/*
	Spacebar: A FOSS re-implementation and extension of the Discord.com backend.
	Copyright (C) 2023 Spacebar and Spacebar Contributors
	
	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Affero General Public License as published
	by the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.
	
	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Affero General Public License for more details.
	
	You should have received a copy of the GNU Affero General Public License
	along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

import bodyParser, { OptionsJson } from "body-parser";
import { NextFunction, Request, Response } from "express";
import { HTTPError } from "lambert-server";

const errorMessages: { [key: string]: [string, number] } = {
    "entity.too.large": ["Request body too large", 413],
    "entity.parse.failed": ["Invalid JSON body", 400],
    "entity.verify.failed": ["Entity verification failed", 403],
    "request.aborted": ["Request aborted", 400],
    "request.size.invalid": ["Request size did not match content length", 400],
    "stream.encoding.set": ["Stream encoding should not be set", 500],
    "stream.not.readable": ["Stream is not readable", 500],
    "parameters.too.many": ["Too many parameters", 413],
    "charset.unsupported": ["Unsupported charset", 415],
    "encoding.unsupported": ["Unsupported content encoding", 415],
};

export function BodyParser(opts?: OptionsJson) {
    const jsonParser = bodyParser.json(opts);

    return (req: Request, res: Response, next: NextFunction) => {
        if (!req.headers["content-type"]) req.headers["content-type"] = "application/json";

        jsonParser(req, res, (err) => {
            if (err) {
                const [message, status] = errorMessages[err.type] || ["Invalid Body", 400];
                const errorMessage = message.includes("charset") || message.includes("encoding") ? `${message} "${err.charset || err.encoding}"` : message;
                return next(new HTTPError(errorMessage, status));
            }
            next();
        });
    };
}
