Snip/backend/internal/adapter/memory/cache.go

package memory

import (
	"context"
	"sync"
	"time"

	"github.com/snip/backend/internal/port"
)

type cacheEntry struct {
	res     port.Resolution
	expires time.Time
}

// Cache is a TTL map standing in for Redis.
type Cache struct {
	mu sync.RWMutex
	m  map[string]cacheEntry
}

func NewCache() *Cache {
	return &Cache{m: make(map[string]cacheEntry)}
}

func (c *Cache) GetResolution(_ context.Context, code string) (port.Resolution, bool, error) {
	c.mu.RLock()
	e, ok := c.m[code]
	c.mu.RUnlock()
	if !ok || time.Now().After(e.expires) {
		return port.Resolution{}, false, nil
	}
	return e.res, true, nil
}

func (c *Cache) SetResolution(_ context.Context, code string, r port.Resolution, ttl time.Duration) error {
	c.mu.Lock()
	c.m[code] = cacheEntry{res: r, expires: time.Now().Add(ttl)}
	c.mu.Unlock()
	return nil
}

func (c *Cache) Invalidate(_ context.Context, code string) error {
	c.mu.Lock()
	delete(c.m, code)
	c.mu.Unlock()
	return nil
}