initial commit

chat.go

@@ -0,0 +1,131 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/revrost/go-openrouter"
+)
+
+type Message struct {
+	Role    string `json:"role"`
+	Content string `json:"content"`
+}
+
+type Request struct {
+	Model       string    `json:"model"`
+	Temperature float64   `json:"temperature"`
+	Messages    []Message `json:"messages"`
+}
+
+func (r *Request) Parse() (*openrouter.ChatCompletionRequest, error) {
+	var request openrouter.ChatCompletionRequest
+
+	if _, ok := ModelMap[r.Model]; !ok {
+		return nil, fmt.Errorf("unknown model: %q", r.Model)
+	}
+
+	request.Model = r.Model
+
+	if r.Temperature < 0 || r.Temperature > 1 {
+		return nil, fmt.Errorf("invalid temperature (0-1): %f", r.Temperature)
+	}
+
+	request.Temperature = float32(r.Temperature)
+
+	for index, message := range r.Messages {
+		if message.Role != openrouter.ChatMessageRoleSystem && message.Role != openrouter.ChatMessageRoleAssistant && message.Role != openrouter.ChatMessageRoleUser {
+			return nil, fmt.Errorf("[%d] invalid role: %q", index+1, message.Role)
+		}
+
+		request.Messages = append(request.Messages, openrouter.ChatCompletionMessage{
+			Role: message.Role,
+			Content: openrouter.Content{
+				Text: message.Content,
+			},
+		})
+	}
+
+	return &request, nil
+}
+
+func HandleChat(w http.ResponseWriter, r *http.Request) {
+	var raw Request
+
+	if err := json.NewDecoder(r.Body).Decode(&raw); err != nil {
+		RespondJson(w, http.StatusBadRequest, map[string]any{
+			"error": err.Error(),
+		})
+
+		return
+	}
+
+	request, err := raw.Parse()
+	if err != nil {
+		RespondJson(w, http.StatusBadRequest, map[string]any{
+			"error": err.Error(),
+		})
+
+		return
+	}
+
+	request.Stream = true
+
+	ctx := r.Context()
+
+	stream, err := OpenRouterStartStream(ctx, *request)
+	if err != nil {
+		RespondJson(w, http.StatusBadRequest, map[string]any{
+			"error": err.Error(),
+		})
+
+		return
+	}
+
+	defer stream.Close()
+
+	response, err := NewStream(w)
+	if err != nil {
+		RespondJson(w, http.StatusBadRequest, map[string]any{
+			"error": err.Error(),
+		})
+
+		return
+	}
+
+	for {
+		chunk, err := stream.Recv()
+		if err != nil {
+			if errors.Is(err, io.EOF) {
+				return
+			}
+
+			response.Send(ErrorChunk(err))
+
+			return
+		}
+
+		if len(chunk.Choices) == 0 {
+			continue
+		}
+
+		choice := chunk.Choices[0]
+
+		if choice.FinishReason == openrouter.FinishReasonContentFilter {
+			response.Send(ErrorChunk(errors.New("stopped due to content_filter")))
+
+			return
+		}
+
+		content := choice.Delta.Content
+
+		if content != "" {
+			response.Send(TextChunk(content))
+		} else if choice.Delta.Reasoning != nil {
+			response.Send(ReasoningChunk(*choice.Delta.Reasoning))
+		}
+	}
+}