package deployer

import (
	"context"
	"errors"
	"strings"

	"github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/container"
	"github.com/docker/docker/api/types/filters"
	"github.com/docker/docker/api/types/swarm"
	"github.com/docker/docker/client"
	"github.com/docker/go-connections/nat"
	"github.com/rs/zerolog/log"

	localcli "localenv/client"
	"localenv/services"
)

const (
	SwarmImageName     string = "localenv-swarm:latest"
	SwarmContainerName string = "localenv-swarm"
)

var (
	ErrSwarmNotFound   = errors.New("unable to find the swarm")
	ErrSwarmClientInit = errors.New("swarm client is not initialized")

	ImagesDeps = []string{
		services.PostgresImageName,
		services.RabbitMQImageName,
		services.NginxImageName,
		services.MailhogImageName,
	}
)

type Deployer struct {
	swarm Swarm
	cli   *client.Client
}

func NewDeployer(ctx context.Context, cli *client.Client) (Deployer, error) {
	var deployer Deployer
	deployer.cli = cli

	if err := deployer.init(ctx); err != nil {
		return deployer, err
	}

	return deployer, nil
}

func (d Deployer) getSwarm(ctx context.Context) (string, error) {
	filterArgs := filters.NewArgs()
	filterArgs.Add("name", SwarmContainerName)
	filterArgs.Add("ancestor", SwarmImageName)

	options := types.ContainerListOptions{
		Filters: filterArgs,
		All:     true,
	}

	containers, err := d.cli.ContainerList(ctx, options)
	if err != nil {
		return "", err
	}

	if len(containers) == 0 {
		return "", ErrSwarmNotFound
	}

	return containers[0].ID, nil
}

func (d Deployer) createSwarm(ctx context.Context) (string, error) {
	containerConfig := container.Config{
		Image: SwarmImageName,
		ExposedPorts: nat.PortSet{
			"4523/tcp":  struct{}{},
			"4443/tcp":  struct{}{},
			"15672/tcp": struct{}{},
		},
	}

	hostConfig := container.HostConfig{
		Runtime: "sysbox-runc",
		PortBindings: nat.PortMap{
			// swarm dockerd
			"4523/tcp": []nat.PortBinding{
				{
					HostIP:   "0.0.0.0",
					HostPort: "4523",
				},
			},
			// nginx ssl
			"4443/tcp": []nat.PortBinding{
				{
					HostIP:   "0.0.0.0",
					HostPort: "4443",
				},
			},
			// rabbitmq admin interface
			"15672/tcp": []nat.PortBinding{
				{
					HostIP:   "0.0.0.0",
					HostPort: "15672",
				},
			},
		},
		NetworkMode: "bridge",
	}

	resp, err := d.cli.ContainerCreate(ctx, &containerConfig, &hostConfig, nil, nil, SwarmContainerName)
	if err != nil {
		return "", err
	}

	log.Info().Msg("swarm created successfully")
	return resp.ID, nil
}

func (d Deployer) initSwarm(ctx context.Context) error {
	req := swarm.InitRequest{
		ListenAddr:    "0.0.0.0:2377",
		AdvertiseAddr: "127.0.0.1",
	}

	if _, err := d.swarm.cli.SwarmInit(ctx, req); err != nil {
		if strings.Contains(err.Error(), "part of a swarm") {
			log.Info().Msg("swarm already initialized")
			return nil
		}
		return err
	}

	return nil
}

func (d Deployer) StopSwarm(ctx context.Context) error {
	if d.swarm.ID == "" {
		log.Warn().Msg("no swarm registered, can't stop")
		return nil
	}

	options := container.StopOptions{}

	if err := d.cli.ContainerStop(ctx, d.swarm.ID, options); err != nil {
		return err
	}

	log.Info().Msg("swarm stopped successfully")
	return nil
}

// TODO(rmanach): get a child context instead
func (d *Deployer) init(ctx context.Context) error {
	swarmID, err := d.getSwarm(ctx)
	if err != nil {
		if !errors.Is(err, ErrSwarmNotFound) {
			return err
		}
	}

	s := Swarm{swarmID, nil}

	if swarmID == "" {
		id, err := d.createSwarm(ctx)
		if err != nil {
			return err
		}
		s.ID = id
	}

	if err := d.cli.ContainerStart(ctx, s.ID, types.ContainerStartOptions{}); err != nil {
		return err
	}

	cli, errInit := localcli.GetSwarmClient()
	if errInit != nil {
		if err := d.StopSwarm(ctx); err != nil {
			log.Err(err).Msg("unable to stop the swarm")
		}
		return errInit
	}

	s.cli = cli
	d.swarm = s

	if err := d.initSwarm(ctx); err != nil {
		return err
	}

	log.Info().Msg("deployer successfully initialized")
	return nil
}

func (d *Deployer) Deploy(ctx context.Context) error {
	if err := d.swarm.deployServices(ctx); err != nil {
		return err
	}

	return nil
}

func (d *Deployer) GetSwarmCLI() (*client.Client, error) {
	if d.swarm.cli == nil {
		return nil, ErrSwarmClientInit
	}

	return d.swarm.cli, nil
}