feat: 支持微信 4.0 数据库解密与富媒体消息查看

- 接入微信 4.0 WCDB 数据库解密，兼容微信 3.0 解密方式
- 支持图片解密及图片预览、缩放、旋转和拖动
- 支持语音解密与播放
- 支持表情包、引用、分享、名片、位置及通话消息解析
- 支持联系人和群聊真实头像
- 优化群聊、联系人分类及排序
- 修复复合消息类型和压缩消息内容解析
- 完善原生解密库打包及数据库错误提示

src/main/sticker-service.ts

@@ -0,0 +1,210 @@
+import crypto from 'crypto'
+import fs from 'fs-extra'
+import http from 'http'
+import https from 'https'
+import os from 'os'
+import path from 'path'
+import { Wcdb4Client } from './wcdb4-client'
+
+type StickerResult = { success: boolean; data?: string; error?: string }
+
+const downloadCache = new Map<string, Promise<StickerResult>>()
+
+export class StickerService {
+  private readonly cacheDir: string
+
+  constructor(private readonly wcdb4Client?: Wcdb4Client | null) {
+    this.cacheDir = path.join(os.homedir(), 'Documents', 'WechatExplorer', 'Emojis')
+  }
+
+  async resolveSticker(cdnUrl?: string, md5?: string): Promise<StickerResult> {
+    const normalizedMd5 = this.normalizeMd5(md5)
+    let url = String(cdnUrl || '').trim()
+
+    if (!url && normalizedMd5 && this.wcdb4Client) {
+      url = this.wcdb4Client.resolveEmoticonCdnUrl(normalizedMd5) || ''
+      if (!url) {
+        console.warn(`[StickerService] emoticon CDN URL not found for md5=${normalizedMd5}`)
+      }
+    }
+
+    if (!url) {
+      return { success: false, error: '未找到表情包 CDN URL' }
+    }
+
+    const cacheKey = normalizedMd5 || crypto.createHash('md5').update(url).digest('hex')
+    const cached = await this.readCached(cacheKey)
+    if (cached) return { success: true, data: cached }
+
+    if (normalizedMd5 && this.wcdb4Client) {
+      const wechatCached = await this.readWechatEmoticonCache(normalizedMd5)
+      if (wechatCached) return { success: true, data: wechatCached }
+    }
+
+    const pending = downloadCache.get(cacheKey)
+    if (pending) return pending
+
+    const task = this.downloadToDataUrl(url, cacheKey)
+    downloadCache.set(cacheKey, task)
+    try {
+      return await task
+    } finally {
+      downloadCache.delete(cacheKey)
+    }
+  }
+
+  private async readCached(cacheKey: string): Promise<string | null> {
+    const extensions = ['.gif', '.png', '.webp', '.jpg', '.jpeg']
+    const cacheDirs = [this.cacheDir, path.join(os.homedir(), 'Documents', 'WechatExplorer', 'Emojis')]
+    for (const cacheDir of cacheDirs) {
+      for (const ext of extensions) {
+        const filePath = path.join(cacheDir, `${cacheKey}${ext}`)
+        if (!fs.existsSync(filePath)) continue
+        const buffer = await fs.readFile(filePath)
+        return this.toDataUrl(buffer, ext)
+      }
+    }
+    return null
+  }
+
+  private async readWechatEmoticonCache(md5: string): Promise<string | null> {
+    const accountRoot = this.wcdb4Client?.getAccountRoot()
+    if (!accountRoot) return null
+
+    const cacheRoot = path.join(accountRoot, 'cache')
+    if (!fs.existsSync(cacheRoot)) return null
+
+    const prefix = md5.slice(0, 2)
+    let months: string[] = []
+    try {
+      months = fs
+        .readdirSync(cacheRoot)
+        .filter((name) => /^\d{4}-\d{2}$/.test(name))
+        .sort()
+        .reverse()
+    } catch {
+      return null
+    }
+
+    for (const month of months) {
+      const filePath = path.join(cacheRoot, month, 'Emoticon', prefix, md5)
+      if (!fs.existsSync(filePath)) continue
+      const buffer = await fs.readFile(filePath)
+      const ext = this.detectExtension(buffer) || '.gif'
+      return this.toDataUrl(buffer, ext)
+    }
+
+    return null
+  }
+
+  private downloadToDataUrl(
+    url: string,
+    cacheKey: string,
+    redirectCount = 0
+  ): Promise<StickerResult> {
+    return new Promise((resolve) => {
+      if (redirectCount > 5) {
+        resolve({ success: false, error: '表情包下载重定向过多' })
+        return
+      }
+
+      const client = url.startsWith('https:') ? https : http
+      const request = client.get(
+        url,
+        {
+          headers: {
+            'User-Agent': 'Mozilla/5.0 MicroMessenger WechatExplorer',
+            Referer: 'https://weixin.qq.com/'
+          }
+        },
+        (response) => {
+          const redirectUrl = response.headers.location
+          if (redirectUrl && [301, 302, 303, 307, 308].includes(Number(response.statusCode || 0))) {
+            const nextUrl = new URL(redirectUrl, url).toString()
+            this.downloadToDataUrl(nextUrl, cacheKey, redirectCount + 1).then(resolve)
+            return
+          }
+
+          if (response.statusCode !== 200) {
+            console.warn(
+              `[StickerService] download failed: HTTP ${response.statusCode}; md5=${cacheKey}; url=${url}`
+            )
+            resolve({ success: false, error: `表情包下载失败: HTTP ${response.statusCode}` })
+            return
+          }
+
+          const chunks: Buffer[] = []
+          response.on('data', (chunk: Buffer) => chunks.push(chunk))
+          response.on('end', async () => {
+            const buffer = Buffer.concat(chunks)
+            if (buffer.length === 0) {
+              resolve({ success: false, error: '表情包内容为空' })
+              return
+            }
+
+            const ext = this.detectExtension(buffer) || this.getExtFromUrl(url) || '.gif'
+            try {
+              await fs.ensureDir(this.cacheDir)
+              await fs.writeFile(path.join(this.cacheDir, `${cacheKey}${ext}`), buffer)
+            } catch {
+              // Cache is best effort; the data URL can still be displayed.
+            }
+            resolve({ success: true, data: this.toDataUrl(buffer, ext) })
+          })
+        }
+      )
+
+      request.on('error', (error) => resolve({ success: false, error: error.message }))
+      request.setTimeout(15000, () => {
+        request.destroy()
+        resolve({ success: false, error: '表情包下载超时' })
+      })
+    })
+  }
+
+  private detectExtension(buffer: Buffer): string | null {
+    if (buffer.length >= 6 && buffer.subarray(0, 3).toString('ascii') === 'GIF') return '.gif'
+    if (
+      buffer.length >= 8 &&
+      buffer.subarray(0, 8).equals(Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]))
+    )
+      return '.png'
+    if (buffer.length >= 3 && buffer[0] === 0xff && buffer[1] === 0xd8 && buffer[2] === 0xff)
+      return '.jpg'
+    if (
+      buffer.length >= 12 &&
+      buffer.subarray(0, 4).toString('ascii') === 'RIFF' &&
+      buffer.subarray(8, 12).toString('ascii') === 'WEBP'
+    ) {
+      return '.webp'
+    }
+    return null
+  }
+
+  private getExtFromUrl(url: string): string | null {
+    try {
+      const ext = path.extname(new URL(url).pathname).toLowerCase()
+      return ['.gif', '.png', '.webp', '.jpg', '.jpeg'].includes(ext) ? ext : null
+    } catch {
+      return null
+    }
+  }
+
+  private toDataUrl(buffer: Buffer, ext: string): string {
+    const mimeTypes: Record<string, string> = {
+      '.gif': 'image/gif',
+      '.png': 'image/png',
+      '.webp': 'image/webp',
+      '.jpg': 'image/jpeg',
+      '.jpeg': 'image/jpeg'
+    }
+    return `data:${mimeTypes[ext] || 'image/gif'};base64,${buffer.toString('base64')}`
+  }
+
+  private normalizeMd5(value?: string): string | undefined {
+    const md5 = String(value || '')
+      .trim()
+      .toLowerCase()
+    return /^[a-f0-9]{32}$/.test(md5) ? md5 : undefined
+  }
+}