package rest

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

	"predictor-refactored/internal/transport/middleware"
	"predictor-refactored/internal/transport/rest/handler"
	api "predictor-refactored/pkg/rest"

	"go.uber.org/zap"
)

// Transport wraps the ogen HTTP server.
type Transport struct {
	srv     *api.Server
	handler *handler.Handler
	port    int
	log     *zap.Logger
}

// New creates a new REST transport.
func New(h *handler.Handler, port int, log *zap.Logger) (*Transport, error) {
	srv, err := api.NewServer(
		h,
		api.WithMiddleware(middleware.Logging(log)),
	)
	if err != nil {
		return nil, fmt.Errorf("create ogen server: %w", err)
	}

	return &Transport{
		srv:     srv,
		handler: h,
		port:    port,
		log:     log,
	}, nil
}

// Run starts the HTTP server. Blocks until the server stops.
func (t *Transport) Run() error {
	mux := http.NewServeMux()
	mux.Handle("/", t.srv)

	httpSrv := &http.Server{
		Addr:    fmt.Sprintf(":%d", t.port),
		Handler: corsMiddleware(mux),
	}

	t.log.Info("starting HTTP server", zap.Int("port", t.port))
	return httpSrv.ListenAndServe()
}

// Shutdown gracefully stops the HTTP server.
func (t *Transport) Shutdown(ctx context.Context) error {
	// The ogen server doesn't have a shutdown method;
	// shutdown is handled by the http.Server in main.go
	return nil
}

func corsMiddleware(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, OPTIONS")
		w.Header().Set("Access-Control-Allow-Headers", "Content-Type")

		if r.Method == http.MethodOptions {
			w.WriteHeader(http.StatusNoContent)
			return
		}

		next.ServeHTTP(w, r)
	})
}