feat: add metadata and preview (#292)

* chore: upload flow uses metadata object and has preview

* chore: remove SwarmFile

* feat: upload metadata and file preview

* feat: add metadata and preview on download

* fix: package the meta and preview files

* fix: upload websites that are inside a folder (#296)

* fix: upload websites that are inside a folder

* docs: few comments to clarify what is going on

* refactor: decrease local variables and fix state order to detect websites properly

Co-authored-by: Cafe137 <aron@aronsoos.com>

src/providers/File.tsx

@@ -1,17 +1,22 @@
 /* eslint-disable @typescript-eslint/no-empty-function */
 
-import { createContext, ReactChild, ReactElement, useState } from 'react'
-import { SwarmFile } from '../utils/SwarmFile'
+import { createContext, ReactChild, ReactElement, useState, useEffect } from 'react'
+import { getMetadata } from '../utils/file'
+import { resize } from '../utils/image'
+import { PREVIEW_DIMENSIONS } from '../constants'
 
 export type UploadOrigin = { origin: 'UPLOAD' | 'FEED'; uuid?: string }
 
 export const defaultUploadOrigin: UploadOrigin = { origin: 'UPLOAD' }
 
 interface ContextInterface {
-  files: SwarmFile[]
-  setFiles: (files: SwarmFile[]) => void
+  files: FilePath[]
+  setFiles: (files: FilePath[]) => void
   uploadOrigin: UploadOrigin
   setUploadOrigin: (uploadOrigin: UploadOrigin) => void
+  metadata?: Metadata
+  previewUri?: string
+  previewBlob?: Blob
 }
 
 const initialValues: ContextInterface = {
@@ -29,8 +34,38 @@ interface Props {
 }
 
 export function Provider({ children }: Props): ReactElement {
-  const [files, setFiles] = useState<SwarmFile[]>(initialValues.files)
+  const [files, setFiles] = useState<FilePath[]>(initialValues.files)
   const [uploadOrigin, setUploadOrigin] = useState<UploadOrigin>(initialValues.uploadOrigin)
+  const [metadata, setMetadata] = useState<Metadata | undefined>(undefined)
+  const [previewUri, setPreviewUri] = useState<string | undefined>(undefined)
+  const [previewBlob, setPreviewBlob] = useState<Blob | undefined>(undefined)
 
-  return <Context.Provider value={{ files, setFiles, uploadOrigin, setUploadOrigin }}>{children}</Context.Provider>
+  useEffect(() => {
+    setMetadata(getMetadata(files))
+
+    if (previewUri) {
+      URL.revokeObjectURL(previewUri) // Clear the preview from memory
+      setPreviewUri(undefined)
+      setPreviewBlob(undefined)
+    }
+
+    if (files.length !== 1 || !files[0].type.startsWith('image')) return
+
+    resize(files[0], PREVIEW_DIMENSIONS.maxWidth, PREVIEW_DIMENSIONS.maxHeight).then(blob => {
+      setPreviewUri(URL.createObjectURL(blob)) // NOTE: Until it is cleared with URL.revokeObjectURL, the file stays allocated in memory
+      setPreviewBlob(blob)
+    })
+
+    return () => {
+      if (previewUri) {
+        URL.revokeObjectURL(previewUri)
+      }
+    }
+  }, [files]) // eslint-disable-line react-hooks/exhaustive-deps
+
+  return (
+    <Context.Provider value={{ files, setFiles, uploadOrigin, setUploadOrigin, metadata, previewUri, previewBlob }}>
+      {children}
+    </Context.Provider>
+  )
 }