const debug = require('debug')('github-events')

const githubSecret = require('./github-secret')

module.exports = (app) => {

app.post('/hooks/github', (req, res) => {

const event = req.headers['x-github-event']

if (!event) {

res.writeHead(400, 'Event Header Missing')

return res.end()

}

if (!githubSecret.isValid(req)) {

res.writeHead(401, 'Invalid Signature')

req.log.error('Invalid GitHub event signature, returning 401')

return res.end()

}

const data = req.body

data.action = data.action ? event + '.' + data.action : event

res.end()

app.emitGhEvent(data, req.log)

})

app.emitGhEvent = function emitGhEvent (data, logger) {

const repo = data.repository.name

const org = data.repository.owner.login || data.organization.login

// Normalize how to fetch the PR / issue number for simpler retrieval in the

// rest of the bot's code. For PRs the number is present in data.number,

// but for webhook events raised for comments it's present in data.issue.number

if (!data.number && data.issue) {

data.number = data.issue.number

}

const pr = data.number

// create unique logger which is easily traceable throughout the entire app

// by having e.g. "nodejs/nodejs.org/#1337" part of every subsequent log statement

const prTrace = `${org}/${repo}/#${pr}`

data.logger = logger.child({ pr: prTrace, action: data.action }, true)

data.logger.info('Emitting GitHub event')

debug(data)

app.emit(data.action, data, org, repo, data.sender.login)

}

}