package main

import (
	"context"
	"log"
	"net/http"
	"os"
	"os/signal"
	"strings"
	"syscall"
	"time"

	"evobgp/internal/birdfmt"
	"evobgp/internal/config"
	"evobgp/internal/dbcli"
	"evobgp/internal/httpapi"
	"evobgp/internal/logging"
	"evobgp/internal/observability"
	"evobgp/internal/platform"
	"evobgp/internal/version"
)

func main() {
	if len(os.Args) > 1 && os.Args[1] == "db" {
		os.Exit(dbcli.Run(os.Args[2:]))
	}
	cfg := config.Load()
	if err := config.ValidateProductionEnforce(); err != nil {
		log.Fatal(err)
	}
	seedDemo := os.Getenv("EVOBGP_SEED_DEMO") != "0"
	opts := httpapi.Options{
		APIKeys:            os.Getenv("EVOBGP_API_KEYS"),
		DatabaseURL:        cfg.DatabaseURL,
		InsecureDev:        os.Getenv("EVOBGP_DEV_INSECURE") == "1",
		SeedDemo:           seedDemo,
		BundleSeedHex:      strings.TrimSpace(os.Getenv("EVOBGP_BUNDLE_SEED_HEX")),
		CORSAllowedOrigins: strings.TrimSpace(os.Getenv("EVOBGP_CORS_ORIGINS")),
		JWTSecret:          firstNonEmpty(os.Getenv("EVOBGP_AUTH_JWT_SECRET"), os.Getenv("AUTH_JWT_SECRET")),
		AuthIssuer:         firstNonEmpty(os.Getenv("EVOBGP_AUTH_ISSUER"), os.Getenv("AUTH_ISSUER")),
		AuthPortalURL:      firstNonEmpty(os.Getenv("EVOBGP_AUTH_PORTAL_URL"), os.Getenv("AUTH_PORTAL_URL")),
		PortalTenantID:     strings.TrimSpace(os.Getenv("EVOBGP_PORTAL_TENANT_ID")),
		AuthRequired:       boolFromEnv("EVOBGP_AUTH_REQUIRED", "AUTH_REQUIRED"),
		AuditIngestSecret:  firstNonEmpty(os.Getenv("EVOBGP_AUTH_AUDIT_INGEST_SECRET"), os.Getenv("AUTH_AUDIT_INGEST_SECRET")),
	}
	srv, err := httpapi.New(opts)
	if err != nil {
		log.Fatal(err)
	}
	defer srv.Close()

	observability.SetBuildInfo(version.Version, version.GitSHA)
	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer stop()
	otelShutdown := observability.StartOTelIfEnabled(ctx)
	defer func() { _ = otelShutdown(context.Background()) }()

	srv.StartBackground(ctx)
	startBirdMetricsPoller(ctx)

	httpSrv := &http.Server{
		Addr:              cfg.HTTPAddr,
		Handler:           srv.Handler(),
		ReadHeaderTimeout: 10 * time.Second,
		ReadTimeout:       60 * time.Second,
		WriteTimeout:      120 * time.Second,
		IdleTimeout:       120 * time.Second,
	}
	go func() {
		svc := platform.ServiceName("evobgp-api")
		logging.Default().Info("listening", "service", svc, "addr", cfg.HTTPAddr)
		logging.Default().Info("bundle signing public key (base64, set on evobgp-node)", "key", srv.BundlePublicKeyBase64())
		if opts.SeedDemo {
			tid, mCDN, mIP, rev, sp := srv.Store().DemoIDs()
			logging.Default().Info("demo ids", "tenant", tid, "module_cdn", mCDN, "module_ip_ranges", mIP, "revision", rev, "speaker", sp)
			logging.Default().Info("example API keys", "hint", "EVOBGP_API_KEYS=op|"+tid+"|operator,node|"+tid+"|node")
			logging.Default().Info("demo auth: Authorization: Bearer dev (operator, demo tenant only)")
		}
		if err := httpSrv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatal(err)
		}
	}()

	<-ctx.Done()
	shutdownCtx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
	defer cancel()
	n := srv.Jobs().RequestCancelAll()
	if n > 0 {
		logging.Default().Info("draining jobs", "count", n)
		if err := srv.Jobs().Drain(shutdownCtx); err != nil {
			logging.Default().Warn("job drain", "err", err)
		}
	}
	if err := httpSrv.Shutdown(shutdownCtx); err != nil {
		logging.Default().Warn("HTTP shutdown", "err", err)
	}
	logging.Default().Info("stopped", "service", platform.ServiceName("evobgp-api"))
}

func firstNonEmpty(candidates ...string) string {
	for _, c := range candidates {
		if v := strings.TrimSpace(c); v != "" {
			return v
		}
	}
	return ""
}

func boolFromEnv(keys ...string) bool {
	for _, k := range keys {
		v := strings.TrimSpace(os.Getenv(k))
		if v == "" {
			continue
		}
		switch strings.ToLower(v) {
		case "1", "true", "yes", "on":
			return true
		case "0", "false", "no", "off":
			return false
		}
	}
	return false
}

func startBirdMetricsPoller(ctx context.Context) {
	sock := strings.TrimSpace(os.Getenv("EVOBGP_BIRDC_SOCKET"))
	if sock == "" {
		return
	}
	interval := 30 * time.Second
	if d, err := time.ParseDuration(strings.TrimSpace(os.Getenv("EVOBGP_BIRDC_INTERVAL"))); err == nil && d > 0 {
		interval = d
	}
	bin := strings.TrimSpace(os.Getenv("EVOBGP_BIRDC_BIN"))
	observability.StartBirdProtocolsPoller(ctx, sock, bin, interval,
		func(ctx context.Context, socket, birdcBin string) (string, error) {
			return birdfmt.ShowProtocols(ctx, socket, birdcBin)
		},
		birdfmt.CountEstablishedBGPSessions,
		birdfmt.ParseBGPProtocolStates,
	)
	log.Printf("birdc protocols poller enabled (socket=%s interval=%s)", sock, interval)
}