sigit.io/src/pages/sign/index.tsx

import {
  Box,
  Button,
  IconButton,
  List,
  ListItem,
  ListSubheader,
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableRow,
  TextField,
  Tooltip,
  Typography,
  useTheme
} from '@mui/material'
import axios from 'axios'
import saveAs from 'file-saver'
import JSZip from 'jszip'
import _ from 'lodash'
import { MuiFileInput } from 'mui-file-input'
import { Event, verifyEvent } from 'nostr-tools'
import { useEffect, useState } from 'react'
import { useSelector } from 'react-redux'
import { useNavigate, useSearchParams } from 'react-router-dom'
import { toast } from 'react-toastify'
import { LoadingSpinner } from '../../components/LoadingSpinner'
import { UserComponent } from '../../components/username'
import { MetadataController, NostrController } from '../../controllers'
import { appPrivateRoutes } from '../../routes'
import { State } from '../../store/rootReducer'
import {
  CreateSignatureEventContent,
  Meta,
  ProfileMetadata,
  User,
  UserRole
} from '../../types'
import {
  decryptArrayBuffer,
  encryptArrayBuffer,
  generateEncryptionKey,
  getHash,
  hexToNpub,
  parseJson,
  npubToHex,
  readContentOfZipEntry,
  sendDM,
  shorten,
  signEventForMetaFile,
  uploadToFileStorage
} from '../../utils'
import styles from './style.module.scss'
import { Download } from '@mui/icons-material'

enum SignedStatus {
  Fully_Signed,
  User_Is_Next_Signer,
  User_Is_Not_Next_Signer
}

export const SignPage = () => {
  const navigate = useNavigate()
  const [searchParams, setSearchParams] = useSearchParams()

  const [displayInput, setDisplayInput] = useState(false)

  const [selectedFile, setSelectedFile] = useState<File | null>(null)
  const [encryptionKey, setEncryptionKey] = useState('')

  const [zip, setZip] = useState<JSZip>()

  const [isLoading, setIsLoading] = useState(true)
  const [loadingSpinnerDesc, setLoadingSpinnerDesc] = useState('')

  const [meta, setMeta] = useState<Meta | null>(null)
  const [signedStatus, setSignedStatus] = useState<SignedStatus>()

  const [submittedBy, setSubmittedBy] = useState<string>()

  const [signers, setSigners] = useState<`npub1${string}`[]>([])
  const [viewers, setViewers] = useState<`npub1${string}`[]>([])
  const [creatorFileHashes, setCreatorFileHashes] = useState<{
    [key: string]: string
  }>({})
  const [currentFileHashes, setCurrentFileHashes] = useState<{
    [key: string]: string | null
  }>({})

  const [signedBy, setSignedBy] = useState<`npub1${string}`[]>([])

  const [nextSinger, setNextSinger] = useState<string>()

  const usersPubkey = useSelector((state: State) => state.auth.usersPubkey)

  const [authUrl, setAuthUrl] = useState<string>()
  const nostrController = NostrController.getInstance()

  useEffect(() => {
    if (zip) {
      const generateCurrentFileHashes = async () => {
        const fileHashes: { [key: string]: string | null } = {}
        const fileNames = Object.values(zip.files)
          .filter((entry) => entry.name.startsWith('files/') && !entry.dir)
          .map((entry) => entry.name)

        // generate hashes for all entries in files folder of zipArchive
        // these hashes can be used to verify the originality of files
        for (const fileName of fileNames) {
          const arrayBuffer = await readContentOfZipEntry(
            zip,
            fileName,
            'arraybuffer'
          )

          if (arrayBuffer) {
            const hash = await getHash(arrayBuffer)

            if (hash) {
              fileHashes[fileName.replace(/^files\//, '')] = hash
            }
          } else {
            fileHashes[fileName.replace(/^files\//, '')] = null
          }
        }

        setCurrentFileHashes(fileHashes)
      }

      generateCurrentFileHashes()
    }
  }, [zip])

  useEffect(() => {
    if (signers.length > 0) {
      // check if all signers have signed then its fully signed
      if (signers.every((signer) => signedBy.includes(signer))) {
        setSignedStatus(SignedStatus.Fully_Signed)
      } else {
        for (const signer of signers) {
          if (!signedBy.includes(signer)) {
            // signers in meta.json are in npub1 format
            // so, convert it to hex before setting to nextSigner
            setNextSinger(npubToHex(signer)!)

            const usersNpub = hexToNpub(usersPubkey!)

            if (signer === usersNpub) {
              // logged in user is the next signer
              setSignedStatus(SignedStatus.User_Is_Next_Signer)
            } else {
              setSignedStatus(SignedStatus.User_Is_Not_Next_Signer)
            }

            break
          }
        }
      }
    } else {
      // there's no signer just viewers. So its fully signed
      setSignedStatus(SignedStatus.Fully_Signed)
    }
  }, [signers, signedBy, usersPubkey])

  useEffect(() => {
    const fileUrl = searchParams.get('file')
    const key = searchParams.get('key')

    if (fileUrl && key) {
      setIsLoading(true)
      setLoadingSpinnerDesc('Fetching file from file server')

      axios
        .get(fileUrl, {
          responseType: 'arraybuffer'
        })
        .then((res) => {
          const fileName = fileUrl.split('/').pop()
          const file = new File([res.data], fileName!)

          decrypt(file, decodeURIComponent(key)).then((arrayBuffer) => {
            if (arrayBuffer) handleDecryptedArrayBuffer(arrayBuffer)
          })
        })
        .catch((err) => {
          console.error(`error occurred in getting file from ${fileUrl}`, err)
          toast.error(
            err.message || `error occurred in getting file from ${fileUrl}`
          )
        })
        .finally(() => {
          setIsLoading(false)
        })
    } else {
      setIsLoading(false)
      setDisplayInput(true)
    }
  }, [searchParams])

  const decrypt = async (file: File, key: string) => {
    setLoadingSpinnerDesc('Decrypting file')

    const encryptedArrayBuffer = await file.arrayBuffer()

    const arrayBuffer = await decryptArrayBuffer(encryptedArrayBuffer, key)
      .catch((err) => {
        console.log('err in decryption:>> ', err)
        toast.error(err.message || 'An error occurred in decrypting file.')
        return null
      })
      .finally(() => {
        setIsLoading(false)
      })

    return arrayBuffer
  }

  const handleDecryptedArrayBuffer = async (arrayBuffer: ArrayBuffer) => {
    const decryptedZipFile = new File([arrayBuffer], 'decrypted.zip')

    setLoadingSpinnerDesc('Parsing zip file')

    const zip = await JSZip.loadAsync(decryptedZipFile).catch((err) => {
      console.log('err in loading zip file :>> ', err)
      toast.error(err.message || 'An error occurred in loading zip file.')
      return null
    })

    if (!zip) return

    setZip(zip)

    setLoadingSpinnerDesc('Parsing meta.json')

    const metaFileContent = await readContentOfZipEntry(
      zip,
      'meta.json',
      'string'
    )

    if (!metaFileContent) {
      setIsLoading(false)
      return
    }

    const parsedMetaJson = await parseJson<Meta>(metaFileContent).catch(
      (err) => {
        console.log('err in parsing the content of meta.json :>> ', err)
        toast.error(
          err.message || 'error occurred in parsing the content of meta.json'
        )
        setIsLoading(false)
        return null
      }
    )

    if (!parsedMetaJson) return

    const createSignatureEvent = await parseJson<Event>(
      parsedMetaJson.createSignature
    ).catch((err) => {
      console.log('err in parsing the createSignature event:>> ', err)
      toast.error(
        err.message || 'error occurred in parsing the create signature event'
      )
      setIsLoading(false)
      return null
    })

    if (!createSignatureEvent) return

    const isValidCreateSignature = verifyEvent(createSignatureEvent)

    if (!isValidCreateSignature) {
      toast.error('Create signature is invalid')
      setIsLoading(false)
      return
    }

    const createSignatureContent = await parseJson<CreateSignatureEventContent>(
      createSignatureEvent.content
    ).catch((err) => {
      console.log(
        `err in parsing the createSignature event's content :>> `,
        err
      )
      toast.error(
        err.message ||
          `error occurred in parsing the create signature event's content`
      )
      setIsLoading(false)
      return null
    })

    if (!createSignatureContent) return

    setSigners(createSignatureContent.signers)
    setViewers(createSignatureContent.viewers)
    setCreatorFileHashes(createSignatureContent.fileHashes)
    setSubmittedBy(createSignatureEvent.pubkey)

    setSignedBy(Object.keys(parsedMetaJson.docSignatures) as `npub1${string}`[])

    setMeta(parsedMetaJson)
  }

  const handleDecrypt = async () => {
    if (!selectedFile || !encryptionKey) return

    setIsLoading(true)
    const arrayBuffer = await decrypt(
      selectedFile,
      decodeURIComponent(encryptionKey)
    )

    if (!arrayBuffer) return

    handleDecryptedArrayBuffer(arrayBuffer)
  }

  const handleSign = async () => {
    if (!zip || !meta) return

    setIsLoading(true)
    setLoadingSpinnerDesc('parsing hashes.json file')

    const hashesFileContent = await readContentOfZipEntry(
      zip,
      'hashes.json',
      'string'
    )

    if (!hashesFileContent) {
      setIsLoading(false)
      return
    }

    let hashes = await parseJson(hashesFileContent).catch((err) => {
      console.log('err in parsing the content of hashes.json :>> ', err)
      toast.error(
        err.message || 'error occurred in parsing the content of hashes.json'
      )
      setIsLoading(false)
      return null
    })

    if (!hashes) return

    setLoadingSpinnerDesc('Generating hashes for files')

    setLoadingSpinnerDesc('Signing nostr event')
    const signedEvent = await signEventForMetaFile(
      JSON.stringify({
        fileHashes: currentFileHashes
      }),
      nostrController,
      setIsLoading
    )

    if (!signedEvent) return

    const metaCopy = _.cloneDeep(meta)

    metaCopy.docSignatures = {
      ...metaCopy.docSignatures,
      [hexToNpub(signedEvent.pubkey)]: JSON.stringify(signedEvent, null, 2)
    }

    const stringifiedMeta = JSON.stringify(metaCopy, null, 2)
    zip.file('meta.json', stringifiedMeta)

    const metaHash = await getHash(stringifiedMeta)
    if (!metaHash) return

    hashes = {
      ...hashes,
      [usersPubkey!]: metaHash
    }

    zip.file('hashes.json', JSON.stringify(hashes, null, 2))

    const arrayBuffer = await zip
      .generateAsync({
        type: 'arraybuffer',
        compression: 'DEFLATE',
        compressionOptions: {
          level: 6
        }
      })
      .catch((err) => {
        console.log('err in zip:>> ', err)
        setIsLoading(false)
        toast.error(err.message || 'Error occurred in generating zip file')
        return null
      })

    if (!arrayBuffer) return

    const key = await generateEncryptionKey()

    setLoadingSpinnerDesc('Encrypting zip file')
    const encryptedArrayBuffer = await encryptArrayBuffer(arrayBuffer, key)

    const blob = new Blob([encryptedArrayBuffer])

    setLoadingSpinnerDesc('Uploading zip file to file storage.')
    const fileUrl = await uploadToFileStorage(blob, nostrController)
      .then((url) => {
        toast.success('zip file uploaded to file storage')
        return url
      })
      .catch((err) => {
        console.log('err in upload:>> ', err)
        setIsLoading(false)
        toast.error(err.message || 'Error occurred in uploading zip file')
        return null
      })

    if (!fileUrl) return

    // check if the current user is the last signer
    const usersNpub = hexToNpub(usersPubkey!)
    const lastSignerIndex = signers.length - 1
    const signerIndex = signers.indexOf(usersNpub)
    const isLastSigner = signerIndex === lastSignerIndex

    // if current user is the last signer, then send DMs to all signers and viewers
    if (isLastSigner) {
      const userSet = new Set<`npub1${string}`>()

      if (submittedBy) {
        userSet.add(hexToNpub(submittedBy))
      }

      signers.forEach((signer) => {
        userSet.add(signer)
      })

      viewers.forEach((viewer) => {
        userSet.add(viewer)
      })

      const users = Array.from(userSet)

      for (const user of users) {
        // todo: execute in parallel
        await sendDM(
          fileUrl,
          key,
          npubToHex(user)!,
          nostrController,
          false,
          setAuthUrl
        )
      }
    } else {
      const nextSigner = signers[signerIndex + 1]
      await sendDM(
        fileUrl,
        key,
        npubToHex(nextSigner)!,
        nostrController,
        false,
        setAuthUrl
      )
    }

    setIsLoading(false)

    // update search params with updated file url and encryption key
    setSearchParams({
      file: fileUrl,
      key: key
    })
  }

  const handleExport = async () => {
    if (!meta || !zip || !usersPubkey) return

    const usersNpub = hexToNpub(usersPubkey)
    if (
      !signers.includes(usersNpub) &&
      !viewers.includes(usersNpub) &&
      submittedBy !== usersNpub
    )
      return

    setIsLoading(true)
    setLoadingSpinnerDesc('Signing nostr event')
    const signedEvent = await signEventForMetaFile(
      JSON.stringify({
        fileHashes: currentFileHashes
      }),
      nostrController,
      setIsLoading
    )

    if (!signedEvent) return

    const exportSignature = JSON.stringify(signedEvent, null, 2)

    const stringifiedMeta = JSON.stringify(
      {
        ...meta,
        exportSignature
      },
      null,
      2
    )
    zip.file('meta.json', stringifiedMeta)

    const arrayBuffer = await zip
      .generateAsync({
        type: 'arraybuffer',
        compression: 'DEFLATE',
        compressionOptions: {
          level: 6
        }
      })
      .catch((err) => {
        console.log('err in zip:>> ', err)
        setIsLoading(false)
        toast.error(err.message || 'Error occurred in generating zip file')
        return null
      })

    if (!arrayBuffer) return

    const blob = new Blob([arrayBuffer])
    saveAs(blob, 'exported.zip')

    setIsLoading(false)

    navigate(appPrivateRoutes.verify)
  }

  if (authUrl) {
    return (
      <iframe
        title="Nsecbunker auth"
        src={authUrl}
        width="100%"
        height="500px"
      />
    )
  }

  return (
    <>
      {isLoading && <LoadingSpinner desc={loadingSpinnerDesc} />}
      <Box className={styles.container}>
        {displayInput && (
          <>
            <Typography component="label" variant="h6">
              Select sigit file
            </Typography>

            <Box className={styles.inputBlock}>
              <MuiFileInput
                placeholder="Select file"
                value={selectedFile}
                onChange={(value) => setSelectedFile(value)}
              />

              {selectedFile && (
                <TextField
                  label="Encryption Key"
                  variant="outlined"
                  value={encryptionKey}
                  onChange={(e) => setEncryptionKey(e.target.value)}
                />
              )}
            </Box>

            {selectedFile && encryptionKey && (
              <Box sx={{ mt: 2, display: 'flex', justifyContent: 'center' }}>
                <Button onClick={handleDecrypt} variant="contained">
                  Decrypt
                </Button>
              </Box>
            )}
          </>
        )}

        {submittedBy && zip && (
          <>
            <DisplayMeta
              zip={zip}
              submittedBy={submittedBy}
              signers={signers}
              viewers={viewers}
              creatorFileHashes={creatorFileHashes}
              currentFileHashes={currentFileHashes}
              signedBy={signedBy}
              nextSigner={nextSinger}
            />
            {signedStatus === SignedStatus.Fully_Signed && (
              <Box sx={{ mt: 1, display: 'flex', justifyContent: 'center' }}>
                <Button onClick={handleExport} variant="contained">
                  Export
                </Button>
              </Box>
            )}

            {signedStatus === SignedStatus.User_Is_Next_Signer && (
              <Box sx={{ mt: 1, display: 'flex', justifyContent: 'center' }}>
                <Button onClick={handleSign} variant="contained">
                  Sign
                </Button>
              </Box>
            )}
          </>
        )}
      </Box>
    </>
  )
}

type DisplayMetaProps = {
  zip: JSZip
  submittedBy: string
  signers: `npub1${string}`[]
  viewers: `npub1${string}`[]
  creatorFileHashes: { [key: string]: string }
  currentFileHashes: { [key: string]: string | null }
  signedBy: `npub1${string}`[]
  nextSigner?: string
}

const DisplayMeta = ({
  zip,
  submittedBy,
  signers,
  viewers,
  creatorFileHashes,
  currentFileHashes,
  signedBy,
  nextSigner
}: DisplayMetaProps) => {
  const theme = useTheme()

  const textColor = theme.palette.getContrastText(
    theme.palette.background.paper
  )

  const [metadata, setMetadata] = useState<{ [key: string]: ProfileMetadata }>(
    {}
  )
  const [users, setUsers] = useState<User[]>([])

  useEffect(() => {
    signers.forEach((signer) => {
      const hexKey = npubToHex(signer)
      setUsers((prev) => {
        if (prev.findIndex((user) => user.pubkey === hexKey) !== -1) return prev

        return [
          ...prev,
          {
            pubkey: hexKey!,
            role: UserRole.signer
          }
        ]
      })
    })

    viewers.forEach((viewer) => {
      const hexKey = npubToHex(viewer)
      setUsers((prev) => {
        if (prev.findIndex((user) => user.pubkey === hexKey) !== -1) return prev

        return [
          ...prev,
          {
            pubkey: hexKey!,
            role: UserRole.viewer
          }
        ]
      })
    })
  }, [signers, viewers])

  useEffect(() => {
    const metadataController = new MetadataController()

    const hexKeys: string[] = [
      npubToHex(submittedBy)!,
      ...users.map((user) => user.pubkey)
    ]

    hexKeys.forEach((key) => {
      if (!(key in metadata)) {
        metadataController
          .findMetadata(key)
          .then((metadataEvent) => {
            const metadataContent =
              metadataController.extractProfileMetadataContent(metadataEvent)

            if (metadataContent)
              setMetadata((prev) => ({
                ...prev,
                [key]: metadataContent
              }))
          })
          .catch((err) => {
            console.error(`error occurred in finding metadata for: ${key}`, err)
          })
      }
    })
  }, [users, submittedBy])

  const downloadFile = async (filename: string) => {
    const arrayBuffer = await readContentOfZipEntry(
      zip,
      `files/${filename}`,
      'arraybuffer'
    )
    if (!arrayBuffer) return

    const blob = new Blob([arrayBuffer])
    saveAs(blob, filename)
  }

  return (
    <List
      sx={{
        bgcolor: 'background.paper',
        marginTop: 2
      }}
      subheader={
        <ListSubheader className={styles.subHeader}>Meta Info</ListSubheader>
      }
    >
      <ListItem
        sx={{
          marginTop: 1,
          gap: '15px'
        }}
      >
        <Typography variant="h6" sx={{ color: textColor }}>
          Submitted By
        </Typography>
        {(function () {
          const profile = metadata[submittedBy]
          return (
            <UserComponent
              pubkey={submittedBy}
              name={
                profile?.display_name || profile?.name || shorten(submittedBy)
              }
              image={profile?.picture}
            />
          )
        })()}
      </ListItem>
      <ListItem
        sx={{
          marginTop: 1,
          flexDirection: 'column',
          alignItems: 'flex-start'
        }}
      >
        <Typography variant="h6" sx={{ color: textColor }}>
          Files
        </Typography>
        <Box className={styles.filesWrapper}>
          {Object.entries(currentFileHashes).map(([filename, hash], index) => {
            const isValidHash = creatorFileHashes[filename] === hash

            return (
              <Box key={`file-${index}`} className={styles.file}>
                <Tooltip title="Download File" arrow>
                  <IconButton onClick={() => downloadFile(filename)}>
                    <Download />
                  </IconButton>
                </Tooltip>
                <Typography
                  component="label"
                  sx={{
                    color: textColor,
                    flexGrow: 1
                  }}
                >
                  {filename}
                </Typography>
                <Typography
                  component="label"
                  sx={{
                    color: isValidHash
                      ? theme.palette.success.light
                      : theme.palette.error.main
                  }}
                >
                  {isValidHash ? 'Valid' : 'Invalid'} hash
                </Typography>
              </Box>
            )
          })}
        </Box>
      </ListItem>
      <ListItem sx={{ marginTop: 1 }}>
        <Table>
          <TableHead>
            <TableRow>
              <TableCell className={styles.tableCell}>User</TableCell>
              <TableCell className={styles.tableCell}>Role</TableCell>
              <TableCell>Signed Status</TableCell>
            </TableRow>
          </TableHead>
          <TableBody>
            {users.map((user, index) => {
              const userMeta = metadata[user.pubkey]

              let signedStatus = '-'

              if (user.role === UserRole.signer) {
                // check if user has signed the document
                const usersNpub = hexToNpub(user.pubkey)
                if (signedBy.includes(usersNpub)) {
                  signedStatus = 'Signed'
                }
                // check if user is the next signer
                else if (user.pubkey === nextSigner) {
                  signedStatus = 'Awaiting Signature'
                }
              }

              return (
                <TableRow key={index}>
                  <TableCell className={styles.tableCell}>
                    <UserComponent
                      pubkey={user.pubkey}
                      name={
                        userMeta?.display_name ||
                        userMeta?.name ||
                        shorten(hexToNpub(user.pubkey))
                      }
                      image={userMeta?.picture}
                    />
                  </TableCell>
                  <TableCell className={styles.tableCell}>
                    {user.role}
                  </TableCell>
                  <TableCell>{signedStatus}</TableCell>
                </TableRow>
              )
            })}
          </TableBody>
        </Table>
      </ListItem>
    </List>
  )
}