import { Trans } from 'react-i18next'
import { Alert, Button } from 'react-bootstrap'
import React, { useCallback, useState } from 'react'
import PropTypes from 'prop-types'
import Uppy from '@uppy/core'
import XHRUpload from '@uppy/xhr-upload'
import { Dashboard, useUppy } from '@uppy/react'
import { useFileTreeActionable } from '../../../contexts/file-tree-actionable'
import { useFileTreeMainContext } from '../../../contexts/file-tree-main'

import '@uppy/core/dist/style.css'
import '@uppy/dashboard/dist/style.css'
import { refreshProjectMetadata } from '../../../util/api'
import ErrorMessage from '../error-message'

export default function FileTreeUploadDoc() {
  const { parentFolderId, cancel, isDuplicate } = useFileTreeActionable()
  const { projectId } = useFileTreeMainContext()

  const [error, setError] = useState()

  const [conflicts, setConflicts] = useState([])
  const [overwrite, setOverwrite] = useState(false)

  const maxNumberOfFiles = 40
  const maxFileSize = window.ExposedSettings.maxUploadSize

  // calculate conflicts
  const buildConflicts = files =>
    Object.values(files).filter(file =>
      isDuplicate(parentFolderId, file.meta.name)
    )

  // initialise the Uppy object
  const uppy = useUppy(() => {
    let endpoint = `/project/${projectId}/upload`

    if (parentFolderId) {
      endpoint += `?folder_id=${parentFolderId}`
    }

    return (
      new Uppy({
        // logger: Uppy.debugLogger,
        allowMultipleUploads: false,
        restrictions: {
          maxNumberOfFiles,
          maxFileSize: maxFileSize || null
        },
        onBeforeUpload: files => {
          let result = true

          setOverwrite(overwrite => {
            if (!overwrite) {
              setConflicts(() => {
                const conflicts = buildConflicts(files)

                result = conflicts.length === 0

                return conflicts
              })
            }

            return overwrite
          })

          return result
        },
        autoProceed: true
      })
        // use the basic XHR uploader
        .use(XHRUpload, {
          endpoint,
          headers: {
            'X-CSRF-TOKEN': window.csrfToken
          },
          // limit: maxConnections || 1,
          limit: 1,
          fieldName: 'qqfile' // "qqfile" field inherited from FineUploader
        })
        // close the modal when all the uploads completed successfully
        .on('complete', result => {
          if (!result.failed.length) {
            // $scope.$emit('done', { name: name })
            cancel()
          }
        })
        // broadcast doc metadata after each successful upload
        .on('upload-success', (file, response) => {
          if (response.body.entity_type === 'doc') {
            window.setTimeout(() => {
              refreshProjectMetadata(projectId, response.body.entity_id)
            }, 250)
          }
        })
        // handle upload errors
        .on('upload-error', (file, error, response) => {
          switch (response.status) {
            case 429:
              setError('rate-limit-hit')
              break

            case 403:
              setError('not-logged-in')
              break

            default:
              // TODO
              break
          }
        })
    )
  })

  // handle forced overwriting of conflicting files
  const handleOverwrite = useCallback(() => {
    setOverwrite(true)
    window.setTimeout(() => {
      uppy.upload()
    }, 10)
  }, [uppy])

  // whether to show a message about conflicting files
  const showConflicts = !overwrite && conflicts.length > 0

  return (
    <>
      {error && (
        <UploadErrorMessage error={error} maxNumberOfFiles={maxNumberOfFiles} />
      )}

      {showConflicts ? (
        <UploadConflicts
          cancel={cancel}
          conflicts={conflicts}
          handleOverwrite={handleOverwrite}
        />
      ) : (
        <Dashboard
          uppy={uppy}
          showProgressDetails
          // note={`Up to ${maxNumberOfFiles} files, up to ${maxFileSize / (1024 * 1024)}MB`}
          height={400}
          width="100%"
          showLinkToFileUploadResult={false}
          proudlyDisplayPoweredByUppy={false}
          locale={{
            strings: {
              // Text to show on the droppable area.
              // `%{browse}` is replaced with a link that opens the system file selection dialog.
              // TODO: 'drag_here' or 'drop_files_here_to_upload'?
              // dropHereOr: `${t('drag_here')} ${t('or')} %{browse}`,
              dropPasteFiles: `Drag here or %{browseFiles}`,
              // Used as the label for the link that opens the system file selection dialog.
              // browseFiles: t('select_from_your_computer')
              browseFiles: 'select from your computer'
            }
          }}
        />
      )}
    </>
  )
}

function UploadErrorMessage({ error, maxNumberOfFiles }) {
  switch (error) {
    case 'too-many-files':
      return (
        <Trans
          i18nKey="maximum_files_uploaded_together"
          values={{ max: maxNumberOfFiles }}
        />
      )

    default:
      return <ErrorMessage error={error} />
  }
}
UploadErrorMessage.propTypes = {
  error: PropTypes.string.isRequired,
  maxNumberOfFiles: PropTypes.number.isRequired
}

function UploadConflicts({ cancel, conflicts, handleOverwrite }) {
  return (
    <Alert bsStyle="warning" className="small">
      <p className="text-center">
        The following files already exist in this project:
      </p>

      <ul className="text-center list-unstyled row-spaced-small">
        {conflicts.map((conflict, index) => (
          <li key={index}>
            <strong>{conflict.meta.name}</strong>
          </li>
        ))}
      </ul>

      <p className="text-center row-spaced-small">
        Do you want to overwrite them?
      </p>

      <p className="text-center">
        <Button bsStyle="primary" onClick={handleOverwrite}>
          Overwrite
        </Button>
        &nbsp;
        <Button bsStyle="primary" onClick={cancel}>
          Cancel
        </Button>
      </p>
    </Alert>
  )
}
UploadConflicts.propTypes = {
  cancel: PropTypes.func.isRequired,
  conflicts: PropTypes.array.isRequired,
  handleOverwrite: PropTypes.func.isRequired
}