package cache

import (
	"fmt"
	"time"

	"git.frostfs.info/TrueCloudLab/frostfs-http-gw/internal/logs"
	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/netmap"
	"github.com/bluele/gcache"
	"go.uber.org/zap"
)

type (
	// NetmapCache provides cache for netmap.
	NetmapCache struct {
		cache  gcache.Cache
		logger *zap.Logger
	}

	// NetmapCacheConfig stores expiration params for cache.
	NetmapCacheConfig struct {
		Lifetime time.Duration
		Logger   *zap.Logger
	}
)

const (
	DefaultNetmapCacheLifetime = time.Minute
	netmapCacheSize            = 1
	netmapKey                  = "netmap"
)

// DefaultNetmapConfig returns new default cache expiration values.
func DefaultNetmapConfig(logger *zap.Logger) *NetmapCacheConfig {
	return &NetmapCacheConfig{
		Lifetime: DefaultNetmapCacheLifetime,
		Logger:   logger,
	}
}

// NewNetmapCache creates an object of NetmapCache.
func NewNetmapCache(config *NetmapCacheConfig) *NetmapCache {
	gc := gcache.New(netmapCacheSize).LRU().Expiration(config.Lifetime).Build()
	return &NetmapCache{cache: gc, logger: config.Logger}
}

func (c *NetmapCache) Get() *netmap.NetMap {
	entry, err := c.cache.Get(netmapKey)
	if err != nil {
		return nil
	}

	result, ok := entry.(netmap.NetMap)
	if !ok {
		c.logger.Warn(logs.InvalidCacheEntryType, zap.String("actual", fmt.Sprintf("%T", entry)),
			zap.String("expected", fmt.Sprintf("%T", result)))
		return nil
	}

	return &result
}

func (c *NetmapCache) Put(nm netmap.NetMap) error {
	return c.cache.Set(netmapKey, nm)
}