package cache

import (
	"backend/internal/domain"
	"backend/pkg/cache"
	"context"
	"encoding/json"
	"fmt"
	"time"

	"github.com/redis/go-redis/v9"
)

type OTPRepository struct {
	redis *cache.Redis
}

func NewOTPRepository(redis *cache.Redis) domain.OTPRepo {
	return &OTPRepository{
		redis: redis,
	}
}

func (r *OTPRepository) Create(ctx context.Context, phone string, otp *domain.OTP) error {
	key := r.getOTPKey(phone)

	otpData, err := json.Marshal(otp)
	if err != nil {
		return fmt.Errorf("failed to marshal otp: %w", err)
	}

	ttl := time.Until(otp.ExpiresAt)
	if ttl <= 0 {
		return fmt.Errorf("OTP expired already")
	}

	if err := r.redis.Client().Set(ctx, key, otpData, ttl).Err(); err != nil {
		return fmt.Errorf("failed to store otp in redis: %w", err)
	}
	return nil
}

func (r *OTPRepository) Delete(ctx context.Context, phone string) error {
	key := r.getOTPKey(phone)

	if err := r.redis.Client().Del(ctx, key).Err(); err != nil {
		return fmt.Errorf("failed to del otp from redis")
	}

	return nil
}

func (r *OTPRepository) Get(ctx context.Context, phone string) (*domain.OTP, error) {
	key := r.getOTPKey(phone)

	result, err := r.redis.Client().Get(ctx, key).Result()
	if err != nil {
		if err == redis.Nil {
			return nil, fmt.Errorf("otp code not found")
		}
		return nil, err
	}

	var otp domain.OTP
	if err := json.Unmarshal([]byte(result), &otp); err != nil {
		return nil, err
	}

	if otp.IsExpired() {
		r.Delete(ctx, phone)
		return nil, fmt.Errorf("otp is expired")
	}
	return &otp, nil

}

func (r *OTPRepository) getOTPKey(phone string) string {
	return fmt.Sprintf("challenge:%s", phone)
}