From 21d06f25c677209ced79857cbea1912c220d798b Mon Sep 17 00:00:00 2001
From: Shigma <1700011071@pku.edu.cn>
Date: Mon, 5 Jul 2021 00:56:23 +0800
Subject: [PATCH] feat(discord): support reaction events

---
 packages/adapter-discord/src/utils.ts | 60 +++++++++++++++++++--------
 packages/adapter-discord/src/ws.ts    |  9 ++--
 2 files changed, 49 insertions(+), 20 deletions(-)

diff --git a/packages/adapter-discord/src/utils.ts b/packages/adapter-discord/src/utils.ts
index 0002e835f0..cd75de0c92 100644
--- a/packages/adapter-discord/src/utils.ts
+++ b/packages/adapter-discord/src/utils.ts
@@ -30,7 +30,7 @@ export const adaptAuthor = (author: DC.User): AuthorInfo => ({
   nickname: author.username,
 })
 
-export async function adaptMessage(bot: DiscordBot, meta: DC.Message, session: Partial<Session> = {}) {
+export function adaptMessage(bot: DiscordBot, meta: DC.Message, session: Partial<Session> = {}) {
   if (meta.author) {
     session.author = adaptAuthor(meta.author)
     session.userId = meta.author.id
@@ -106,8 +106,8 @@ export async function adaptMessage(bot: DiscordBot, meta: DC.Message, session: P
   return session
 }
 
-async function adaptMessageSession(bot: DiscordBot, meta: DC.Message, session: Partial<Session> = {}) {
-  await adaptMessage(bot, meta, session)
+function adaptMessageSession(bot: DiscordBot, meta: DC.Message, session: Partial<Session> = {}) {
+  adaptMessage(bot, meta, session)
   session.messageId = meta.id
   session.timestamp = new Date(meta.timestamp).valueOf() || Date.now()
   // 遇到过 cross post 的消息在这里不会传消息 id
@@ -118,6 +118,23 @@ async function adaptMessageSession(bot: DiscordBot, meta: DC.Message, session: P
   return session
 }
 
+function prepareMessageSession(session: Partial<Session>, data: DC.Message) {
+  session.groupId = data.guild_id
+  session.subtype = data.guild_id ? 'group' : 'private'
+  session.channelId = data.channel_id
+}
+
+function prepareReactionSession(session: Partial<Session>, data: any) {
+  session.userId = data.user_id
+  session.messageId = data.message_id
+  session.groupId = data.guild_id
+  session.channelId = data.channel_id
+  session.subtype = data.guild_id ? 'group' : 'private'
+  if (!data.emoji) return
+  const { id, name } = data.emoji
+  session.content = id ? `${name}:${id}` : name
+}
+
 export async function adaptSession(bot: DiscordBot, input: DC.Payload) {
   const session: Partial<Session> = {
     selfId: bot.selfId,
@@ -125,31 +142,40 @@ export async function adaptSession(bot: DiscordBot, input: DC.Payload) {
   }
   if (input.t === 'MESSAGE_CREATE') {
     session.type = 'message'
-    const msg = input.d as DC.Message
-    session.groupId = msg.guild_id
-    session.subtype = msg.guild_id ? 'group' : 'private'
-    session.channelId = msg.channel_id
-    await adaptMessageSession(bot, input.d, session)
+    prepareMessageSession(session, input.d)
+    adaptMessageSession(bot, input.d, session)
     // dc 情况特殊 可能有 embeds 但是没有消息主体
     // if (!session.content) return
     if (session.userId === bot.selfId) return
   } else if (input.t === 'MESSAGE_UPDATE') {
     session.type = 'message-updated'
-    const d = input.d as DC.Message
-    session.groupId = d.guild_id
-    session.subtype = d.guild_id ? 'group' : 'private'
-    session.channelId = d.channel_id
-    const msg = await bot.$getMessage(d.channel_id, d.id)
+    prepareMessageSession(session, input.d)
+    const msg = await bot.$getMessage(input.d.channel_id, input.d.id)
     // Unlike creates, message updates may contain only a subset of the full message object payload
     // https://discord.com/developers/docs/topics/gateway#message-update
-    await adaptMessageSession(bot, msg, session)
+    adaptMessageSession(bot, msg, session)
     // if (!session.content) return
     if (session.userId === bot.selfId) return
   } else if (input.t === 'MESSAGE_DELETE') {
     session.type = 'message-deleted'
-    session.messageId = input.d.id
-    session.groupId = input.d.guild_id
-    session.channelId = input.d.channel_id
+    prepareMessageSession(session, input.d)
+  } else if (input.t === 'MESSAGE_REACTION_ADD') {
+    session.type = 'reaction-added'
+    prepareReactionSession(session, input.d)
+  } else if (input.t === 'MESSAGE_REACTION_REMOVE') {
+    session.type = 'reaction-deleted'
+    session.subtype = 'one'
+    prepareReactionSession(session, input.d)
+  } else if (input.t === 'MESSAGE_REACTION_REMOVE_ALL') {
+    session.type = 'reaction-deleted'
+    session.subtype = 'all'
+    prepareReactionSession(session, input.d)
+  } else if (input.t === 'MESSAGE_REACTION_REMOVE_EMOJI') {
+    session.type = 'reaction-deleted'
+    session.subtype = 'emoji'
+    prepareReactionSession(session, input.d)
+  } else {
+    return
   }
   return new Session(bot.app, session)
 }
diff --git a/packages/adapter-discord/src/ws.ts b/packages/adapter-discord/src/ws.ts
index 8124e5151a..bab70e955f 100644
--- a/packages/adapter-discord/src/ws.ts
+++ b/packages/adapter-discord/src/ws.ts
@@ -6,7 +6,7 @@ import WebSocket from 'ws'
 
 const logger = new Logger('discord')
 
-// https://discord.com/developers/docs/topics/gateway
+/** https://discord.com/developers/docs/topics/gateway */
 export default class WsClient extends Adapter.WsClient<'discord'> {
   constructor(app: App) {
     super(app, DiscordBot, app.options.discord)
@@ -59,10 +59,13 @@ export default class WsClient extends Adapter.WsClient<'discord'> {
               token: bot.token,
               properties: {},
               compress: false,
-              intents: (1 << 9) + (1 << 12),
+              // https://discord.com/developers/docs/topics/gateway#gateway-intents
+              intents: (1 << 9) + (1 << 10) + (1 << 12) + (1 << 13),
             },
           }))
-        } else if (parsed.op === Opcode.Dispatch) {
+        }
+
+        if (parsed.op === Opcode.Dispatch) {
           if (parsed.t === 'READY') {
             bot._sessionId = parsed.d.session_id
             const self: any = adaptUser(parsed.d.user)