factor out index download logic

Co-authored-by: Alessio Perugini <alessioper.98@gmail.com>

Author: umbynos

index/index.go

@@ -135,3 +135,15 @@ func checkGPGSig(signed, signature io.Reader) error {
 	_, err = openpgp.CheckDetachedSignature(keyring, signed, signature)
 	return err
 }
+
+// Read will read the index file. In case it doesn't exists or the latest downloaded
+// version is older than 1 hour, it will be downloaded again.
+func (ir *Resource) Read() ([]byte, error) {
+	if !ir.IndexFile.Exist() || time.Since(ir.LastRefresh) > 1*time.Hour {
+		// Download the file again and save it
+		if err := ir.DownloadAndVerify(); err != nil {
+			return nil, err
+		}
+	}
+	return ir.IndexFile.ReadFile()
+}

tools/download.go

@@ -34,7 +34,6 @@ import (
 	"path/filepath"
 	"runtime"
 	"strings"
-	"time"
 
 	"github.com/arduino/arduino-create-agent/utilities"
 	"github.com/arduino/arduino-create-agent/v2/pkgs"
@@ -79,15 +78,7 @@ func pathExists(path string) bool {
 // if it already exists.
 func (t *Tools) Download(pack, name, version, behaviour string) error {
 
-	if !t.Index.IndexFile.Exist() || time.Since(t.Index.LastRefresh) > 1*time.Hour {
-		// Download the file again and save it
-		err := t.Index.DownloadAndVerify()
-		if err != nil {
-			return err
-		}
-	}
-
-	body, err := os.ReadFile(t.Index.IndexFile.String())
+	body, err := t.Index.Read()
 	if err != nil {
 		return err
 	}

v2/pkgs/tools.go

@@ -29,7 +29,6 @@ import (
 	"path/filepath"
 	"runtime"
 	"strings"
-	"time"
 
 	"github.com/arduino/arduino-create-agent/gen/tools"
 	"github.com/arduino/arduino-create-agent/index"
@@ -57,15 +56,7 @@ type Tools struct {
 
 // Available crawles the downloaded package index files and returns a list of tools that can be installed.
 func (c *Tools) Available(ctx context.Context) (res tools.ToolCollection, err error) {
-	if !c.Index.IndexFile.Exist() || time.Since(c.Index.LastRefresh) > 1*time.Hour {
-		// Download the file again and save it
-		err := c.Index.DownloadAndVerify()
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	body, err := os.ReadFile(c.Index.IndexFile.String())
+	body, err := c.Index.Read()
 	if err != nil {
 		return nil, err
 	}
@@ -149,15 +140,7 @@ func (c *Tools) Install(ctx context.Context, payload *tools.ToolPayload) (*tools
 	}
 
 	// otherwise we install from the default index
-	if !c.Index.IndexFile.Exist() || time.Since(c.Index.LastRefresh) > 1*time.Hour {
-		// Download the file again and save it
-		err := c.Index.DownloadAndVerify()
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	body, err := os.ReadFile(c.Index.IndexFile.String())
+	body, err := c.Index.Read()
 	if err != nil {
 		return nil, err
 	}