package ps

import (
	"os"
	"path/filepath"
	"regexp"
	"sort"
	"strconv"
	"strings"
	"time"

	"github.com/containers/libpod/libpod"
	"github.com/containers/libpod/libpod/define"
	lpfilters "github.com/containers/libpod/libpod/filters"
	"github.com/containers/libpod/pkg/domain/entities"
	psdefine "github.com/containers/libpod/pkg/ps/define"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
)

func GetContainerLists(runtime *libpod.Runtime, options entities.ContainerListOptions) ([]entities.ListContainer, error) {
	var (
		filterFuncs []libpod.ContainerFilter
		pss         []entities.ListContainer
	)
	all := options.All
	if len(options.Filters) > 0 {
		for k, v := range options.Filters {
			for _, val := range v {
				generatedFunc, err := lpfilters.GenerateContainerFilterFuncs(k, val, runtime)
				if err != nil {
					return nil, err
				}
				filterFuncs = append(filterFuncs, generatedFunc)
			}
		}
	}

	// Docker thinks that if status is given as an input, then we should override
	// the all setting and always deal with all containers.
	if len(options.Filters["status"]) > 0 {
		all = true
	}
	if !all {
		runningOnly, err := lpfilters.GenerateContainerFilterFuncs("status", define.ContainerStateRunning.String(), runtime)
		if err != nil {
			return nil, err
		}
		filterFuncs = append(filterFuncs, runningOnly)
	}

	cons, err := runtime.GetContainers(filterFuncs...)
	if err != nil {
		return nil, err
	}
	if options.Last > 0 {
		// Sort the containers we got
		sort.Sort(SortCreateTime{SortContainers: cons})
		// we should perform the lopping before we start getting
		// the expensive information on containers
		if options.Last < len(cons) {
			cons = cons[len(cons)-options.Last:]
		}
	}
	for _, con := range cons {
		listCon, err := ListContainerBatch(runtime, con, options)
		if err != nil {
			return nil, err
		}
		pss = append(pss, listCon)

	}
	return pss, nil
}

// BatchContainerOp is used in ps to reduce performance hits by "batching"
// locks.
func ListContainerBatch(rt *libpod.Runtime, ctr *libpod.Container, opts entities.ContainerListOptions) (entities.ListContainer, error) {
	var (
		conConfig                               *libpod.ContainerConfig
		conState                                define.ContainerStatus
		err                                     error
		exitCode                                int32
		exited                                  bool
		pid                                     int
		size                                    *psdefine.ContainerSize
		startedTime                             time.Time
		exitedTime                              time.Time
		cgroup, ipc, mnt, net, pidns, user, uts string
	)

	batchErr := ctr.Batch(func(c *libpod.Container) error {
		conConfig = c.Config()
		conState, err = c.State()
		if err != nil {
			return errors.Wrapf(err, "unable to obtain container state")
		}

		exitCode, exited, err = c.ExitCode()
		if err != nil {
			return errors.Wrapf(err, "unable to obtain container exit code")
		}
		startedTime, err = c.StartedTime()
		if err != nil {
			logrus.Errorf("error getting started time for %q: %v", c.ID(), err)
		}
		exitedTime, err = c.FinishedTime()
		if err != nil {
			logrus.Errorf("error getting exited time for %q: %v", c.ID(), err)
		}

		if !opts.Size && !opts.Namespace {
			return nil
		}

		if opts.Namespace {
			pid, err = c.PID()
			if err != nil {
				return errors.Wrapf(err, "unable to obtain container pid")
			}
			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"))
		}
		if opts.Size {
			size = new(psdefine.ContainerSize)

			rootFsSize, err := c.RootFsSize()
			if err != nil {
				logrus.Errorf("error getting root fs size for %q: %v", c.ID(), err)
			}

			rwSize, err := c.RWSize()
			if err != nil {
				logrus.Errorf("error getting rw size for %q: %v", c.ID(), err)
			}

			size.RootFsSize = rootFsSize
			size.RwSize = rwSize
		}
		return nil
	})

	if batchErr != nil {
		return entities.ListContainer{}, batchErr
	}

	ps := entities.ListContainer{
		Command:   conConfig.Command,
		Created:   conConfig.CreatedTime.Unix(),
		Exited:    exited,
		ExitCode:  exitCode,
		ExitedAt:  exitedTime.Unix(),
		ID:        conConfig.ID,
		Image:     conConfig.RootfsImageName,
		ImageID:   conConfig.RootfsImageID,
		IsInfra:   conConfig.IsInfra,
		Labels:    conConfig.Labels,
		Mounts:    ctr.UserVolumes(),
		Names:     []string{conConfig.Name},
		Pid:       pid,
		Pod:       conConfig.Pod,
		Ports:     conConfig.PortMappings,
		Size:      size,
		StartedAt: startedTime.Unix(),
		State:     conState.String(),
	}
	if opts.Pod && len(conConfig.Pod) > 0 {
		pod, err := rt.GetPod(conConfig.Pod)
		if err != nil {
			return entities.ListContainer{}, err
		}
		ps.PodName = pod.Name()
	}

	if opts.Namespace {
		ps.Namespaces = entities.ListContainerNamespaces{
			Cgroup: cgroup,
			IPC:    ipc,
			MNT:    mnt,
			NET:    net,
			PIDNS:  pidns,
			User:   user,
			UTS:    uts,
		}
	}
	return ps, nil
}

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
}

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

// SortContainers helps us set-up ability to sort by createTime
type SortContainers []*libpod.Container

func (a SortContainers) Len() int      { return len(a) }
func (a SortContainers) Swap(i, j int) { a[i], a[j] = a[j], a[i] }

type SortCreateTime struct{ SortContainers }

func (a SortCreateTime) Less(i, j int) bool {
	return a.SortContainers[i].CreatedTime().Before(a.SortContainers[j].CreatedTime())
}