feat: add filepicker package

packages/filepicker/src/Streaming/StreamingApi.ts

@@ -0,0 +1,112 @@
+import {
+  FileSystemApi,
+  DirectoryHandle,
+  FileHandleReadWrite,
+  FileHandleRead,
+  FileSystemNoSelection,
+  FileSystemResult,
+} from '@standardnotes/services'
+
+interface WebDirectoryHandle extends DirectoryHandle {
+  nativeHandle: FileSystemDirectoryHandle
+}
+interface WebFileHandleReadWrite extends FileHandleReadWrite {
+  nativeHandle: FileSystemFileHandle
+  writableStream: FileSystemWritableFileStream
+}
+
+interface WebFileHandleRead extends FileHandleRead {
+  nativeHandle: FileSystemFileHandle
+}
+
+export class StreamingFileApi implements FileSystemApi {
+  async selectDirectory(): Promise<DirectoryHandle | FileSystemNoSelection> {
+    try {
+      const nativeHandle = await window.showDirectoryPicker()
+
+      return { nativeHandle }
+    } catch (error) {
+      return 'aborted'
+    }
+  }
+
+  async createFile(directory: WebDirectoryHandle, name: string): Promise<WebFileHandleReadWrite> {
+    const nativeHandle = await directory.nativeHandle.getFileHandle(name, { create: true })
+    const writableStream = await nativeHandle.createWritable()
+
+    return {
+      nativeHandle,
+      writableStream,
+    }
+  }
+
+  async createDirectory(
+    parentDirectory: WebDirectoryHandle,
+    name: string,
+  ): Promise<WebDirectoryHandle | FileSystemNoSelection> {
+    const nativeHandle = await parentDirectory.nativeHandle.getDirectoryHandle(name, { create: true })
+    return { nativeHandle }
+  }
+
+  async saveBytes(file: WebFileHandleReadWrite, bytes: Uint8Array): Promise<'success' | 'failed'> {
+    await file.writableStream.write(bytes)
+
+    return 'success'
+  }
+
+  async saveString(file: WebFileHandleReadWrite, contents: string): Promise<'success' | 'failed'> {
+    await file.writableStream.write(contents)
+
+    return 'success'
+  }
+
+  async closeFileWriteStream(file: WebFileHandleReadWrite): Promise<'success' | 'failed'> {
+    await file.writableStream.close()
+
+    return 'success'
+  }
+
+  async selectFile(): Promise<WebFileHandleRead | FileSystemNoSelection> {
+    try {
+      const selection = await window.showOpenFilePicker()
+
+      const file = selection[0]
+
+      return {
+        nativeHandle: file,
+      }
+    } catch (_) {
+      return 'aborted'
+    }
+  }
+
+  async readFile(
+    fileHandle: WebFileHandleRead,
+    onBytes: (bytes: Uint8Array, isLast: boolean) => Promise<void>,
+  ): Promise<FileSystemResult> {
+    const file = await fileHandle.nativeHandle.getFile()
+    const stream = file.stream() as unknown as ReadableStream
+    const reader = stream.getReader()
+
+    let previousChunk: Uint8Array
+
+    const processChunk = async (result: ReadableStreamDefaultReadResult<Uint8Array>): Promise<void> => {
+      if (result.done) {
+        await onBytes(previousChunk, true)
+        return
+      }
+
+      if (previousChunk) {
+        await onBytes(previousChunk, false)
+      }
+
+      previousChunk = result.value
+
+      return reader.read().then(processChunk)
+    }
+
+    await reader.read().then(processChunk)
+
+    return 'success'
+  }
+}