feat: cache

cache/file.go

@@ -0,0 +1,77 @@
+package cache
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"time"
+
+	"git.nakama.town/fmartingr/gotoolkit/model"
+)
+
+var _ model.Cache = (*FileCache)(nil)
+
+type FileCache struct {
+	path string
+}
+
+func (c *FileCache) Get(key string) (result any, err error) {
+	path := filepath.Join(c.path, key)
+
+	contents, err := os.ReadFile(path)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) || errors.Is(err, os.ErrPermission) {
+			return result, model.ErrCacheKeyDontExist
+		}
+		return
+	}
+
+	return contents, nil
+}
+
+func (c *FileCache) GetWithExpiry(key string, expiration time.Duration) (result any, err error) {
+	path := filepath.Join(c.path, key)
+	info, err := os.Stat(path)
+	if err != nil {
+		return result, model.ErrCacheKeyDontExist
+	}
+
+	if info.ModTime().Add(expiration).Before(time.Now()) {
+		c.Delete(key)
+		return result, model.ErrCacheKeyDontExist
+	}
+
+	return c.Get(key)
+}
+
+func (c *FileCache) Set(key string, value any) error {
+	path := filepath.Join(c.path, key)
+
+	if err := os.WriteFile(path, value.([]byte), 0766); err != nil {
+		return fmt.Errorf("error writting cache file: %s", err)
+	}
+
+	return nil
+}
+
+func (c *FileCache) Delete(key string) error {
+	path := filepath.Join(c.path, key)
+	return os.Remove(path)
+}
+
+func NewFileCache(folderName string) (*FileCache, error) {
+	userCacheDir, err := os.UserCacheDir()
+	if err != nil {
+		return nil, fmt.Errorf("Could not retrieve user cache directory: %w", err)
+	}
+	path := filepath.Join(userCacheDir, folderName)
+
+	if err := os.MkdirAll(path, 0755); err != nil {
+		return nil, fmt.Errorf("couldn't create cache directory: %w", err)
+	}
+
+	return &FileCache{
+		path: path,
+	}, nil
+}