetValue(ret, fieldname, value);
        });

        busb.on("finish", function () {
            resolve(ret);
        });

        busb.on("error", reject);
    });
}

function setRetValue(
    ret: { [x: string]: any }, // eslint-disable-line @typescript-eslint/no-explicit-any
    fieldname: string,
    value: { filename: string; encoding: string; mimetype: string; filePath?: string } | any // eslint-disable-line @typescript-eslint/no-explicit-any
) {
    if (fieldname.endsWith("[]")) {
        fieldname = fieldname.slice(0, fieldname.length - 2);
        if (Array.isArray(ret[fieldname])) {
            ret[fieldname].push(value);
        } else {
            ret[fieldname] = [value];
        }
    } else {
        if (Array.isArray(ret[fieldname])) {
            ret[fieldname].push(value);
        } else if (ret[fieldname]) {
            ret[fieldname] = [ret[fieldname], value];
        } else {
            ret[fieldname] = value;
        }
    }
}

export default formData;