push-notifications.js

const jwt = require('jsonwebtoken');
const http = require('http');
const https = require('https');

const SDK_VERSION = '1.2.6';
const INTERESTS_REGEX = new RegExp('^(_|\\-|=|@|,|\\.|;|[A-Z]|[a-z]|[0-9])*$');
const {
    INTEREST_STRING_MAX_LENGTH,
    INTEREST_ARRAY_MAX_LENGTH,
    USERS_ARRAY_MAX_LENGTH,
    USERS_STRING_MAX_LENGTH
} = require('./utils');

function PushNotifications(options) {
    if (options === null || typeof options !== 'object') {
        throw new Error('PushNotifications options object is required');
    }
    if (!options.hasOwnProperty('instanceId')) {
        throw new Error(
            '"instanceId" is required in PushNotifications options'
        );
    }
    if (typeof options.instanceId !== 'string') {
        throw new Error('"instanceId" must be a string');
    }
    if (!options.hasOwnProperty('secretKey')) {
        throw new Error('"secretKey" is required in PushNotifications options');
    }
    if (typeof options.secretKey !== 'string') {
        throw new Error('"secretKey" must be a string');
    }
    this.instanceId = options.instanceId;
    this.secretKey = options.secretKey;

    this.port = options.port || null;

    if (!options.hasOwnProperty('endpoint')) {
        this.protocol = 'https';
        this.endpoint = `${this.instanceId}.pushnotifications.pusher.com`;
    } else if (typeof options.endpoint !== 'string') {
        throw new Error('endpoint must be a string');
    } else {
        this.protocol = 'http';
        this.endpoint = options.endpoint;
    }
}

/**
 * Alias of publishToInterests
 * @deprecated Use publishToInterests instead
 */

PushNotifications.prototype.publish = function(interests, publishRequest) {
    console.warn('`publish` is deprecated. Use `publishToInterests` instead.');
    return this.publishToInterests(interests, publishRequest);
};

PushNotifications.prototype.generateToken = function(userId) {
    if (userId === undefined || userId === null) {
        throw new Error('userId argument is required');
    }
    if (userId === '') {
        throw new Error('userId cannot be the empty string');
    }
    if (typeof userId !== 'string') {
        throw new Error('userId must be a string');
    }
    if (userId.length > USERS_STRING_MAX_LENGTH) {
        throw new Error(
            `userId is longer than the maximum length of ${USERS_STRING_MAX_LENGTH}`
        );
    }
    const options = {
        expiresIn: '24h',
        issuer: `https://${this.instanceId}.pushnotifications.pusher.com`,
        subject: userId
    };
    const token = jwt.sign({}, this.secretKey, options);

    return {
        token: token
    };
};

PushNotifications.prototype.publishToInterests = function(
    interests,
    publishRequest
) {
    if (interests === undefined || interests === null) {
        return Promise.reject(new Error('interests argument is required'));
    }
    if (!(interests instanceof Array)) {
        return Promise.reject(
            new Error('interests argument is must be an array')
        );
    }
    if (interests.length < 1) {
        return Promise.reject(
            new Error(
                'Publish requests must target at least one interest to be delivered'
            )
        );
    }
    if (interests.length > INTEREST_ARRAY_MAX_LENGTH) {
        return Promise.reject(
            new Error(
                `Number of interests (${
                    interests.length
                }) exceeds maximum of ${INTEREST_ARRAY_MAX_LENGTH}.`
            )
        );
    }
    if (publishRequest === undefined || publishRequest === null) {
        return Promise.reject(new Error('publishRequest argument is required'));
    }
    for (const interest of interests) {
        if (typeof interest !== 'string') {
            return Promise.reject(
                new Error(`interest ${interest} is not a string`)
            );
        }
        if (interest.length > INTEREST_STRING_MAX_LENGTH) {
            return Promise.reject(
                new Error(
                    `interest ${interest} is longer than the maximum of ` +
                        `${INTEREST_STRING_MAX_LENGTH} characters`
                )
            );
        }
        if (!INTERESTS_REGEX.test(interest)) {
            return Promise.reject(
                new Error(
                    `interest "${interest}" contains a forbidden character. ` +
                        'Allowed characters are: ASCII upper/lower-case letters, ' +
                        'numbers or one of _-=@,.;'
                )
            );
        }
    }

    const body = Object.assign({}, publishRequest, { interests });

    const options = {
        path: `/publish_api/v1/instances/${
            this.instanceId
        }/publishes/interests`,
        method: 'POST',
        body
    };

    return this._doRequest(options);
};

PushNotifications.prototype.publishToUsers = function(users, publishRequest) {
    if (users === undefined || users === null) {
        return Promise.reject(new Error('users argument is required'));
    }
    if (!(users instanceof Array)) {
        return Promise.reject(new Error('users argument is must be an array'));
    }
    if (users.length < 1) {
        return Promise.reject(
            new Error(
                'Publish requests must target at least one interest to be delivered'
            )
        );
    }
    if (users.length > USERS_ARRAY_MAX_LENGTH) {
        return Promise.reject(
            new Error(
                `Number of users (${
                    users.length
                }) exceeds maximum of ${USERS_ARRAY_MAX_LENGTH}.`
            )
        );
    }
    if (publishRequest === undefined || publishRequest === null) {
        return Promise.reject(new Error('publishRequest argument is required'));
    }
    for (const user of users) {
        if (typeof user !== 'string') {
            return Promise.reject(new Error(`user ${user} is not a string`));
        }
        if (user.length > INTEREST_STRING_MAX_LENGTH) {
            return Promise.reject(
                new Error(
                    `user ${user} is longer than the maximum of ` +
                        `${INTEREST_STRING_MAX_LENGTH} characters`
                )
            );
        }
    }

    const body = Object.assign({}, publishRequest, { users });
    const options = {
        path: `/publish_api/v1/instances/${this.instanceId}/publishes/users`,
        method: 'POST',
        body
    };

    return this._doRequest(options);
};

PushNotifications.prototype.deleteUser = function(userId) {
    if (userId === undefined || userId === null) {
        return Promise.reject(new Error('User ID argument is required'));
    }
    if (typeof userId !== 'string') {
        return Promise.reject(new Error('User ID argument must be a string'));
    }
    if (userId.length > USERS_STRING_MAX_LENGTH) {
        return Promise.reject(new Error('User ID argument is too long'));
    }

    const options = {
        path: `/user_api/v1/instances/${
            this.instanceId
        }/users/${encodeURIComponent(userId)}`,
        method: 'DELETE'
    };
    return this._doRequest(options);
};

PushNotifications.prototype._doRequest = function(options) {
    const httpLib = this.protocol === 'http' ? http : https;
    const reqOptions = {
        method: options.method,
        path: options.path,
        host: this.endpoint,
        headers: {
            Accept: 'application/json',
            Authorization: `Bearer ${this.secretKey}`,
            'X-Pusher-Library': `pusher-push-notifications-node ${SDK_VERSION}`
        }
    };

    if (this.port) {
        reqOptions.port = this.port;
    }

    let reqBodyStr;
    if (options.body) {
        reqBodyStr = JSON.stringify(options.body);
        reqOptions.headers['Content-Type'] = 'application/json';
        reqOptions.headers['Content-Length'] = Buffer.byteLength(reqBodyStr);
    }

    return new Promise(function(resolve, reject) {
        try {
            const req = httpLib.request(reqOptions, function(response) {
                let resBodyStr = '';
                response.on('data', function(chunk) {
                    resBodyStr += chunk;
                });

                response.on('end', function() {
                    let resBody;

                    if (resBodyStr) {
                        try {
                            resBody = JSON.parse(resBodyStr);
                        } catch (_) {
                            reject(new Error('Could not parse response body'));
                            return;
                        }
                    }

                    if (
                        response.statusCode >= 200 &&
                        response.statusCode < 300
                    ) {
                        resolve(resBody);
                    } else {
                        if (!resBody.error || !resBody.description) {
                            reject(new Error('Could not parse response body'));
                        } else {
                            reject(
                                new Error(
                                    `${response.statusCode} ${
                                        resBody.error
                                    } - ${resBody.description}`
                                )
                            );
                        }
                    }
                });
            });

            req.on('error', function(error) {
                reject(error);
            });

            if (reqBodyStr) {
                req.write(reqBodyStr);
            }
            req.end();
        } catch (e) {
            reject(e);
        }
    });
};

module.exports = PushNotifications;