import { STATUS_CODES } from 'http';

import { ServerResponse } from '../../types';
import { RootHandler } from './RootHandler';
import { JSONStringify } from '../../lib';

export const augmentResponse = (res: ServerResponse, rootHandler: RootHandler) => {
    res.json = json(res);
    res.send = sendType(res);
    res.sendError = sendError(res);
};

const json = (res: ServerResponse) => (
    data: object,
    code?: number,
    headers?: { [name: string]: string | number },
    replacer?: (key: string, value: any) => any,
    spaces?: string | number,
    escape?: boolean
) => {
    sendType(res, replacer, spaces, escape)(data, code, headers);
};

const sendError = (res: ServerResponse) => (code: number, data: any, headers?: { [name: string]: string | number }) => {
    sendType(res)(data, code, headers);
};

const SEND_TYPE = 'Content-Type';
const SEND_OSTREAM = 'application/octet-stream';

const sendType = (
    res: ServerResponse,
    replacer?: (key: string, value: any) => any,
    spaces?: string | number,
    escape?: boolean
) => (data: any = '', code = 200, headers: { [name: string]: string | number } = {}) => {
    let type = headers[SEND_TYPE];

    if (!!data && typeof data.pipe === 'function') {
        res.setHeader(SEND_TYPE, type || SEND_OSTREAM);
        return data.pipe(res);
    }

    if (data instanceof Buffer) {
        type = type || SEND_OSTREAM; // prefer given
    } else if (typeof data === 'object') {
        const tmp = JSONStringify;
        data = JSONStringify(data, replacer, spaces, escape);
        type = 'application/json;charset=utf-8';
    } else {
        data = data || STATUS_CODES[code];
    }

    headers[SEND_TYPE] = type || 'text/plain';
    headers['Content-Length'] = Buffer.byteLength(data);

    res.writeHead(code, headers);
    res.end(data);
};

const send = (res: ServerResponse) => (
    data: any = '',
    code = 200,
    headers: { [name: string]: string | number } = {}
) => {
    res.writeHead(code, headers);
    res.end(data || STATUS_CODES[code]);
};