package main

import (
	"encoding/json"
	"fmt"
	"io"
	"os"
	"text/tabwriter"
)

// formatSize returns a human-friendly representation of a byte count.
func formatSize(bytes int64) string {
	const (
		kb = 1024
		mb = kb * 1024
		gb = mb * 1024
		tb = gb * 1024
	)

	switch {
	case bytes >= tb:
		return fmt.Sprintf("%.1f TB", float64(bytes)/float64(tb))
	case bytes >= gb:
		return fmt.Sprintf("%.1f GB", float64(bytes)/float64(gb))
	case bytes >= mb:
		return fmt.Sprintf("%.1f MB", float64(bytes)/float64(mb))
	case bytes >= kb:
		return fmt.Sprintf("%.1f KB", float64(bytes)/float64(kb))
	default:
		return fmt.Sprintf("%d B", bytes)
	}
}

// printJSON marshals v as indented JSON and writes it to stdout.
func printJSON(v any) error {
	enc := json.NewEncoder(os.Stdout)
	enc.SetIndent("", "  ")
	return enc.Encode(v)
}

// printTable writes a table with the given headers and rows.
// Each row must have the same number of columns as headers.
func printTable(w io.Writer, headers []string, rows [][]string) {
	tw := tabwriter.NewWriter(w, 0, 0, 2, ' ', 0)
	// Print header.
	for i, h := range headers {
		if i > 0 {
			_, _ = fmt.Fprint(tw, "\t")
		}
		_, _ = fmt.Fprint(tw, h)
	}
	_, _ = fmt.Fprintln(tw)

	// Print rows.
	for _, row := range rows {
		for i, col := range row {
			if i > 0 {
				_, _ = fmt.Fprint(tw, "\t")
			}
			_, _ = fmt.Fprint(tw, col)
		}
		_, _ = fmt.Fprintln(tw)
	}
	_ = tw.Flush()
}