package main

import (
	"os"
	"syscall"

	"fmt"
	"github.com/containers/libpod/cmd/podman/libpodruntime"
	"github.com/containers/libpod/libpod"
	"github.com/containers/libpod/pkg/rootless"
	"github.com/docker/docker/pkg/signal"
	"github.com/pkg/errors"
	"github.com/urfave/cli"
)

var (
	killFlags = []cli.Flag{
		cli.BoolFlag{
			Name:  "all, a",
			Usage: "Signal all running containers",
		},
		cli.StringFlag{
			Name:  "signal, s",
			Usage: "Signal to send to the container",
			Value: "KILL",
		},
		LatestFlag,
	}
	killDescription = "The main process inside each container specified will be sent SIGKILL, or any signal specified with option --signal."
	killCommand     = cli.Command{
		Name:                   "kill",
		Usage:                  "Kill one or more running containers with a specific signal",
		Description:            killDescription,
		Flags:                  killFlags,
		Action:                 killCmd,
		ArgsUsage:              "CONTAINER-NAME [CONTAINER-NAME ...]",
		UseShortOptionHandling: true,
		OnUsageError:           usageErrorHandler,
	}
)

// killCmd kills one or more containers with a signal
func killCmd(c *cli.Context) error {
	args := c.Args()
	if (!c.Bool("all") && !c.Bool("latest")) && len(args) == 0 {
		return errors.Errorf("you must specify one or more containers to kill")
	}
	if (c.Bool("all") || c.Bool("latest")) && len(args) > 0 {
		return errors.Errorf("you cannot specify any containers to kill with --latest or --all")
	}
	if c.Bool("all") && c.Bool("latest") {
		return errors.Errorf("--all and --latest cannot be used together")
	}
	if len(args) < 1 && !c.Bool("all") && !c.Bool("latest") {
		return errors.Errorf("you must provide at least one container name or id")
	}
	if err := validateFlags(c, killFlags); err != nil {
		return err
	}

	rootless.SetSkipStorageSetup(true)
	runtime, err := libpodruntime.GetRuntime(c)
	if err != nil {
		return errors.Wrapf(err, "could not get runtime")
	}
	defer runtime.Shutdown(false)

	var killSignal uint = uint(syscall.SIGTERM)
	if c.String("signal") != "" {
		// Check if the signalString provided by the user is valid
		// Invalid signals will return err
		sysSignal, err := signal.ParseSignal(c.String("signal"))
		if err != nil {
			return err
		}
		killSignal = uint(sysSignal)
	}

	var filterFuncs []libpod.ContainerFilter
	var containers []*libpod.Container
	var lastError error
	if c.Bool("all") {
		// only get running containers
		filterFuncs = append(filterFuncs, func(c *libpod.Container) bool {
			state, _ := c.State()
			return state == libpod.ContainerStateRunning
		})
		containers, err = runtime.GetContainers(filterFuncs...)
		if err != nil {
			return errors.Wrapf(err, "unable to get running containers")
		}
	} else if c.Bool("latest") {
		lastCtr, err := runtime.GetLatestContainer()
		if err != nil {
			return errors.Wrapf(err, "unable to get last created container")
		}
		containers = append(containers, lastCtr)
	} else {
		for _, i := range args {
			container, err := runtime.LookupContainer(i)
			if err != nil {
				if lastError != nil {
					fmt.Fprintln(os.Stderr, lastError)
				}
				lastError = errors.Wrapf(err, "unable to find container %s", i)
				continue
			}
			containers = append(containers, container)
		}
	}

	for _, ctr := range containers {
		if err := ctr.Kill(killSignal); err != nil {
			if lastError != nil {
				fmt.Fprintln(os.Stderr, lastError)
			}
			lastError = errors.Wrapf(err, "unable to find container %v", ctr.ID())
		} else {
			fmt.Println(ctr.ID())
		}
	}
	return lastError
}