feat: migrate backend from rust to go

This commit replaces the Axum/Rust backend with a Gin/Go implementation. The original Rust code has been archived in the 'rust' branch.

internal/server/server.go

@@ -0,0 +1,326 @@
+package server
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"llm-proxy/internal/config"
+	"llm-proxy/internal/db"
+	"llm-proxy/internal/middleware"
+	"llm-proxy/internal/models"
+	"llm-proxy/internal/providers"
+	"llm-proxy/internal/utils"
+
+	"github.com/gin-gonic/gin"
+)
+
+type Server struct {
+	router    *gin.Engine
+	cfg       *config.Config
+	database  *db.DB
+	providers map[string]providers.Provider
+	sessions  *SessionManager
+	hub       *Hub
+	logger    *RequestLogger
+}
+
+func NewServer(cfg *config.Config, database *db.DB) *Server {
+	router := gin.Default()
+	hub := NewHub()
+	
+	s := &Server{
+		router:    router,
+		cfg:       cfg,
+		database:  database,
+		providers: make(map[string]providers.Provider),
+		sessions:  NewSessionManager(cfg.KeyBytes, 24*time.Hour),
+		hub:       hub,
+		logger:    NewRequestLogger(database, hub),
+	}
+
+	// Initialize providers
+	if cfg.Providers.OpenAI.Enabled {
+		apiKey, _ := cfg.GetAPIKey("openai")
+		s.providers["openai"] = providers.NewOpenAIProvider(cfg.Providers.OpenAI, apiKey)
+	}
+	if cfg.Providers.Gemini.Enabled {
+		apiKey, _ := cfg.GetAPIKey("gemini")
+		s.providers["gemini"] = providers.NewGeminiProvider(cfg.Providers.Gemini, apiKey)
+	}
+	if cfg.Providers.DeepSeek.Enabled {
+		apiKey, _ := cfg.GetAPIKey("deepseek")
+		s.providers["deepseek"] = providers.NewDeepSeekProvider(cfg.Providers.DeepSeek, apiKey)
+	}
+	if cfg.Providers.Grok.Enabled {
+		apiKey, _ := cfg.GetAPIKey("grok")
+		s.providers["grok"] = providers.NewGrokProvider(cfg.Providers.Grok, apiKey)
+	}
+
+	s.setupRoutes()
+	return s
+}
+
+func (s *Server) setupRoutes() {
+	s.router.Use(middleware.AuthMiddleware(s.database))
+
+	// Static files
+	s.router.Static("/static", "./static")
+	s.router.StaticFile("/", "./static/index.html")
+	s.router.StaticFile("/favicon.ico", "./static/favicon.ico")
+
+	// WebSocket
+	s.router.GET("/ws", s.handleWebSocket)
+
+	v1 := s.router.Group("/v1")
+	{
+		v1.POST("/chat/completions", s.handleChatCompletions)
+	}
+
+	// Dashboard API Group
+	api := s.router.Group("/api")
+	{
+		api.POST("/auth/login", s.handleLogin)
+		api.GET("/auth/status", s.handleAuthStatus)
+		api.POST("/auth/logout", s.handleLogout)
+		
+		// Protected dashboard routes (need admin session)
+		admin := api.Group("/")
+		admin.Use(s.adminAuthMiddleware())
+		{
+			admin.GET("/usage/summary", s.handleUsageSummary)
+			admin.GET("/usage/time-series", s.handleTimeSeries)
+			admin.GET("/analytics/breakdown", s.handleAnalyticsBreakdown)
+			
+			admin.GET("/clients", s.handleGetClients)
+			admin.POST("/clients", s.handleCreateClient)
+			admin.DELETE("/clients/:id", s.handleDeleteClient)
+			
+			admin.GET("/clients/:id/tokens", s.handleGetClientTokens)
+			admin.POST("/clients/:id/tokens", s.handleCreateClientToken)
+			admin.DELETE("/clients/:id/tokens/:token_id", s.handleDeleteClientToken)
+
+			admin.GET("/providers", s.handleGetProviders)
+			admin.PUT("/providers/:name", s.handleUpdateProvider)
+			admin.GET("/models", s.handleGetModels)
+
+			admin.GET("/users", s.handleGetUsers)
+			admin.POST("/users", s.handleCreateUser)
+			admin.PUT("/users/:id", s.handleUpdateUser)
+			admin.DELETE("/users/:id", s.handleDeleteUser)
+
+			admin.GET("/system/health", s.handleSystemHealth)
+		}
+	}
+
+	s.router.GET("/health", func(c *gin.Context) {
+		c.JSON(http.StatusOK, gin.H{"status": "ok"})
+	})
+}
+
+func (s *Server) handleChatCompletions(c *gin.Context) {
+	startTime := time.Now()
+	var req models.ChatCompletionRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	// Select provider based on model name
+	providerName := "openai" // default
+	if strings.Contains(req.Model, "gemini") {
+		providerName = "gemini"
+	} else if strings.Contains(req.Model, "deepseek") {
+		providerName = "deepseek"
+	} else if strings.Contains(req.Model, "grok") {
+		providerName = "grok"
+	}
+
+	provider, ok := s.providers[providerName]
+	if !ok {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": fmt.Sprintf("Provider %s not enabled or supported", providerName)})
+		return
+	}
+
+	// Convert ChatCompletionRequest to UnifiedRequest
+	unifiedReq := &models.UnifiedRequest{
+		Model:            req.Model,
+		Messages:         []models.UnifiedMessage{},
+		Temperature:      req.Temperature,
+		TopP:             req.TopP,
+		TopK:             req.TopK,
+		N:                req.N,
+		MaxTokens:        req.MaxTokens,
+		PresencePenalty:  req.PresencePenalty,
+		FrequencyPenalty: req.FrequencyPenalty,
+		Stream:           req.Stream != nil && *req.Stream,
+		Tools:            req.Tools,
+		ToolChoice:       req.ToolChoice,
+	}
+
+	// Handle Stop sequences
+	if req.Stop != nil {
+		var stop []string
+		if err := json.Unmarshal(req.Stop, &stop); err == nil {
+			unifiedReq.Stop = stop
+		} else {
+			var singleStop string
+			if err := json.Unmarshal(req.Stop, &singleStop); err == nil {
+				unifiedReq.Stop = []string{singleStop}
+			}
+		}
+	}
+
+	// Convert messages
+	for _, msg := range req.Messages {
+		unifiedMsg := models.UnifiedMessage{
+			Role:             msg.Role,
+			Content:          []models.UnifiedContentPart{},
+			ReasoningContent: msg.ReasoningContent,
+			ToolCalls:        msg.ToolCalls,
+			Name:             msg.Name,
+			ToolCallID:       msg.ToolCallID,
+		}
+
+		// Handle multimodal content
+		if strContent, ok := msg.Content.(string); ok {
+			unifiedMsg.Content = append(unifiedMsg.Content, models.UnifiedContentPart{
+				Type: "text",
+				Text: strContent,
+			})
+		} else if parts, ok := msg.Content.([]interface{}); ok {
+			for _, part := range parts {
+				if partMap, ok := part.(map[string]interface{}); ok {
+					partType, _ := partMap["type"].(string)
+					if partType == "text" {
+						text, _ := partMap["text"].(string)
+						unifiedMsg.Content = append(unifiedMsg.Content, models.UnifiedContentPart{
+							Type: "text",
+							Text: text,
+						})
+					} else if partType == "image_url" {
+						if imgURLMap, ok := partMap["image_url"].(map[string]interface{}); ok {
+							url, _ := imgURLMap["url"].(string)
+							imageInput := &models.ImageInput{}
+							if strings.HasPrefix(url, "data:") {
+								mime, data, err := utils.ParseDataURL(url)
+								if err == nil {
+									imageInput.Base64 = data
+									imageInput.MimeType = mime
+								}
+							} else {
+								imageInput.URL = url
+							}
+							unifiedMsg.Content = append(unifiedMsg.Content, models.UnifiedContentPart{
+								Type:  "image",
+								Image: imageInput,
+							})
+							unifiedReq.HasImages = true
+						}
+					}
+				}
+			}
+		}
+
+		unifiedReq.Messages = append(unifiedReq.Messages, unifiedMsg)
+	}
+
+	clientID := "default"
+	if auth, ok := c.Get("auth"); ok {
+		if authInfo, ok := auth.(models.AuthInfo); ok {
+			unifiedReq.ClientID = authInfo.ClientID
+			clientID = authInfo.ClientID
+		}
+	} else {
+		unifiedReq.ClientID = clientID
+	}
+
+	if unifiedReq.Stream {
+		ch, err := provider.ChatCompletionStream(c.Request.Context(), unifiedReq)
+		if err != nil {
+			s.logRequest(startTime, clientID, providerName, req.Model, nil, err, unifiedReq.HasImages)
+			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+			return
+		}
+
+		c.Header("Content-Type", "text/event-stream")
+		c.Header("Cache-Control", "no-cache")
+		c.Header("Connection", "keep-alive")
+
+		var lastUsage *models.Usage
+		c.Stream(func(w io.Writer) bool {
+			chunk, ok := <-ch
+			if !ok {
+				fmt.Fprintf(w, "data: [DONE]\n\n")
+				s.logRequest(startTime, clientID, providerName, req.Model, lastUsage, nil, unifiedReq.HasImages)
+				return false
+			}
+			if chunk.Usage != nil {
+				lastUsage = chunk.Usage
+			}
+			data, err := json.Marshal(chunk)
+			if err != nil {
+				return false
+			}
+			fmt.Fprintf(w, "data: %s\n\n", data)
+			return true
+		})
+		return
+	}
+
+	resp, err := provider.ChatCompletion(c.Request.Context(), unifiedReq)
+	if err != nil {
+		s.logRequest(startTime, clientID, providerName, req.Model, nil, err, unifiedReq.HasImages)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	s.logRequest(startTime, clientID, providerName, req.Model, resp.Usage, nil, unifiedReq.HasImages)
+	c.JSON(http.StatusOK, resp)
+}
+
+func (s *Server) logRequest(start time.Time, clientID, provider, model string, usage *models.Usage, err error, hasImages bool) {
+	entry := RequestLog{
+		Timestamp:  start,
+		ClientID:   clientID,
+		Provider:   provider,
+		Model:      model,
+		Status:     "success",
+		DurationMS: time.Since(start).Milliseconds(),
+		HasImages:  hasImages,
+	}
+
+	if err != nil {
+		entry.Status = "error"
+		entry.ErrorMessage = err.Error()
+	}
+
+	if usage != nil {
+		entry.PromptTokens = usage.PromptTokens
+		entry.CompletionTokens = usage.CompletionTokens
+		entry.TotalTokens = usage.TotalTokens
+		if usage.ReasoningTokens != nil {
+			entry.ReasoningTokens = *usage.ReasoningTokens
+		}
+		if usage.CacheReadTokens != nil {
+			entry.CacheReadTokens = *usage.CacheReadTokens
+		}
+		if usage.CacheWriteTokens != nil {
+			entry.CacheWriteTokens = *usage.CacheWriteTokens
+		}
+		// TODO: Calculate cost properly based on pricing
+		entry.Cost = 0.0 
+	}
+
+	s.logger.LogRequest(entry)
+}
+
+func (s *Server) Run() error {
+	go s.hub.Run()
+	s.logger.Start()
+	addr := fmt.Sprintf("%s:%d", s.cfg.Server.Host, s.cfg.Server.Port)
+	return s.router.Run(addr)
+}