/* eslint-env mocha */
/* eslint max-nested-callbacks: ["error", 6] */
'use strict'

const chai = require('chai')
const { expect } = chai
const sinon = require('sinon')

const pDefer = require('p-defer')
const pWaitFor = require('p-wait-for')
const uint8ArrayFromString = require('uint8arrays/from-string')
const uint8ArrayToString = require('uint8arrays/to-string')

const {
  first,
  expectSet
} = require('./utils')

const topic = 'foo'

function shouldNotHappen (_) {
  expect.fail()
}

module.exports = (common) => {
  describe('pubsub with two nodes', () => {
    describe('fresh nodes', () => {
      let psA, psB

      // Create pubsub nodes and connect them
      before(async () => {
        [psA, psB] = await common.setup(2)

        expect(psA.peers.size).to.be.eql(0)
        expect(psB.peers.size).to.be.eql(0)

        // Start pubsub and connect nodes
        psA.start()
        psB.start()

        await psA._libp2p.dial(psB.peerId)

        // Wait for peers to be ready in pubsub
        await pWaitFor(() => psA.peers.size === 1 && psB.peers.size === 1)
      })

      after(async () => {
        sinon.restore()

        psA && psA.stop()
        psB && psB.stop()

        await common.teardown()
      })

      it('Subscribe to a topic in nodeA', () => {
        const defer = pDefer()

        psB.once('pubsub:subscription-change', (changedPeerId, changedSubs) => {
          expectSet(psA.subscriptions, [topic])
          expect(psB.peers.size).to.equal(1)
          expectSet(psB.topics.get(topic), [psA.peerId.toB58String()])
          expect(changedPeerId.toB58String()).to.equal(first(psB.peers).id.toB58String())
          expect(changedSubs).to.be.eql([{ topicID: topic, subscribe: true }])
          defer.resolve()
        })
        psA.subscribe(topic)

        return defer.promise
      })

      it('Publish to a topic in nodeA', () => {
        const defer = pDefer()

        psA.once(topic, (msg) => {
          expect(uint8ArrayToString(msg.data)).to.equal('hey')
          psB.removeListener(topic, shouldNotHappen)
          defer.resolve()
        })

        psB.once(topic, shouldNotHappen)

        psA.publish(topic, uint8ArrayFromString('hey'))

        return defer.promise
      })

      it('Publish to a topic in nodeB', () => {
        const defer = pDefer()

        psA.once(topic, (msg) => {
          psA.once(topic, shouldNotHappen)
          expect(uint8ArrayToString(msg.data)).to.equal('banana')

          setTimeout(() => {
            psA.removeListener(topic, shouldNotHappen)
            psB.removeListener(topic, shouldNotHappen)

            defer.resolve()
          }, 100)
        })

        psB.once(topic, shouldNotHappen)

        psB.publish(topic, uint8ArrayFromString('banana'))

        return defer.promise
      })

      it('Publish 10 msg to a topic in nodeB', () => {
        const defer = pDefer()
        let counter = 0

        psB.once(topic, shouldNotHappen)
        psA.on(topic, receivedMsg)

        function receivedMsg (msg) {
          expect(uint8ArrayToString(msg.data)).to.equal('banana')
          expect(msg.from).to.be.eql(psB.peerId.toB58String())
          expect(msg.seqno).to.be.a('Uint8Array')
          expect(msg.topicIDs).to.be.eql([topic])

          if (++counter === 10) {
            psA.removeListener(topic, receivedMsg)
            psB.removeListener(topic, shouldNotHappen)

            defer.resolve()
          }
        }

        Array.from({ length: 10 }, (_, i) => psB.publish(topic, uint8ArrayFromString('banana')))

        return defer.promise
      })

      it('Unsubscribe from topic in nodeA', () => {
        const defer = pDefer()

        psA.unsubscribe(topic)
        expect(psA.subscriptions.size).to.equal(0)

        psB.once('pubsub:subscription-change', (changedPeerId, changedSubs) => {
          expect(psB.peers.size).to.equal(1)
          expectSet(psB.topics.get(topic), [])
          expect(changedPeerId.toB58String()).to.equal(first(psB.peers).id.toB58String())
          expect(changedSubs).to.be.eql([{ topicID: topic, subscribe: false }])

          defer.resolve()
        })

        return defer.promise
      })

      it('Publish to a topic:Z in nodeA nodeB', () => {
        const defer = pDefer()

        psA.once('Z', shouldNotHappen)
        psB.once('Z', shouldNotHappen)

        setTimeout(() => {
          psA.removeListener('Z', shouldNotHappen)
          psB.removeListener('Z', shouldNotHappen)
          defer.resolve()
        }, 100)

        psB.publish('Z', uint8ArrayFromString('banana'))
        psA.publish('Z', uint8ArrayFromString('banana'))

        return defer.promise
      })
    })

    describe('nodes send state on connection', () => {
      let psA, psB

      // Create pubsub nodes and connect them
      before(async () => {
        [psA, psB] = await common.setup(2)

        expect(psA.peers.size).to.be.eql(0)
        expect(psB.peers.size).to.be.eql(0)

        // Start pubsub and connect nodes
        psA.start()
        psB.start()
      })

      // Make subscriptions prior to nodes connected
      before(() => {
        psA.subscribe('Za')
        psB.subscribe('Zb')

        expect(psA.peers.size).to.equal(0)
        expectSet(psA.subscriptions, ['Za'])
        expect(psB.peers.size).to.equal(0)
        expectSet(psB.subscriptions, ['Zb'])
      })

      after(async () => {
        sinon.restore()

        psA && psA.stop()
        psB && psB.stop()

        await common.teardown()
      })

      it('existing subscriptions are sent upon peer connection', async function () {
        this.timeout(10e3)

        await Promise.all([
          psA._libp2p.dial(psB.peerId),
          new Promise((resolve) => psA.once('pubsub:subscription-change', resolve)),
          new Promise((resolve) => psB.once('pubsub:subscription-change', resolve))
        ])

        expect(psA.peers.size).to.equal(1)
        expect(psB.peers.size).to.equal(1)

        expectSet(psA.subscriptions, ['Za'])
        expectSet(psB.topics.get('Za'), [psA.peerId.toB58String()])

        expectSet(psB.subscriptions, ['Zb'])
        expectSet(psA.topics.get('Zb'), [psB.peerId.toB58String()])
      })
    })
  })
}