// NextNVR v0.1.0 — HTTP server and routing
// Serves the embedded SPA and API endpoints.
package main

import (
	"embed"
	"encoding/json"
	"io/fs"
	"log"
	"net/http"
	"strings"
)

//go:embed public/*
var publicFiles embed.FS

// Server wraps the HTTP server and application state.
type Server struct {
	config    Config
	http      *http.Server
	mux       *http.ServeMux
	appConfig *Config // mutable config reference for hot-reload
}

// NewServer creates and configures the HTTP server.
func NewServer(cfg Config) (*Server, error) {
	s := &Server{
		config:    cfg,
		appConfig: &cfg,
		mux:       http.NewServeMux(),
	}

	s.registerRoutes()

	s.http = &http.Server{
		Addr:    cfg.Server.BindHost + cfg.Server.Port,
		Handler: s.middleware(s.mux),
	}

	return s, nil
}

// ListenAndServe starts the HTTP server.
func (s *Server) ListenAndServe() error {
	log.Printf("HTTP server listening on %s", s.http.Addr)
	return s.http.ListenAndServe()
}

// Close shuts down the HTTP server.
func (s *Server) Close() {
	if s.http != nil {
		s.http.Close()
	}
}

// registerRoutes sets up all API and static file routes.
func (s *Server) registerRoutes() {
	// API endpoints.
	s.mux.HandleFunc("/api/cameras", s.handleCameras)
	s.mux.HandleFunc("/api/cameras/", s.handleCameraByID)
	s.mux.HandleFunc("/api/config", s.handleConfig)
	s.mux.HandleFunc("/api/scan", s.handleScan)
	s.mux.HandleFunc("/api/status", s.handleStatus)
	s.mux.HandleFunc("/api/recordings", s.handleRecordings)

	// Static file server for recordings (actual video files on disk).
	s.mux.Handle("/recordings/", http.StripPrefix("/recordings/",
		http.FileServer(http.Dir(s.config.Storage.RecordingsPath))))

	// Static file server for embedded SPA.
	publicFS, _ := fs.Sub(publicFiles, "public")
	s.mux.Handle("/", http.FileServer(http.FS(publicFS)))
}

// middleware wraps handlers with CORS and logging.
func (s *Server) middleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Access-Control-Allow-Origin", "*")
		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")
		w.Header().Set("Access-Control-Allow-Headers", "Content-Type")

		if r.Method == "OPTIONS" {
			w.WriteHeader(http.StatusOK)
			return
		}

		// API logging.
		if strings.HasPrefix(r.URL.Path, "/api/") {
			log.Printf("%s %s", r.Method, r.URL.Path)
		}

		next.ServeHTTP(w, r)
	})
}

// jsonResponse writes a JSON response with the given status code.
func jsonResponse(w http.ResponseWriter, status int, resp APIResponse) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	json.NewEncoder(w).Encode(resp)
}