feat(grid): support binary cell downloads

apps/desktop/src/lib/binaryCellDownload.ts

@@ -0,0 +1,118 @@
+import type { CellValue } from "@/lib/cellValue";
+import { isTauriRuntime } from "@/lib/tauriRuntime";
+
+export type BinaryCellDownloadMode = "binary" | "utf8" | "gbk";
+
+export interface BinaryCellDownloadPayload {
+  data: Uint8Array | string;
+  mimeType: string;
+  extension: string;
+}
+
+export interface BinaryCellDownloadResult {
+  kind: "saved" | "browser-download" | "cancelled";
+  path?: string;
+  fileName?: string;
+}
+
+export const BINARY_CELL_DOWNLOAD_MODES: BinaryCellDownloadMode[] = ["binary", "utf8", "gbk"];
+
+const HEX_VALUE_RE = /^(?:0[xX]|\\x)([0-9a-fA-F\s]+)$/;
+const BINARY_TYPE_RE =
+  /^(?:blob|tinyblob|mediumblob|longblob|bytea|bytes|binary|varbinary|image|raw|long\s+raw)(?:\b|\()/i;
+
+export function parseBinaryCellHexValue(value: CellValue): Uint8Array | null {
+  if (typeof value !== "string") return null;
+  const match = value.trim().match(HEX_VALUE_RE);
+  if (!match) return null;
+
+  const hex = match[1].replace(/\s+/g, "");
+  if (!hex || hex.length % 2 !== 0) return null;
+
+  const bytes = new Uint8Array(hex.length / 2);
+  for (let i = 0; i < bytes.length; i++) {
+    const parsed = Number.parseInt(hex.slice(i * 2, i * 2 + 2), 16);
+    if (Number.isNaN(parsed)) return null;
+    bytes[i] = parsed;
+  }
+  return bytes;
+}
+
+export function isBinaryCellColumnType(columnType?: string): boolean {
+  const type = (columnType ?? "").trim();
+  return !!type && BINARY_TYPE_RE.test(type);
+}
+
+export function canDownloadBinaryCellValue(value: CellValue, columnType?: string): boolean {
+  if (!parseBinaryCellHexValue(value)) return false;
+  return isBinaryCellColumnType(columnType) || typeof value === "string";
+}
+
+export function binaryCellDownloadPayload(value: CellValue, mode: BinaryCellDownloadMode): BinaryCellDownloadPayload {
+  const bytes = parseBinaryCellHexValue(value);
+  if (!bytes) {
+    throw new Error("Cell value is not a hexadecimal binary value.");
+  }
+
+  if (mode === "binary") {
+    return {
+      data: bytes,
+      mimeType: "application/octet-stream",
+      extension: "bin",
+    };
+  }
+
+  const decoder = new TextDecoder(mode === "gbk" ? "gbk" : "utf-8", { fatal: false });
+  return {
+    data: decoder.decode(bytes),
+    mimeType: "text/plain;charset=utf-8",
+    extension: "txt",
+  };
+}
+
+export function binaryCellDownloadFileName(options: {
+  column: string;
+  rowNumber: number;
+  mode: BinaryCellDownloadMode;
+  extension: string;
+}): string {
+  const column = options.column
+    .trim()
+    .replace(/[\\/:*?"<>|]+/g, "-")
+    .replace(/\s+/g, "_")
+    .slice(0, 48);
+  const safeColumn = column || "cell";
+  const suffix = options.mode === "binary" ? "" : `-${options.mode}`;
+  return `${safeColumn}-row-${options.rowNumber}${suffix}.${options.extension}`;
+}
+
+export async function downloadBinaryCellPayload(
+  payload: BinaryCellDownloadPayload,
+  fileName: string,
+): Promise<BinaryCellDownloadResult> {
+  if (isTauriRuntime()) {
+    const [{ save }, fs] = await Promise.all([import("@tauri-apps/plugin-dialog"), import("@tauri-apps/plugin-fs")]);
+    const path = await save({
+      defaultPath: fileName,
+      filters: [{ name: payload.extension.toUpperCase(), extensions: [payload.extension] }],
+    });
+    if (!path) return { kind: "cancelled" };
+    if (typeof payload.data === "string") {
+      await fs.writeTextFile(path, payload.data);
+    } else {
+      await fs.writeFile(path, payload.data);
+    }
+    return { kind: "saved", path };
+  }
+
+  const blob = new Blob([payload.data], { type: payload.mimeType });
+  const url = URL.createObjectURL(blob);
+  const a = document.createElement("a");
+  a.href = url;
+  a.download = fileName;
+  document.body.appendChild(a);
+  a.click();
+  a.remove();
+  URL.revokeObjectURL(url);
+  return { kind: "browser-download", fileName };
+}