feat: add filepicker package

packages/filepicker/src/utils.ts

@@ -0,0 +1,56 @@
+export async function readFile(file: File): Promise<Uint8Array> {
+  const reader = new FileReader()
+  reader.readAsArrayBuffer(file)
+  return new Promise((resolve) => {
+    reader.onload = (readerEvent) => {
+      const target = readerEvent.target as FileReader
+      const content = target.result as ArrayBuffer
+      resolve(new Uint8Array(content))
+    }
+  })
+}
+
+export function parseFileName(fileName: string): {
+  name: string
+  ext: string
+} {
+  const pattern = /(?:\.([^.]+))?$/
+  const extMatches = pattern.exec(fileName)
+  const ext = extMatches?.[1] || ''
+  const name = fileName.includes('.') ? fileName.substring(0, fileName.lastIndexOf('.')) : fileName
+
+  return { name, ext }
+}
+
+export function saveFile(name: string, bytes: Uint8Array): void {
+  const link = document.createElement('a')
+  const blob = new Blob([bytes], {
+    type: 'text/plain;charset=utf-8',
+  })
+  link.href = window.URL.createObjectURL(blob)
+  link.setAttribute('download', name)
+  document.body.appendChild(link)
+  link.click()
+  link.remove()
+  window.URL.revokeObjectURL(link.href)
+}
+
+const BYTES_IN_ONE_KILOBYTE = 1_024
+const BYTES_IN_ONE_MEGABYTE = 1_048_576
+const BYTES_IN_ONE_GIGABYTE = 1_073_741_824
+
+export function formatSizeToReadableString(bytes: number): string {
+  let size = bytes
+  let unit = 'B'
+  if (bytes >= BYTES_IN_ONE_GIGABYTE) {
+    size = bytes / BYTES_IN_ONE_GIGABYTE
+    unit = 'GB'
+  } else if (bytes >= BYTES_IN_ONE_MEGABYTE) {
+    size = bytes / BYTES_IN_ONE_MEGABYTE
+    unit = 'MB'
+  } else if (bytes >= BYTES_IN_ONE_KILOBYTE) {
+    size = bytes / BYTES_IN_ONE_KILOBYTE
+    unit = 'KB'
+  }
+  return `${Number.isInteger(size) ? size : size.toFixed(2)} ${unit}`
+}