// Command podgap shows the gap between what Kubernetes pods reserve
// (requests/limits) and what they actually use, live in a terminal UI.
//
// The default mode opens an interactive TUI that refreshes in place and marks
// whether each pod's usage rose or fell since the last refresh. The json/csv
// output modes are one-shot dumps for scripting.
package main

import (
	"context"
	"fmt"
	"os"
	"time"

	"git.unkin.net/unkin/benvin-utils/common/kube"

	"github.com/spf13/pflag"
)

type options struct {
	namespace  string
	sortKey    string
	top        int
	interval   time.Duration
	output     string
	kubeconfig string
	overOnly   bool
	underOnly  bool
	threshold  float64
}

func main() {
	opts := options{}
	pflag.StringVarP(&opts.namespace, "namespace", "n", "", "namespace to inspect (default: all namespaces)")
	pflag.StringVarP(&opts.sortKey, "sort", "s", "cpu-waste", "sort by: cpu-waste, mem-waste, cpu-util, mem-util, cpu-use, mem-use, name")
	pflag.IntVar(&opts.top, "top", 0, "show only the top N rows after sorting (0 = all)")
	pflag.DurationVarP(&opts.interval, "interval", "i", 0, "TUI refresh interval (e.g. 5s); 0 = default 3s")
	pflag.StringVarP(&opts.output, "output", "o", "tui", "output: tui (interactive), json, csv")
	pflag.StringVar(&opts.kubeconfig, "kubeconfig", "", "path to kubeconfig (default: $KUBECONFIG or ~/.kube/config)")
	pflag.BoolVar(&opts.overOnly, "over", false, "show only over-provisioned pods (util below --threshold)")
	pflag.BoolVar(&opts.underOnly, "under", false, "show only under-provisioned pods (usage above request or limit)")
	pflag.Float64Var(&opts.threshold, "threshold", 0.5, "utilization fraction below which a pod is 'over-provisioned' (with --over)")
	pflag.Parse()

	if err := run(opts); err != nil {
		fmt.Fprintln(os.Stderr, "error:", err)
		os.Exit(1)
	}
}

func run(opts options) error {
	core, mc, err := kube.Clients(opts.kubeconfig)
	if err != nil {
		return err
	}

	// json/csv are one-shot, script-friendly dumps; anything else opens the TUI.
	switch opts.output {
	case "json", "csv":
		rows, err := collect(context.Background(), core, mc, opts.namespace)
		if err != nil {
			return err
		}
		rows = filterRows(rows, opts)
		sortRows(rows, opts.sortKey)
		if opts.top > 0 && len(rows) > opts.top {
			rows = rows[:opts.top]
		}
		return render(os.Stdout, rows, opts.output)
	default:
		return runTUI(core, mc, opts)
	}
}