fix(slack): transfer message attachments through file APIs

src/langbot/pkg/platform/adapters/slack/adapter.py

@@ -8,6 +8,7 @@ import pydantic
 
 from langbot.libs.slack_api.api import SlackClient
 from langbot.libs.slack_api.slackevent import SlackEvent
+from langbot.libs.slack_api.media import send_chain
 from langbot.pkg.platform.adapters.slack.api_impl import SlackAPIMixin
 from langbot.pkg.platform.adapters.slack.errors import NotSupportedError
 from langbot.pkg.platform.adapters.slack.event_converter import SlackEventConverter
@@ -96,8 +97,7 @@ class SlackAdapter(SlackAPIMixin, abstract_platform_adapter.AbstractPlatformAdap
         target_id: str,
         message: platform_message.MessageChain,
     ) -> platform_events.MessageResult:
-        content = await SlackMessageConverter.yiri2target(message)
-        raw = await self._send_text(str(target_type), str(target_id), content)
+        raw = await send_chain(self.bot, self._normalize_target_type(str(target_type)), str(target_id), message)
         return platform_events.MessageResult(raw=raw)
 
     async def reply_message(
@@ -111,7 +111,7 @@ class SlackAdapter(SlackAPIMixin, abstract_platform_adapter.AbstractPlatformAdap
             raise ValueError('Slack reply_message requires a SlackEvent source object')
         target_type = 'channel' if source.type == 'channel' else 'person'
         target_id = source.channel_id if source.type == 'channel' else source.user_id
-        raw = await self._send_text(target_type, target_id, await SlackMessageConverter.yiri2target(message))
+        raw = await send_chain(self.bot, target_type, target_id, message)
         return platform_events.MessageResult(message_id=source.message_id, raw=raw)
 
     async def call_platform_api(self, action: str, params: dict = {}) -> dict:

src/langbot/pkg/platform/adapters/slack/message_converter.py

@@ -4,6 +4,7 @@ import datetime
 
 from langbot.libs.slack_api.slackevent import SlackEvent
 from langbot.pkg.utils import image
+from langbot.libs.slack_api.media import download_media
 import langbot_plugin.api.definition.abstract.platform.adapter as abstract_platform_adapter
 from langbot_plugin.api.entities.builtin.platform import message as platform_message
 
@@ -55,15 +56,24 @@ class SlackMessageConverter(abstract_platform_adapter.AbstractMessageConverter):
         if event.type == 'channel':
             components.append(platform_message.At(target='SlackBot'))
 
-        if event.pic_url:
-            try:
+        for file in event.get('event', {}).get('files', []):
+            url = file.get('url_private_download') or file.get('url_private')
+            if not url:
+                raise ValueError('Slack attachment is missing its download URL')
+            data, mime = await download_media(url, bot_token)
+            mime = file.get('mimetype') or mime
+            encoded = await image.encode_base64(data)
+            if mime.startswith('image/') and mime != 'image/svg+xml':
+                components.append(platform_message.Image(base64=f'data:{mime};base64,{encoded}'))
+            else:
                 components.append(
-                    platform_message.Image(
-                        url=event.pic_url, base64=await image.get_slack_image_to_base64(event.pic_url, bot_token)
+                    platform_message.File(
+                        id=file.get('id', ''),
+                        name=file.get('name') or file.get('title') or 'attachment',
+                        size=len(data),
+                        base64=encoded,
                     )
                 )
-            except Exception:
-                components.append(platform_message.Image(url=event.pic_url))
 
         if event.text:
             components.append(platform_message.Plain(text=event.text))

src/langbot/pkg/platform/sources/slack.py

@@ -6,6 +6,8 @@ import traceback
 import datetime
 
 from langbot.libs.slack_api.api import SlackClient
+from langbot.libs.slack_api.media import send_chain
+from langbot.pkg.platform.adapters.slack.message_converter import SlackMessageConverter as OmniMessageConverter
 import langbot_plugin.api.definition.abstract.platform.adapter as abstract_platform_adapter
 from langbot.libs.slack_api.slackevent import SlackEvent
 import langbot_plugin.api.entities.builtin.platform.events as platform_events
@@ -61,12 +63,9 @@ class SlackEventConverter(abstract_platform_adapter.AbstractEventConverter):
 
     @staticmethod
     async def target2yiri(event: SlackEvent, bot: SlackClient):
-        yiri_chain = await SlackMessageConverter.target2yiri(
-            message=event.text, message_id=event.message_id, pic_url=event.pic_url, bot=bot
-        )
+        yiri_chain = await OmniMessageConverter.target2yiri(event, bot.bot_token)
 
         if event.type == 'channel':
-            yiri_chain.insert(0, platform_message.At(target='SlackBot'))
 
             sender = platform_entities.GroupMember(
                 id=event.user_id,
@@ -127,27 +126,13 @@ class SlackAdapter(abstract_platform_adapter.AbstractMessagePlatformAdapter):
     ):
         slack_event = await SlackEventConverter.yiri2target(message_source)
 
-        content_list = await SlackMessageConverter.yiri2target(message)
-
-        for content in content_list:
-            # Both text and image (URL) are sent as text messages
-            # Slack will auto-unfurl image URLs
-            message_content = content['content']
-            if slack_event.type == 'channel':
-                await self.bot.send_message_to_channel(message_content, slack_event.channel_id)
-            if slack_event.type == 'im':
-                await self.bot.send_message_to_one(message_content, slack_event.user_id)
+        target_type = 'channel' if slack_event.type == 'channel' else 'person'
+        target_id = slack_event.channel_id if target_type == 'channel' else slack_event.user_id
+        return await send_chain(self.bot, target_type, target_id, message)
 
     async def send_message(self, target_type: str, target_id: str, message: platform_message.MessageChain):
-        content_list = await SlackMessageConverter.yiri2target(message)
-        for content in content_list:
-            # Both text and image (URL) are sent as text messages
-            # Slack will auto-unfurl image URLs
-            message_content = content['content']
-            if target_type == 'person':
-                await self.bot.send_message_to_one(message_content, target_id)
-            if target_type == 'group':
-                await self.bot.send_message_to_channel(message_content, target_id)
+        target_type = 'channel' if target_type in {'group', 'channel'} else target_type
+        return await send_chain(self.bot, target_type, target_id, message)
 
     def register_listener(
         self,