package privilegewc

import (
	"context"
	"fmt"
	"github.com/go-redis/redis/v8"
	"github.com/twmb/franz-go/pkg/kgo"
	"penahub.gitlab.yandexcloud.net/backend/quiz/common.git/dal"
	"penahub.gitlab.yandexcloud.net/backend/quiz/common.git/model"
	"penahub.gitlab.yandexcloud.net/backend/quiz/worker/wctools"
	"strings"
	"time"
)

// Config содержит параметры конфигурации.
type Config struct {
	KafkaBroker    string
	KafkaTopic     string
	ServiceKey     string
	TickerInterval time.Duration
	ErrChan        chan<- error
}

type KafkaConsumerWorker struct {
	config       Config
	client       *kgo.Client
	redis        *redis.Client
	privilegeDAL *dal.DAL
}

// NewKafkaConsumerWorker создает новый экземпляр KafkaConsumerWorker.
func NewKafkaConsumerWorker(config Config, redis *redis.Client, privilegeDAL *dal.DAL) (*KafkaConsumerWorker, error) {
	client, err := kgo.NewClient(
		kgo.SeedBrokers(config.KafkaBroker),
		kgo.ConsumerGroup("squiz1"),
		kgo.ConsumeTopics(config.KafkaTopic),
		kgo.ConsumeResetOffset(kgo.NewOffset().AfterMilli(time.Now().UnixMilli())),
	)
	if err != nil {
		return nil, err
	}

	return &KafkaConsumerWorker{
		config:       config,
		client:       client,
		privilegeDAL: privilegeDAL,
		redis:        redis,
	}, nil
}

// Start запускает.
func (w *KafkaConsumerWorker) Start(ctx context.Context) {
	ticker := time.NewTicker(w.config.TickerInterval)
	defer ticker.Stop()

	for {
		fmt.Println("KONSUMER", w.config.TickerInterval)
		select {
		case <-ticker.C:
			w.fetchMessages(ctx)
		case <-ctx.Done():
			fmt.Println("Kafka worker terminated")
			return
		}
	}
}

// fetchAndProcessMessages извлекает сообщения из темы Kafka и обрабатывает их.
func (w *KafkaConsumerWorker) fetchMessages(ctx context.Context) {
	fetches := w.client.PollFetches(ctx)
	iter := fetches.RecordIter()

	fmt.Println("KONSUMER1", fetches, w.config.ServiceKey)
	for !iter.Done() {
		record := iter.Next()

		privilege, userID, err := wctools.IsValidMessage(record.Value, w.config.ServiceKey)
		fmt.Println("KONSUMER2", err, userID)
		if err != nil {
			fmt.Println("Error validating Kafka message", err)
		}

		err = w.processValidMessage(ctx, privilege, userID)
		if err != nil {
			fmt.Println("Error processing valid message", err)
		}
	}
}

// processValidMessage обрабатывает валидное сообщение.
func (w *KafkaConsumerWorker) processValidMessage(ctx context.Context, privilege []model.PrivilegeMessage, userID string) error {

	// TODO: refactor getting accountId

	accountId, err := w.privilegeDAL.AccountRepo.GetAccountByID(ctx, userID)
	fmt.Println("KONSUMEROOO", userID, accountId, err, privilege)
	if err != nil {
		return err
	}

	currentPrivilegeMap := make(map[string]model.ShortPrivilege)
	for i := range accountId.Privileges {
		currentPrivilegeMap[accountId.Privileges[i].PrivilegeID] = accountId.Privileges[i]
	}

	for _, receivedPrivilege := range privilege {
		fmt.Println("KONSUMERl", privilege, receivedPrivilege.PrivilegeID, wctools.FindPrivilegeName(receivedPrivilege.PrivilegeID))
		if matchingCurrentPrivilege, found := currentPrivilegeMap[receivedPrivilege.PrivilegeID]; found {
			matchingCurrentPrivilege.Amount += receivedPrivilege.Amount
			matchingCurrentPrivilege.CreatedAt = time.Now()

			err := w.privilegeDAL.AccountRepo.UpdatePrivilege(ctx, &matchingCurrentPrivilege, accountId.ID)
			if err != nil {
				return err
			}
		} else {
			newPrivilege := &model.ShortPrivilege{
				PrivilegeID:   receivedPrivilege.PrivilegeID,
				PrivilegeName: wctools.FindPrivilegeName(receivedPrivilege.PrivilegeID),
				Amount:        receivedPrivilege.Amount,
				CreatedAt:     time.Now(),
			}

			err := w.privilegeDAL.AccountRepo.InsertPrivilege(ctx, newPrivilege, accountId.ID)
			if err != nil {
				return err
			}
		}
	}

	fmt.Println("RESET STALE", w.resetStaleMessages(ctx, accountId.ID))

	return nil
}

func (w *KafkaConsumerWorker) resetStaleMessages(ctx context.Context, accountID string) error {
	keys, err := w.redis.Keys(ctx, accountID+":*").Result()
	if err != nil {
		return err
	}
	for _, key := range keys {
		renameRes := w.redis.Rename(ctx, key, strings.TrimPrefix(key, accountID+":"))
		if renameRes == nil {
			return renameRes.Err()
		}
	}

	return nil
}