dbmedialab/reader-critics

//
// LESERKRITIKK v2 (aka Reader Critics)
// Copyright (C) 2017 DB Medialab/Aller Media AS, Oslo, Norway
// https://github.com/dbmedialab/reader-critics/
//
// This program is free software: you can redistribute it and/or modify it under
// the terms of the GNU 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License along with
// this program. If not, see <http://www.gnu.org/licenses/>.
//

import { Response } from 'express';

import * as app from 'app/util/applib';

import {
    NotFoundError,
    SchemaValidationError,
} from 'app/util/errors';

const log = app.createLog('api');

// Response Options
export interface ResponseOptions {
    status? : number;
}

// Send a "success" response

export function okResponse(
    resp : Response,
    data? : any,
    options? : ResponseOptions
) : void {
    const response : any = {
        success: true,
    };

    response.data = data || {};

    let statusCode = 200;

    if (options !== undefined) {
        Object.assign(response, options);

        if (options.status) {
            statusCode = options.status;
        }
    }

    resp.status(statusCode).end(stringify(response));
    return null;
}

/**
 * Sends success API response
 * API means JSON
 */
export function okApiResponse(
    resp : Response,
    data? : any,
    options? : ResponseOptions
) : void {
    const response : any = {
        success: true,
    };

    response.data = data || {};

    let statusCode = 200;

    if (options !== undefined) {
        Object.assign(response, options);

        if (options.status) {
            statusCode = options.status;
        }
    }

    resp.status(statusCode).json(response);
    return null;
}

// Send a "failure" response

export function errorResponse(
    resp : Response,
    error? : Error,
    message? : string,
    options? : ResponseOptions
) : void {
    const response : any = {
        success: false,
        message: (message !== undefined) ? message : (
            (error !== undefined) ? error.message : 'Internal server error'
        ),
    };

    if (error instanceof NotFoundError) {
        response.status = 404;
    }
    else if (error instanceof SchemaValidationError) {
        response.status = 400;
    }
    else {
        response.status = 500;
    }

    if (error !== undefined) {
        response.error = error.message;
    }

    if (options !== undefined) {
        Object.assign(response, options, { success: false });
    }
    resp.status(response.status).send(stringify(response));

    if (response.status === 500) {
        log(error.stack || error);
    }
    return null;
}

// Return the response JSON. Pretty printed format in development mode, because
// humans read error messages, too!

function stringify (value : any) : string {
    return app.isProduction ? JSON.stringify(value) : JSON.stringify(value, null, 2) + '\n';
}

/*
 * Responds with collection of entities
 * if empty - will respond with 404
 * JSON format
 */
export function bulkResponse (resp, collection) {
    const notFound = 'Resource not found';
    if (collection.length > 0) {
        return okApiResponse(resp, collection);
    } else {
        return errorResponse(resp, undefined, notFound, { status: 404 });
    }
}