package cli

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

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

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

type deleteArgsT struct {
	labels   string
	noPrompt bool
}

var filterLabels []string
var deleteArgs deleteArgsT
var deleteFlagSet = newDeleteFlagSet(&deleteArgs)

func newDeleteFlagSet(deleteArgs *deleteArgsT) *flag.FlagSet {
	deletef := newFlagSet("delete")
	deletef.BoolVar(&deleteArgs.noPrompt, "no-prompt", false, "Determines whether the user will be prompted to confirm each deletion.")
	deletef.StringVar(&deleteArgs.labels, "with-labels", "", "Comma separated list of labels to filter the list of metric descriptors to delete. Only metric descriptors that contain this label will be deleted.")
	return deletef
}

var deleteCmd = &ffcli.Command{
	Name:       "delete",
	ShortUsage: "delete [flags]",
	ShortHelp:  "Used to delete metric descriptors.",
	LongHelp: strings.TrimSpace(`
Deletes one or more metric descriptors from one or more projects, with an optional label filter.
`),
	FlagSet: withGlobalFlags(deleteFlagSet),
	Exec:    runDelete,
}

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

	if len(args) > 0 {
		Fatalf("too many non-flag arguments: %q", args)
	}
	if !checkDeleteFlags() {
		_, _ = Println()
		return flag.ErrHelp
	}

	// retrieve list of metric descriptors for all projectIDs specified
	projects := strings.Split(strings.ReplaceAll(projectID, " ", ""), ",")
	d, err := retrieveDescriptors(ctx, projects)
	if err != nil {
		return Errorf("failed to metricDescriptors for multiple projects: %w", err)
	}

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

	// filter by labels
	if len(deleteArgs.labels) != 0 {
		filterLabels = strings.Split(strings.ReplaceAll(deleteArgs.labels, " ", ""), ",")
		d, err = d.FilterLabels(filterLabels)
		if err != nil {
			return err
		}
	}

	// parse through descriptors list to delete
	var dR metrics.DeleteReport
	for i := 0; i < len(d.Descriptor); i++ {
		var err error
		var confirmed = false
		if !deleteArgs.noPrompt && !silent {
			monutil.ClearTerminal()
			_ = metrics.TmplDesc.Execute(Stdout, d.Descriptor[i])
			confirmed = monutil.PromptYesNoCancel("Do you wish to delete this metric descriptor?")
		}

		if confirmed || silent || deleteArgs.noPrompt {
			dR.Attempted++
			err = deleteDescriptor(ctx, &d.Descriptor[i])
		} else {
			dR.Skipped = append(dR.Skipped, d.Descriptor[i].Name)
			continue
		}

		if err != nil {
			dR.Failed = append(dR.Failed, d.Descriptor[i].Name)
		} else {
			dR.Completed++
			dR.Deleted = append(dR.Deleted, d.Descriptor[i].Name)
		}
	}

	if silent { // output report to json
		_ = metrics.TmplJSON.Execute(Stdout, dR)
	} else { // output visual layout of align report
		monutil.ClearTerminal()
		_ = metrics.TmplDeleteReport.Execute(Stdout, dR)
		fmt.Printf("\n\n%s", monutil.White(mmBroomTitle))
	}
	return nil
}

// checkGetFlags validates the required get subcommand flags have been provided.
func checkDeleteFlags() bool {
	return true
}

// create client and delete request
func deleteDescriptor(ctx context.Context, d *metrics.Descriptor) error {
	pID := metrics.ParseProjectID(d.Name)
	mName := metrics.ParseMetricName(d.Name)
	prefix := metrics.ParsePrefix(d.Name)

	dClient, err := metrics.New(ctx, pID)
	if err != nil {
		return err
	}

	return dClient.DeleteDescriptor(prefix, mName)
}