const express = require('express')
const bodyParser = require('body-parser')
const path = require('path')
const { URLSafeTimedSerializer } = require("@constemi/itsdangerjs")

require('dotenv').config()

// set up debug
let DEBUG

if (process.env.DEBUG || process.env.CROWDFUNDING_SITE_DEBUG) {
  DEBUG = true
} else {
  DEBUG = false
}

if (DEBUG) console.log('Starting website in debug mode')

// set up secret key
let secretKey
if (process.env.CROWDFUNDING_SITE_SECRET_KEY) {
  secretKey = process.env.CROWDFUNDING_SITE_SECRET_KEY
} else {
  if (DEBUG) {
    secretKey = 'NotReallyASecret'
    console.warn("Secret key is not set! We're falling back to the default one which is INSECURE and NOT TO BE USED IN PRODUCTION")
  } else {
    console.error('No secret key is set. You cannot run this in production without setting a secret key because that would be very insecure. Sorry.')
    process.exit()
  }
}

// get goal details
const goalPeople = Number(process.env.CROWDFUNDING_SITE_GOAL_PEOPLE) || 750
const goalRupees = Number(process.env.CROWDFUNDING_SITE_GOAL_RUPEES) || 500000

// set up knex (for database)
const knex = require('knex')({
  client:'sqlite3',
  connection:{
    filename:'./donors.sqlite'
  },
  useNullAsDefault: true
})

// schema to save pledges
let pledgeSchema = function(t) {
  t.increments('id').primary()
  t.timestamp('created_at').defaultTo(knex.fn.now()).notNullable()
  t.boolean('was_robot').defaultTo(true)

  t.integer('amount').notNullable()
  t.boolean('overseas')
  t.string('name', 128)
  t.boolean('anonymous')
  t.string('email', 128)
  t.string('phone', 32)
  t.integer('retry_times').defaultTo(10)
  t.boolean('get_newsletter').defaultTo(false)
  t.text('other_message')
}

// make sure pledges table exists
knex.schema.hasTable('pledges').then(function(exists) {
  if (!exists) {
    if (DEBUG) console.debug('No pledge table exists! Creating one now...')
    return knex.schema.createTable('pledges', pledgeSchema)
  }
})

// make sure unverified pledge table exists
knex.schema.hasTable('unverified_pledges').then(function(exists) {
  if (!exists) {
    if (DEBUG) console.debug('No unverified pledge table exists! Creating one now...')
    return knex.schema.createTable('unverified_pledges', pledgeSchema)
  }
})

// set up bookshelf (for easy interface for database)
bookshelf = require('bookshelf')(knex)

const Pledge = bookshelf.model('Pledge', {
  tableName: 'pledges',
})

const UnverifiedPledge = bookshelf.model('UnverifiedPledge', {
  tableName: 'unverified_pledges',
})

// decide base url and port for app (can be configured)
const baseUrl = process.env.CROWDFUNDING_SITE_BASE_URL || '/'
const port = process.env.CROWDFUNDING_SITE_PORT || 5000

// set up twing
const {TwingEnvironment, TwingLoaderFilesystem} = require('twing')
let loader = new TwingLoaderFilesystem(path.resolve(__dirname, '..', 'dist'))
let twing = new TwingEnvironment(loader)

// set up express
const app = express()

const router = express.Router()
app.use(baseUrl, router)

router.use(bodyParser.urlencoded({
  extended: true,
}))

// main views
router.get('/', async (req, res) => {
  if (DEBUG) console.debug('Returning home page')

  // count people
  // TODO: optimise to do using SQL only
  let total_people = 0
  let total_rupees = 0
  let result = await Pledge.fetchAll()

  for (let pledge of result.models) {
    total_people += 1
    total_rupees += pledge.get('amount')
  }

  twing.render('index.html', {
    'goal_rupees': Number(goalRupees).toLocaleString('en-IN'),
    'goal_people': Number(goalPeople).toLocaleString('en-IN'),
    'progress_rupees': Number(total_rupees).toLocaleString('en-IN'),
    'progress_people': Number(total_people).toLocaleString('en-IN'),
    'percent_rupees': `style="width: ${total_rupees/goalRupees*100}%"`,
    'percent_people': `style="width: ${total_people/goalPeople*100}%"`,
  }).then((output) => {
    res.end(output)
  })
})

// function to validate pledges before saving
function validatePledge(body, PledgeModel = Pledge) {
  // errors get saved here
  let errors = []

  let was_robot = body.was_robot
  if(was_robot != 'no') {
    errors.push('Only humans are allowed to donate money. Robots are too digital 🙁')
  }

  let amount = body.amount
  if (!amount || amount == 'custom') {
    amount = body['amount-custom']
  }
  if (!amount || amount <= 0) {
    errors.push('Pledge amount too small. Please choose at least a rupee!')
  }
  try {
    amount = Number(amount)
  } catch (err) {
    errors.push('Invalid amount. Please choose a positive number!')
  }

	let name = body.name
	if (name.length <=0) {
		errors.push('What is your name? You can be anonymous to the world but at least we should know...')
	}

	let anonymous = body.anonymous == 'on' ? true : false

	let email = body.email
	if (email.length < 5) {
		errors.push('Please enter a valid email address')
	}

	let phone = body.phone

  let retry_times
  try {
    retry_times = body.retry_times
  } catch (err) {
    errors.push('Invalid retry count. Please choose a positive number!')
  }

	let get_newsletter = body.get_newsletter == 'yes' ? true : false
	let overseas = body.overseas == 'yes' ? true : false
	let other_message = body.other_message

	// enter the info
	let pledge = new PledgeModel() // may be Pledge or UnverifiedPledge
	pledge.set('was_robot', was_robot)
	pledge.set('amount', amount)
	pledge.set('overseas', overseas)
	pledge.set('name', name)
	pledge.set('anonymous', anonymous)
	pledge.set('email', email)
	pledge.set('phone', phone)
  pledge.set('retry_times', retry_times)
	pledge.set('get_newsletter', get_newsletter)
	pledge.set('other_message', other_message)

  // return it all!
  return {
    pledge: pledge,
    errors: errors,
  }
}

router.post('/pledge', async (req, res) => {
  if (DEBUG) console.debug('New pledge:', req.body)

  // check that the right submit button was pressed
  let submit = req.body.submit
  if (submit != 'Save Pledge') {
		errors.push("This request seems to have been tampered with. Are you sure it wasn't you doing the tampering?")
	}

  // process the pledge with our handy function
  let {pledge, errors} = validatePledge(req.body, UnverifiedPledge)

  // fail if there were errors
  if (!!errors.length) {
		res.send(`Errors: ${'' + errors}`)
		return
	}

  // save if there weren't
	if (DEBUG) console.debug (`Saving pledge: ${JSON.stringify(pledge)}`)
	try {
		await pledge.save()
	} catch (err) {
		res.send("Sorry, something went wrong while saving your pledge and we don't know what 🙁. Please try again...")
		return
	}

  // check for existing pledge
  let existingPledge
  try {
    existingPledge = await (Pledge
      .query({
        where: {
          'email': req.query.email,
          'amount': amount,
        },
      })
    .orderBy('created_at', 'DESC')
    .fetch())
  } catch(e) {
    if (e.name == 'EmptyResponse' && DEBUG) {
      console.debug('No existing pledge')
    } else {
      console.warn(`Weird error happened: ${e}`)
    }
  }

  // generate verification link
  let serialiser = URLSafeTimedSerializer(secretKey, pledge.get('email'))
  let verificationLink = `${req.protocol}://${req.hostname}/verify?email=${encodeURIComponent(pledge.get('email'))}&key=${encodeURIComponent(serialiser.dumps(pledge.get('amount')))}`

  // TODO: send out the email, along with existing pledge deets
  console.debug(`Verification link generated: ${verificationLink}`)

	res.send("Thank you! We're still working on setting up this website, so as you can see this page doesn't look great at the moment, but we will be sending you a confirmation email in a few days. Watch out for an email from editors@snipettemag.com, and if it doesn't reach, check your spam box :P")
})

// save pledge after verification complete
router.get('/verify', async (req, res) => {
  if (DEBUG) console.debug('Validating pledge:', req.query)

  // unpack verification link (unless it's expired)
  let serialiser = URLSafeTimedSerializer(secretKey, req.query.email)
  let amount

  try {
    amount = serialiser.loads(req.query.key, 300) // number in seconds
  } catch(e) {
    if (e.name == 'SignatureExpired') {
      res.send("Oops, looks like your link has expired. Please go back and try pledging again. Sorry :(")
      return
    } else {
      res.send("An unknown error occurred. Please generate a new link and try again. Sorry for the inconvenience :(")
      return
    }
  }

  // check against database
  let pledge
  try {
    pledge = await (UnverifiedPledge
      .query({
        where: {
          'email': req.query.email,
          'amount': amount,
        },
      })
    .orderBy('created_at', 'DESC')
    .fetch())
  } catch(e) {
    if (e.name == 'EmptyResponse') {
      res.send('That pledge was not found in our records. Are you sure you made it? Please go back and try again :(')
      return
    } else {
      throw e
      res.send("An unknown error occurred. Please generate a new link and try again. Sorry for the inconvenience :(")
      return
    }
  }

  // prepare our new pledge
  let newPledge = new Pledge()

  newPledge.set('was_robot', pledge.get('was_robot'))
	newPledge.set('amount', pledge.get('amount'))
	newPledge.set('overseas', pledge.get('overseas'))
	newPledge.set('name', pledge.get('name'))
	newPledge.set('anonymous', pledge.get('anonymous'))
	newPledge.set('email', pledge.get('email'))
	newPledge.set('phone', pledge.get('phone'))
  newPledge.set('retry_times', pledge.get('retry_times'))
	newPledge.set('get_newsletter', pledge.get('get_newsletter'))
	newPledge.set('other_message', pledge.get('other_message'))

  // destroy previous pledges by that user
  try {
    await (Pledge
      .query({
        where: {
          email: req.query.email,
        }
      })
      .destroy())
  } catch(e) {
    if (e.message != 'No Rows Deleted') throw e
  }

  // save the new pledge
  await newPledge.save()

  // dummy message
  res.send('all done (not)')
})

router.use(express.static('dist'))

// start the listener!
app.listen(port, () => {
  console.log(`Server is up at port ${port}`)
})

// end note: in case we want to import this somewhere for testing
module.exports = {
  knex,
  bookshelf,
  Pledge,
  UnverifiedPledge,
  router,
}