From 2a5ccb0e2d445c2df07722394a037c608b3ff1d8 Mon Sep 17 00:00:00 2001
From: Max <shadow.iqka@qq.com>
Date: Sat, 25 Jan 2025 15:42:51 +0800
Subject: [PATCH] Add latest chat retrieval endpoint to Neo API

- Implemented a new `/chats/latest` endpoint to fetch the most recent chat or generate a placeholder
- Added `handleChatLatest` method in the DSL to support retrieving the latest chat for a given session
- Introduced `GetPlaceholder()` method in the Assistant interface to support placeholder generation
- Enhanced API flexibility by allowing optional assistant ID specification for placeholder retrieval

This change improves the chat retrieval capabilities of the Neo API, providing a convenient way to access the most recent chat or generate a starting point for new conversations.
---
 neo/api.go             | 59 ++++++++++++++++++++++++++++++++++++++++++
 neo/assistant/api.go   |  5 ++++
 neo/assistant/types.go |  2 ++
 3 files changed, 66 insertions(+)

diff --git a/neo/api.go b/neo/api.go
index 4d9de7db..f047053f 100644
--- a/neo/api.go
+++ b/neo/api.go
@@ -95,6 +95,10 @@ func (neo *DSL) API(router *gin.Engine, path string) error {
 	// curl -X GET 'http://localhost:5099/api/__yao/neo/chats?page=1&pagesize=20&keywords=search+term&order=desc&token=xxx'
 	router.GET(path+"/chats", append(middlewares, neo.handleChatList)...)
 
+	// Get latest chat example:
+	// curl -X GET 'http://localhost:5099/api/__yao/neo/chats/latest?assistant_id=assistant_123&token=xxx'
+	router.GET(path+"/chats/latest", append(middlewares, neo.handleChatLatest)...)
+
 	// Get chat details example:
 	// curl -X GET 'http://localhost:5099/api/__yao/neo/chats/chat_123?token=xxx'
 	router.GET(path+"/chats/:id", append(middlewares, neo.handleChatDetail)...)
@@ -447,6 +451,61 @@ func (neo *DSL) defaultGuard(c *gin.Context) {
 	c.Next()
 }
 
+// handleChatLatest handles getting the latest chat
+func (neo *DSL) handleChatLatest(c *gin.Context) {
+	sid := c.GetString("__sid")
+	if sid == "" {
+		c.JSON(400, gin.H{"message": "sid is required", "code": 400})
+		c.Done()
+		return
+	}
+
+	// Get the chats
+	chats, err := neo.Store.GetChats(sid, store.ChatFilter{Page: 1})
+	if err != nil {
+		c.JSON(500, gin.H{"message": err.Error(), "code": 500})
+		c.Done()
+		return
+	}
+
+	// Create a new chat
+	if len(chats.Groups) == 0 || len(chats.Groups[0].Chats) == 0 {
+
+		ast := neo.Assistant
+		assistantID := c.Query("assistant_id")
+		if assistantID != "" {
+			ast, err = assistant.Get(assistantID)
+			if err != nil {
+				c.JSON(500, gin.H{"message": err.Error(), "code": 500})
+				c.Done()
+				return
+			}
+		}
+
+		c.JSON(200, map[string]interface{}{"data": map[string]interface{}{"placeholder": ast.GetPlaceholder()}})
+		c.Done()
+		return
+	}
+
+	// Get the chat_id
+	chatID, ok := chats.Groups[0].Chats[0]["chat_id"].(string)
+	if !ok {
+		c.JSON(404, gin.H{"message": "chat_id not found", "code": 404})
+		c.Done()
+		return
+	}
+
+	chat, err := neo.Store.GetChat(sid, chatID)
+	if err != nil {
+		c.JSON(500, gin.H{"message": err.Error(), "code": 500})
+		c.Done()
+		return
+	}
+
+	c.JSON(200, map[string]interface{}{"data": chat})
+	c.Done()
+}
+
 // handleChatDetail handles getting a single chat's details
 func (neo *DSL) handleChatDetail(c *gin.Context) {
 	sid := c.GetString("__sid")
diff --git a/neo/assistant/api.go b/neo/assistant/api.go
index 06a850e6..0c63e8a0 100644
--- a/neo/assistant/api.go
+++ b/neo/assistant/api.go
@@ -170,6 +170,11 @@ func (next *NextAction) Execute(c *gin.Context, ctx chatctx.Context) error {
 	}
 }
 
+// GetPlaceholder returns the placeholder of the assistant
+func (ast *Assistant) GetPlaceholder() *Placeholder {
+	return ast.Placeholder
+}
+
 // Call implements the call functionality
 func (ast *Assistant) Call(c *gin.Context, payload APIPayload) (interface{}, error) {
 	scriptCtx, err := ast.Script.NewContext(payload.Sid, nil)
diff --git a/neo/assistant/types.go b/neo/assistant/types.go
index ca3b24a2..76cc9158 100644
--- a/neo/assistant/types.go
+++ b/neo/assistant/types.go
@@ -24,6 +24,8 @@ type API interface {
 	Upload(ctx context.Context, file *multipart.FileHeader, reader io.Reader, option map[string]interface{}) (*File, error)
 	Download(ctx context.Context, fileID string) (*FileResponse, error)
 	ReadBase64(ctx context.Context, fileID string) (string, error)
+
+	GetPlaceholder() *Placeholder
 	Execute(c *gin.Context, ctx chatctx.Context, input string, options map[string]interface{}) error
 	Call(c *gin.Context, payload APIPayload) (interface{}, error)
 }