From d3f5387df90a00ed5765a82820c00360d03be958 Mon Sep 17 00:00:00 2001
From: chndfang <chndfang@outlook.com>
Date: Tue, 6 May 2025 17:35:40 +0800
Subject: [PATCH] feat: utils

---
 src/services/utils.ts | 86 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)

diff --git a/src/services/utils.ts b/src/services/utils.ts
index e69de29..85a1c7d 100644
--- a/src/services/utils.ts
+++ b/src/services/utils.ts
@@ -0,0 +1,86 @@
+/**
+ * 文件下载
+ * *将实时创建<a>标签并在下载完成后自动移除
+ * @param url 文件地址
+ * @param name 文件名
+ */
+export function downloadFile(url: string, name?: string): void {
+  if (!url) return;
+  const element = document.createElement('a');
+  element.href = url;
+  if (name) {
+    element.download = name;
+  }
+  element.click();
+  element.remove();
+}
+
+/**
+ * 文件选择
+ * @param accept 支持的文件类型
+ * @param limit 文件大小限制（byte）
+ * @returns 选中的文件域
+ */
+export async function selectFile(accept?: string, limit?: number): Promise<File | void> {
+  const element = document.createElement('input');
+  element.type = 'file';
+  element.accept = accept ?? '';
+  try {
+    return await new Promise<File | void>((resolve, reject) => {
+      element.onchange = () => {
+        const file = element.files?.[0];
+        if (!file?.size) return resolve();
+        if (limit && limit < file.size) return reject(`文件大小不能超过${~~(limit / 1000)}KB`);
+        const extension = file.name.split('.').pop()!.toLowerCase();
+        if (accept && !accept.toLowerCase().includes(extension)) return reject(`仅支持${accept}文件`);
+        resolve(file);
+      };
+      element.oncancel = () => resolve();
+      element.click();
+    });
+  } finally {
+    element.onchange = null;
+    element.oncancel = null;
+    element.remove();
+  }
+}
+
+/**
+ * Base64图片转二进制
+ * @param base64:Base64 图片数据
+ * @returns 二进制数据
+ */
+export function base64ToBlob(base64: string): Blob | undefined {
+  const [prefix, data] = base64?.split('base64,', 2) ?? [];
+  const type = prefix?.match(/:(.*?);/)?.[1];
+  const str = atob(data ?? '');
+  if (!type || !str?.length) return;
+  let n = str.length;
+  const buffer = new Uint8Array(n);
+  while (n--) {
+    buffer[n] = str.charCodeAt(n);
+  }
+  return new Blob([buffer], { type });
+}
+
+/**
+ * 文本转二进制
+ * @param text 文本字符
+ * @returns 二进制数据
+ */
+export function textToBlob(text: string): Blob | undefined {
+  if (!text.length) return;
+  return new Blob([text], { type: 'text/plain' });
+}
+
+/**
+ * 文本文件解码
+ * @param file 文件域
+ * @returns 文本字符串
+ */
+export async function decodeTextFile(file: File): Promise<string | undefined> {
+  if (!file.size) return;
+  const decoder = new TextDecoder();
+  const buffer = await file.arrayBuffer();
+  return decoder.decode(buffer);
+}