// Package api provides the HTTP API server implementation for the CLI Proxy API.// It includes the main server struct, routing setup, middleware for CORS and authentication,// and integration with various AI API handlers (OpenAI, Claude, Gemini).// The server supports hot-reloading of clients and configuration.package api import (	"context"	"errors"	"fmt"	"net/http"	"strings" 	"github.com/gin-gonic/gin"	"github.com/luispater/CLIProxyAPI/internal/api/handlers"	"github.com/luispater/CLIProxyAPI/internal/api/handlers/claude"	"github.com/luispater/CLIProxyAPI/internal/api/handlers/gemini"	"github.com/luispater/CLIProxyAPI/internal/api/handlers/openai"	"github.com/luispater/CLIProxyAPI/internal/api/middleware"	"github.com/luispater/CLIProxyAPI/internal/config"	"github.com/luispater/CLIProxyAPI/internal/interfaces"	"github.com/luispater/CLIProxyAPI/internal/logging"	log "github.com/sirupsen/logrus") // Server represents the main API server.// It encapsulates the Gin engine, HTTP server, handlers, and configuration.type Server struct {	// engine is the Gin web framework engine instance.	engine *gin.Engine 	// server is the underlying HTTP server.	server *http.Server 	// handlers contains the API handlers for processing requests.	handlers *handlers.BaseAPIHandler 	// cfg holds the current server configuration.	cfg *config.Config 	// requestLogger is the request logger instance for dynamic configuration updates.	requestLogger *logging.FileRequestLogger} // NewServer creates and initializes a new API server instance.// It sets up the Gin engine, middleware, routes, and handlers.//// Parameters://   - cfg: The server configuration//   - cliClients: A slice of AI service clients//// Returns://   - *Server: A new server instancefunc NewServer(cfg *config.Config, cliClients []interfaces.Client) *Server {	// Set gin mode	if !cfg.Debug {		gin.SetMode(gin.ReleaseMode)	} 	// Create gin engine	engine := gin.New() 	// Add middleware	engine.Use(gin.Logger())	engine.Use(gin.Recovery()) 	// Add request logging middleware (positioned after recovery, before auth)	requestLogger := logging.NewFileRequestLogger(cfg.RequestLog, "logs")	engine.Use(middleware.RequestLoggingMiddleware(requestLogger)) 	engine.Use(corsMiddleware()) 	// Create server instance	s := &Server{		engine:        engine,		handlers:      handlers.NewBaseAPIHandlers(cliClients, cfg),		cfg:           cfg,		requestLogger: requestLogger,	} 	// Setup routes	s.setupRoutes() 	// Create HTTP server	s.server = &http.Server{		Addr:    fmt.Sprintf(":%d", cfg.Port),		Handler: engine,	} 	return s} // setupRoutes configures the API routes for the server.// It defines the endpoints and associates them with their respective handlers.func (s *Server) setupRoutes() {	openaiHandlers := openai.NewOpenAIAPIHandler(s.handlers)	geminiHandlers := gemini.NewGeminiAPIHandler(s.handlers)	geminiCLIHandlers := gemini.NewGeminiCLIAPIHandler(s.handlers)	claudeCodeHandlers := claude.NewClaudeCodeAPIHandler(s.handlers) 	// OpenAI compatible API routes	v1 := s.engine.Group("/v1")	v1.Use(AuthMiddleware(s.cfg))	{		v1.GET("/models", s.unifiedModelsHandler(openaiHandlers, claudeCodeHandlers))		v1.POST("/chat/completions", openaiHandlers.ChatCompletions)		v1.POST("/completions", openaiHandlers.Completions)		v1.POST("/messages", claudeCodeHandlers.ClaudeMessages)	} 	// Gemini compatible API routes	v1beta := s.engine.Group("/v1beta")	v1beta.Use(AuthMiddleware(s.cfg))	{		v1beta.GET("/models", geminiHandlers.GeminiModels)		v1beta.POST("/models/:action", geminiHandlers.GeminiHandler)		v1beta.GET("/models/:action", geminiHandlers.GeminiGetHandler)	} 	// Root endpoint	s.engine.GET("/", func(c *gin.Context) {		c.JSON(http.StatusOK, gin.H{			"message": "CLI Proxy API Server",			"version": "1.0.0",			"endpoints": []string{				"POST /v1/chat/completions",				"POST /v1/completions",				"GET /v1/models",			},		})	})	s.engine.POST("/v1internal:method", geminiCLIHandlers.CLIHandler)} // unifiedModelsHandler creates a unified handler for the /v1/models endpoint// that routes to different handlers based on the User-Agent header.// If User-Agent starts with "claude-cli", it routes to Claude handler,// otherwise it routes to OpenAI handler.func (s *Server) unifiedModelsHandler(openaiHandler *openai.OpenAIAPIHandler, claudeHandler *claude.ClaudeCodeAPIHandler) gin.HandlerFunc {	return func(c *gin.Context) {		userAgent := c.GetHeader("User-Agent") 		// Route to Claude handler if User-Agent starts with "claude-cli"		if strings.HasPrefix(userAgent, "claude-cli") {			// log.Debugf("Routing /v1/models to Claude handler for User-Agent: %s", userAgent)			claudeHandler.ClaudeModels(c)		} else {			// log.Debugf("Routing /v1/models to OpenAI handler for User-Agent: %s", userAgent)			openaiHandler.OpenAIModels(c)		}	}} // Start begins listening for and serving HTTP requests.// It's a blocking call and will only return on an unrecoverable error.//// Returns://   - error: An error if the server fails to startfunc (s *Server) Start() error {	log.Debugf("Starting API server on %s", s.server.Addr) 	// Start the HTTP server.	if err := s.server.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {		return fmt.Errorf("failed to start HTTP server: %v", err)	} 	return nil} // Stop gracefully shuts down the API server without interrupting any// active connections.//// Parameters://   - ctx: The context for graceful shutdown//// Returns://   - error: An error if the server fails to stopfunc (s *Server) Stop(ctx context.Context) error {	log.Debug("Stopping API server...") 	// Shutdown the HTTP server.	if err := s.server.Shutdown(ctx); err != nil {		return fmt.Errorf("failed to shutdown HTTP server: %v", err)	} 	log.Debug("API server stopped")	return nil} // corsMiddleware returns a Gin middleware handler that adds CORS headers// to every response, allowing cross-origin requests.//// Returns://   - gin.HandlerFunc: The CORS middleware handlerfunc corsMiddleware() gin.HandlerFunc {	return func(c *gin.Context) {		c.Header("Access-Control-Allow-Origin", "*")		c.Header("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")		c.Header("Access-Control-Allow-Headers", "Origin, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization") 		if c.Request.Method == "OPTIONS" {			c.AbortWithStatus(http.StatusNoContent)			return		} 		c.Next()	}} // UpdateClients updates the server's client list and configuration.// This method is called when the configuration or authentication tokens change.//// Parameters://   - clients: The new slice of AI service clients//   - cfg: The new application configurationfunc (s *Server) UpdateClients(clients []interfaces.Client, cfg *config.Config) {	// Update request logger enabled state if it has changed	if s.requestLogger != nil && s.cfg.RequestLog != cfg.RequestLog {		s.requestLogger.SetEnabled(cfg.RequestLog)		log.Debugf("request logging updated from %t to %t", s.cfg.RequestLog, cfg.RequestLog)	} 	s.cfg = cfg	s.handlers.UpdateClients(clients, cfg)	log.Infof("server clients and configuration updated: %d clients", len(clients))} // AuthMiddleware returns a Gin middleware handler that authenticates requests// using API keys. If no API keys are configured, it allows all requests.//// Parameters://   - cfg: The server configuration containing API keys//// Returns://   - gin.HandlerFunc: The authentication middleware handlerfunc AuthMiddleware(cfg *config.Config) gin.HandlerFunc {	return func(c *gin.Context) {		if cfg.AllowLocalhostUnauthenticated && strings.HasPrefix(c.Request.RemoteAddr, "127.0.0.1:") {			c.Next()			return		} 		if len(cfg.APIKeys) == 0 {			c.Next()			return		} 		// Get the Authorization header		authHeader := c.GetHeader("Authorization")		authHeaderGoogle := c.GetHeader("X-Goog-Api-Key")		authHeaderAnthropic := c.GetHeader("X-Api-Key") 		// Get the API key from the query parameter		apiKeyQuery, _ := c.GetQuery("key") 		if authHeader == "" && authHeaderGoogle == "" && authHeaderAnthropic == "" && apiKeyQuery == "" {			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{				"error": "Missing API key",			})			return		} 		// Extract the API key		parts := strings.Split(authHeader, " ")		var apiKey string		if len(parts) == 2 && strings.ToLower(parts[0]) == "bearer" {			apiKey = parts[1]		} else {			apiKey = authHeader		} 		// Find the API key in the in-memory list		var foundKey string		for i := range cfg.APIKeys {			if cfg.APIKeys[i] == apiKey || cfg.APIKeys[i] == authHeaderGoogle || cfg.APIKeys[i] == authHeaderAnthropic || cfg.APIKeys[i] == apiKeyQuery {				foundKey = cfg.APIKeys[i]				break			}		}		if foundKey == "" {			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{				"error": "Invalid API key",			})			return		} 		// Store the API key and user in the context		c.Set("apiKey", foundKey) 		c.Next()	}}