const Raven = require('raven-js')
const METAMASK_DEBUG = process.env.METAMASK_DEBUG
const extractEthjsErrorMessage = require('./extractEthjsErrorMessage')
const PROD = 'https://3567c198f8a8412082d32655da2961d0@sentry.io/273505'
const DEV = 'https://f59f3dd640d2429d9d0e2445a87ea8e1@sentry.io/273496'

module.exports = setupRaven

// Setup raven / sentry remote error reporting
function setupRaven(opts) {
  const { release } = opts
  let ravenTarget

  if (METAMASK_DEBUG) {
    console.log('Setting up Sentry Remote Error Reporting: DEV')
    ravenTarget = DEV
  } else {
    console.log('Setting up Sentry Remote Error Reporting: PROD')
    ravenTarget = PROD
  }

  const client = Raven.config(ravenTarget, {
    release,
    transport: function(opts) {
      const report = opts.data
      try {
        // handle error-like non-error exceptions
        nonErrorException(report)
        // simplify certain complex error messages (e.g. Ethjs)
        simplifyErrorMessages(report)
        // modify report urls
        rewriteReportUrls(report)
      } catch (err) {
        console.warn(err)
      }
      // make request normally
      client._makeRequest(opts)
    },
  })
  client.install()

  return Raven
}

function nonErrorException(report) {
  // handle errors that lost their error-ness in serialization
  if (report.message.includes('Non-Error exception captured with keys: message')) {
    if (!(report.extra && report.extra.__serialized__)) return
    report.message = `Non-Error Exception: ${report.extra.__serialized__.message}`
  }
}

function simplifyErrorMessages(report) {
  if (report.exception && report.exception.values) {
    report.exception.values.forEach(item => {
      let errorMessage = item.value
      // simplify ethjs error messages
      errorMessage = extractEthjsErrorMessage(errorMessage)
      // simplify 'Transaction Failed: known transaction'
      if (errorMessage.indexOf('Transaction Failed: known transaction') === 0) {
        // cut the hash from the error message
        errorMessage = 'Transaction Failed: known transaction'
      }
      // finalize
      item.value = errorMessage
    })
  }
}

function rewriteReportUrls(report) {
  // update request url
  report.request.url = toMetamaskUrl(report.request.url)
  // update exception stack trace
  if (report.exception && report.exception.values) {
    report.exception.values.forEach(item => {
      item.stacktrace.frames.forEach(frame => {
        frame.filename = toMetamaskUrl(frame.filename)
      })
    })
  }
}

function toMetamaskUrl(origUrl) {
  const filePath = origUrl.split(location.origin)[1]
  if (!filePath) return origUrl
  const metamaskUrl = `metamask${filePath}`
  return metamaskUrl
}