feat: add openai provider support for chat completion

mobius/internal/connectrpc/mux.go

@@ -5,13 +5,13 @@ import (
 	"fmt"
 	"log"
 	"net/http"
-	"time"
 
 	"connectrpc.com/connect"
 	"connectrpc.com/grpchealth"
 	"connectrpc.com/grpcreflect"
 	"connectrpc.com/validate"
 	"connectrpc.com/vanguard"
+	"github.com/missingstudio/studio/backend/internal/providers"
 	llmv1 "github.com/missingstudio/studio/protos/pkg/llm"
 	"github.com/missingstudio/studio/protos/pkg/llm/llmv1connect"
 )
@@ -65,12 +65,15 @@ func (s *LLMServer) ChatCompletions(
 ) (*connect.Response[llmv1.CompletionResponse], error) {
 	log.Println("Request headers: ", req.Header())
 
-	res := connect.NewResponse(&llmv1.CompletionResponse{
-		Id:      "1",
-		Object:  "chat.compilation",
-		Created: uint64(time.Now().Unix()),
-		Model:   "random",
-		Choices: []*llmv1.CompletionChoice{},
-	})
-	return res, nil
+	provider, err := providers.NewLLMProvider(req.Header())
+	if err != nil {
+		return nil, connect.NewError(connect.CodeInternal, err)
+	}
+
+	data, err := provider.ChatCompilation(ctx, req.Msg)
+	if err != nil {
+		return nil, connect.NewError(connect.CodeInternal, err)
+	}
+
+	return connect.NewResponse(data), nil
 }

mobius/internal/providers/openai/openai.go

@@ -0,0 +1,48 @@
+package openai
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+
+	llmv1 "github.com/missingstudio/studio/protos/pkg/llm"
+)
+
+var OpenAIAPIURL = "https://api.openai.com/v1/chat/completions"
+
+type OpenAI struct {
+	APIKey string
+}
+
+func (oai OpenAI) ChatCompilation(ctx context.Context, cr *llmv1.CompletionRequest) (*llmv1.CompletionResponse, error) {
+	payload, err := json.Marshal(cr)
+	if err != nil {
+		return nil, err
+	}
+
+	client := &http.Client{}
+	req, _ := http.NewRequestWithContext(ctx, "POST", OpenAIAPIURL, bytes.NewReader(payload))
+	req.Header.Add("Content-Type", "application/json")
+	req.Header.Add("Authorization", "Bearer "+oai.APIKey)
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	var data llmv1.CompletionResponse
+	err = json.Unmarshal(body, &data)
+	if err != nil {
+		return nil, err
+	}
+
+	return &data, nil
+}

mobius/internal/providers/providers.go

@@ -0,0 +1,27 @@
+package providers
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"strings"
+
+	"connectrpc.com/connect"
+	"github.com/missingstudio/studio/backend/internal/providers/openai"
+	llmv1 "github.com/missingstudio/studio/protos/pkg/llm"
+)
+
+type LLMProvider interface {
+	ChatCompilation(ctx context.Context, ra *llmv1.CompletionRequest) (*llmv1.CompletionResponse, error)
+}
+
+func NewLLMProvider(headers http.Header) (LLMProvider, error) {
+	provider := headers.Get("x-ms-provider")
+	if provider == "" {
+		return nil, connect.NewError(connect.CodeNotFound, errors.New("provider not found"))
+	}
+	authHeader := headers.Get("Authorization")
+	accessToken := strings.Replace(authHeader, "Bearer ", "", 1)
+
+	return &openai.OpenAI{APIKey: accessToken}, nil
+}

mobius/pkg/utils/interceptor.go

@@ -0,0 +1,19 @@
+package utils
+
+import (
+	"context"
+
+	"connectrpc.com/connect"
+)
+
+func NewLogInterceptor() connect.UnaryInterceptorFunc {
+	interceptor := func(next connect.UnaryFunc) connect.UnaryFunc {
+		return connect.UnaryFunc(func(
+			ctx context.Context,
+			req connect.AnyRequest,
+		) (connect.AnyResponse, error) {
+			return next(ctx, req)
+		})
+	}
+	return connect.UnaryInterceptorFunc(interceptor)
+}

protos/proto/llm/service.proto

@@ -30,7 +30,7 @@ message Role {
 
 message ChatMessage {
   // role of the message author. One of "system", "user", "assistant".
-  Role role = 1;
+  string role = 1;
   // content of the message
   string content = 2;
 }
@@ -62,8 +62,7 @@ message CompletionChoice {
   // index of the choice in the list of choices.
   uint32 index = 1;
   // message generated by the model.
-  repeated ChatMessage messages = 2;
-  FinishReason finish_reason = 3;
+  ChatMessage message = 2;
 }
 
 message Usage {

protos/src/llm/service_pb.ts

@@ -102,9 +102,9 @@ export class ChatMessage extends Message<ChatMessage> {
   /**
    * role of the message author. One of "system", "user", "assistant".
    *
-   * @generated from field: llm.v1.Role role = 1;
+   * @generated from field: string role = 1;
    */
-  role?: Role;
+  role = "";
 
   /**
    * content of the message
@@ -121,7 +121,7 @@ export class ChatMessage extends Message<ChatMessage> {
   static readonly runtime: typeof proto3 = proto3;
   static readonly typeName = "llm.v1.ChatMessage";
   static readonly fields: FieldList = proto3.util.newFieldList(() => [
-    { no: 1, name: "role", kind: "message", T: Role },
+    { no: 1, name: "role", kind: "scalar", T: 9 /* ScalarType.STRING */ },
     { no: 2, name: "content", kind: "scalar", T: 9 /* ScalarType.STRING */ },
   ]);
 
@@ -298,14 +298,9 @@ export class CompletionChoice extends Message<CompletionChoice> {
   /**
    * message generated by the model.
    *
-   * @generated from field: repeated llm.v1.ChatMessage messages = 2;
-   */
-  messages: ChatMessage[] = [];
-
-  /**
-   * @generated from field: llm.v1.FinishReason finish_reason = 3;
+   * @generated from field: llm.v1.ChatMessage message = 2;
    */
-  finishReason = FinishReason.NULL;
+  message?: ChatMessage;
 
   constructor(data?: PartialMessage<CompletionChoice>) {
     super();
@@ -316,8 +311,7 @@ export class CompletionChoice extends Message<CompletionChoice> {
   static readonly typeName = "llm.v1.CompletionChoice";
   static readonly fields: FieldList = proto3.util.newFieldList(() => [
     { no: 1, name: "index", kind: "scalar", T: 13 /* ScalarType.UINT32 */ },
-    { no: 2, name: "messages", kind: "message", T: ChatMessage, repeated: true },
-    { no: 3, name: "finish_reason", kind: "enum", T: proto3.getEnumType(FinishReason) },
+    { no: 2, name: "message", kind: "message", T: ChatMessage },
   ]);
 
   static fromBinary(bytes: Uint8Array, options?: Partial<BinaryReadOptions>): CompletionChoice {