import { getAccessTokenFromAuthCode, registerApplication, generateAuthLink } from '../_api/oauth'
import { getInstanceInfo } from '../_api/instance'
import { goto } from 'sapper/runtime.js'
import { switchToTheme } from '../_utils/themeEngine'
import { store } from '../_store/store'
import { updateVerifyCredentialsForInstance } from './instances'
import { updateCustomEmojiForInstance } from './emoji'
import { setInstanceInfo as setInstanceInfoInDatabase } from '../_database/meta'

const REDIRECT_URI = (typeof location !== 'undefined'
  ? location.origin : 'https://pinafore.social') + '/settings/instances/add'

async function redirectToOauth () {
  let instanceName = store.get('instanceNameInSearch')
  let loggedInInstances = store.get('loggedInInstances')
  instanceName = instanceName.replace(/^https?:\/\//, '').replace(/\/$/, '').replace('/$', '').toLowerCase()
  if (Object.keys(loggedInInstances).includes(instanceName)) {
    store.set({logInToInstanceError: `You've already logged in to ${instanceName}`})
    return
  }
  let registrationPromise = registerApplication(instanceName, REDIRECT_URI)
  let instanceInfo = await getInstanceInfo(instanceName)
  await setInstanceInfoInDatabase(instanceName, instanceInfo) // cache for later
  let instanceData = await registrationPromise
  store.set({
    currentRegisteredInstanceName: instanceName,
    currentRegisteredInstance: instanceData
  })
  store.save()
  let oauthUrl = generateAuthLink(
    instanceName,
    instanceData.client_id,
    REDIRECT_URI
  )
  document.location.href = oauthUrl
}

export async function logInToInstance () {
  store.set({
    logInToInstanceLoading: true,
    logInToInstanceError: null
  })
  try {
    await redirectToOauth()
  } catch (err) {
    console.error(err)
    let error = `${err.message || err.name}. ` +
      (navigator.onLine
        ? `Is this a valid Mastodon instance? Is a browser extension blocking the request?`
        : `Are you offline?`)
    store.set({
      logInToInstanceError: error,
      logInToInstanceErrorForText: store.get('instanceNameInSearch')
    })
  } finally {
    store.set({logInToInstanceLoading: false})
  }
}

async function registerNewInstance (code) {
  let currentRegisteredInstanceName = store.get('currentRegisteredInstanceName')
  let currentRegisteredInstance = store.get('currentRegisteredInstance')
  let instanceData = await getAccessTokenFromAuthCode(
    currentRegisteredInstanceName,
    currentRegisteredInstance.client_id,
    currentRegisteredInstance.client_secret,
    code,
    REDIRECT_URI
  )
  let loggedInInstances = store.get('loggedInInstances')
  let loggedInInstancesInOrder = store.get('loggedInInstancesInOrder')
  let instanceThemes = store.get('instanceThemes')
  instanceThemes[currentRegisteredInstanceName] = 'default'
  loggedInInstances[currentRegisteredInstanceName] = instanceData
  if (!loggedInInstancesInOrder.includes(currentRegisteredInstanceName)) {
    loggedInInstancesInOrder.push(currentRegisteredInstanceName)
  }
  store.set({
    instanceNameInSearch: '',
    currentRegisteredInstanceName: null,
    currentRegisteredInstance: null,
    loggedInInstances: loggedInInstances,
    currentInstance: currentRegisteredInstanceName,
    loggedInInstancesInOrder: loggedInInstancesInOrder,
    instanceThemes: instanceThemes
  })
  store.save()
  switchToTheme('default')
  // fire off these requests so they're cached
  /* no await */ updateVerifyCredentialsForInstance(currentRegisteredInstanceName)
  /* no await */ updateCustomEmojiForInstance(currentRegisteredInstanceName)
  goto('/')
}

export async function handleOauthCode (code) {
  try {
    store.set({logInToInstanceLoading: true})
    await registerNewInstance(code)
  } catch (err) {
    store.set({logInToInstanceError: `${err.message || err.name}. Failed to connect to instance.`})
  } finally {
    store.set({logInToInstanceLoading: false})
  }
}
