package state

import (
	"database/sql/driver"
	"encoding/json"

	log "github.com/sirupsen/logrus"

	"github.com/zachmann/mytoken/internal/db"
	"github.com/zachmann/mytoken/internal/server/config"
	"github.com/zachmann/mytoken/internal/utils/hashUtils"
)

type State struct {
	state       string
	hash        string
	pollingCode string
}

func NewState(state string) *State {
	return &State{
		state: state,
	}
}

func (s *State) Hash() string {
	if len(s.hash) == 0 {
		s.hash = hashUtils.SHA512Str([]byte(s.state))
	}
	return s.hash
}

func (s *State) PollingCode() string {
	if len(s.pollingCode) == 0 {
		s.pollingCode = hashUtils.HMACSHA512Str([]byte(s.state), []byte("polling_code"))[:config.Get().Features.Polling.Len]
		log.WithField("state", s.state).WithField("polling_code", s.pollingCode).Debug("Created polling_code for state")
	}
	return s.pollingCode
}

func (s State) State() string {
	return s.state
}

// Value implements the driver.Valuer interface
func (s State) Value() (driver.Value, error) {
	return s.Hash(), nil
}

// Scan implements the sql.Scanner interface
func (s *State) Scan(src interface{}) error {
	if src == nil {
		return nil
	}
	ns := db.NewNullString("")
	if err := ns.Scan(src); err != nil {
		return err
	}
	s.hash = ns.String
	return nil
}

// UnmarshalJSON implements the json.Unmarshaler interface
func (s *State) UnmarshalJSON(data []byte) error {
	err := json.Unmarshal(data, &s.state)
	return err
}

// MarshalJSON implements the json.Marshaler interface
func (s State) MarshalJSON() ([]byte, error) {
	return json.Marshal(s.state)
}