feat(assets): basic asset provider

packages/plugin-assets/package.json

@@ -0,0 +1,37 @@
+{
+  "name": "koishi-plugin-assets",
+  "description": "GitHub webhook plugin for Koishi",
+  "version": "3.0.0",
+  "main": "dist/index.js",
+  "typings": "dist/index.d.ts",
+  "files": [
+    "dist"
+  ],
+  "author": "Shigma <1700011071@pku.edu.cn>",
+  "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/koishijs/plugin-assets.git"
+  },
+  "bugs": {
+    "url": "https://github.com/koishijs/plugin-assets/issues"
+  },
+  "homepage": "https://koishi.js.org/plugins/other/assets",
+  "keywords": [
+    "bot",
+    "qqbot",
+    "cqhttp",
+    "coolq",
+    "chatbot",
+    "koishi",
+    "plugin",
+    "assets",
+    "server"
+  ],
+  "peerDependencies": {
+    "koishi-core": "^3.4.0"
+  },
+  "dependencies": {
+    "axios": "^0.21.1"
+  }
+}

packages/plugin-assets/src/index.ts

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+import { Assets, Context, Random, sanitize, trimSlash } from 'koishi-core'
+import axios, { AxiosRequestConfig } from 'axios'
+import { promises as fs, createReadStream, existsSync } from 'fs'
+import { extname, resolve } from 'path'
+import { createHmac } from 'crypto'
+
+interface ServerConfig {
+  path?: string
+  root?: string
+  selfUrl?: string
+  secret?: string
+  axiosConfig?: AxiosRequestConfig
+}
+
+class AssetServer implements Assets {
+  types: ['video', 'audio', 'image']
+
+  private _promise: Promise<void>
+  private _stats: Assets.Stats = {
+    assetCount: 0,
+    assetSize: 0,
+  }
+
+  constructor(public ctx: Context, public config: ServerConfig) {
+    const path = sanitize(config.path || '/assets')
+    config.root ||= resolve(__dirname, '../public')
+
+    if (config.selfUrl) {
+      config.selfUrl = trimSlash(config.selfUrl)
+    } else if (!(config.selfUrl = ctx.app.options.selfUrl)) {
+      throw new Error(`missing configuration "selfUrl" or "server"`)
+    }
+
+    ctx.router.get(path, async (ctx) => {
+      return ctx.body = await this.stats()
+    })
+
+    ctx.router.get(path + '/:name', (ctx) => {
+      const filename = resolve(config.root, ctx.params.name)
+      ctx.type = extname(filename)
+      return ctx.body = createReadStream(filename)
+    })
+
+    ctx.router.post(path, async (ctx) => {
+      const { salt, sign, url, file } = ctx.query
+      if (Array.isArray(file) || Array.isArray(url)) {
+        return ctx.status = 400
+      }
+
+      if (config.secret) {
+        if (!salt || !sign) return ctx.status = 400
+        const hash = createHmac('sha1', config.secret).update(file + salt).digest('hex')
+        if (hash !== sign) return ctx.status = 403
+      }
+
+      await this.upload(url, file)
+      return ctx.status = 200
+    })
+
+    this._promise = this.init()
+  }
+
+  async init() {
+    const root = this.config.root
+    await fs.mkdir(root, { recursive: true })
+    const filenames = await fs.readdir(root)
+    this._stats.assetCount = filenames.length
+    await Promise.all(filenames.map(async (file) => {
+      const { size } = await fs.stat(resolve(root, file))
+      this._stats.assetSize += size
+    }))
+  }
+
+  async upload(url: string, file: string) {
+    await this._promise
+    const { selfUrl, path, root, axiosConfig } = this.config
+    const filename = resolve(root, file)
+    if (!existsSync(filename)) {
+      const { data } = await axios.get<ArrayBuffer>(url, {
+        ...axiosConfig,
+        responseType: 'arraybuffer',
+      })
+      await fs.writeFile(filename, Buffer.from(data))
+      this._stats.assetCount += 1
+      this._stats.assetSize += data.byteLength
+    }
+    return `${selfUrl}${path}/${file}`
+  }
+
+  async stats() {
+    await this._promise
+    return this._stats
+  }
+}
+
+interface ClientConfig {
+  server: string
+  secret?: string
+  axiosConfig?: AxiosRequestConfig
+}
+
+class AssetClient implements Assets {
+  types: ['video', 'audio', 'image']
+
+  constructor(public ctx: Context, public config: ClientConfig) {}
+
+  async upload(url: string, file: string) {
+    const { server, secret, axiosConfig } = this.config
+    const params = { url, file } as any
+    if (secret) {
+      params.salt = Random.uuid()
+      params.sign = createHmac('sha1', secret).update(file + params.salt).digest('hex')
+    }
+    const { data } = await axios.post(server, { ...axiosConfig, params })
+    return data
+  }
+
+  async stats() {
+    const { data } = await axios.get(this.config.server, this.config.axiosConfig)
+    return data
+  }
+}
+
+export type Config = ServerConfig | ClientConfig
+
+export const name = 'assets'
+
+export function apply(ctx: Context, config: Config = {}) {
+  config.axiosConfig = {
+    ...ctx.app.options.axiosConfig,
+    ...config.axiosConfig,
+  }
+
+  ctx.assets = 'server' in config
+    ? new AssetClient(ctx, config)
+    : new AssetServer(ctx, config)
+}

packages/plugin-assets/tsconfig.json

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+{
+  "extends": "../../tsconfig.base",
+  "compilerOptions": {
+    "outDir": "dist",
+    "rootDir": "src",
+  },
+  "include": [
+    "src",
+  ],
+}