feat: openai integration added to http transport

Author: Pratham-Mishra04

transports/bifrost-http/integrations/openai/router.go

@@ -0,0 +1,77 @@
+package openai
+
+import (
+	"encoding/json"
+
+	"github.com/fasthttp/router"
+	bifrost "github.com/maximhq/bifrost/core"
+	"github.com/maximhq/bifrost/transports/bifrost-http/lib"
+	"github.com/valyala/fasthttp"
+)
+
+// OpenAIRouter holds route registrations for OpenAI endpoints.
+// It supports standard chat completions and image-enabled vision capabilities.
+//
+// Vision API Support:
+// The /openai/v1/chat/completions endpoint supports messages with mixed text and image content.
+//
+// Example Vision API Request:
+//
+//	{
+//	  "model": "gpt-4o",
+//	  "messages": [{
+//	    "role": "user",
+//	    "content": [
+//	      {"type": "text", "text": "What's in this image? Keep the response short."},
+//	      {"type": "image_url", "image_url": {"url": "data:image/png;base64,..."}}
+//	    ]
+//	  }]
+//	}
+type OpenAIRouter struct {
+	client *bifrost.Bifrost
+}
+
+// NewOpenAIRouter creates a new OpenAIRouter with the given bifrost client.
+func NewOpenAIRouter(client *bifrost.Bifrost) *OpenAIRouter {
+	return &OpenAIRouter{client: client}
+}
+
+// RegisterRoutes registers all OpenAI routes on the given router.
+func (o *OpenAIRouter) RegisterRoutes(r *router.Router) {
+	r.POST("/openai/v1/chat/completions", o.handleChatCompletion)
+}
+
+// handleChatCompletion handles POST /v1/chat/completions
+func (o *OpenAIRouter) handleChatCompletion(ctx *fasthttp.RequestCtx) {
+	var req OpenAIChatRequest
+	if err := json.Unmarshal(ctx.PostBody(), &req); err != nil {
+		ctx.SetStatusCode(fasthttp.StatusBadRequest)
+		errorResponse, _ := json.Marshal(map[string]string{"error": err.Error()})
+		ctx.SetBody(errorResponse)
+		return
+	}
+
+	if req.Model == "" {
+		ctx.SetStatusCode(fasthttp.StatusBadRequest)
+		ctx.SetBodyString("Model parameter is required")
+		return
+	}
+
+	bifrostReq := req.ConvertToBifrostRequest()
+
+	bifrostCtx := lib.ConvertToBifrostContext(ctx)
+
+	result, err := o.client.ChatCompletionRequest(*bifrostCtx, bifrostReq)
+	if err != nil {
+		ctx.SetStatusCode(fasthttp.StatusInternalServerError)
+		errorResponse, _ := json.Marshal(err)
+		ctx.SetBody(errorResponse)
+		return
+	}
+
+	openaiResponse := DeriveOpenAIFromBifrostResponse(result)
+	ctx.SetStatusCode(fasthttp.StatusOK)
+	ctx.SetContentType("application/json")
+	responseBody, _ := json.Marshal(openaiResponse)
+	ctx.SetBody(responseBody)
+}