package server

import (
	"context"
	"fmt"
	"log/slog"
	"net/http"

	toolkitModel "git.nakama.town/fmartingr/gotoolkit/model"
	"git.nakama.town/fmartingr/hako/internal/archival/archiver"
	archivalDomain "git.nakama.town/fmartingr/hako/internal/archival/domain"
	archivalRules "git.nakama.town/fmartingr/hako/internal/archival/rules"
	archivalStore "git.nakama.town/fmartingr/hako/internal/archival/store"
	"git.nakama.town/fmartingr/hako/internal/auth"
	authDomain "git.nakama.town/fmartingr/hako/internal/auth/domain"
	"git.nakama.town/fmartingr/hako/internal/auth/store"
	"git.nakama.town/fmartingr/hako/internal/config"
	"git.nakama.town/fmartingr/hako/internal/database"
	"git.nakama.town/fmartingr/hako/internal/dependencies"
	"git.nakama.town/fmartingr/hako/internal/extractors"
	"git.nakama.town/fmartingr/hako/internal/jobs"
	"git.nakama.town/fmartingr/hako/internal/model"
	"git.nakama.town/fmartingr/hako/internal/server/handlers"
	"git.nakama.town/fmartingr/hako/internal/server/middleware"
	"git.nakama.town/fmartingr/hako/internal/storage"
	"git.nakama.town/fmartingr/hako/webapp"
)

// HTTPServer wraps the HTTP server and routes
type HTTPServer struct {
	logger *slog.Logger
	server *http.Server
	router *http.ServeMux
	fs     http.FileSystem
	worker *jobs.Worker
	config *config.Config
}

// Ensure HTTPServer implements model.Server interface
var _ toolkitModel.Server = (*HTTPServer)(nil)

// NewServer creates a new server instance
func NewServer(cfg *config.Config, logger *slog.Logger) (*HTTPServer, error) {
	// Prepare webapp filesystem
	fs, err := webapp.GetFilesystem()
	if err != nil {
		return nil, fmt.Errorf("failed to prepare webapp filesystem: %w", err)
	}
	// Connect to databases (read/write separation)
	dbConnections, err := database.NewConnections(cfg.DatabaseReadURL, cfg.DatabaseURL)
	if err != nil {
		return nil, fmt.Errorf("failed to connect to databases: %w", err)
	}

	// Run migrations to initialize/update schema
	if err := database.InitSchema(dbConnections); err != nil {
		_ = dbConnections.Close()
		return nil, fmt.Errorf("failed to run migrations: %w", err)
	}

	// Create dependencies instance
	deps := dependencies.NewDependencies(logger, dbConnections, cfg)

	// Initialize store layer with read/write connections
	userStore := store.NewUserStore(dbConnections.Read, dbConnections.Write)
	linkStore := archivalStore.NewLinkStore(dbConnections.Read, dbConnections.Write)
	archiveStore := archivalStore.NewArchiveStore(dbConnections.Read, dbConnections.Write)
	archiveFileStore := archivalStore.NewArchiveFileStore(dbConnections.Read, dbConnections.Write)
	categoryStore := archivalStore.NewCategoryStore(dbConnections.Read, dbConnections.Write)
	linkCategoryStore := archivalStore.NewLinkCategoryStore(dbConnections.Read, dbConnections.Write)
	archiverConfigStore := archivalStore.NewArchiverConfigStore(dbConnections.Read, dbConnections.Write)
	settingsStore := archivalStore.NewSettingsStore(dbConnections.Read, dbConnections.Write)

	// Initialize rule engine
	// Load rules configuration from database
	ctx := context.Background()
	rulesConfig, err := settingsStore.GetRulesConfig(ctx)
	if err != nil {
		return nil, fmt.Errorf("failed to load rules configuration: %w", err)
	}
	ruleEngine := archivalRules.NewEngineWithLogger(rulesConfig, logger)

	// Initialize JWT service
	jwtService := auth.NewJWTService(cfg.JWTSecret, cfg.JWTExpiration)

	// Initialize storage
	stor := storage.NewLocalStorage(cfg.ArchiveStoragePath)

	// Initialize archiver manager
	archiverMgr := archiver.NewManager()
	// Register obelisk archiver (default)
	if err := archiverMgr.Register(archiver.NewObeliskExtractor()); err != nil {
		return nil, fmt.Errorf("failed to register obelisk archiver: %w", err)
	}
	// Register direct download archiver (fallback)
	if err := archiverMgr.Register(archiver.NewDirectDownloadExtractor()); err != nil {
		return nil, fmt.Errorf("failed to register archiver: %w", err)
	}
	// Register thumbnail archiver
	if err := archiverMgr.Register(archiver.NewThumbnailExtractor()); err != nil {
		return nil, fmt.Errorf("failed to register thumbnail archiver: %w", err)
	}
	// Register yt-dlp archiver (optional - may be disabled when binary not available)
	if err := archiverMgr.Register(archiver.NewYtDlpArchiver()); err != nil {
		logger.Warn("Failed to register yt-dlp archiver", "error", err)
	}

	// Initialize extractor manager
	extractorMgr := extractors.NewManager(logger)
	if err := extractorMgr.Register(extractors.NewPDFExtractor()); err != nil {
		// Log error but don't fail server startup - extractor will be marked as unavailable
		logger.Error("Failed to register PDF extractor", "error", err)
	}
	if err := extractorMgr.Register(extractors.NewReadableExtractor()); err != nil {
		// Log error but don't fail server startup - extractor will be marked as unavailable
		logger.Error("Failed to register readable extractor", "error", err)
	}

	// Initialize job queue
	queue := jobs.NewMemoryQueue()

	// Set stores and other dependencies in dependencies
	deps.LinkStore = linkStore
	deps.ArchiveStore = archiveStore
	deps.ArchiveFileStore = archiveFileStore
	deps.LinkCategoryStore = linkCategoryStore
	deps.CategoryStore = categoryStore
	deps.ArchiverConfigStore = archiverConfigStore
	deps.SettingsStore = settingsStore
	deps.UserStore = userStore
	deps.Storage = stor
	deps.Queue = queue
	deps.ArchiverMgr = archiverMgr
	deps.ExtractorMgr = extractorMgr
	deps.RuleEngine = ruleEngine
	deps.JWTService = jwtService

	// Initialize domains and set them in dependencies
	deps.Domains().SetLinks(archivalDomain.NewLinkDomain(deps))
	deps.Domains().SetArchives(archivalDomain.NewArchiveDomain(deps))
	deps.Domains().SetCategories(archivalDomain.NewCategoryDomain(deps))
	deps.Domains().SetAuth(authDomain.NewAuthDomain(deps))

	// Initialize worker
	worker := jobs.NewWorker(queue, archiverMgr, extractorMgr, deps.Domains().Archives(), archiveStore, archiveFileStore, linkStore, cfg.ArchiveStoragePath, logger)

	// Initialize handlers
	authHandler := handlers.NewAuthHandler(deps)
	linkHandler := handlers.NewLinkHandler(deps, logger)
	archiveHandler := handlers.NewArchiveHandler(deps)
	categoryHandler := handlers.NewCategoryHandler(deps)
	userHandler := handlers.NewUserHandler(deps)

	// Initialize system handler (needed for extractors and archivers endpoints)
	systemHandler := handlers.NewSystemHandler(func(ctx context.Context) (string, error) {
		// Return hako application version (set via ldflags at build time)
		return model.BuildVersion, nil
	}, extractorMgr, archiverMgr, archiverConfigStore, settingsStore)

	// Initialize middleware
	// CORS middleware - handles cross-origin requests from Vite dev server
	corsMiddleware := middleware.CORSMiddleware()
	// Global auth middleware - sets context if token is present (doesn't block)
	// Also verifies that the user exists in the database
	globalAuthMiddleware := middleware.AuthMiddleware(jwtService, deps.UserStore)
	// Require auth middleware - blocks if not authenticated
	requireAuthMiddleware := middleware.RequireAuthMiddleware()
	// Require admin middleware - blocks if not admin
	requireAdminMiddleware := middleware.RequireAdminMiddleware()

	srv := &HTTPServer{
		logger: logger,
		router: http.NewServeMux(),
		fs:     fs,
		worker: worker,
		config: cfg,
	}

	// Start background worker
	go func() {
		if err := worker.Start(context.Background()); err != nil {
			logger.Error("Worker stopped", "error", err)
		}
	}()

	// Create HTTP server with middleware chain
	// Order: (Logging) → CORS → Auth → Routes
	// Logging logs all requests (if enabled), CORS handles cross-origin requests, Auth sets user context if token is present
	addr, err := cfg.GetBindAddress()
	if err != nil {
		return nil, fmt.Errorf("failed to get bind address: %w", err)
	}

	// Build middleware chain conditionally
	handler := http.Handler(srv.router)
	handler = globalAuthMiddleware(handler)
	handler = corsMiddleware(handler)

	// Add access logging middleware if enabled
	if cfg.EnableAccessLog {
		loggingMiddleware := middleware.LoggingMiddleware(logger)
		handler = loggingMiddleware(handler)
	}

	srv.server = &http.Server{
		Addr:    addr,
		Handler: handler,
	}

	// Set up API v1 routes
	// Login is public, so we handle it separately
	srv.router.HandleFunc("/api/v1/auth/login", authHandler.HandleLogin)

	// Categories endpoint (public, read-only)
	srv.router.HandleFunc("/api/v1/categories", categoryHandler.HandleListCategories)

	// Admin-only routes (all system endpoints) - register first for longest match
	adminRouter := http.NewServeMux()
	adminRouter.HandleFunc("GET /system/extractors", systemHandler.HandleExtractors)
	adminRouter.HandleFunc("GET /system/archivers", systemHandler.HandleArchivers)
	adminRouter.HandleFunc("GET /system/archivers/{key}/config", systemHandler.HandleGetArchiverConfig)
	adminRouter.HandleFunc("PUT /system/archivers/{key}/config", systemHandler.HandleSaveArchiverConfig)
	adminRouter.HandleFunc("DELETE /system/archivers/{key}/config", systemHandler.HandleDeleteArchiverConfig)
	adminRouter.HandleFunc("GET /system/rules/config", systemHandler.HandleGetRulesConfig)
	adminRouter.HandleFunc("PUT /system/rules/config", systemHandler.HandleSaveRulesConfig)
	adminRouter.HandleFunc("GET /system/users", userHandler.HandleListUsers)
	adminRouter.HandleFunc("POST /system/users", userHandler.HandleCreateUser)
	adminRouter.HandleFunc("PUT /system/users/{id}", userHandler.HandleUpdateUser)
	adminRouter.HandleFunc("PUT /system/users/{id}/password", userHandler.HandleUpdatePassword)
	adminRouter.HandleFunc("DELETE /system/users/{id}", userHandler.HandleDeleteUser)

	// Apply require auth and admin middleware to admin routes
	// The global auth middleware already set context if token was present
	adminHandler := http.StripPrefix("/api/v1", adminRouter)
	srv.router.Handle("/api/v1/system/", requireAuthMiddleware(requireAdminMiddleware(adminHandler)))

	// Protected routes require authentication
	protectedRouter := http.NewServeMux()
	protectedRouter.HandleFunc("/auth/me", authHandler.HandleGetCurrentUser)

	// Link routes
	protectedRouter.HandleFunc("POST /links", linkHandler.HandleCreateLink)
	protectedRouter.HandleFunc("GET /links", linkHandler.HandleListLinks)
	protectedRouter.HandleFunc("GET /links/{id}", linkHandler.HandleGetLink)
	protectedRouter.HandleFunc("DELETE /links/{id}", linkHandler.HandleDeleteLink)

	// Archive routes
	protectedRouter.HandleFunc("GET /links/{linkId}/archives", archiveHandler.HandleGetArchiveHistory)
	protectedRouter.HandleFunc("POST /links/{linkId}/archives", archiveHandler.HandleReArchiveLink)
	protectedRouter.HandleFunc("GET /archives/{archiveId}", archiveHandler.HandleGetArchive)
	protectedRouter.HandleFunc("DELETE /archives/{archiveId}", archiveHandler.HandleDeleteArchive)
	protectedRouter.HandleFunc("GET /archives/{archiveId}/files", archiveHandler.HandleGetArchiveFiles)
	protectedRouter.HandleFunc("GET /archives/{archiveId}/files/{fileId}/download", archiveHandler.HandleDownloadFile)

	// Apply require auth middleware to protected routes
	// The global auth middleware already set context if token was present
	protectedHandler := http.StripPrefix("/api/v1", protectedRouter)
	srv.router.Handle("/api/v1/", requireAuthMiddleware(protectedHandler))

	// System route (public) - uses handler that checks authentication
	srv.router.HandleFunc("/system", systemHandler.HandleSystem)

	// WebSocket route
	srv.router.HandleFunc("/ws", srv.handleWebSocket)

	// Static files and SPA fallback (serve last to catch all other routes)
	fileServer := http.FileServer(fs)
	srv.router.HandleFunc("/", srv.handleWebapp(fileServer))

	return srv, nil
}

// IsEnabled implements the model.Server interface
func (s *HTTPServer) IsEnabled() bool {
	return true
}

// Start starts the server - implements the model.Server interface
func (s *HTTPServer) Start(ctx context.Context) error {
	addr := s.server.Addr
	url, err := s.config.GetServerURL()
	if err != nil {
		// If we can't get the URL, log a warning but continue
		s.logger.Warn("Failed to get server URL", "error", err)
		s.logger.Info("Starting HTTP server", "address", addr)
	} else {
		s.logger.Info("Starting HTTP server", "url", url, "address", addr)
	}
	return s.server.ListenAndServe()
}

// Stop stops the server - implements the model.Server interface
func (s *HTTPServer) Stop(ctx context.Context) error {
	s.logger.Info("Stopping HTTP server")
	return s.server.Shutdown(ctx)
}

// handleWebSocket handles WebSocket connections
func (s *HTTPServer) handleWebSocket(w http.ResponseWriter, r *http.Request) {
	// WebSocket implementation will be added later
	w.WriteHeader(http.StatusNotImplemented)
	_, _ = w.Write([]byte(`{"message":"WebSocket endpoint not implemented yet"}`))
}

// handleWebapp serves the webapp with SPA fallback support
func (s *HTTPServer) handleWebapp(fileServer http.Handler) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		// Check if this is a request for a static asset (JS, CSS, images, etc.)
		// These typically have file extensions or are in /assets/ directory
		path := r.URL.Path

		// Try to open the file to see if it exists
		file, err := s.fs.Open(path)
		if err == nil {
			_ = file.Close()
			// File exists, serve it
			fileServer.ServeHTTP(w, r)
			return
		}

		// Check if it's a request for a directory or a file with extension
		// If it has an extension, it's likely a static file that doesn't exist (404)
		if hasExtension(path) {
			http.NotFound(w, r)
			return
		}

		// For all other routes, serve index.html (SPA fallback)
		// This allows Vue Router to handle client-side routing
		indexFile, err := s.fs.Open("/index.html")
		if err != nil {
			http.NotFound(w, r)
			return
		}
		defer func() { _ = indexFile.Close() }()

		stat, err := indexFile.Stat()
		if err != nil {
			http.NotFound(w, r)
			return
		}

		w.Header().Set("Content-Type", "text/html; charset=utf-8")
		http.ServeContent(w, r, "index.html", stat.ModTime(), indexFile)
	}
}

// hasExtension checks if a path has a file extension
func hasExtension(path string) bool {
	// Common static file extensions
	extensions := []string{".js", ".css", ".json", ".png", ".jpg", ".jpeg", ".gif", ".svg", ".ico", ".woff", ".woff2", ".ttf", ".eot", ".map"}
	for _, ext := range extensions {
		if len(path) >= len(ext) && path[len(path)-len(ext):] == ext {
			return true
		}
	}
	return false
}