initial gpt hook up with htmx

.gitignore

@@ -0,0 +1 @@
+.env

clients/openai.go

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+package openai
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+	"os"
+	"sync"
+
+	"github.com/joho/godotenv"
+)
+
+const OpenAIEndpoint = "https://api.openai.com/v1/chat/completions"
+
+type OpenAIClient struct {
+	APIKey string
+	Model  string
+}
+
+type ChatMessage struct {
+	Role    string `json:"role"`
+	Content string `json:"content"`
+}
+
+type ChatRequest struct {
+	Model       string        `json:"model"`
+	Messages    []ChatMessage `json:"messages"`
+	Stream      bool          `json:"stream,omitempty"`
+	Temperature float32       `json:"temperature,omitempty"`
+}
+
+type ChatResponse struct {
+	Choices []struct {
+		Delta struct {
+			Content string `json:"content"`
+		} `json:"delta"`
+		Message ChatMessage `json:"message"`
+	} `json:"choices"`
+}
+
+// ensures .env is only loaded once
+var loadEnvOnce sync.Once
+
+// NewClient loads env and returns a configured client
+func NewClient(model string) *OpenAIClient {
+	loadEnvOnce.Do(func() {
+		_ = godotenv.Load()
+	})
+
+	return &OpenAIClient{
+		APIKey: os.Getenv("OPENAI_API_KEY"),
+		Model:  model,
+	}
+}
+
+func (c *OpenAIClient) Chat(messages []ChatMessage) (string, error) {
+	reqBody, _ := json.Marshal(ChatRequest{
+		Model:    c.Model,
+		Messages: messages,
+	})
+	req, _ := http.NewRequest("POST", OpenAIEndpoint, bytes.NewBuffer(reqBody))
+	req.Header.Set("Authorization", "Bearer "+c.APIKey)
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return "", errors.New(string(body))
+	}
+
+	var result ChatResponse
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return "", err
+	}
+	return result.Choices[0].Message.Content, nil
+}
+
+func (c *OpenAIClient) StreamChat(messages []ChatMessage, onDelta func(string)) error {
+	reqBody, _ := json.Marshal(ChatRequest{
+		Model:    c.Model,
+		Messages: messages,
+		Stream:   true,
+	})
+	req, _ := http.NewRequest("POST", OpenAIEndpoint, bytes.NewBuffer(reqBody))
+	req.Header.Set("Authorization", "Bearer "+c.APIKey)
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return errors.New(string(body))
+	}
+
+	scanner := bufio.NewScanner(resp.Body)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if line == "" || line == "data: [DONE]" {
+			continue
+		}
+		var chunk ChatResponse
+		if err := json.Unmarshal([]byte(line[6:]), &chunk); err != nil {
+			continue
+		}
+		if len(chunk.Choices) > 0 {
+			delta := chunk.Choices[0].Delta.Content
+			onDelta(delta)
+		}
+	}
+	return nil
+}

go.mod

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+module bdsc
+
+go 1.22.2
+
+require (
+	github.com/gorilla/websocket v1.5.3
+	github.com/joho/godotenv v1.5.1
+)

go.sum

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+github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
+github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=

main.go

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+package main
+
+import (
+	openai "bdsc/clients"
+	"fmt"
+	"html/template"
+	"net/http"
+	"sync"
+
+	"github.com/gorilla/websocket"
+)
+
+var (
+	tmpl        = template.Must(template.ParseFiles("templates/chat.html"))
+	upgrader    = websocket.Upgrader{}
+	clients     = make(map[*websocket.Conn]bool)
+	broadcast   = make(chan string)
+	clientMutex sync.Mutex
+
+	openAIClient = openai.NewClient("gpt-3.5-turbo")
+	chatHistory  []openai.ChatMessage
+	historyMutex sync.Mutex
+)
+
+type PageData struct {
+	Greeting template.HTML
+}
+
+func main() {
+	http.HandleFunc("/", chatHandler)
+	http.HandleFunc("/send", sendHandler)
+	http.HandleFunc("/ws", wsHandler)
+	http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))
+
+	go handleMessages()
+
+	fmt.Println("Listening on :8080")
+	http.ListenAndServe(":8080", nil)
+}
+
+func chatHandler(w http.ResponseWriter, r *http.Request) {
+
+	historyMutex.Lock()
+	defer historyMutex.Unlock()
+
+	chatHistory = append(chatHistory,
+		openai.ChatMessage{Role: "system", Content: "You are a friendly and helpful assistant."},
+	)
+	resp, err := openAIClient.Chat(chatHistory)
+	if err != nil {
+		fmt.Println("GPT error:", err)
+		return
+	}
+
+	chatHistory = append(chatHistory, openai.ChatMessage{Role: "assistant", Content: resp})
+	html := fmt.Sprintf(`<div><b>Assistant:</b> %s</div>`, template.HTMLEscapeString(resp))
+	tmpl.Execute(w, PageData{Greeting: template.HTML(html)})
+}
+
+func sendHandler(w http.ResponseWriter, r *http.Request) {
+	r.ParseForm()
+	message := r.FormValue("message")
+
+	historyMutex.Lock()
+	chatHistory = append(chatHistory, openai.ChatMessage{
+		Role:    "user",
+		Content: message,
+	})
+	historyMutex.Unlock()
+
+	userHTML := fmt.Sprintf(`<div><b>You:</b> %s</div>`, template.HTMLEscapeString(message))
+	broadcast <- userHTML
+
+	historyMutex.Lock()
+	resp, err := openAIClient.Chat(chatHistory)
+	if err != nil {
+		historyMutex.Unlock()
+		http.Error(w, "Gpt failed", http.StatusInternalServerError)
+		return
+	}
+
+	chatHistory = append(chatHistory, openai.ChatMessage{
+		Role:    "assistant",
+		Content: resp,
+	})
+	historyMutex.Unlock()
+
+	gptHTML := fmt.Sprintf(`<div><b>Assistant:</b> %s</div>`, template.HTMLEscapeString(resp))
+	broadcast <- gptHTML
+
+	w.Header().Set("Content-Type", "text/html")
+	fmt.Fprint(w, userHTML+gptHTML)
+}
+
+func wsHandler(w http.ResponseWriter, r *http.Request) {
+	conn, err := upgrader.Upgrade(w, r, nil)
+	if err != nil {
+		return
+	}
+
+	clientMutex.Lock()
+	clients[conn] = true
+	clientMutex.Unlock()
+
+	defer func() {
+		clientMutex.Lock()
+		delete(clients, conn)
+		clientMutex.Unlock()
+		conn.Close()
+	}()
+
+	for {
+		_, _, err := conn.ReadMessage()
+		if err != nil {
+			break
+		}
+	}
+}
+
+func handleMessages() {
+	for {
+		msg := <-broadcast
+		fmt.Print("Message is brodcasting:", msg, "\n")
+		clientMutex.Lock()
+		for client := range clients {
+			err := client.WriteMessage(websocket.TextMessage, []byte(msg))
+			if err != nil {
+				fmt.Print("error sending message to client")
+				client.Close()
+				delete(clients, client)
+			}
+		}
+		clientMutex.Unlock()
+	}
+}

templates/chat.html

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+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <title>GPT Chat</title>
+  <script src="https://unpkg.com/htmx.org@2.0.4" integrity="sha384-HGfztofotfshcF7+8n44JQL2oJmowVChPTg48S+jvZoztPfvwD79OC/LTtG6dMp+" crossorigin="anonymous"></script>
+  <script src="https://unpkg.com/htmx-ext-ws@2.0.2" integrity="sha384-vuKxTKv5TX/b3lLzDKP2U363sOAoRo5wSvzzc3LJsbaQRSBSS+3rKKHcOx5J8doU" crossorigin="anonymous"></script>
+  <style>
+    body {
+      font-family: sans-serif;
+      margin: 2rem;
+    }
+    #messages {
+      border: 1px solid #ccc;
+      padding: 1rem;
+      height: 300px;
+      overflow-y: auto;
+      margin-bottom: 1rem;
+    }
+    form {
+      display: flex;
+      gap: 0.5rem;
+    }
+    input[type="text"] {
+      flex: 1;
+      padding: 0.5rem;
+    }
+  </style>
+
+
+</head>
+<body>
+<script>
+  const realWS = WebSocket;
+  WebSocket = function (...args) {
+    const ws = new realWS(...args);
+    ws.addEventListener("message", (e) => {
+      console.log("🔥 Raw WS message:", e.data);
+    });
+    return ws;
+  };
+</script>
+  <h1>Chat with GPT</h1>
+
+  <!-- WebSocket-connected chat window -->
+  <div id="messages"
+       hx-ext="ws"
+       ws-connect="/ws"
+       hx-swap="beforeend">
+      {{ .Greeting }}
+  </div>
+
+  <!-- Form to send messages to GPT -->
+  <form hx-post="/send" hx-target="#messages" hx-swap="beforeend" hx-on::after-request="if(event.detail.successful) this.reset()">
+    <input type="text" name="message" placeholder="Say something..." required />
+    <button type="submit">Send</button>
+  </form>
+
+</body>
+</html>
+