fix(googlereader): /items/contents should accept short form item IDs

internal/googlereader/item.go

@@ -0,0 +1,65 @@
+// SPDX-FileCopyrightText: Copyright The Miniflux Authors. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package googlereader // import "miniflux.app/v2/internal/googlereader"
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+const (
+	ItemIDPrefix = "tag:google.com,2005:reader/item/"
+)
+
+func convertEntryIDToLongFormItemID(entryID int64) string {
+	// The entry ID is a 64-bit integer, so we need to format it as a 16-character hexadecimal string.
+	return ItemIDPrefix + fmt.Sprintf("%016x", entryID)
+}
+
+// parseItemID parses a Google Reader ID string.
+// It supports both the long form (tag:google.com,2005:reader/item/<hex_id>) and the short form (<decimal_id>).
+// It returns the parsed ID as a int64 and an error if parsing fails.
+func parseItemID(itemIDValue string) (int64, error) {
+	if strings.HasPrefix(itemIDValue, ItemIDPrefix) {
+		hexID := strings.TrimPrefix(itemIDValue, ItemIDPrefix)
+
+		// It's always 16 characters wide.
+		if len(hexID) != 16 {
+			return 0, errors.New("long form ID has incorrect length")
+		}
+
+		parsedID, err := strconv.ParseInt(hexID, 16, 64)
+		if err != nil {
+			return 0, errors.New("failed to parse long form hex ID: " + err.Error())
+		}
+		return parsedID, nil
+	} else {
+		parsedID, err := strconv.ParseInt(itemIDValue, 10, 64)
+		if err != nil {
+			return 0, errors.New("failed to parse short form decimal ID: " + err.Error())
+		}
+		return parsedID, nil
+	}
+}
+
+func parseItemIDsFromRequest(r *http.Request) ([]int64, error) {
+	items := r.Form[ParamItemIDs]
+	if len(items) == 0 {
+		return nil, fmt.Errorf("googlereader: no items requested")
+	}
+
+	itemIDs := make([]int64, len(items))
+	for i, item := range items {
+		itemID, err := parseItemID(item)
+		if err != nil {
+			return nil, fmt.Errorf("googlereader: failed to parse item ID %s: %w", item, err)
+		}
+		itemIDs[i] = itemID
+	}
+
+	return itemIDs, nil
+}