package cli

import (
	"context"
	"flag"
	"fmt"
	"strings"

	"github.com/peterbourgon/ff/v3/ffcli"

	metrics "edge-infra.dev/pkg/lib/gcp/monitoring/metrics"
	"edge-infra.dev/pkg/lib/gcp/monitoring/monutil"
)

type listArgsT struct {
	byProject bool
	byMetric  bool
	labels    string
}

var (
	listArgs    listArgsT
	listFlagSet = newListFlagSet(&listArgs)
)

func newListFlagSet(listArgs *listArgsT) *flag.FlagSet {
	listf := newFlagSet("list")
	listf.BoolVar(&listArgs.byProject, "by-project", false, "Lists metric descriptors sorted by project ID. (cannot be used with --by-metric or --by-label)")
	listf.BoolVar(&listArgs.byMetric, "by-metric", false, "Lists metric descriptors sorted by metric. (cannot be used with --by-project or --by-label)")
	return listf
}

var listCmd = &ffcli.Command{
	Name:       "list",
	ShortUsage: "list [flags]",
	ShortHelp:  "list metric descriptors from a project",
	LongHelp: strings.TrimSpace(`
Lists metric descriptors for one or more projects that match the specified metric type.
`),
	FlagSet: withGlobalFlags(listFlagSet),
	Exec:    runList,
}

func runList(ctx context.Context, args []string) error {
	var err error

	if len(args) > 0 {
		Fatalf("too many non-flag arguments: %q", args)
	}
	if !checkListFlags() || !checkGlobalFlags() {
		return flag.ErrHelp
	}

	projects := strings.Split(strings.ReplaceAll(projectID, " ", ""), ",")
	d, err := retrieveDescriptors(ctx, projects)
	if err != nil {
		return Errorf("failed to get retrieve of metricDescriptors: %w", err)
	}

	// necessary when comparing specific projects as foreman is a multi-project source
	if filterForeman {
		projects := strings.Split(strings.ReplaceAll(projectID, " ", ""), ",")
		f, err := d.FilterProjects(projects)
		if err != nil {
			return err
		}
		d = f
	}

	if len(d.Descriptor) == 0 && !silent {
		fmt.Println(monutil.White("No metric descriptors found for the specified project(s) as specified."))
	}

	// output the list to the appropriate template
	switch {
	case listArgs.byMetric && !jsonFormat:
		_ = metrics.TmplMetricList.Execute(Stdout, d.ListMetrics())

	case listArgs.byProject && !jsonFormat:
		_ = metrics.TmplProjectList.Execute(Stdout, d.ListProjects())

	case listArgs.byMetric && jsonFormat:
		_ = metrics.TmplJSON.Execute(Stdout, d.ListMetrics())

	case listArgs.byProject && jsonFormat:
		_ = metrics.TmplJSON.Execute(Stdout, d.ListProjects())

	case !listArgs.byMetric && !listArgs.byProject && jsonFormat:
		_ = metrics.TmplJSON.Execute(Stdout, d)

	default:
		_ = metrics.TmplDescList.Execute(Stdout, d)
	}

	return nil
}

// checkListFlags validates the required List subcommand flags have been provided.
func checkListFlags() bool {
	// filter descriptors for those that contain the specified label(s)
	if len(listArgs.labels) != 0 {
		// filterLabels = true
		// labelFilter = strings.Split(listArgs.labels, ",")

		// TBD - remove stop error once label support is complete
		fmt.Println("Error: 'with-label' not supported yet - coming soon")
		return false
	}

	if listArgs.byMetric && listArgs.byProject {
		fmt.Println("Error: 'by-metric' and 'by-project' were selected - only one sort method allowed")
		return false
	}

	return true
}