/*
Copyright (c) Edgeless Systems GmbH

SPDX-License-Identifier: AGPL-3.0-only
*/

package cmd

import (
	"context"
	"fmt"
	"io"
	"log"
	"net"
	"strconv"

	"github.com/edgelesssys/constellation/v2/debugd/internal/bootstrapper"
	"github.com/edgelesssys/constellation/v2/debugd/internal/debugd"
	pb "github.com/edgelesssys/constellation/v2/debugd/service"
	"github.com/edgelesssys/constellation/v2/internal/config"
	"github.com/edgelesssys/constellation/v2/internal/constants"
	"github.com/edgelesssys/constellation/v2/internal/file"
	"github.com/spf13/afero"
	"github.com/spf13/cobra"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
)

func newDeployCmd() *cobra.Command {
	deployCmd := &cobra.Command{
		Use:   "deploy",
		Short: "Deploys a self-compiled bootstrapper binary on the current constellation",
		Long: `Deploys a self-compiled bootstrapper binary on the current constellation.
	Uses config provided by --config and reads constellation config from its default location.
	If required, you can override the IP addresses that are used for a deployment by specifying "--ips" and a list of IP addresses.
	Specifying --bootstrapper will upload the bootstrapper from the specified path.`,
		RunE:    runDeploy,
		Example: "cdbg deploy\ncdbg deploy --config /path/to/config\ncdbg deploy --bootstrapper /path/to/bootstrapper --ips 192.0.2.1,192.0.2.2,192.0.2.3 --config /path/to/config",
	}
	deployCmd.Flags().StringSlice("ips", nil, "override the ips that the bootstrapper will be uploaded to (defaults to ips from constellation config)")
	deployCmd.Flags().String("bootstrapper", "./bootstrapper", "override the path to the bootstrapper binary uploaded to instances")
	deployCmd.Flags().StringToString("info", nil, "additional info to be passed to the debugd, in the form --info key1=value1,key2=value2")
	return deployCmd
}

func runDeploy(cmd *cobra.Command, args []string) error {
	configName, err := cmd.Flags().GetString("config")
	if err != nil {
		return fmt.Errorf("parsing config path argument: %w", err)
	}
	fileHandler := file.NewHandler(afero.NewOsFs())
	constellationConfig, err := config.FromFile(fileHandler, configName)
	if err != nil {
		return err
	}

	return deploy(cmd, fileHandler, constellationConfig, bootstrapper.NewFileStreamer(afero.NewOsFs()))
}

func deploy(cmd *cobra.Command, fileHandler file.Handler, constellationConfig *config.Config, reader fileToStreamReader) error {
	bootstrapperPath, err := cmd.Flags().GetString("bootstrapper")
	if err != nil {
		return err
	}

	if constellationConfig.IsReleaseImage() {
		log.Println("WARNING: Constellation image does not look like a debug image. Are you using a debug image?")
	}

	if !constellationConfig.IsDebugCluster() {
		log.Println("WARNING: The Constellation config has debugCluster set to false.")
		log.Println("cdbg will likely not work unless you manually adjust the firewall / load balancing rules.")
		log.Println("If you create the cluster with a debug image, you should also set debugCluster to true.")
	}

	ips, err := cmd.Flags().GetStringSlice("ips")
	if err != nil {
		return err
	}
	if len(ips) == 0 {
		var idFile clusterIDsFile
		if err := fileHandler.ReadJSON(constants.ClusterIDsFileName, &idFile); err != nil {
			return fmt.Errorf("reading cluster IDs file: %w", err)
		}
		ips = []string{idFile.IP}
	}

	infos, err := cmd.Flags().GetStringToString("info")
	if err != nil {
		return err
	}

	for _, ip := range ips {

		input := deployOnEndpointInput{
			debugdEndpoint:   ip,
			infos:            infos,
			bootstrapperPath: bootstrapperPath,
			reader:           reader,
		}
		if err := deployOnEndpoint(cmd.Context(), input); err != nil {
			return err
		}
	}

	return nil
}

type deployOnEndpointInput struct {
	debugdEndpoint   string
	bootstrapperPath string
	infos            map[string]string
	reader           fileToStreamReader
}

// deployOnEndpoint deploys a custom built bootstrapper binary to a debugd endpoint.
func deployOnEndpoint(ctx context.Context, in deployOnEndpointInput) error {
	log.Printf("Deploying on %v\n", in.debugdEndpoint)

	client, closer, err := newDebugdClient(ctx, in.debugdEndpoint)
	if err != nil {
		return fmt.Errorf("creating debugd client: %w", err)
	}
	defer closer.Close()

	if err := setInfo(ctx, client, in.infos); err != nil {
		return fmt.Errorf("sending info: %w", err)
	}

	if err := uploadBootstrapper(ctx, client, in); err != nil {
		return fmt.Errorf("uploading bootstrapper: %w", err)
	}

	return nil
}

func newDebugdClient(ctx context.Context, ip string) (pb.DebugdClient, io.Closer, error) {
	conn, err := grpc.DialContext(
		ctx,
		net.JoinHostPort(ip, strconv.Itoa(constants.DebugdPort)),
		grpc.WithTransportCredentials(insecure.NewCredentials()),
	)
	if err != nil {
		return nil, nil, fmt.Errorf("connecting to other instance via gRPC: %w", err)
	}

	return pb.NewDebugdClient(conn), conn, nil
}

func setInfo(ctx context.Context, client pb.DebugdClient, infos map[string]string) error {
	ctx, cancel := context.WithTimeout(ctx, debugd.GRPCTimeout)
	defer cancel()

	log.Printf("Setting info with length %d", len(infos))

	var infosPb []*pb.Info
	for key, value := range infos {
		infosPb = append(infosPb, &pb.Info{Key: key, Value: value})
	}

	req := &pb.SetInfoRequest{Info: infosPb}

	if _, err := client.SetInfo(ctx, req, grpc.WaitForReady(true)); err != nil {
		return fmt.Errorf("setting info: %w", err)
	}

	log.Println("Info set")
	return nil
}

func uploadBootstrapper(ctx context.Context, client pb.DebugdClient, in deployOnEndpointInput) error {
	ctx, cancel := context.WithTimeout(ctx, debugd.GRPCTimeout)
	defer cancel()

	log.Println("Uploading bootstrapper")

	stream, err := client.UploadBootstrapper(ctx, grpc.WaitForReady(true))
	if err != nil {
		return fmt.Errorf("starting bootstrapper upload to instance %v: %w", in.debugdEndpoint, err)
	}
	streamErr := in.reader.ReadStream(in.bootstrapperPath, stream, debugd.Chunksize, true)

	uploadResponse, closeErr := stream.CloseAndRecv()
	if closeErr != nil {
		return fmt.Errorf("closing upload stream after uploading bootstrapper to %v: %w", in.debugdEndpoint, closeErr)
	}
	if uploadResponse.Status == pb.UploadBootstrapperStatus_UPLOAD_BOOTSTRAPPER_FILE_EXISTS {
		log.Println("Bootstrapper was already uploaded")
		return nil
	}
	if uploadResponse.Status != pb.UploadBootstrapperStatus_UPLOAD_BOOTSTRAPPER_SUCCESS || streamErr != nil {
		return fmt.Errorf("uploading bootstrapper to instance %v failed: %v / %w", in.debugdEndpoint, uploadResponse, streamErr)
	}

	log.Println("Uploaded bootstrapper")
	return nil
}

type fileToStreamReader interface {
	ReadStream(filename string, stream bootstrapper.WriteChunkStream, chunksize uint, showProgress bool) error
}

type clusterIDsFile struct {
	ClusterID string
	OwnerID   string
	IP        string
}