package service

import (
	"fmt"
	"strconv"
	"strings"
	"time"

	"github.com/docker/docker/api/types/container"
	"github.com/docker/docker/api/types/swarm"
	"github.com/docker/docker/opts"
	runconfigopts "github.com/docker/docker/runconfig/opts"
	"github.com/docker/go-connections/nat"
	units "github.com/docker/go-units"
	"github.com/spf13/cobra"
)

type int64Value interface {
	Value() int64
}

type memBytes int64

func (m *memBytes) String() string {
	return units.BytesSize(float64(m.Value()))
}

func (m *memBytes) Set(value string) error {
	val, err := units.RAMInBytes(value)
	*m = memBytes(val)
	return err
}

func (m *memBytes) Type() string {
	return "MemoryBytes"
}

func (m *memBytes) Value() int64 {
	return int64(*m)
}

// PositiveDurationOpt is an option type for time.Duration that uses a pointer.
// It bahave similarly to DurationOpt but only allows positive duration values.
type PositiveDurationOpt struct {
	DurationOpt
}

// Set a new value on the option. Setting a negative duration value will cause
// an error to be returned.
func (d *PositiveDurationOpt) Set(s string) error {
	err := d.DurationOpt.Set(s)
	if err != nil {
		return err
	}
	if *d.DurationOpt.value < 0 {
		return fmt.Errorf("duration cannot be negative")
	}
	return nil
}

// DurationOpt is an option type for time.Duration that uses a pointer. This
// allows us to get nil values outside, instead of defaulting to 0
type DurationOpt struct {
	value *time.Duration
}

// Set a new value on the option
func (d *DurationOpt) Set(s string) error {
	v, err := time.ParseDuration(s)
	d.value = &v
	return err
}

// Type returns the type of this option
func (d *DurationOpt) Type() string {
	return "duration-ptr"
}

// String returns a string repr of this option
func (d *DurationOpt) String() string {
	if d.value != nil {
		return d.value.String()
	}
	return "none"
}

// Value returns the time.Duration
func (d *DurationOpt) Value() *time.Duration {
	return d.value
}

// Uint64Opt represents a uint64.
type Uint64Opt struct {
	value *uint64
}

// Set a new value on the option
func (i *Uint64Opt) Set(s string) error {
	v, err := strconv.ParseUint(s, 0, 64)
	i.value = &v
	return err
}

// Type returns the type of this option
func (i *Uint64Opt) Type() string {
	return "uint64-ptr"
}

// String returns a string repr of this option
func (i *Uint64Opt) String() string {
	if i.value != nil {
		return fmt.Sprintf("%v", *i.value)
	}
	return "none"
}

// Value returns the uint64
func (i *Uint64Opt) Value() *uint64 {
	return i.value
}

type updateOptions struct {
	parallelism     uint64
	delay           time.Duration
	monitor         time.Duration
	onFailure       string
	maxFailureRatio float32
}

type resourceOptions struct {
	limitCPU      opts.NanoCPUs
	limitMemBytes memBytes
	resCPU        opts.NanoCPUs
	resMemBytes   memBytes
}

func (r *resourceOptions) ToResourceRequirements() *swarm.ResourceRequirements {
	return &swarm.ResourceRequirements{
		Limits: &swarm.Resources{
			NanoCPUs:    r.limitCPU.Value(),
			MemoryBytes: r.limitMemBytes.Value(),
		},
		Reservations: &swarm.Resources{
			NanoCPUs:    r.resCPU.Value(),
			MemoryBytes: r.resMemBytes.Value(),
		},
	}
}

type restartPolicyOptions struct {
	condition   string
	delay       DurationOpt
	maxAttempts Uint64Opt
	window      DurationOpt
}

func (r *restartPolicyOptions) ToRestartPolicy() *swarm.RestartPolicy {
	return &swarm.RestartPolicy{
		Condition:   swarm.RestartPolicyCondition(r.condition),
		Delay:       r.delay.Value(),
		MaxAttempts: r.maxAttempts.Value(),
		Window:      r.window.Value(),
	}
}

func convertNetworks(networks []string) []swarm.NetworkAttachmentConfig {
	nets := []swarm.NetworkAttachmentConfig{}
	for _, network := range networks {
		nets = append(nets, swarm.NetworkAttachmentConfig{Target: network})
	}
	return nets
}

type endpointOptions struct {
	mode  string
	ports opts.ListOpts
}

func (e *endpointOptions) ToEndpointSpec() *swarm.EndpointSpec {
	portConfigs := []swarm.PortConfig{}
	// We can ignore errors because the format was already validated by ValidatePort
	ports, portBindings, _ := nat.ParsePortSpecs(e.ports.GetAll())

	for port := range ports {
		portConfigs = append(portConfigs, convertPortToPortConfig(port, portBindings)...)
	}

	return &swarm.EndpointSpec{
		Mode:  swarm.ResolutionMode(strings.ToLower(e.mode)),
		Ports: portConfigs,
	}
}

func convertPortToPortConfig(
	port nat.Port,
	portBindings map[nat.Port][]nat.PortBinding,
) []swarm.PortConfig {
	ports := []swarm.PortConfig{}

	for _, binding := range portBindings[port] {
		hostPort, _ := strconv.ParseUint(binding.HostPort, 10, 16)
		ports = append(ports, swarm.PortConfig{
			//TODO Name: ?
			Protocol:      swarm.PortConfigProtocol(strings.ToLower(port.Proto())),
			TargetPort:    uint32(port.Int()),
			PublishedPort: uint32(hostPort),
		})
	}
	return ports
}

type logDriverOptions struct {
	name string
	opts opts.ListOpts
}

func newLogDriverOptions() logDriverOptions {
	return logDriverOptions{opts: opts.NewListOpts(runconfigopts.ValidateEnv)}
}

func (ldo *logDriverOptions) toLogDriver() *swarm.Driver {
	if ldo.name == "" {
		return nil
	}

	// set the log driver only if specified.
	return &swarm.Driver{
		Name:    ldo.name,
		Options: runconfigopts.ConvertKVStringsToMap(ldo.opts.GetAll()),
	}
}

type healthCheckOptions struct {
	cmd           string
	interval      PositiveDurationOpt
	timeout       PositiveDurationOpt
	retries       int
	noHealthcheck bool
}

func (opts *healthCheckOptions) toHealthConfig() (*container.HealthConfig, error) {
	var healthConfig *container.HealthConfig
	haveHealthSettings := opts.cmd != "" ||
		opts.interval.Value() != nil ||
		opts.timeout.Value() != nil ||
		opts.retries != 0
	if opts.noHealthcheck {
		if haveHealthSettings {
			return nil, fmt.Errorf("--%s conflicts with --health-* options", flagNoHealthcheck)
		}
		healthConfig = &container.HealthConfig{Test: []string{"NONE"}}
	} else if haveHealthSettings {
		var test []string
		if opts.cmd != "" {
			test = []string{"CMD-SHELL", opts.cmd}
		}
		var interval, timeout time.Duration
		if ptr := opts.interval.Value(); ptr != nil {
			interval = *ptr
		}
		if ptr := opts.timeout.Value(); ptr != nil {
			timeout = *ptr
		}
		healthConfig = &container.HealthConfig{
			Test:     test,
			Interval: interval,
			Timeout:  timeout,
			Retries:  opts.retries,
		}
	}
	return healthConfig, nil
}

// ValidatePort validates a string is in the expected format for a port definition
func ValidatePort(value string) (string, error) {
	portMappings, err := nat.ParsePortSpec(value)
	for _, portMapping := range portMappings {
		if portMapping.Binding.HostIP != "" {
			return "", fmt.Errorf("HostIP is not supported by a service.")
		}
	}
	return value, err
}

type serviceOptions struct {
	name            string
	labels          opts.ListOpts
	containerLabels opts.ListOpts
	image           string
	args            []string
	hostname        string
	env             opts.ListOpts
	envFile         opts.ListOpts
	workdir         string
	user            string
	groups          []string
	mounts          opts.MountOpt

	resources resourceOptions
	stopGrace DurationOpt

	replicas Uint64Opt
	mode     string

	restartPolicy restartPolicyOptions
	constraints   []string
	update        updateOptions
	networks      []string
	endpoint      endpointOptions

	registryAuth bool

	logDriver logDriverOptions

	healthcheck healthCheckOptions
}

func newServiceOptions() *serviceOptions {
	return &serviceOptions{
		labels:          opts.NewListOpts(runconfigopts.ValidateEnv),
		containerLabels: opts.NewListOpts(runconfigopts.ValidateEnv),
		env:             opts.NewListOpts(runconfigopts.ValidateEnv),
		envFile:         opts.NewListOpts(nil),
		endpoint: endpointOptions{
			ports: opts.NewListOpts(ValidatePort),
		},
		logDriver: newLogDriverOptions(),
	}
}

func (opts *serviceOptions) ToService() (swarm.ServiceSpec, error) {
	var service swarm.ServiceSpec

	envVariables, err := runconfigopts.ReadKVStrings(opts.envFile.GetAll(), opts.env.GetAll())
	if err != nil {
		return service, err
	}

	currentEnv := make([]string, 0, len(envVariables))
	for _, env := range envVariables { // need to process each var, in order
		k := strings.SplitN(env, "=", 2)[0]
		for i, current := range currentEnv { // remove duplicates
			if current == env {
				continue // no update required, may hide this behind flag to preserve order of envVariables
			}
			if strings.HasPrefix(current, k+"=") {
				currentEnv = append(currentEnv[:i], currentEnv[i+1:]...)
			}
		}
		currentEnv = append(currentEnv, env)
	}

	service = swarm.ServiceSpec{
		Annotations: swarm.Annotations{
			Name:   opts.name,
			Labels: runconfigopts.ConvertKVStringsToMap(opts.labels.GetAll()),
		},
		TaskTemplate: swarm.TaskSpec{
			ContainerSpec: swarm.ContainerSpec{
				Image:           opts.image,
				Args:            opts.args,
				Env:             currentEnv,
				Hostname:        opts.hostname,
				Labels:          runconfigopts.ConvertKVStringsToMap(opts.containerLabels.GetAll()),
				Dir:             opts.workdir,
				User:            opts.user,
				Groups:          opts.groups,
				Mounts:          opts.mounts.Value(),
				StopGracePeriod: opts.stopGrace.Value(),
			},
			Networks:      convertNetworks(opts.networks),
			Resources:     opts.resources.ToResourceRequirements(),
			RestartPolicy: opts.restartPolicy.ToRestartPolicy(),
			Placement: &swarm.Placement{
				Constraints: opts.constraints,
			},
			LogDriver: opts.logDriver.toLogDriver(),
		},
		Networks: convertNetworks(opts.networks),
		Mode:     swarm.ServiceMode{},
		UpdateConfig: &swarm.UpdateConfig{
			Parallelism:     opts.update.parallelism,
			Delay:           opts.update.delay,
			Monitor:         opts.update.monitor,
			FailureAction:   opts.update.onFailure,
			MaxFailureRatio: opts.update.maxFailureRatio,
		},
		EndpointSpec: opts.endpoint.ToEndpointSpec(),
	}

	healthConfig, err := opts.healthcheck.toHealthConfig()
	if err != nil {
		return service, err
	}
	service.TaskTemplate.ContainerSpec.Healthcheck = healthConfig

	switch opts.mode {
	case "global":
		if opts.replicas.Value() != nil {
			return service, fmt.Errorf("replicas can only be used with replicated mode")
		}

		service.Mode.Global = &swarm.GlobalService{}
	case "replicated":
		service.Mode.Replicated = &swarm.ReplicatedService{
			Replicas: opts.replicas.Value(),
		}
	default:
		return service, fmt.Errorf("Unknown mode: %s", opts.mode)
	}
	return service, nil
}

// addServiceFlags adds all flags that are common to both `create` and `update`.
// Any flags that are not common are added separately in the individual command
func addServiceFlags(cmd *cobra.Command, opts *serviceOptions) {
	flags := cmd.Flags()

	flags.StringVarP(&opts.workdir, flagWorkdir, "w", "", "Working directory inside the container")
	flags.StringVarP(&opts.user, flagUser, "u", "", "Username or UID (format: <name|uid>[:<group|gid>])")

	flags.Var(&opts.resources.limitCPU, flagLimitCPU, "Limit CPUs")
	flags.Var(&opts.resources.limitMemBytes, flagLimitMemory, "Limit Memory")
	flags.Var(&opts.resources.resCPU, flagReserveCPU, "Reserve CPUs")
	flags.Var(&opts.resources.resMemBytes, flagReserveMemory, "Reserve Memory")
	flags.Var(&opts.stopGrace, flagStopGracePeriod, "Time to wait before force killing a container")

	flags.Var(&opts.replicas, flagReplicas, "Number of tasks")

	flags.StringVar(&opts.restartPolicy.condition, flagRestartCondition, "", "Restart when condition is met (none, on-failure, or any)")
	flags.Var(&opts.restartPolicy.delay, flagRestartDelay, "Delay between restart attempts")
	flags.Var(&opts.restartPolicy.maxAttempts, flagRestartMaxAttempts, "Maximum number of restarts before giving up")
	flags.Var(&opts.restartPolicy.window, flagRestartWindow, "Window used to evaluate the restart policy")

	flags.Uint64Var(&opts.update.parallelism, flagUpdateParallelism, 1, "Maximum number of tasks updated simultaneously (0 to update all at once)")
	flags.DurationVar(&opts.update.delay, flagUpdateDelay, time.Duration(0), "Delay between updates")
	flags.DurationVar(&opts.update.monitor, flagUpdateMonitor, time.Duration(0), "Duration after each task update to monitor for failure")
	flags.StringVar(&opts.update.onFailure, flagUpdateFailureAction, "pause", "Action on update failure (pause|continue)")
	flags.Float32Var(&opts.update.maxFailureRatio, flagUpdateMaxFailureRatio, 0, "Failure rate to tolerate during an update")

	flags.StringVar(&opts.endpoint.mode, flagEndpointMode, "", "Endpoint mode (vip or dnsrr)")

	flags.BoolVar(&opts.registryAuth, flagRegistryAuth, false, "Send registry authentication details to swarm agents")

	flags.StringVar(&opts.logDriver.name, flagLogDriver, "", "Logging driver for service")
	flags.Var(&opts.logDriver.opts, flagLogOpt, "Logging driver options")

	flags.StringVar(&opts.healthcheck.cmd, flagHealthCmd, "", "Command to run to check health")
	flags.Var(&opts.healthcheck.interval, flagHealthInterval, "Time between running the check")
	flags.Var(&opts.healthcheck.timeout, flagHealthTimeout, "Maximum time to allow one check to run")
	flags.IntVar(&opts.healthcheck.retries, flagHealthRetries, 0, "Consecutive failures needed to report unhealthy")
	flags.BoolVar(&opts.healthcheck.noHealthcheck, flagNoHealthcheck, false, "Disable any container-specified HEALTHCHECK")
}

const (
	flagConstraint            = "constraint"
	flagConstraintRemove      = "constraint-rm"
	flagConstraintAdd         = "constraint-add"
	flagContainerLabel        = "container-label"
	flagContainerLabelRemove  = "container-label-rm"
	flagContainerLabelAdd     = "container-label-add"
	flagEndpointMode          = "endpoint-mode"
	flagHostname              = "hostname"
	flagEnv                   = "env"
	flagEnvFile               = "env-file"
	flagEnvRemove             = "env-rm"
	flagEnvAdd                = "env-add"
	flagGroup                 = "group"
	flagGroupAdd              = "group-add"
	flagGroupRemove           = "group-rm"
	flagLabel                 = "label"
	flagLabelRemove           = "label-rm"
	flagLabelAdd              = "label-add"
	flagLimitCPU              = "limit-cpu"
	flagLimitMemory           = "limit-memory"
	flagMode                  = "mode"
	flagMount                 = "mount"
	flagMountRemove           = "mount-rm"
	flagMountAdd              = "mount-add"
	flagName                  = "name"
	flagNetwork               = "network"
	flagPublish               = "publish"
	flagPublishRemove         = "publish-rm"
	flagPublishAdd            = "publish-add"
	flagReplicas              = "replicas"
	flagReserveCPU            = "reserve-cpu"
	flagReserveMemory         = "reserve-memory"
	flagRestartCondition      = "restart-condition"
	flagRestartDelay          = "restart-delay"
	flagRestartMaxAttempts    = "restart-max-attempts"
	flagRestartWindow         = "restart-window"
	flagStopGracePeriod       = "stop-grace-period"
	flagUpdateDelay           = "update-delay"
	flagUpdateFailureAction   = "update-failure-action"
	flagUpdateMaxFailureRatio = "update-max-failure-ratio"
	flagUpdateMonitor         = "update-monitor"
	flagUpdateParallelism     = "update-parallelism"
	flagUser                  = "user"
	flagWorkdir               = "workdir"
	flagRegistryAuth          = "with-registry-auth"
	flagLogDriver             = "log-driver"
	flagLogOpt                = "log-opt"
	flagHealthCmd             = "health-cmd"
	flagHealthInterval        = "health-interval"
	flagHealthRetries         = "health-retries"
	flagHealthTimeout         = "health-timeout"
	flagNoHealthcheck         = "no-healthcheck"
)