package redis

import (
	"context"
	"time"

	rclient "github.com/go-redis/redis/v8"
	"go-micro.dev/v6/cache"
)

// NewRedisCache returns a new redis cache.
func NewRedisCache(opts ...cache.Option) cache.Cache {
	options := cache.NewOptions(opts...)
	return &redisCache{
		opts:   options,
		client: newUniversalClient(options),
	}
}

type redisCache struct {
	opts   cache.Options
	client rclient.UniversalClient
}

func (c *redisCache) Get(ctx context.Context, key string) (interface{}, time.Time, error) {
	val, err := c.client.Get(ctx, key).Bytes()
	if err != nil && err == rclient.Nil {
		return nil, time.Time{}, cache.ErrKeyNotFound
	} else if err != nil {
		return nil, time.Time{}, err
	}

	dur, err := c.client.TTL(ctx, key).Result()
	if err != nil {
		return nil, time.Time{}, err
	}
	if dur == -1 {
		return val, time.Unix(1<<63-1, 0), nil
	}
	if dur == -2 {
		return val, time.Time{}, cache.ErrItemExpired
	}

	return val, time.Now().Add(dur), nil
}

func (c *redisCache) Put(ctx context.Context, key string, val interface{}, dur time.Duration) error {
	return c.client.Set(ctx, key, val, dur).Err()
}

func (c *redisCache) Delete(ctx context.Context, key string) error {
	return c.client.Del(ctx, key).Err()
}

func (c *redisCache) String() string {
	return "redis"
}
