src/pages/create/index.tsx

@@ -221,57 +221,67 @@ export const CreatePage = () => {
     )
   }
 
-  const handleCreate = async () => {
+  // Validate inputs before proceeding
+  const validateInputs = (): boolean => {
     if (!title.trim()) {
       toast.error('Title can not be empty')
-      return
+      return false
     }
 
     if (users.length === 0) {
       toast.error(
         'No signer/viewer is provided. At least add one signer or viewer.'
       )
-      return
+      return false
     }
 
     if (selectedFiles.length === 0) {
       toast.error('No file is selected. Select at least 1 file')
-      return
+      return false
     }
 
-    setIsLoading(true)
-    setLoadingSpinnerDesc('Generating hashes for files')
+    return true
+  }
 
-    const fileHashes: { [key: string]: string } = {}
-
-    // generating file hashes
-    for (const file of selectedFiles) {
-      const arraybuffer = await file.arrayBuffer().catch((err) => {
+  // Handle errors during file arrayBuffer conversion
+  const handleFileError = (file: File) => (err: any) => {
     console.log(
-          `err while getting arrayBuffer of file ${file.name} :>> `,
+      `Error while getting arrayBuffer of file ${file.name} :>> `,
       err
     )
     toast.error(
-          err.message || `err while getting arrayBuffer of file ${file.name}`
+      err.message || `Error while getting arrayBuffer of file ${file.name}`
     )
     return null
-      })
+  }
 
-      if (!arraybuffer) return
+  // Generate hash for each selected file
+  const generateFileHashes = async (): Promise<{
+    [key: string]: string
+  } | null> => {
+    const fileHashes: { [key: string]: string } = {}
+
+    for (const file of selectedFiles) {
+      const arraybuffer = await file.arrayBuffer().catch(handleFileError(file))
+      if (!arraybuffer) return null
 
       const hash = await getHash(arraybuffer)
-
       if (!hash) {
-        setIsLoading(false)
-        return
+        return null
       }
 
       fileHashes[file.name] = hash
     }
 
+    return fileHashes
+  }
+
+  // Create a zip file with the selected files and sign the event
+  const createZipFile = async (fileHashes: {
+    [key: string]: string
+  }): Promise<{ zip: JSZip; createSignature: string } | null> => {
     const zip = new JSZip()
 
-    // zipping files
     selectedFiles.forEach((file) => {
       zip.file(`files/${file.name}`, file)
     })
@@ -280,6 +290,7 @@ export const CreatePage = () => {
     const viewers = users.filter((user) => user.role === UserRole.viewer)
 
     setLoadingSpinnerDesc('Signing nostr event')
+
     const createSignature = await signEventForMetaFile(
       JSON.stringify({
         signers: signers.map((signer) => hexToNpub(signer.pubkey)),
@@ -290,12 +301,27 @@ export const CreatePage = () => {
       setIsLoading
     )
 
-    if (!createSignature) return
+    if (!createSignature) return null
 
+    try {
+      return {
+        zip,
+        createSignature: JSON.stringify(createSignature, null, 2)
+      }
+    } catch (error) {
+      return null
+    }
+  }
+
+  // Add metadata and file hashes to the zip file
+  const addMetaToZip = async (
+    zip: JSZip,
+    createSignature: string
+  ): Promise<string | null> => {
     // create content for meta file
     const meta: Meta = {
       title,
-      createSignature: JSON.stringify(createSignature, null, 2),
+      createSignature,
       docSignatures: {}
     }
 
@@ -304,68 +330,103 @@ export const CreatePage = () => {
       zip.file('meta.json', stringifiedMeta)
 
       const metaHash = await getHash(stringifiedMeta)
-      if (!metaHash) return
+      if (!metaHash) return null
 
       const metaHashJson = {
         [usersPubkey!]: metaHash
       }
 
       zip.file('hashes.json', JSON.stringify(metaHashJson, null, 2))
+      return metaHash
     } catch (err) {
       console.error(err)
       toast.error('An error occurred in converting meta json to string')
-      return
+      return null
+    }
   }
 
+  // Handle errors during zip file generation
+  const handleZipError = (err: any) => {
+    console.log('Error in zip:>> ', err)
+    setIsLoading(false)
+    toast.error(err.message || 'Error occurred in generating zip file')
+    return null
+  }
+
+  // Generate the zip file
+  const generateZipFile = async (zip: JSZip): Promise<ArrayBuffer | null> => {
     setLoadingSpinnerDesc('Generating zip file')
 
     const arraybuffer = await zip
       .generateAsync({
         type: 'arraybuffer',
         compression: 'DEFLATE',
-        compressionOptions: {
-          level: 6
+        compressionOptions: { level: 6 }
+      })
+      .catch(handleZipError)
+
+    return arraybuffer
   }
-      })
-      .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 encryptionKey = await generateEncryptionKey()
 
+  // Encrypt the zip file with the generated encryption key
+  const encryptZipFile = async (
+    arraybuffer: ArrayBuffer,
+    encryptionKey: string
+  ): Promise<ArrayBuffer> => {
     setLoadingSpinnerDesc('Encrypting zip file')
-    const encryptedArrayBuffer = await encryptArrayBuffer(
-      arraybuffer,
-      encryptionKey
-    ).finally(() => setIsLoading(false))
-
-    const blob = new Blob([encryptedArrayBuffer])
+    return encryptArrayBuffer(arraybuffer, encryptionKey).finally(() =>
+      setIsLoading(false)
+    )
+  }
 
+  // Handle file upload and further actions based on online/offline status
+  const handleFileUpload = async (blob: Blob, encryptionKey: string) => {
     if (await isOnline()) {
+      const fileUrl = await uploadFile(blob)
+
+      if (!fileUrl) return
+
+      await sendDMs(fileUrl, encryptionKey)
+      setIsLoading(false)
+
+      navigate(
+        `${appPrivateRoutes.sign}?file=${encodeURIComponent(fileUrl)}&key=${encodeURIComponent(encryptionKey)}`
+      )
+    } else {
+      handleOffline(blob, encryptionKey)
+    }
+  }
+
+  // Handle errors during file upload
+  const handleUploadError = (err: any) => {
+    console.log('Error in upload:>> ', err)
+    setIsLoading(false)
+    toast.error(err.message || 'Error occurred in uploading zip file')
+    return null
+  }
+
+  // Upload the file to the storage and send DMs to signers/viewers
+  const uploadFile = async (blob: Blob): Promise<string | null> => {
     setIsLoading(true)
     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
-        })
+      .catch(handleUploadError)
 
-      if (!fileUrl) return
+    return fileUrl
+  }
 
+  // Send DMs to signers and viewers with the file URL and encryption key
+  const sendDMs = async (fileUrl: string, encryptionKey: string) => {
     setLoadingSpinnerDesc('Sending DM to signers/viewers')
 
-      // send DM to first signer if exists
+    const signers = users.filter((user) => user.role === UserRole.signer)
+    const viewers = users.filter((user) => user.role === UserRole.viewer)
+
     if (signers.length > 0) {
       await sendDM(
         fileUrl,
@@ -376,9 +437,7 @@ export const CreatePage = () => {
         setAuthUrl
       )
     } else {
-        // send DM to all viewers if no signer
       for (const viewer of viewers) {
-          // todo: execute in parallel
         await sendDM(
           fileUrl,
           encryptionKey,
@@ -389,27 +448,58 @@ export const CreatePage = () => {
         )
       }
     }
-      setIsLoading(false)
+  }
+
+  // Manage offline scenarios for signing or viewing the file
+  const handleOffline = (blob: Blob, encryptionKey: string) => {
+    const signers = users.filter((user) => user.role === UserRole.signer)
 
-      navigate(
-        `${appPrivateRoutes.sign}?file=${encodeURIComponent(
-          fileUrl
-        )}&key=${encodeURIComponent(encryptionKey)}`
-      )
-    } else {
     if (signers[0] && signers[0].pubkey === usersPubkey) {
-        // Create a File object with the Blob data
+      // Create a File object with the Blob data for offline signing
       const file = new File([blob], `compressed.sigit`, {
         type: 'application/sigit'
       })
-
       navigate(appPrivateRoutes.sign, { state: { file, encryptionKey } })
     } else {
+      // Save the file and show encryption key for offline viewing
       saveAs(blob, 'request.sigit')
       setTextToCopy(encryptionKey)
       setOpenCopyModel(true)
     }
   }
+
+  const handleCreate = async () => {
+    if (!validateInputs()) return
+
+    setIsLoading(true)
+    setLoadingSpinnerDesc('Generating hashes for files')
+
+    const fileHashes = await generateFileHashes()
+    if (!fileHashes) return
+
+    const createZipResponse = await createZipFile(fileHashes)
+    if (!createZipResponse) return
+
+    const { zip, createSignature } = createZipResponse
+
+    const metaHash = await addMetaToZip(zip, createSignature)
+    if (!metaHash) return
+
+    setLoadingSpinnerDesc('Generating zip file')
+
+    const arraybuffer = await generateZipFile(zip)
+    if (!arraybuffer) return
+
+    const encryptionKey = await generateEncryptionKey()
+
+    setLoadingSpinnerDesc('Encrypting zip file')
+    const encryptedArrayBuffer = await encryptZipFile(
+      arraybuffer,
+      encryptionKey
+    )
+    const blob = new Blob([encryptedArrayBuffer])
+
+    return await handleFileUpload(blob, encryptionKey)
   }
 
   if (authUrl) {