'use strict'

const gql = require('graphql-tag')

const { mergeQueries } = require('../../core/base-service/graphql')

const { BaseGraphqlService, BaseJsonService } = require('..')

function createRequestFetcher(context, config) {

const { sendAndCacheRequestWithCallbacks, githubApiProvider } = context

return async (url, options) =>

githubApiProvider.requestAsPromise(

sendAndCacheRequestWithCallbacks,

url,

options

)

}

class GithubAuthV3Service extends BaseJsonService {

constructor(context, config) {

super(context, config)

this._requestFetcher = createRequestFetcher(context, config)

this.staticAuthConfigured = true

}

}

// Use Github auth, but only when static auth is configured. By using this

// class, in production it will behave like GithubAuthV3Service, and in self-

// hosting (i.e. with a configured token) like BaseJsonService. This is

// useful when consuming GitHub endpoints which are not rate-limited: it

// avoids wasting API quota on them in production.

class ConditionalGithubAuthV3Service extends BaseJsonService {

constructor(context, config) {

super(context, config)

if (context.githubApiProvider.globalToken) {

this._requestFetcher = createRequestFetcher(context, config)

this.staticAuthConfigured = true

} else {

this.staticAuthConfigured = false

}

}

}

class GithubAuthV4Service extends BaseGraphqlService {

constructor(context, config) {

super(context, config)

this._requestFetcher = createRequestFetcher(context, config)

this.staticAuthConfigured = true

}

async _requestGraphql(attrs) {

const url = `/graphql`

/*

The Github v4 API requires us to query the rateLimit object to return

rate limit info in the query body instead of the headers:

https://developer.github.com/v4/guides/resource-limitations/#returning-a-calls-rate-limit-status

This appends the relevant rateLimit query clause to each

call to the GH v4 API so we can keep track of token usage.

*/

const query = mergeQueries(

attrs.query,

gql`

query {

rateLimit {

limit

cost

remaining

resetAt

}

}

`

)

return super._requestGraphql({ ...attrs, ...{ url, query } })

}

}

/*

Choosing between the Github V3 and V4 APIs when creating a new badge:

With the V3 API, one request = one point off the usage limit.

With the V4 API one request may be many points off the usage limit depending

on the query (but will be a minimum of one).

https://developer.github.com/v4/guides/resource-limitations/#calculating-nodes-in-a-call

If we can save ourselves some usage limit it may be worth going with a

REST (V3) call over a graphql query.

All other things being equal, a graphql query will almost always be a smaller

number of bytes over the wire and a smaller/simpler object to parse.

*/

module.exports = {

GithubAuthV3Service,

ConditionalGithubAuthV3Service,

GithubAuthV4Service,

}