⚡ Introduce a new high-performing standalone chat API (#1200)

Closes #1154

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **New Features**
	- Added authentication functionality for user sessions in chat API.
- Introduced chat-related API endpoints for starting, previewing, and
continuing chat sessions, and streaming messages.
- Implemented WhatsApp API webhook handling for receiving and processing
messages.
- Added environment variable `NEXT_PUBLIC_CHAT_API_URL` for chat API URL
configuration.

- **Bug Fixes**
	- Adjusted file upload logic to correctly determine the API host.
	- Fixed message streaming URL in chat integration with OpenAI.

- **Documentation**
- Updated guides for creating blocks, local installation, self-hosting,
and deployment to use `bun` instead of `pnpm`.

- **Refactor**
	- Refactored chat API functionalities to use modular architecture.
- Simplified client log saving and session update functionalities by
using external functions.
	- Transitioned package management and workflow commands to use `bun`.

- **Chores**
- Switched to `bun` for package management in Dockerfiles and GitHub
workflows.
	- Added new Dockerfile for chat API service setup with Bun framework.
	- Updated `.prettierignore` and documentation with new commands.

- **Style**
	- No visible changes to end-users.

- **Tests**
	- No visible changes to end-users.

- **Revert**
	- No reverts in this release.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

apps/viewer/src/features/chat/api/continueChat.ts

@@ -1,14 +1,7 @@
 import { publicProcedure } from '@/helpers/server/trpc'
 import { continueChatResponseSchema } from '@typebot.io/schemas/features/chat/schema'
-import { TRPCError } from '@trpc/server'
-import { getSession } from '@typebot.io/bot-engine/queries/getSession'
-import { saveStateToDatabase } from '@typebot.io/bot-engine/saveStateToDatabase'
-import { continueBotFlow } from '@typebot.io/bot-engine/continueBotFlow'
-import { parseDynamicTheme } from '@typebot.io/bot-engine/parseDynamicTheme'
-import { isDefined, isNotDefined } from '@typebot.io/lib/utils'
 import { z } from 'zod'
-import { filterPotentiallySensitiveLogs } from '@typebot.io/bot-engine/logs/filterPotentiallySensitiveLogs'
-import { computeCurrentProgress } from '@typebot.io/bot-engine/computeCurrentProgress'
+import { continueChat as continueChatFn } from '@typebot.io/bot-engine/apiHandlers/continueChat'
 
 export const continueChat = publicProcedure
   .meta({
@@ -29,92 +22,12 @@ export const continueChat = publicProcedure
     })
   )
   .output(continueChatResponseSchema)
-  .mutation(async ({ input: { sessionId, message }, ctx: { res, origin } }) => {
-    const session = await getSession(sessionId)
-
-    if (!session) {
-      throw new TRPCError({
-        code: 'NOT_FOUND',
-        message: 'Session not found.',
-      })
-    }
-
-    const isSessionExpired =
-      session &&
-      isDefined(session.state.expiryTimeout) &&
-      session.updatedAt.getTime() + session.state.expiryTimeout < Date.now()
-
-    if (isSessionExpired)
-      throw new TRPCError({
-        code: 'NOT_FOUND',
-        message: 'Session expired. You need to start a new session.',
-      })
-
-    if (
-      session?.state.allowedOrigins &&
-      session.state.allowedOrigins.length > 0
-    ) {
-      if (origin && session.state.allowedOrigins.includes(origin))
-        res.setHeader('Access-Control-Allow-Origin', origin)
-      else
-        res.setHeader(
-          'Access-Control-Allow-Origin',
-          session.state.allowedOrigins[0]
-        )
-    }
-
-    const {
-      messages,
-      input,
-      clientSideActions,
-      newSessionState,
-      logs,
-      lastMessageNewFormat,
-      visitedEdges,
-    } = await continueBotFlow(message, {
-      version: 2,
-      state: session.state,
-      startTime: Date.now(),
+  .mutation(async ({ input: { sessionId, message }, ctx: { origin, res } }) => {
+    const { corsOrigin, ...response } = await continueChatFn({
+      origin,
+      sessionId,
+      message,
     })
-
-    if (newSessionState)
-      await saveStateToDatabase({
-        session: {
-          id: session.id,
-          state: newSessionState,
-        },
-        input,
-        logs,
-        clientSideActions,
-        visitedEdges,
-        hasCustomEmbedBubble: messages.some(
-          (message) => message.type === 'custom-embed'
-        ),
-      })
-
-    const isPreview = isNotDefined(session.state.typebotsQueue[0].resultId)
-
-    const isEnded =
-      newSessionState.progressMetadata &&
-      !input?.id &&
-      (clientSideActions?.filter((c) => c.expectsDedicatedReply).length ??
-        0) === 0
-
-    return {
-      messages,
-      input,
-      clientSideActions,
-      dynamicTheme: parseDynamicTheme(newSessionState),
-      logs: isPreview ? logs : logs?.filter(filterPotentiallySensitiveLogs),
-      lastMessageNewFormat,
-      progress: newSessionState.progressMetadata
-        ? isEnded
-          ? 100
-          : computeCurrentProgress({
-              typebotsQueue: newSessionState.typebotsQueue,
-              progressMetadata: newSessionState.progressMetadata,
-              currentInputBlockId: input?.id,
-            })
-        : undefined,
-    }
+    if (corsOrigin) res.setHeader('Access-Control-Allow-Origin', corsOrigin)
+    return response
   })