package cache

import (
	"electricity_bill_calc/global"
	"electricity_bill_calc/model"
	"fmt"
	"time"

	"github.com/go-redis/redis/v8"
	"github.com/vmihailenco/msgpack/v5"
)

func CacheSession(session *model.Session) error {
	key := fmt.Sprintf("session:%s", session.Token)
	serializedSession, err := msgpack.Marshal(session)

	if err != nil {
		return err
	}

	validRemains := time.Until(session.ExpiresAt)
	cmd := global.RedisConn.SetNX(global.Ctx, key, serializedSession, validRemains)
	return cmd.Err()
}

func RetreiveSession(token string) (*model.Session, error) {
	key := fmt.Sprintf("session:%s", token)
	result, err := global.RedisConn.Get(global.Ctx, key).Result()
	if err != nil {
		if err == redis.Nil {
			return nil, nil
		} else {
			return nil, err
		}
	}
	session := &model.Session{}
	err = msgpack.Unmarshal([]byte(result), session)
	if err != nil {
		return nil, err
	}
	return session, nil
}