package pgmonitor

import (
	"sync"
	"time"
)

type cacheEntry struct {
	at   time.Time
	data any
}

type ttlCache struct {
	mu    sync.RWMutex
	ttl   time.Duration
	items map[string]cacheEntry
}

func newTTLCache(ttl time.Duration) *ttlCache {
	return &ttlCache{ttl: ttl, items: make(map[string]cacheEntry)}
}

func (c *ttlCache) get(key string) (any, bool) {
	c.mu.RLock()
	defer c.mu.RUnlock()
	e, ok := c.items[key]
	if !ok || time.Since(e.at) > c.ttl {
		return nil, false
	}
	return e.data, true
}

func (c *ttlCache) set(key string, data any) {
	c.mu.Lock()
	defer c.mu.Unlock()
	c.items[key] = cacheEntry{at: time.Now().UTC(), data: data}
}