1import fs from "node:fs";
2import path from "node:path";
3import {
4  type WechatUploadAsset,
5  detectImageFormatFromBuffer,
6} from "./wechat-image-processor.ts";
7 
8export type { WechatUploadAsset };
9 
10const MIME_TYPES_BY_EXT: Record<string, string> = {
11  ".jpg": "image/jpeg",
12  ".jpeg": "image/jpeg",
13  ".png": "image/png",
14  ".gif": "image/gif",
15  ".webp": "image/webp",
16  ".bmp": "image/bmp",
17  ".tiff": "image/tiff",
18  ".tif": "image/tiff",
19  ".svg": "image/svg+xml",
20  ".ico": "image/x-icon",
21};
22 
23export async function loadUploadAsset(
24  imagePath: string,
25  baseDir?: string,
26): Promise<WechatUploadAsset> {
27  let fileBuffer: Buffer;
28  let filename: string;
29  let contentType: string;
30  let fileSize = 0;
31  let fileExt = "";
32 
33  if (imagePath.startsWith("http://") || imagePath.startsWith("https://")) {
34    const response = await fetch(imagePath);
35    if (!response.ok) {
36      throw new Error(`Failed to download image: ${imagePath}`);
37    }
38    const buffer = await response.arrayBuffer();
39    if (buffer.byteLength === 0) {
40      throw new Error(`Remote image is empty: ${imagePath}`);
41    }
42    fileBuffer = Buffer.from(buffer);
43    fileSize = buffer.byteLength;
44    const urlPath = imagePath.split("?")[0]!;
45    filename = path.basename(urlPath) || "image.jpg";
46    fileExt = path.extname(filename).toLowerCase();
47    contentType = response.headers.get("content-type") || "image/jpeg";
48  } else {
49    const resolvedPath = path.isAbsolute(imagePath)
50      ? imagePath
51      : path.resolve(baseDir || process.cwd(), imagePath);
52 
53    if (!fs.existsSync(resolvedPath)) {
54      throw new Error(`Image not found: ${resolvedPath}`);
55    }
56    const stats = fs.statSync(resolvedPath);
57    if (stats.size === 0) {
58      throw new Error(`Local image is empty: ${resolvedPath}`);
59    }
60    fileSize = stats.size;
61    fileBuffer = fs.readFileSync(resolvedPath);
62    filename = path.basename(resolvedPath);
63    fileExt = path.extname(filename).toLowerCase();
64    contentType = MIME_TYPES_BY_EXT[fileExt] || "image/jpeg";
65  }
66 
67  const detected = detectImageFormatFromBuffer(fileBuffer);
68  if (detected && detected.contentType !== contentType) {
69    console.error(`[wechat-api] Format mismatch: ${filename} declared as ${contentType}, actual ${detected.contentType}`);
70    contentType = detected.contentType;
71    fileExt = detected.fileExt;
72    filename = `${path.basename(filename, path.extname(filename))}${detected.fileExt}`;
73  }
74 
75  return {
76    buffer: fileBuffer,
77    filename,
78    contentType,
79    fileExt,
80    fileSize,
81  };
82}
83