import React, { Component } from 'react'

import PropTypes from 'prop-types'
import classnames from 'classnames'
import PubNub from 'pubnub'
import qrCode from 'qrcode-generator'
import { DEFAULT_ROUTE } from '../../helpers/constants/routes'

import Button from '../../components/ui/button'
import LoadingScreen from '../../components/ui/loading-screen'

const PASSWORD_PROMPT_SCREEN = 'PASSWORD_PROMPT_SCREEN'
const REVEAL_SEED_SCREEN = 'REVEAL_SEED_SCREEN'
const KEYS_GENERATION_TIME = 30000

export default class MobileSyncPage extends Component {
  static contextTypes = {
    t: PropTypes.func,
  }

  static propTypes = {
    history: PropTypes.object.isRequired,
    selectedAddress: PropTypes.string.isRequired,
    displayWarning: PropTypes.func.isRequired,
    fetchInfoToSync: PropTypes.func.isRequired,
    requestRevealSeedWords: PropTypes.func.isRequired,
  }


  state = {
    screen: PASSWORD_PROMPT_SCREEN,
    password: '',
    seedWords: null,
    error: null,
    syncing: false,
    completed: false,
    channelName: undefined,
    cipherKey: undefined,
  }

  syncing = false

  componentDidMount () {
    const passwordBox = document.getElementById('password-box')
    if (passwordBox) {
      passwordBox.focus()
    }
  }

  handleSubmit (event) {
    event.preventDefault()
    this.setState({ seedWords: null, error: null })
    this.props.requestRevealSeedWords(this.state.password)
      .then((seedWords) => {
        this.startKeysGeneration()
        this.setState({ seedWords, screen: REVEAL_SEED_SCREEN })
      })
      .catch((error) => this.setState({ error: error.message }))
  }

  startKeysGeneration () {
    this.handle && clearTimeout(this.handle)
    this.disconnectWebsockets()
    this.generateCipherKeyAndChannelName()
    this.initWebsockets()
    this.handle = setTimeout(() => {
      this.startKeysGeneration()
    }, KEYS_GENERATION_TIME)
  }

  generateCipherKeyAndChannelName () {
    this.cipherKey = `${this.props.selectedAddress.substr(-4)}-${PubNub.generateUUID()}`
    this.channelName = `mm-${PubNub.generateUUID()}`
    this.setState({ cipherKey: this.cipherKey, channelName: this.channelName })
  }

  initWithCipherKeyAndChannelName (cipherKey, channelName) {
    this.cipherKey = cipherKey
    this.channelName = channelName
  }

  initWebsockets () {
    // Make sure there are no existing listeners
    this.disconnectWebsockets()

    this.pubnub = new PubNub({
      subscribeKey: process.env.PUBNUB_SUB_KEY,
      publishKey: process.env.PUBNUB_PUB_KEY,
      cipherKey: this.cipherKey,
      ssl: true,
    })

    this.pubnubListener = {
      message: (data) => {
        const { channel, message } = data
        // handle message
        if (channel !== this.channelName || !message) {
          return false
        }

        if (message.event === 'start-sync') {
          this.startSyncing()
        } else if (message.event === 'connection-info') {
          this.handle && clearTimeout(this.handle)
          this.disconnectWebsockets()
          this.initWithCipherKeyAndChannelName(message.cipher, message.channel)
          this.initWebsockets()
        } else if (message.event === 'end-sync') {
          this.disconnectWebsockets()
          this.setState({ syncing: false, completed: true })
        }
      },
    }

    this.pubnub.addListener(this.pubnubListener)

    this.pubnub.subscribe({
      channels: [this.channelName],
      withPresence: false,
    })

  }

  disconnectWebsockets () {
    if (this.pubnub && this.pubnubListener) {
      this.pubnub.removeListener(this.pubnubListener)
    }
  }

  // Calculating a PubNub Message Payload Size.
  calculatePayloadSize (channel, message) {
    return encodeURIComponent(
      channel + JSON.stringify(message)
    ).length + 100
  }

  chunkString (str, size) {
    const numChunks = Math.ceil(str.length / size)
    const chunks = new Array(numChunks)
    for (let i = 0, o = 0; i < numChunks; ++i, o += size) {
      chunks[i] = str.substr(o, size)
    }
    return chunks
  }

  notifyError (errorMsg) {
    return new Promise((resolve, reject) => {
      this.pubnub.publish(
        {
          message: {
            event: 'error-sync',
            data: errorMsg,
          },
          channel: this.channelName,
          sendByPost: false, // true to send via post
          storeInHistory: false,
        },
        (status, response) => {
          if (!status.error) {
            resolve()
          } else {
            reject(response)
          }
        })
    })
  }

  async startSyncing () {
    if (this.syncing) {
      return false
    }
    this.syncing = true
    this.setState({ syncing: true })

    const { accounts, network, preferences, transactions } = await this.props.fetchInfoToSync()

    const allDataStr = JSON.stringify({
      accounts,
      network,
      preferences,
      transactions,
      udata: {
        pwd: this.state.password,
        seed: this.state.seedWords,
      },
    })

    const chunks = this.chunkString(allDataStr, 17000)
    const totalChunks = chunks.length
    try {
      for (let i = 0; i < totalChunks; i++) {
        await this.sendMessage(chunks[i], i + 1, totalChunks)
      }
    } catch (e) {
      this.props.displayWarning('Sync failed :(')
      this.setState({ syncing: false })
      this.syncing = false
      this.notifyError(e.toString())
    }
  }

  sendMessage (data, pkg, count) {
    return new Promise((resolve, reject) => {
      this.pubnub.publish(
        {
          message: {
            event: 'syncing-data',
            data,
            totalPkg: count,
            currentPkg: pkg,
          },
          channel: this.channelName,
          sendByPost: false, // true to send via post
          storeInHistory: false,
        },
        (status, response) => {
          if (!status.error) {
            resolve()
          } else {
            reject(response)
          }
        }
      )
    })
  }


  componentWillUnmount () {
    this.disconnectWebsockets()
  }

  renderWarning (text) {
    return (
      <div className="page-container__warning-container">
        <div className="page-container__warning-message">
          <div>{text}</div>
        </div>
      </div>
    )
  }

  renderContent () {
    const { syncing, completed, screen } = this.state
    const { t } = this.context

    if (syncing) {
      return (
        <LoadingScreen loadingMessage="Sync in progress" />
      )
    }

    if (completed) {
      return (
        <div className="reveal-seed__content">
          <label
            className="reveal-seed__label"
            style={{
              width: '100%',
              textAlign: 'center',
            }}
          >
            {t('syncWithMobileComplete')}
          </label>
        </div>
      )
    }

    return screen === PASSWORD_PROMPT_SCREEN
      ? (
        <div>
          {this.renderWarning(this.context.t('mobileSyncText'))}
          <div className="reveal-seed__content">
            {this.renderPasswordPromptContent()}
          </div>
        </div>
      )
      : (
        <div>
          {this.renderWarning(this.context.t('syncWithMobileBeCareful'))}
          <div className="reveal-seed__content">
            {this.renderRevealSeedContent()}
          </div>
        </div>
      )
  }

  renderPasswordPromptContent () {
    const { t } = this.context

    return (
      <form onSubmit={(event) => this.handleSubmit(event)}>
        <label className="input-label" htmlFor="password-box">
          {t('enterPasswordContinue')}
        </label>
        <div className="input-group">
          <input
            type="password"
            placeholder={t('password')}
            id="password-box"
            value={this.state.password}
            onChange={(event) => this.setState({ password: event.target.value })}
            className={classnames('form-control', {
              'form-control--error': this.state.error,
            })}
          />
        </div>
        {this.state.error && (
          <div className="reveal-seed__error">
            {this.state.error}
          </div>
        )}
      </form>
    )
  }

  renderRevealSeedContent () {
    const qrImage = qrCode(0, 'M')
    qrImage.addData(`metamask-sync:${this.state.channelName}|@|${this.state.cipherKey}`)
    qrImage.make()

    const { t } = this.context
    return (
      <div>
        <label
          className="reveal-seed__label"
          style={{
            width: '100%',
            textAlign: 'center',
          }}
        >
          {t('syncWithMobileScanThisCode')}
        </label>
        <div
          className="div qr-wrapper"
          style={{
            display: 'flex',
            justifyContent: 'center',
          }}
          dangerouslySetInnerHTML={{
            __html: qrImage.createTableTag(4),
          }}
        />
      </div>
    )
  }

  renderFooter () {
    return this.state.screen === PASSWORD_PROMPT_SCREEN
      ? this.renderPasswordPromptFooter()
      : this.renderRevealSeedFooter()
  }

  renderPasswordPromptFooter () {
    const { t } = this.context
    const { history } = this.props
    const { password } = this.state

    return (
      <div className="new-account-import-form__buttons" style={{ padding: 30 }}>
        <Button
          type="default"
          large
          className="new-account-create-form__button"
          onClick={() => history.push(DEFAULT_ROUTE)}
        >
          {t('cancel')}
        </Button>
        <Button
          type="secondary"
          large
          className="new-account-create-form__button"
          onClick={(event) => this.handleSubmit(event)}
          disabled={password === ''}
        >
          {t('next')}
        </Button>
      </div>
    )
  }

  renderRevealSeedFooter () {
    const { t } = this.context
    const { history } = this.props

    return (
      <div className="page-container__footer" style={{ padding: 30 }}>
        <Button
          type="default"
          large
          className="page-container__footer-button"
          onClick={() => history.push(DEFAULT_ROUTE)}
        >
          {t('close')}
        </Button>
      </div>
    )
  }

  render () {
    const { t } = this.context
    const { screen } = this.state

    return (
      <div className="page-container">
        <div className="page-container__header">
          <div className="page-container__title">
            {t('syncWithMobileTitle')}
          </div>
          {
            screen === PASSWORD_PROMPT_SCREEN
              ? (
                <div className="page-container__subtitle">
                  {t('syncWithMobileDesc')}
                </div>
              )
              : null
          }
          {
            screen === PASSWORD_PROMPT_SCREEN
              ? (
                <div className="page-container__subtitle">
                  {t('syncWithMobileDescNewUsers')}
                </div>
              )
              : null
          }
        </div>
        <div className="page-container__content">
          {this.renderContent()}
        </div>
        {this.renderFooter()}
      </div>
    )
  }
}