package main

import (
	"fmt"
	"os"
	"path/filepath"
	"reflect"
	"regexp"
	"strconv"
	"strings"
	"time"

	"github.com/docker/go-units"
	specs "github.com/opencontainers/runtime-spec/specs-go"
	"github.com/pkg/errors"
	"github.com/projectatomic/libpod/cmd/kpod/formats"
	"github.com/projectatomic/libpod/libpod"
	"github.com/projectatomic/libpod/oci"
	"github.com/urfave/cli"
	"k8s.io/apimachinery/pkg/fields"
)

type psOptions struct {
	all       bool
	filter    string
	format    string
	last      int
	latest    bool
	noTrunc   bool
	quiet     bool
	size      bool
	label     string
	namespace bool
}

type psTemplateParams struct {
	ID         string
	Image      string
	Command    string
	CreatedAt  string
	RunningFor string
	Status     string
	Ports      string
	Size       string
	Names      string
	Labels     string
	Mounts     string
	PID        int
	Cgroup     string
	IPC        string
	MNT        string
	NET        string
	PIDNS      string
	User       string
	UTS        string
}

// psJSONParams is only used when the JSON format is specified,
// and is better for data processing from JSON.
// psJSONParams will be populated by data from libpod.Container,
// the members of the struct are the sama data types as their sources.
type psJSONParams struct {
	ID               string              `json:"id"`
	Image            string              `json:"image"`
	ImageID          string              `json:"image_id"`
	Command          string              `json:"command"`
	CreatedAt        time.Time           `json:"createdAt"`
	RunningFor       time.Duration       `json:"runningFor"`
	Status           string              `json:"status"`
	Ports            map[string]struct{} `json:"ports"`
	Size             uint                `json:"size"`
	Names            string              `json:"names"`
	Labels           fields.Set          `json:"labels"`
	Mounts           []specs.Mount       `json:"mounts"`
	ContainerRunning bool                `json:"ctrRunning"`
	Namespaces       *namespace          `json:"namespace,omitempty"`
}

type namespace struct {
	PID    string `json:"pid,omitempty"`
	Cgroup string `json:"cgroup,omitempty"`
	IPC    string `json:"ipc,omitempty"`
	MNT    string `json:"mnt,omitempty"`
	NET    string `json:"net,omitempty"`
	PIDNS  string `json:"pidns,omitempty"`
	User   string `json:"user,omitempty"`
	UTS    string `json:"uts,omitempty"`
}

var (
	psFlags = []cli.Flag{
		cli.BoolFlag{
			Name:  "all, a",
			Usage: "Show all the containers, default is only running containers",
		},
		cli.StringFlag{
			Name:  "filter, f",
			Usage: "Filter output based on conditions given",
		},
		cli.StringFlag{
			Name:  "format",
			Usage: "Pretty-print containers to JSON or using a Go template",
		},
		cli.IntFlag{
			Name:  "last, n",
			Usage: "Print the n last created containers (all states)",
			Value: -1,
		},
		cli.BoolFlag{
			Name:  "latest, l",
			Usage: "Show the latest container created (all states)",
		},
		cli.BoolFlag{
			Name:  "no-trunc",
			Usage: "Display the extended information",
		},
		cli.BoolFlag{
			Name:  "quiet, q",
			Usage: "Print the numeric IDs of the containers only",
		},
		cli.BoolFlag{
			Name:  "size, s",
			Usage: "Display the total file sizes",
		},
		cli.BoolFlag{
			Name:  "namespace, ns",
			Usage: "Display namespace information",
		},
	}
	psDescription = "Prints out information about the containers"
	psCommand     = cli.Command{
		Name:                   "ps",
		Usage:                  "List containers",
		Description:            psDescription,
		Flags:                  psFlags,
		Action:                 psCmd,
		ArgsUsage:              "",
		UseShortOptionHandling: true,
	}
)

func psCmd(c *cli.Context) error {
	if err := validateFlags(c, psFlags); err != nil {
		return err
	}

	// latest, and last are mutually exclusive.
	if c.Int("last") >= 0 && c.Bool("latest") {
		return errors.Errorf("last and latest are mutually exclusive")
	}

	runtime, err := getRuntime(c)
	if err != nil {
		return errors.Wrapf(err, "error creating libpod runtime")
	}

	defer runtime.Shutdown(false)

	if len(c.Args()) > 0 {
		return errors.Errorf("too many arguments, ps takes no arguments")
	}

	format := genPsFormat(c.Bool("quiet"), c.Bool("size"), c.Bool("namespace"))
	if c.IsSet("format") {
		format = c.String("format")
	}

	opts := psOptions{
		all:       c.Bool("all"),
		filter:    c.String("filter"),
		format:    format,
		last:      c.Int("last"),
		latest:    c.Bool("latest"),
		noTrunc:   c.Bool("no-trunc"),
		quiet:     c.Bool("quiet"),
		size:      c.Bool("size"),
		namespace: c.Bool("namespace"),
	}

	var filterFuncs []libpod.ContainerFilter
	// When we are dealing with latest or last=n, we need to
	// get all containers.
	if !opts.all && !opts.latest && opts.last < 1 {
		// only get running containers
		filterFuncs = append(filterFuncs, func(c *libpod.Container) bool {
			state, _ := c.State()
			return state == libpod.ContainerStateRunning
		})
	}

	if opts.filter != "" {
		filters := strings.Split(opts.filter, ",")
		for _, f := range filters {
			filterSplit := strings.Split(f, "=")
			if len(filterSplit) < 2 {
				return errors.Errorf("filter input must be in the form of filter=value: %s is invalid", f)
			}
			generatedFunc, err := generateContainerFilterFuncs(filterSplit[0], filterSplit[1], runtime)
			if err != nil {
				return errors.Wrapf(err, "invalid filter")
			}
			filterFuncs = append(filterFuncs, generatedFunc)
		}
	}

	containers, err := runtime.GetContainers(filterFuncs...)
	var outputContainers []*libpod.Container
	if opts.latest && len(containers) > 0 {
		outputContainers = append(outputContainers, containers[0])
	} else if opts.last > 0 && opts.last <= len(containers) {
		outputContainers = append(outputContainers, containers[:opts.last]...)
	} else {
		outputContainers = containers
	}

	return generatePsOutput(outputContainers, opts)
}

func generateContainerFilterFuncs(filter, filterValue string, runtime *libpod.Runtime) (func(container *libpod.Container) bool, error) {
	switch filter {
	case "id":
		return func(c *libpod.Container) bool {
			return c.ID() == filterValue
		}, nil
	case "label":
		return func(c *libpod.Container) bool {
			for _, label := range c.Labels() {
				if label == filterValue {
					return true
				}
			}
			return false
		}, nil
	case "name":
		return func(c *libpod.Container) bool {
			return c.Name() == filterValue
		}, nil
	case "exited":
		exitCode, err := strconv.ParseInt(filterValue, 10, 32)
		if err != nil {
			return nil, errors.Wrapf(err, "exited code out of range %q", filterValue)
		}
		return func(c *libpod.Container) bool {
			ec, err := c.ExitCode()
			if ec == int32(exitCode) && err == nil {
				return true
			}
			return false
		}, nil
	case "status":
		if !libpod.StringInSlice(filterValue, []string{"created", "restarting", "running", "paused", "exited", "unknown"}) {
			return nil, errors.Errorf("%s is not a valid status", filterValue)
		}
		return func(c *libpod.Container) bool {
			status, err := c.State()
			if err != nil {
				return false
			}
			return status.String() == filterValue
		}, nil
	case "ancestor":
		// This needs to refine to match docker
		// - ancestor=(<image-name>[:tag]|<image-id>| ⟨image@digest⟩) - containers created from an image or a descendant.
		return func(c *libpod.Container) bool {
			containerConfig := c.Config()
			if containerConfig.RootfsImageID == filterValue || containerConfig.RootfsImageName == filterValue {
				return true
			}
			return false
		}, nil
	case "before":
		ctr, err := runtime.LookupContainer(filterValue)
		if err != nil {
			return nil, errors.Errorf("unable to find container by name or id of %s", filterValue)
		}
		containerConfig := ctr.Config()
		createTime := containerConfig.CreatedTime
		return func(c *libpod.Container) bool {
			cc := c.Config()
			return createTime.After(cc.CreatedTime)
		}, nil
	case "since":
		ctr, err := runtime.LookupContainer(filterValue)
		if err != nil {
			return nil, errors.Errorf("unable to find container by name or id of %s", filterValue)
		}
		containerConfig := ctr.Config()
		createTime := containerConfig.CreatedTime
		return func(c *libpod.Container) bool {
			cc := c.Config()
			return createTime.Before(cc.CreatedTime)
		}, nil
	case "volume":
		//- volume=(<volume-name>|<mount-point-destination>)
		return func(c *libpod.Container) bool {
			containerConfig := c.Config()
			//TODO We need to still lookup against volumes too
			return containerConfig.MountLabel == filterValue
		}, nil
	}
	return nil, errors.Errorf("%s is an invalid filter", filter)
}

// generate the template based on conditions given
func genPsFormat(quiet, size, namespace bool) (format string) {
	if quiet {
		return formats.IDString
	}
	if namespace {
		format = "table {{.ID}}\t{{.Names}}\t{{.PID}}\t{{.Cgroup}}\t{{.IPC}}\t{{.MNT}}\t{{.NET}}\t{{.PIDNS}}\t{{.User}}\t{{.UTS}}\t"
		return
	}
	format = "table {{.ID}}\t{{.Image}}\t{{.Command}}\t{{.CreatedAt}}\t{{.Status}}\t{{.Ports}}\t{{.Names}}\t"
	if size {
		format += "{{.Size}}\t"
	}
	return
}

func psToGeneric(templParams []psTemplateParams, JSONParams []psJSONParams) (genericParams []interface{}) {
	if len(templParams) > 0 {
		for _, v := range templParams {
			genericParams = append(genericParams, interface{}(v))
		}
		return
	}
	for _, v := range JSONParams {
		genericParams = append(genericParams, interface{}(v))
	}
	return
}

// generate the accurate header based on template given
func (p *psTemplateParams) headerMap() map[string]string {
	v := reflect.Indirect(reflect.ValueOf(p))
	values := make(map[string]string)

	for i := 0; i < v.NumField(); i++ {
		key := v.Type().Field(i).Name
		value := key
		if value == "ID" {
			value = "Container" + value
		}
		values[key] = strings.ToUpper(splitCamelCase(value))
	}
	return values
}

// getTemplateOutput returns the modified container information
func getTemplateOutput(containers []*libpod.Container, opts psOptions) ([]psTemplateParams, error) {
	var psOutput []psTemplateParams
	var status string
	for _, ctr := range containers {
		ctrID := ctr.ID()
		conConfig := ctr.Config()
		conState, err := ctr.State()
		if err != nil {
			return psOutput, errors.Wrapf(err, "unable to obtain container state")
		}
		exitCode, err := ctr.ExitCode()
		if err != nil {
			return psOutput, errors.Wrapf(err, "unable to obtain container exit code")
		}
		pid, err := ctr.PID()
		if err != nil {
			return psOutput, errors.Wrapf(err, "unable to obtain container pid")
		}
		runningFor := units.HumanDuration(time.Since(conConfig.CreatedTime))
		createdAt := runningFor + " ago"
		imageName := conConfig.RootfsImageName

		// TODO We currently dont have the ability to get many of
		// these data items.  Uncomment as progress is made

		//command := getStrFromSquareBrackets(ctr.ImageCreatedBy)
		command := strings.Join(ctr.Spec().Process.Args, " ")
		//mounts := getMounts(ctr.Mounts, opts.noTrunc)
		//ports := getPorts(ctr.Config.ExposedPorts)
		//size := units.HumanSize(float64(ctr.SizeRootFs))
		labels := formatLabels(ctr.Labels())
		ns := getNamespaces(pid)

		switch conState {
		case libpod.ContainerStateStopped:
			status = fmt.Sprintf("Exited (%d) %s ago", exitCode, runningFor)
		case libpod.ContainerStateRunning:
			status = "Up " + runningFor + " ago"
		case libpod.ContainerStatePaused:
			status = "Paused"
		case libpod.ContainerStateCreated:
			status = "Created"
		default:
			status = "Dead"
		}

		if !opts.noTrunc {
			ctrID = ctr.ID()[:idTruncLength]
			imageName = conConfig.RootfsImageName
		}

		// TODO We currently dont have the ability to get many of
		// these data items.  Uncomment as progress is made

		params := psTemplateParams{
			ID:         ctrID,
			Image:      imageName,
			Command:    command,
			CreatedAt:  createdAt,
			RunningFor: runningFor,
			Status:     status,
			//Ports:      ports,
			//Size:       size,
			Names:  ctr.Name(),
			Labels: labels,
			//Mounts:     mounts,
			PID:    pid,
			Cgroup: ns.Cgroup,
			IPC:    ns.IPC,
			MNT:    ns.MNT,
			NET:    ns.NET,
			PIDNS:  ns.PID,
			User:   ns.User,
			UTS:    ns.UTS,
		}
		psOutput = append(psOutput, params)
	}
	return psOutput, nil
}

func getNamespaces(pid int) *namespace {
	ctrPID := strconv.Itoa(pid)
	cgroup, _ := getNamespaceInfo(filepath.Join("/proc", ctrPID, "ns", "cgroup"))
	ipc, _ := getNamespaceInfo(filepath.Join("/proc", ctrPID, "ns", "ipc"))
	mnt, _ := getNamespaceInfo(filepath.Join("/proc", ctrPID, "ns", "mnt"))
	net, _ := getNamespaceInfo(filepath.Join("/proc", ctrPID, "ns", "net"))
	pidns, _ := getNamespaceInfo(filepath.Join("/proc", ctrPID, "ns", "pid"))
	user, _ := getNamespaceInfo(filepath.Join("/proc", ctrPID, "ns", "user"))
	uts, _ := getNamespaceInfo(filepath.Join("/proc", ctrPID, "ns", "uts"))

	return &namespace{
		PID:    ctrPID,
		Cgroup: cgroup,
		IPC:    ipc,
		MNT:    mnt,
		NET:    net,
		PIDNS:  pidns,
		User:   user,
		UTS:    uts,
	}
}

func getNamespaceInfo(path string) (string, error) {
	val, err := os.Readlink(path)
	if err != nil {
		return "", errors.Wrapf(err, "error getting info from %q", path)
	}
	return getStrFromSquareBrackets(val), nil
}

// getJSONOutput returns the container info in its raw form
func getJSONOutput(containers []*libpod.Container, nSpace bool) ([]psJSONParams, error) {
	var psOutput []psJSONParams
	var ns *namespace
	for _, ctr := range containers {
		pid, err := ctr.PID()
		if err != nil {
			return psOutput, errors.Wrapf(err, "unable to obtain container pid")
		}
		if nSpace {
			ns = getNamespaces(pid)
		}
		cc := ctr.Config()
		conState, err := ctr.State()
		if err != nil {
			return psOutput, errors.Wrapf(err, "unable to obtain container state for JSON output")
		}
		params := psJSONParams{
			// TODO When we have ability to obtain the commented out data, we need
			// TODO to add it
			ID:      ctr.ID(),
			Image:   cc.RootfsImageName,
			ImageID: cc.RootfsImageID,
			//Command:          getStrFromSquareBrackets(ctr.ImageCreatedBy),
			Command:    strings.Join(ctr.Spec().Process.Args, " "),
			CreatedAt:  cc.CreatedTime,
			RunningFor: time.Since(cc.CreatedTime),
			Status:     conState.String(),
			//Ports:            cc.Spec.Linux.Resources.Network.
			//Size:             ctr.SizeRootFs,
			Names:            cc.Name,
			Labels:           cc.Labels,
			Mounts:           cc.Spec.Mounts,
			ContainerRunning: conState.String() == oci.ContainerStateRunning,
			Namespaces:       ns,
		}
		psOutput = append(psOutput, params)
	}
	return psOutput, nil
}

func generatePsOutput(containers []*libpod.Container, opts psOptions) error {
	if len(containers) == 0 && opts.format != formats.JSONString {
		return nil
	}
	var out formats.Writer

	switch opts.format {
	case formats.JSONString:
		psOutput, err := getJSONOutput(containers, opts.namespace)
		if err != nil {
			return errors.Wrapf(err, "unable to create JSON for output")
		}
		out = formats.JSONStructArray{Output: psToGeneric([]psTemplateParams{}, psOutput)}
	default:
		psOutput, err := getTemplateOutput(containers, opts)
		if err != nil {
			return errors.Wrapf(err, "unable to create output")
		}
		out = formats.StdoutTemplateArray{Output: psToGeneric(psOutput, []psJSONParams{}), Template: opts.format, Fields: psOutput[0].headerMap()}
	}

	return formats.Writer(out).Out()
}

// getStrFromSquareBrackets gets the string inside [] from a string
func getStrFromSquareBrackets(cmd string) string {
	reg, err := regexp.Compile(".*\\[|\\].*")
	if err != nil {
		return ""
	}
	arr := strings.Split(reg.ReplaceAllLiteralString(cmd, ""), ",")
	return strings.Join(arr, ",")
}

// getImageName shortens the image name
func getImageName(img string) string {
	arr := strings.Split(img, "/")
	if arr[0] == "docker.io" && arr[1] == "library" {
		img = strings.Join(arr[2:], "/")
	} else if arr[0] == "docker.io" {
		img = strings.Join(arr[1:], "/")
	}
	return img
}

// getLabels converts the labels to a string of the form "key=value, key2=value2"
func formatLabels(labels map[string]string) string {
	var arr []string
	if len(labels) > 0 {
		for key, val := range labels {
			temp := key + "=" + val
			arr = append(arr, temp)
		}
		return strings.Join(arr, ",")
	}
	return ""
}

// getMounts converts the volumes mounted to a string of the form "mount1, mount2"
// it truncates it if noTrunc is false
func getMounts(mounts []specs.Mount, noTrunc bool) string {
	var arr []string
	if len(mounts) == 0 {
		return ""
	}
	for _, mount := range mounts {
		if noTrunc {
			arr = append(arr, mount.Source)
			continue
		}
		tempArr := strings.SplitAfter(mount.Source, "/")
		if len(tempArr) >= 3 {
			arr = append(arr, strings.Join(tempArr[:3], ""))
		} else {
			arr = append(arr, mount.Source)
		}
	}
	return strings.Join(arr, ",")
}

// getPorts converts the ports used to a string of the from "port1, port2"
func getPorts(ports map[string]struct{}) string {
	var arr []string
	if len(ports) == 0 {
		return ""
	}
	for key := range ports {
		arr = append(arr, key)
	}
	return strings.Join(arr, ",")
}

// FilterParamsPS contains the filter options for ps
type FilterParamsPS struct {
	id       string
	label    string
	name     string
	exited   int32
	status   string
	ancestor string
	before   time.Time
	since    time.Time
	volume   string
}

// parseFilter takes a filter string and a list of containers and filters it
func parseFilter(filter string, containers []*oci.Container) (*FilterParamsPS, error) {
	params := new(FilterParamsPS)
	allFilters := strings.Split(filter, ",")

	for _, param := range allFilters {
		pair := strings.SplitN(param, "=", 2)
		switch strings.TrimSpace(pair[0]) {
		case "id":
			params.id = pair[1]
		case "label":
			params.label = pair[1]
		case "name":
			params.name = pair[1]
		case "exited":
			exitedCode, err := strconv.ParseInt(pair[1], 10, 32)
			if err != nil {
				return nil, errors.Errorf("exited code out of range %q", pair[1])
			}
			params.exited = int32(exitedCode)
		case "status":
			params.status = pair[1]
		case "ancestor":
			params.ancestor = pair[1]
		case "before":
			if ctr, err := findContainer(containers, pair[1]); err == nil {
				params.before = ctr.CreatedAt()
			} else {
				return nil, errors.Wrapf(err, "no such container %q", pair[1])
			}
		case "since":
			if ctr, err := findContainer(containers, pair[1]); err == nil {
				params.before = ctr.CreatedAt()
			} else {
				return nil, errors.Wrapf(err, "no such container %q", pair[1])
			}
		case "volume":
			params.volume = pair[1]
		default:
			return nil, errors.Errorf("invalid filter %q", pair[0])
		}
	}
	return params, nil
}

// findContainer finds a container with a specific name or id from a list of containers
func findContainer(containers []*oci.Container, ref string) (*oci.Container, error) {
	for _, ctr := range containers {
		if strings.HasPrefix(ctr.ID(), ref) || ctr.Name() == ref {
			return ctr, nil
		}
	}
	return nil, errors.Errorf("could not find container")
}