import { marked } from 'marked'
import Uppy from '@uppy/core'
import DropTarget from '@uppy/drop-target'
import Dashboard from '@uppy/dashboard'
import Transloadit from '@uppy/transloadit'
import RemoteSources from '@uppy/remote-sources'
import Webcam from '@uppy/webcam'
import ImageEditor from '@uppy/image-editor'

import '@uppy/core/dist/style.css'
import '@uppy/dashboard/dist/style.css'
import '@uppy/image-editor/dist/style.css'

const TRANSLOADIT_EXAMPLE_KEY = '35c1aed03f5011e982b6afe82599b6a0'
const TRANSLOADIT_EXAMPLE_TEMPLATE = '0b2ee2bc25dc43619700c2ce0a75164a'

function matchFilesAndThumbs (results) {
  const filesById = {}
  const thumbsById = {}

  for (const [stepName, result] of Object.entries(results)) {
    // eslint-disable-next-line no-shadow
    result.forEach(result => {
      if (stepName === 'thumbnails') {
        thumbsById[result.original_id] = result
      } else {
        filesById[result.original_id] = result
      }
    })
  }

  return Object.keys(filesById).map((key) => ({
    file: filesById[key],
    thumb: thumbsById[key],
  }))
}

/**
 * A textarea for markdown text, with support for file attachments.
 */
class MarkdownTextarea {
  constructor (element) {
    this.element = element
    this.controls = document.createElement('div')
    this.controls.classList.add('mdtxt-controls')
    this.uploadLine = document.createElement('button')
    this.uploadLine.setAttribute('type', 'button')
    this.uploadLine.classList.add('form-upload')

    this.uploadLine.appendChild(
      document.createTextNode('Tap here to upload an attachment'),
    )
  }

  install () {
    const { element } = this
    const wrapper = document.createElement('div')
    wrapper.classList.add('mdtxt')
    element.parentNode.replaceChild(wrapper, element)
    wrapper.appendChild(this.controls)
    wrapper.appendChild(element)
    wrapper.appendChild(this.uploadLine)

    this.setupUppy()
  }

  setupUppy = () => {
    this.uppy = new Uppy({ autoProceed: true })
      .use(Transloadit, {
        waitForEncoding: true,
        params: {
          auth: { key: TRANSLOADIT_EXAMPLE_KEY },
          template_id: TRANSLOADIT_EXAMPLE_TEMPLATE,
        },
      })
      .use(DropTarget, { target: this.element })
      .use(Dashboard, { closeAfterFinish: true, trigger: '.form-upload' })
      .use(ImageEditor, { target: Dashboard })
      .use(Webcam, { target: Dashboard })
      .use(RemoteSources, { companionUrl: Transloadit.COMPANION })

    this.uppy.on('complete', (result) => {
      const { successful, failed, transloadit } = result
      if (successful.length !== 0) {
        this.insertAttachments(
          matchFilesAndThumbs(transloadit[0].results),
        )
      } else {
        failed.forEach(error => {
          console.error(error)
          this.reportUploadError(error)
        })
      }
      this.uppy.cancelAll()
    })
  }

  reportUploadError (err) {
    this.uploadLine.classList.add('error')
    const message = document.createElement('span')
    message.appendChild(document.createTextNode(err.message))
    this.uploadLine.insertChild(message, this.uploadLine.firstChild)
  }

  unreportUploadError () {
    this.uploadLine.classList.remove('error')
    const message = this.uploadLine.querySelector('message')
    if (message) {
      this.uploadLine.removeChild(message)
    }
  }

  insertAttachments (attachments) {
    attachments.forEach((attachment) => {
      const { file, thumb } = attachment
      const link = `\n[LABEL](${file.ssl_url})\n`
      const labelText = `View File ${file.basename}`
      if (thumb) {
        this.element.value += link.replace('LABEL', `![${labelText}](${thumb.ssl_url})`)
      } else {
        this.element.value += link.replace('LABEL', labelText)
      }
    })
  }

  uploadFiles = (files) => {
    const filesForUppy = files.map(file => {
      return {
        data: file,
        type: file.type,
        name: file.name,
        meta: file.meta || {},
      }
    })
    this.uppy.addFiles(filesForUppy)
  }
}

const textarea = new MarkdownTextarea(document.querySelector('#new textarea'))
textarea.install()

function renderSnippet (title, text) {
  const template = document.querySelector('#snippet')
  const newSnippet = document.importNode(template.content, true)
  const titleEl = newSnippet.querySelector('.snippet-title')
  const contentEl = newSnippet.querySelector('.snippet-content')

  titleEl.appendChild(document.createTextNode(title))
  contentEl.innerHTML = marked.parse(text)

  const list = document.querySelector('#snippets')
  list.insertBefore(newSnippet, list.firstChild)
}

function saveSnippet (title, text) {
  const id = parseInt(localStorage.numSnippets || 0, 10)
  localStorage[`snippet_${id}`] = JSON.stringify({ title, text })
  localStorage.numSnippets = id + 1
}

function loadSnippets () {
  for (let id = 0; localStorage[`snippet_${id}`] != null; id += 1) {
    const { title, text } = JSON.parse(localStorage[`snippet_${id}`])
    renderSnippet(title, text)
  }
}

document.querySelector('#new').addEventListener('submit', (event) => {
  event.preventDefault()

  const title = event.target.elements['title'].value
    || 'Unnamed Snippet'
  const text = textarea.element.value

  saveSnippet(title, text)
  renderSnippet(title, text)

  // eslint-disable-next-line no-param-reassign
  event.target.querySelector('input').value = ''
  // eslint-disable-next-line no-param-reassign
  event.target.querySelector('textarea').value = ''
})

window.addEventListener('DOMContentLoaded', loadSnippets, { once: true })