// Package `metrics` contains the billman CLI for calculating
// metric billing data.
package metrics

import (
	"context"
	"flag"

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

	"edge-infra.dev/pkg/edge/monitoring/billman/cmd"
	"edge-infra.dev/pkg/edge/monitoring/billman/costs"
	"edge-infra.dev/pkg/edge/monitoring/billman/gcp"
)

const (
	name = "metrics"
)

// config for the metrics subcommand
type config struct {
	RootConfig  *cmd.Config
	DisplayType string
}

// New returns a usable ffcli.Command for the metrics subcommand.
func New(rootConfig *cmd.Config) *ffcli.Command {
	cfg := config{
		RootConfig:  rootConfig,
		DisplayType: name,
	}

	fs := flag.NewFlagSet("billman"+name, flag.ExitOnError)

	return &ffcli.Command{
		Name:       name,
		ShortUsage: "billman " + name + " [flags]",
		ShortHelp:  "Print the estimated billing costs for metrics",
		FlagSet:    cmd.WithGlobalFlags(fs),
		Exec:       cfg.Exec,
	}
}

// Exec runs the `billman metrics` command. Only metric
// data will be calculated.
func (c *config) Exec(_ context.Context, _ []string) error {
	err := cmd.CheckRequiredFlags(cmd.GlobalFlags)
	if err != nil {
		return err
	}
	err = cmd.CheckPeriod(c.RootConfig.Period)
	if err != nil {
		return err
	}
	samples, err := gcp.GetMetricSamples(c.RootConfig.TopLevelProjectID, c.RootConfig.ClusterID, c.RootConfig.Period)
	if err != nil {
		return err
	}
	md := costs.MetricData{
		Samples: samples,
		Cost:    costs.MetricCosts(samples, c.RootConfig.MetricsRate),
	}
	b := costs.Billing{
		Cluster:     c.RootConfig.Cluster,
		LogData:     costs.LogData{},
		MetricData:  md,
		Options:     c.RootConfig.Options,
		DisplayType: c.DisplayType,
	}
	costs.PrintClusterCosts(b)
	return nil
}