package aaa

import (
	"bytes"
	"crypto/hmac"
	"crypto/sha1"
	"encoding/base32"
	"encoding/binary"
	"math"
	"strings"
	"time"

	ice "shylinux.com/x/icebergs"
	"shylinux.com/x/icebergs/base/mdb"
	kit "shylinux.com/x/toolkits"
)

func _totp_gen(per int64) string {
	buf := bytes.NewBuffer([]byte{})
	binary.Write(buf, binary.BigEndian, time.Now().Unix()/per)
	b := hmac.New(sha1.New, buf.Bytes()).Sum(nil)
	return strings.ToUpper(base32.StdEncoding.EncodeToString(b[:]))
}
func _totp_get(key string, num int, per int64) string {
	now := kit.Int64(time.Now().Unix() / per)

	buf := []byte{}
	for i := 0; i < 8; i++ {
		buf = append(buf, byte((uint64(now) >> uint64(((7 - i) * 8)))))
	}

	if l := len(key) % 8; l != 0 {
		key += strings.Repeat("=", 8-l)
	}
	s, _ := base32.StdEncoding.DecodeString(strings.ToUpper(key))

	hm := hmac.New(sha1.New, s)
	hm.Write(buf)
	b := hm.Sum(nil)

	n := b[len(b)-1] & 0x0F
	res := int64(b[n]&0x7F)<<24 | int64(b[n+1]&0xFF)<<16 | int64(b[n+2]&0xFF)<<8 | int64(b[n+3]&0xFF)
	return kit.Format(kit.Format("%%0%dd", num), res%int64(math.Pow10(num)))
}

func TOTP_GET(key string, num int, per int64) string { return _totp_get(key, num, per) }

const (
	SECRET = "secret"
	PERIOD = "period"
	NUMBER = "number"
)
const TOTP = "totp"

func init() {
	Index.Merge(&ice.Context{Configs: map[string]*ice.Config{
		TOTP: {Name: TOTP, Help: "动态令牌", Value: kit.Data(
			kit.MDB_SHORT, kit.MDB_NAME, kit.MDB_FIELD, "time,name,secret,period,number",
			kit.MDB_LINK, "otpauth://totp/%s?secret=%s",
		)},
	}, Commands: map[string]*ice.Command{
		TOTP: {Name: "totp name auto create", Help: "动态令牌", Action: ice.MergeAction(map[string]*ice.Action{
			mdb.CREATE: {Name: "create name secret period=30 number=6", Help: "添加", Hand: func(m *ice.Message, arg ...string) {
				if m.Option(SECRET) == "" { // 创建密钥
					m.Option(SECRET, _totp_gen(kit.Int64(m.Option(PERIOD))))
				}

				m.Cmd(mdb.INSERT, TOTP, "", mdb.HASH, m.OptionSimple(kit.MDB_NAME, SECRET, PERIOD, NUMBER))
			}},
		}, mdb.HashAction()), Hand: func(m *ice.Message, c *ice.Context, cmd string, arg ...string) {
			mdb.HashSelect(m.Spawn(), arg...).Table(func(index int, value map[string]string, head []string) {
				m.Push(kit.MDB_TIME, m.Time())
				m.Push(kit.MDB_NAME, value[kit.MDB_NAME])

				period := kit.Int64(value[PERIOD])
				m.Push("rest", period-time.Now().Unix()%period)
				m.Push("code", _totp_get(value[SECRET], kit.Int(value[NUMBER]), period))

				if len(arg) > 0 {
					m.PushQRCode("scan", kit.Format(m.Config(kit.MDB_LINK), value[kit.MDB_NAME], value[SECRET]))
					m.Echo(_totp_get(value[SECRET], kit.Int(value[NUMBER]), kit.Int64(value[PERIOD])))
				}
			})
		}},
	}})
}