package app

import (
	"context"
	"flag"
	"fmt"
	"os"

	awsconfig "github.com/aws/aws-sdk-go-v2/config"
	"github.com/go-logr/logr"
	"github.com/spf13/cobra"
	"github.com/spf13/pflag"
	"go.uber.org/zap"
	"k8s.io/component-base/version"
	"k8s.io/kubectl/pkg/scheme"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/healthz"
	zapopt "sigs.k8s.io/controller-runtime/pkg/log/zap"
	"sigs.k8s.io/controller-runtime/pkg/manager"

	"github.com/tidbcloud/infra-provider/network-policy-controller/cmd/controller/app/config"
	"github.com/tidbcloud/infra-provider/network-policy-controller/cmd/controller/app/options"
	"github.com/tidbcloud/infra-provider/network-policy-controller/pkg/apply"
	"github.com/tidbcloud/infra-provider/network-policy-controller/pkg/controllers/networkpolicy"
)

// NewCommand returns app command.
func NewCommand() *cobra.Command {
	setupLog := ctrl.Log.WithName("setup")

	opts := options.New()
	lvl := zap.NewAtomicLevelAt(zap.FatalLevel)
	zapOpts := zapopt.Options{
		Development:     true,
		StacktraceLevel: &lvl,
	}

	cmd := &cobra.Command{
		Use:  "controller",
		Long: "controller for network policy",
		Run: func(cmd *cobra.Command, _ []string) {
			fmt.Printf("%v\n", version.Get())

			ctrl.SetLogger(zapopt.New(zapopt.UseFlagOptions(&zapOpts)))
			printFlags(setupLog, cmd.Flags())

			cfg, err := opts.Config()
			if err != nil {
				setupLog.Error(err, "can't parse options to config")
				os.Exit(-1)
			}

			setupLog.Info("begin to start network policy controller")
			if err := Run(cfg); err != nil {
				setupLog.Error(err, "run controller failed")
				os.Exit(-1)
			}
		},
	}
	opts.AddFlags(cmd.Flags())
	zapOpts.BindFlags(flag.CommandLine)

	cmd.AddCommand(NewVersionCmd())

	return cmd
}

// NewVersionCmd return cmd reports version.
func NewVersionCmd() *cobra.Command {
	cmd := &cobra.Command{
		Use:  "version",
		Long: "controller version",
		Run: func(_ *cobra.Command, _ []string) {
			fmt.Printf("%v\n", version.Get())
		},
	}

	return cmd
}

// Run runs the operator.
// nolint: funlen // need more funlen
func Run(cfg *config.Config) error {
	mgr, err := newManager(cfg)
	if err != nil {
		return err
	}
	applier, err := apply.NewApplier(cfg.Kubeconfig)
	if err != nil {
		return err
	}
	awscfg, err := awsconfig.LoadDefaultConfig(context.Background())
	if err != nil {
		return err
	}
	if awscfg.Region == "" {
		return fmt.Errorf("aws region is not set")
	}

	if err = (&networkpolicy.Reconciler{
		Applier:           applier,
		DNSNamespace:      cfg.DNSNamespace,
		DNSPodSelector:    cfg.DNSPodSelector,
		LoadBalancerCIDRs: cfg.LoadBalancerCIDRs,
		ControlPlaneCIDRs: cfg.ControlPlaneCIDRs,
		O11yCIDRs:         cfg.O11yCIDRs,
		AWSConfig:         &awscfg,
	}).SetupWithManager(mgr); err != nil {
		return fmt.Errorf("unable to create NetworkPolicy controller: %w", err)
	}

	if err := mgr.AddHealthzCheck("healthz", healthz.Ping); err != nil {
		return fmt.Errorf("unable to set up health check: %w", err)
	}
	if err := mgr.AddReadyzCheck("readyz", healthz.Ping); err != nil {
		return fmt.Errorf("unable to set up ready check: %w", err)
	}

	if err := mgr.Start(ctrl.SetupSignalHandler()); err != nil {
		return fmt.Errorf("problem running manager: %w", err)
	}

	return nil
}

func newManager(cfg *config.Config) (manager.Manager, error) {
	mgr, err := manager.New(cfg.Kubeconfig, manager.Options{
		Scheme:                 scheme.Scheme,
		MetricsBindAddress:     cfg.MetricsBindAddress,
		Port:                   cfg.WebhookPort,
		HealthProbeBindAddress: cfg.HealthProbeBindAddress,
		LeaderElection:         cfg.EnableLeaderElection,
		LeaderElectionID:       "3dd07112.pingcap.com",
	})
	if err != nil {
		return nil, fmt.Errorf("unable to create manager: %w", err)
	}

	return mgr, nil
}

func printFlags(logger logr.Logger, fs *pflag.FlagSet) {
	fs.VisitAll(func(f *pflag.Flag) {
		logger.Info("FLAG", f.Name, f.Value)
	})
}