feat: resize oversize images before sending

package.json

@@ -45,6 +45,7 @@
     "eslint-plugin-n": "^16.6.2",
     "eslint-plugin-promise": "^6.1.1",
     "jest-mock": "^28.1.3",
+    "jimp": "^0.22.12",
     "mocha": "^9.2.2",
     "prettier": "^3.2.5",
     "sass": "^1.62.1",

packages/core/src/command.tsx

@@ -1,7 +1,7 @@
 /* eslint-disable no-fallthrough */
 import { Channel, Context, Random, Session, User } from 'koishi'
 
-import { Config, OutputType, SpoilerType, preferSizes } from '.'
+import { Config, OutputType, SpoilerType, preferSizes, preferSizesToSize } from '.'
 
 export const inject = {
   required: ['booru'],
@@ -84,13 +84,20 @@ export function apply(ctx: Context, config: Config) {
         url ||= image.url
 
         if (config.asset && ctx.assets) {
+          if (config.autoResize && config.preferSize !== 'original') {
+            url = await ctx.booru.imgResize(url, preferSizesToSize[config.preferSize])
+          }
           url = await ctx.booru.imgUrlToAssetUrl(url)
           if (!url) {
             children.unshift(<i18n path='commands.booru.messages.no-image'></i18n>)
             continue
           }
         } else if (config.base64) {
-          url = await ctx.booru.imgUrlToBase64(url)
+          if (config.autoResize && config.preferSize !== 'original') {
+            url = await ctx.booru.imgResize(url, preferSizesToSize[config.preferSize])
+          } else if (!url.startsWith('data:')) {
+            url = await ctx.booru.imgUrlToBase64(url)
+          }
           if (!url) {
             children.unshift(<i18n path='commands.booru.messages.no-image'></i18n>)
             continue

packages/core/src/index.ts

@@ -1,3 +1,4 @@
+import Jimp from 'jimp'
 import { Context, Logger, Quester, Schema, Service, remove } from 'koishi'
 import LanguageDetect from 'languagedetect'
 
@@ -90,6 +91,34 @@ class ImageService extends Service {
     return undefined
   }
 
+  async imgResize(url: string, size: number): Promise<string> {
+    if (size < 0) {
+      return url
+    }
+    try {
+      const resp = await this.ctx.http(url, { method: 'GET', responseType: 'arraybuffer', proxyAgent: '' })
+      let img = await Jimp.read(Buffer.from(resp.data))
+      const width = img.bitmap.width
+      const height = img.bitmap.height
+      const ratio = size / Math.max(width, height)
+      if (ratio < 1) {
+        img = img.resize(Math.floor(width * ratio), Math.floor(height * ratio)).quality(80)
+        const buffer = await img.getBufferAsync('image/jpeg')
+        return `data:image/jpeg;base64,${buffer.toString('base64')}`
+      }
+      return url
+    } catch (err) {
+      if (Quester.Error.is(err)) {
+        logger.warn(
+          `Resize images failed with HTTP status ${err.response?.status}: ${JSON.stringify(err.response?.data)}.`,
+        )
+      } else {
+        logger.error(`Resize images failed with error: ${err.message}.`)
+      }
+      return url
+    }
+  }
+
   async imgUrlToAssetUrl(url: string): Promise<string> {
     return await this.ctx.assets.upload(url, Date.now().toString()).catch(() => {
       logger.warn('Request failed when trying to store image with assets service.')
@@ -101,7 +130,7 @@ class ImageService extends Service {
     return this.ctx
       .http(url, { method: 'GET', responseType: 'arraybuffer', proxyAgent: '' })
       .then((resp) => {
-        return `data:${resp.headers['content-type']};base64,${Buffer.from(resp.data).toString('base64')}`
+        return `data:${resp.headers.get('content-type')};base64,${Buffer.from(resp.data).toString('base64')}`
       })
       .catch((err) => {
         if (Quester.Error.is(err)) {
@@ -144,6 +173,7 @@ export interface Config {
   output: OutputType
   outputMethod: 'one-by-one' | 'merge-multiple' | 'forward-all' | 'forward-multiple'
   preferSize: ImageSource.PreferSize
+  autoResize: boolean
   nsfw: boolean
   asset: boolean
   base64: boolean
@@ -199,6 +229,7 @@ export const Config = Schema.intersect([
     ])
       .description('优先使用图片的最大尺寸。')
       .default('large'),
+    autoResize: Schema.boolean().default(false).description('自动缩小过大的图片(需开启assets或者base64)。'),
     asset: Schema.boolean().default(false).description('优先使用 [assets服务](https://assets.koishi.chat/) 转存图片。'),
     base64: Schema.boolean().default(false).description('使用 base64 发送图片。'),
     spoiler: Schema.union([

packages/core/src/source.ts

@@ -91,3 +91,4 @@ export namespace ImageSource {
 }
 
 export const preferSizes = ['thumbnail', 'large', 'medium', 'small', 'original'] as const
+export const preferSizesToSize = { thumbnail: 128, large: 1280, medium: 640, small: 320, original: -1 } as const