package main

import (
	"bytes"
	"flag"
	"log"
	"net"
	"os"
	"path/filepath"

	"google.golang.org/grpc"
	"gopkg.in/yaml.v3"

	statsv1 "github.com/bergabruh/stats-gateway/gen/stats/v1"
	"github.com/bergabruh/stats-gateway/internal/auth"
	"github.com/bergabruh/stats-gateway/internal/service"
	"github.com/bergabruh/stats-gateway/internal/storage"
	"github.com/bergabruh/stats-gateway/internal/tunnel"
)

func main() {
	addr := flag.String("addr", "127.0.0.1:50051", "listen address")
	dbPath := flag.String("db", "/var/lib/stats-gateway/stats.db", "sqlite path")
	cfgDir := flag.String("config-dir", "/etc/stats-gateway", "config dir (jwt.key, tunnel.yaml, revoked.txt)")
	flag.Parse()

	st, err := storage.Open(*dbPath)
	if err != nil {
		log.Fatalf("storage: %v", err)
	}
	defer st.Close()

	secret, err := os.ReadFile(filepath.Join(*cfgDir, "jwt.key"))
	if err != nil {
		log.Fatalf("read jwt.key: %v", err)
	}
	secret = bytes.TrimSpace(secret)

	cfgBytes, err := os.ReadFile(filepath.Join(*cfgDir, "tunnel.yaml"))
	if err != nil {
		log.Fatalf("read tunnel.yaml: %v", err)
	}
	var tunnelCfg struct {
		Egress tunnel.EgressConfig `yaml:"egress"`
	}
	if err := yaml.Unmarshal(cfgBytes, &tunnelCfg); err != nil {
		log.Fatalf("parse tunnel.yaml: %v", err)
	}

	revoked, err := auth.LoadRevokedFile(filepath.Join(*cfgDir, "revoked.txt"))
	if err != nil {
		log.Fatalf("load revoked: %v", err)
	}

	verifier := auth.NewVerifier(secret, revoked)
	handler := tunnel.NewHandler(tunnelCfg.Egress)

	lis, err := net.Listen("tcp", *addr)
	if err != nil {
		log.Fatalf("listen: %v", err)
	}

	srv := grpc.NewServer()
	statsv1.RegisterSpeedStatusServer(srv, service.New(st, verifier, handler))

	log.Printf("stats-gateway listening on %s (egress=%d targets, rate=%.0fmbps)",
		*addr, len(tunnelCfg.Egress.Allowed), tunnelCfg.Egress.RateMbps)
	if err := srv.Serve(lis); err != nil {
		log.Fatalf("serve: %v", err)
	}
}