// SPDX-FileCopyrightText: 2023-2025 Steffen Vogel <post@steffenvogel.de>
// SPDX-License-Identifier: Apache-2.0

package tty

import (
	"fmt"
	"strings"
	"time"
)

const (
	day  = 24 * time.Hour
	year = 365 * day
)

// PrettyDuration pretty prints a time just like `wg show`
// See: https://github.com/WireGuard/wireguard-tools/blob/71799a8f6d1450b63071a21cad6ed434b348d3d5/src/show.c#L129
func PrettyDuration(left time.Duration) string {
	out := []string{}
	comps := []struct {
		name    string
		divisor time.Duration
	}{
		{"year", year},
		{"day", day},
		{"hour", time.Hour},
		{"minute", time.Minute},
		{"second", time.Second},
	}

	for _, comp := range comps {
		num := left / comp.divisor

		if num > 0 {
			left -= num * comp.divisor //nolint:durationcheck

			unit := comp.name
			if num > 1 {
				unit += "s" // plural s
			}

			out = append(out, fmt.Sprintf("%d "+Mods("%s", FgCyan), num, unit))
		}
	}

	return strings.Join(out, ", ")
}

// Ago pretty prints a duration with an `ago` suffix.
// See: https://github.com/WireGuard/wireguard-tools/blob/71799a8f6d1450b63071a21cad6ed434b348d3d5/src/show.c#L157
func Ago(ts time.Time) string {
	d := time.Since(ts)

	if d < time.Second {
		return "Now"
	}

	return PrettyDuration(d) + " ago"
}

// Every pretty prints a duration with an `every` prefix
// See: https://github.com/WireGuard/wireguard-tools/blob/71799a8f6d1450b63071a21cad6ed434b348d3d5/src/show.c#L176
func Every(d time.Duration) string {
	return "every " + PrettyDuration(d)
}

// PrettyBytes pretty prints a byte count
// See: https://github.com/WireGuard/wireguard-tools/blob/71799a8f6d1450b63071a21cad6ed434b348d3d5/src/show.c#L184
func PrettyBytes(b int64) string {
	var (
		f float32
		i int
	)

	suffices := []rune{'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'}
	for i, f = 0, float32(b); i < len(suffices) && f >= 1024; i, f = i+1, f/1024 { //nolint:revive
	}

	if i == 0 {
		return fmt.Sprintf("%.0f "+Mods("B", FgCyan), f)
	}

	return fmt.Sprintf("%.2f "+Mods("%ciB", FgCyan), f, suffices[i-1])
}