package server

import (
	"io/fs"
	"net/http"
	"time"

	"git.eeqj.de/sneak/chat/web"

	sentryhttp "github.com/getsentry/sentry-go/http"
	"github.com/go-chi/chi"
	"github.com/go-chi/chi/middleware"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"github.com/spf13/viper"
)

const routeTimeout = 60 * time.Second

// SetupRoutes configures the HTTP routes and middleware chain.
func (s *Server) SetupRoutes() {
	s.router = chi.NewRouter()

	s.router.Use(middleware.Recoverer)
	s.router.Use(middleware.RequestID)
	s.router.Use(s.mw.Logging())

	if viper.GetString("METRICS_USERNAME") != "" {
		s.router.Use(s.mw.Metrics())
	}

	s.router.Use(s.mw.CORS())
	s.router.Use(middleware.Timeout(routeTimeout))

	if s.sentryEnabled {
		sentryHandler := sentryhttp.New(sentryhttp.Options{
			Repanic: true,
		})
		s.router.Use(sentryHandler.Handle)
	}

	// Health check
	s.router.Get("/.well-known/healthcheck.json", s.h.HandleHealthCheck())

	// Protected metrics endpoint
	if viper.GetString("METRICS_USERNAME") != "" {
		s.router.Group(func(r chi.Router) {
			r.Use(s.mw.MetricsAuth())
			r.Get("/metrics", http.HandlerFunc(promhttp.Handler().ServeHTTP))
		})
	}

	// API v1
	s.router.Route("/api/v1", func(r chi.Router) {
		r.Get("/server", s.h.HandleServerInfo())
		r.Post("/session", s.h.HandleCreateSession())

		// Unified state and message endpoints
		r.Get("/state", s.h.HandleState())
		r.Get("/messages", s.h.HandleGetMessages())
		r.Post("/messages", s.h.HandleSendCommand())
		r.Get("/history", s.h.HandleGetHistory())

		// Channels
		r.Get("/channels", s.h.HandleListAllChannels())
		r.Get("/channels/{channel}/members", s.h.HandleChannelMembers())
	})

	// Serve embedded SPA
	distFS, err := fs.Sub(web.Dist, "dist")
	if err != nil {
		s.log.Error("failed to get web dist filesystem", "error", err)
	} else {
		fileServer := http.FileServer(http.FS(distFS))

		s.router.Get("/*", func(w http.ResponseWriter, r *http.Request) {
			s.serveSPA(distFS, fileServer, w, r)
		})
	}
}

func (s *Server) serveSPA(
	distFS fs.FS,
	fileServer http.Handler,
	w http.ResponseWriter,
	r *http.Request,
) {
	readFS, ok := distFS.(fs.ReadFileFS)
	if !ok {
		http.Error(w, "filesystem error", http.StatusInternalServerError)

		return
	}

	// Try to serve the file; fall back to index.html for SPA routing.
	f, err := readFS.ReadFile(r.URL.Path[1:])
	if err != nil || len(f) == 0 {
		indexHTML, _ := readFS.ReadFile("index.html")

		w.Header().Set("Content-Type", "text/html; charset=utf-8")
		w.WriteHeader(http.StatusOK)
		_, _ = w.Write(indexHTML)

		return
	}

	fileServer.ServeHTTP(w, r)
}