package http

import (
	"context"
	"errors"
	"strings"
	"time"

	"github.com/gofiber/fiber/v3"
	"github.com/redis/go-redis/v9"
)

type redisLimiterStorage struct {
	client redis.UniversalClient
	prefix string
}

var (
	errRateLimitRedisConfigNil  = errors.New("rate limit redis config is nil")
	errRateLimitRedisAddrsEmpty = errors.New("rate limit redis addrs is empty")
)

func newRedisLimiterStorage(config *RateLimitRedis) (fiber.Storage, error) {
	if config == nil {
		return nil, errRateLimitRedisConfigNil
	}
	if len(config.Addrs) == 0 {
		return nil, errRateLimitRedisAddrsEmpty
	}

	client := redis.NewUniversalClient(&redis.UniversalOptions{
		Addrs:    config.Addrs,
		Username: config.Username,
		Password: config.Password,
		DB:       config.DB,
	})

	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
	defer cancel()
	if err := client.Ping(ctx).Err(); err != nil {
		_ = client.Close()

		return nil, err
	}

	prefix := strings.TrimSpace(config.Prefix)

	return &redisLimiterStorage{
		client: client,
		prefix: prefix,
	}, nil
}

func (s *redisLimiterStorage) GetWithContext(ctx context.Context, key string) ([]byte, error) {
	if s == nil || key == "" {
		return nil, nil
	}
	val, err := s.client.Get(ctx, s.key(key)).Bytes()
	if errors.Is(err, redis.Nil) {
		return nil, nil
	}

	return val, err
}

func (s *redisLimiterStorage) Get(key string) ([]byte, error) {
	return s.GetWithContext(context.Background(), key)
}

func (s *redisLimiterStorage) SetWithContext(ctx context.Context, key string, val []byte, exp time.Duration) error {
	if s == nil || key == "" || len(val) == 0 {
		return nil
	}

	return s.client.Set(ctx, s.key(key), val, exp).Err()
}

func (s *redisLimiterStorage) Set(key string, val []byte, exp time.Duration) error {
	return s.SetWithContext(context.Background(), key, val, exp)
}

func (s *redisLimiterStorage) DeleteWithContext(ctx context.Context, key string) error {
	if s == nil || key == "" {
		return nil
	}

	return s.client.Del(ctx, s.key(key)).Err()
}

func (s *redisLimiterStorage) Delete(key string) error {
	return s.DeleteWithContext(context.Background(), key)
}

func (s *redisLimiterStorage) ResetWithContext(ctx context.Context) error {
	if s == nil {
		return nil
	}

	return s.client.FlushDB(ctx).Err()
}

func (s *redisLimiterStorage) Reset() error {
	return s.ResetWithContext(context.Background())
}

func (s *redisLimiterStorage) Close() error {
	if s == nil {
		return nil
	}

	return s.client.Close()
}

func (s *redisLimiterStorage) key(raw string) string {
	if s.prefix == "" {
		return raw
	}

	return s.prefix + raw
}