// getActualResources returns the actual resource usage of the allocations.
func getActualResources(client *api.Client, runningAllocs []*api.Allocation, node *api.Node) ([]string, error) {
	// Compute the total
	total := computeNodeTotalResources(node)

	// Get Resources
	var cpu float64
	var mem uint64
	for _, alloc := range runningAllocs {
		// Make the call to the client to get the actual usage.
		stats, err := client.Allocations().Stats(alloc, nil)
		if err != nil {
			return nil, err
		}

		cpu += stats.ResourceUsage.CpuStats.TotalTicks
		mem += stats.ResourceUsage.MemoryStats.RSS
	}

	resources := make([]string, 2)
	resources[0] = "CPU|Memory"
	resources[1] = fmt.Sprintf("%v/%v MHz|%v/%v",
		math.Floor(cpu),
		total.CPU,
		humanize.IBytes(mem),
		humanize.IBytes(uint64(total.MemoryMB*bytesPerMegabyte)))

	return resources, nil
}

// followFile outputs the contents of the file to stdout relative to the end of
// the file.
func (l *LogsCommand) followFile(client *api.Client, alloc *api.Allocation,
	follow bool, task, logType, origin string, offset int64) (io.ReadCloser, error) {

	cancel := make(chan struct{})
	frames, err := client.AllocFS().Logs(alloc, follow, task, logType, origin, offset, cancel, nil)
	if err != nil {
		return nil, err
	}
	signalCh := make(chan os.Signal, 1)
	signal.Notify(signalCh, os.Interrupt, syscall.SIGTERM)

	// Create a reader
	var r io.ReadCloser
	frameReader := api.NewFrameReader(frames, cancel)
	frameReader.SetUnblockTime(500 * time.Millisecond)
	r = frameReader

	go func() {
		<-signalCh

		// End the streaming
		r.Close()
	}()

	return r, nil
}

// outputPeriodicInfo prints information about the passed periodic job. If a
// request fails, an error is returned.
func (c *StatusCommand) outputPeriodicInfo(client *api.Client, job *api.Job) error {
	// Generate the prefix that matches launched jobs from the periodic job.
	prefix := fmt.Sprintf("%s%s", job.ID, structs.PeriodicLaunchSuffix)
	children, _, err := client.Jobs().PrefixList(prefix)
	if err != nil {
		return fmt.Errorf("Error querying job: %s", err)
	}

	if len(children) == 0 {
		c.Ui.Output("\nNo instances of periodic job found")
		return nil
	}

	out := make([]string, 1)
	out[0] = "ID|Status"
	for _, child := range children {
		// Ensure that we are only showing jobs whose parent is the requested
		// job.
		if child.ParentID != job.ID {
			continue
		}

		out = append(out, fmt.Sprintf("%s|%s",
			child.ID,
			child.Status))
	}

	c.Ui.Output(fmt.Sprintf("\nPreviously launched jobs:\n%s", formatList(out)))
	return nil
}

// followFile outputs the contents of the file to stdout relative to the end of
// the file. If numLines does not equal -1, then tail -n behavior is used.
func (f *FSCommand) followFile(client *api.Client, alloc *api.Allocation,
	path, origin string, offset, numLines int64) (io.ReadCloser, error) {

	cancel := make(chan struct{})
	frames, err := client.AllocFS().Stream(alloc, path, origin, offset, cancel, nil)
	if err != nil {
		return nil, err
	}
	signalCh := make(chan os.Signal, 1)
	signal.Notify(signalCh, os.Interrupt, syscall.SIGTERM)

	// Create a reader
	var r io.ReadCloser
	frameReader := api.NewFrameReader(frames, cancel)
	frameReader.SetUnblockTime(500 * time.Millisecond)
	r = frameReader

	// If numLines is set, wrap the reader
	if numLines != -1 {
		r = NewLineLimitReader(r, int(numLines), int(numLines*bytesToLines), 1*time.Second)
	}

	go func() {
		<-signalCh

		// End the streaming
		r.Close()
	}()

	return r, nil
}

// regionLeaders returns a map of regions to the IP of the member that is the
// leader.
func regionLeaders(client *api.Client, mem []*api.AgentMember) (map[string]string, error) {
	// Determine the unique regions.
	leaders := make(map[string]string)
	regions := make(map[string]struct{})
	for _, m := range mem {
		regions[m.Tags["region"]] = struct{}{}
	}

	if len(regions) == 0 {
		return leaders, nil
	}

	status := client.Status()
	for reg := range regions {
		l, err := status.RegionLeader(reg)
		if err != nil {
			// This error means that region has no leader.
			if strings.Contains(err.Error(), "No cluster leader") {
				continue
			}
			return nil, err
		}

		leaders[reg] = l
	}

	return leaders, nil
}

// getRunningAllocs returns a slice of allocation id's running on the node
func getRunningAllocs(client *api.Client, nodeID string) ([]*api.Allocation, error) {
	var allocs []*api.Allocation

	// Query the node allocations
	nodeAllocs, _, err := client.Nodes().Allocations(nodeID, nil)
	// Filter list to only running allocations
	for _, alloc := range nodeAllocs {
		if alloc.ClientStatus == "running" {
			allocs = append(allocs, alloc)
		}
	}
	return allocs, err
}

// outputJobInfo prints information about the passed non-periodic job. If a
// request fails, an error is returned.
func (c *StatusCommand) outputJobInfo(client *api.Client, job *api.Job) error {
	var evals, allocs []string

	// Query the evaluations
	jobEvals, _, err := client.Jobs().Evaluations(job.ID, nil)
	if err != nil {
		return fmt.Errorf("Error querying job evaluations: %s", err)
	}

	// Query the allocations
	jobAllocs, _, err := client.Jobs().Allocations(job.ID, nil)
	if err != nil {
		return fmt.Errorf("Error querying job allocations: %s", err)
	}

	// Format the evals
	evals = make([]string, len(jobEvals)+1)
	evals[0] = "ID|Priority|TriggeredBy|Status"
	for i, eval := range jobEvals {
		evals[i+1] = fmt.Sprintf("%s|%d|%s|%s",
			eval.ID[:c.length],
			eval.Priority,
			eval.TriggeredBy,
			eval.Status)
	}

	// Format the allocs
	allocs = make([]string, len(jobAllocs)+1)
	allocs[0] = "ID|EvalID|NodeID|TaskGroup|Desired|Status"
	for i, alloc := range jobAllocs {
		allocs[i+1] = fmt.Sprintf("%s|%s|%s|%s|%s|%s",
			alloc.ID[:c.length],
			alloc.EvalID[:c.length],
			alloc.NodeID[:c.length],
			alloc.TaskGroup,
			alloc.DesiredStatus,
			alloc.ClientStatus)
	}

	c.Ui.Output("\n==> Evaluations")
	c.Ui.Output(formatList(evals))
	c.Ui.Output("\n==> Allocations")
	c.Ui.Output(formatList(allocs))
	return nil
}

// getAllocs returns information about every running allocation on the node
func getAllocs(client *api.Client, node *api.Node, length int) ([]string, error) {
	var allocs []string
	// Query the node allocations
	nodeAllocs, _, err := client.Nodes().Allocations(node.ID, nil)
	// Format the allocations
	allocs = make([]string, len(nodeAllocs)+1)
	allocs[0] = "ID|Eval ID|Job ID|Task Group|Desired Status|Client Status"
	for i, alloc := range nodeAllocs {
		allocs[i+1] = fmt.Sprintf("%s|%s|%s|%s|%s|%s",
			limit(alloc.ID, length),
			limit(alloc.EvalID, length),
			alloc.JobID,
			alloc.TaskGroup,
			alloc.DesiredStatus,
			alloc.ClientStatus)
	}
	return allocs, err
}

// getLocalNodeID returns the node ID of the local Nomad Client and an error if
// it couldn't be determined or the Agent is not running in Client mode.
func getLocalNodeID(client *api.Client) (string, error) {
	info, err := client.Agent().Self()
	if err != nil {
		return "", fmt.Errorf("Error querying agent info: %s", err)
	}
	var stats map[string]interface{}
	stats, _ = info["stats"]
	clientStats, ok := stats["client"].(map[string]interface{})
	if !ok {
		return "", fmt.Errorf("Nomad not running in client mode")
	}

	nodeID, ok := clientStats["node_id"].(string)
	if !ok {
		return "", fmt.Errorf("Failed to determine node ID")
	}

	return nodeID, nil
}

// Get Random Allocation ID from a known jobID. Prefer to use a running allocation,
// but use a dead allocation if no running allocations are found
func getRandomJobAlloc(client *api.Client, jobID string) (string, error) {
	var runningAllocs []*api.AllocationListStub
	allocs, _, err := client.Jobs().Allocations(jobID, nil)

	// Check that the job actually has allocations
	if len(allocs) == 0 {
		return "", fmt.Errorf("job %q doesn't exist or it has no allocations", jobID)
	}

	for _, v := range allocs {
		if v.ClientStatus == "running" {
			runningAllocs = append(runningAllocs, v)
		}
	}
	// If we don't have any allocations running, use dead allocations
	if len(runningAllocs) < 1 {
		runningAllocs = allocs
	}

	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	allocID := runningAllocs[r.Intn(len(runningAllocs))].ID
	return allocID, err
}

func (c *NodeStatusCommand) formatNode(client *api.Client, node *api.Node) int {
	// Format the header output
	basic := []string{
		fmt.Sprintf("ID|%s", limit(node.ID, c.length)),
		fmt.Sprintf("Name|%s", node.Name),
		fmt.Sprintf("Class|%s", node.NodeClass),
		fmt.Sprintf("DC|%s", node.Datacenter),
		fmt.Sprintf("Drain|%v", node.Drain),
		fmt.Sprintf("Status|%s", node.Status),
	}

	if c.short {
		c.Ui.Output(c.Colorize().Color(formatKV(basic)))
	} else {
		// Get the host stats
		hostStats, nodeStatsErr := client.Nodes().Stats(node.ID, nil)
		if nodeStatsErr != nil {
			c.Ui.Output("")
			c.Ui.Error(fmt.Sprintf("error fetching node stats (HINT: ensure Client.Advertise.HTTP is set): %v", nodeStatsErr))
		}
		if hostStats != nil {
			uptime := time.Duration(hostStats.Uptime * uint64(time.Second))
			basic = append(basic, fmt.Sprintf("Uptime|%s", uptime.String()))
		}
		c.Ui.Output(c.Colorize().Color(formatKV(basic)))

		// Get list of running allocations on the node
		runningAllocs, err := getRunningAllocs(client, node.ID)
		if err != nil {
			c.Ui.Error(fmt.Sprintf("Error querying node for running allocations: %s", err))
			return 1
		}

		allocatedResources := getAllocatedResources(client, runningAllocs, node)
		c.Ui.Output(c.Colorize().Color("\n[bold]Allocated Resources[reset]"))
		c.Ui.Output(formatList(allocatedResources))

		actualResources, err := getActualResources(client, runningAllocs, node)
		if err == nil {
			c.Ui.Output(c.Colorize().Color("\n[bold]Allocation Resource Utilization[reset]"))
			c.Ui.Output(formatList(actualResources))
		}

		hostResources, err := getHostResources(hostStats, node)
		if err != nil {
			c.Ui.Output("")
			c.Ui.Error(fmt.Sprintf("error fetching node stats (HINT: ensure Client.Advertise.HTTP is set): %v", err))
		}
		if err == nil {
			c.Ui.Output(c.Colorize().Color("\n[bold]Host Resource Utilization[reset]"))
			c.Ui.Output(formatList(hostResources))
		}

		if hostStats != nil && c.stats {
			c.Ui.Output(c.Colorize().Color("\n[bold]CPU Stats[reset]"))
			c.printCpuStats(hostStats)
			c.Ui.Output(c.Colorize().Color("\n[bold]Memory Stats[reset]"))
			c.printMemoryStats(hostStats)
			c.Ui.Output(c.Colorize().Color("\n[bold]Disk Stats[reset]"))
			c.printDiskStats(hostStats)
		}
	}

	allocs, err := getAllocs(client, node, c.length)
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error querying node allocations: %s", err))
		return 1
	}

	if len(allocs) > 1 {
		c.Ui.Output(c.Colorize().Color("\n[bold]Allocations[reset]"))
		c.Ui.Output(formatList(allocs))
	}

	if c.verbose {
		c.formatAttributes(node)
	}
	return 0

}

// outputJobInfo prints information about the passed non-periodic job. If a
// request fails, an error is returned.
func (c *StatusCommand) outputJobInfo(client *api.Client, job *api.Job) error {
	var evals, allocs []string

	// Query the allocations
	jobAllocs, _, err := client.Jobs().Allocations(job.ID, nil)
	if err != nil {
		return fmt.Errorf("Error querying job allocations: %s", err)
	}

	// Query the evaluations
	jobEvals, _, err := client.Jobs().Evaluations(job.ID, nil)
	if err != nil {
		return fmt.Errorf("Error querying job evaluations: %s", err)
	}

	// Determine latest evaluation with failures whose follow up hasn't
	// completed, this is done while formatting
	var latestFailedPlacement *api.Evaluation
	blockedEval := false

	// Format the evals
	evals = make([]string, len(jobEvals)+1)
	evals[0] = "ID|Priority|Triggered By|Status|Placement Failures"
	for i, eval := range jobEvals {
		failures, _ := evalFailureStatus(eval)
		evals[i+1] = fmt.Sprintf("%s|%d|%s|%s|%s",
			limit(eval.ID, c.length),
			eval.Priority,
			eval.TriggeredBy,
			eval.Status,
			failures,
		)

		if eval.Status == "blocked" {
			blockedEval = true
		}

		if len(eval.FailedTGAllocs) == 0 {
			// Skip evals without failures
			continue
		}

		if latestFailedPlacement == nil || latestFailedPlacement.CreateIndex < eval.CreateIndex {
			latestFailedPlacement = eval
		}
	}

	if c.verbose || c.showEvals {
		c.Ui.Output(c.Colorize().Color("\n[bold]Evaluations[reset]"))
		c.Ui.Output(formatList(evals))
	}

	if blockedEval && latestFailedPlacement != nil {
		c.outputFailedPlacements(latestFailedPlacement)
	}

	// Format the allocs
	c.Ui.Output(c.Colorize().Color("\n[bold]Allocations[reset]"))
	if len(jobAllocs) > 0 {
		allocs = make([]string, len(jobAllocs)+1)
		allocs[0] = "ID|Eval ID|Node ID|Task Group|Desired|Status"
		for i, alloc := range jobAllocs {
			allocs[i+1] = fmt.Sprintf("%s|%s|%s|%s|%s|%s",
				limit(alloc.ID, c.length),
				limit(alloc.EvalID, c.length),
				limit(alloc.NodeID, c.length),
				alloc.TaskGroup,
				alloc.DesiredStatus,
				alloc.ClientStatus)
		}

		c.Ui.Output(formatList(allocs))
	} else {
		c.Ui.Output("No allocations placed")
	}
	return nil
}