feat(discord): Optimize segment.image sending

packages/adapter-discord/src/bot.ts

@@ -126,16 +126,59 @@ export class DiscordBot extends Bot<'discord'> {
             })
             sentMessageId = r.id
           } else {
-            try {
+            const { axiosConfig, discord = {} } = this.app.options
+            type SendMode = 'auto' | 'download' | 'direct'
+            const sendMode =
+              data.mode as SendMode || // define in segment
+              discord.handleExternalAssets as SendMode || // define in app options
+              'auto' // default
+
+            // Utils
+            async function downloadSend() {
               const a = await axios.get(data.url, {
+                ...axiosConfig,
+                ...discord.axiosConfig,
                 responseType: 'arraybuffer',
               })
-              const r = await this.sendEmbedMessage(requestUrl, a.data, {
+              const r = await that.sendEmbedMessage(requestUrl, a.data, {
                 ...addition,
               })
               sentMessageId = r.id
-            } catch (e) {
-              throw new SenderError(data.url, data, this.selfId)
+            }
+            async function directSend() {
+              const r = await that.request('POST', requestUrl, {
+                content: data.url,
+                ...addition,
+              })
+              sentMessageId = r.id
+            }
+
+            if (sendMode === 'direct') {
+              // send url directly
+              await directSend()
+            } else if (sendMode === 'download') {
+              // download send
+              await downloadSend()
+            } else {
+              // auto mode
+              axios.head(data.url, {
+                ...axiosConfig,
+                ...discord.axiosConfig,
+              })
+                .then(async ({ headers }) => {
+                  if (headers?.['content-type']?.includes('image')) {
+                    await directSend()
+                  } else {
+                    await downloadSend()
+                  }
+                })
+                .catch(async () => {
+                  try {
+                    await downloadSend()
+                  } catch (e) {
+                    throw new SenderError(data.url, data, this.selfId)
+                  }
+                })
             }
           }
         }

packages/adapter-discord/src/index.ts

@@ -8,6 +8,7 @@ export * from './bot'
 interface DiscordOptions extends Adapter.WsClientOptions {
   endpoint?: string
   axiosConfig?: AxiosRequestConfig
+  handleExternalAssets?: 'auto' | 'download' | 'direct'
 }
 
 declare module 'koishi-core' {