4 files changed, 90 insertions, 3 deletions

diff --git a/internal/feed/cache.go b/internal/feed/cache.go
index 5674de4..45cefd0 100644
--- a/internal/feed/cache.go
+++ b/internal/feed/cache.go
@@ -20,6 +20,8 @@ const (
 type Cache interface {
 	findItem(*Feed) CachedFeed
 	Version() Version
+	Info() string
+	SpecificInfo(interface{}) string
 	transformToCurrent() (Cache, error)
 }
 
@@ -75,7 +77,7 @@ func newCache() (Cache, error) {
 	return cacheForVersion(currentVersion)
 }
 
-func loadCache(fileName string) (Cache, error) {
+func LoadCache(fileName string) (Cache, error) {
 	f, err := os.Open(fileName)
 	if err != nil {
 		if errors.Is(err, os.ErrNotExist) {
diff --git a/internal/feed/cache_v1.go b/internal/feed/cache_v1.go
index 02890e1..b5d6b3e 100644
--- a/internal/feed/cache_v1.go
+++ b/internal/feed/cache_v1.go
@@ -6,6 +6,7 @@ import (
 	"encoding/hex"
 	"fmt"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/google/uuid"
@@ -25,6 +26,11 @@ func (id feedId) String() string {
 	return strconv.FormatUint(uint64(id), 16)
 }
 
+func idFromString(s string) feedId {
+	id, _ := strconv.ParseUint(s, 16, 64)
+	return feedId(id)
+}
+
 type v1Cache struct {
 	Ids    map[feedDescriptor]feedId
 	NextId uint64
@@ -58,12 +64,15 @@ type cachedItem struct {
 
 func (item cachedItem) String() string {
 	return fmt.Sprintf(`{
+  ID: %s
   Title: %q
   Guid: %q
   Link: %q
   Date: %s
   Hash: %s
-}`, item.Title, item.Guid, item.Link, util.TimeFormat(item.Date), item.Hash)
+}`,
+		base64.RawURLEncoding.EncodeToString(item.ID[:]),
+		item.Title, item.Guid, item.Link, util.TimeFormat(item.Date), item.Hash)
 }
 
 func (cf *cachedFeed) Checked(withFailure bool) {
@@ -97,6 +106,46 @@ func (cache *v1Cache) Version() Version {
 	return v1Version
 }
 
+func (cache *v1Cache) Info() string {
+	b := strings.Builder{}
+	for descr, id := range cache.Ids {
+		b.WriteString(fmt.Sprintf("%3s: %s (%s)\n", id.String(), descr.Name, descr.Url))
+	}
+	return b.String()
+}
+
+func (cache *v1Cache) SpecificInfo(i interface{}) string {
+	id := idFromString(i.(string))
+
+	b := strings.Builder{}
+	feed := cache.Feeds[id]
+
+	for descr, fId := range cache.Ids {
+		if id == fId {
+			b.WriteString(descr.Name)
+			b.WriteString(" -- ")
+			b.WriteString(descr.Url)
+			b.WriteByte('\n')
+			break
+		}
+	}
+
+	b.WriteString(fmt.Sprintf(`
+Last Check: %s
+Num Failures: %d
+Num Items: %d
+`,
+		util.TimeFormat(feed.LastCheck),
+		feed.NumFailures,
+		len(feed.Items)))
+
+	for _, item := range feed.Items {
+		b.WriteString("\n--------------------\n")
+		b.WriteString(item.String())
+	}
+	return b.String()
+}
+
 func newV1Cache() *v1Cache {
 	cache := v1Cache{
 		Ids:    map[feedDescriptor]feedId{},
diff --git a/internal/feed/state.go b/internal/feed/state.go
index 5831ff4..dae0917 100644
--- a/internal/feed/state.go
+++ b/internal/feed/state.go
@@ -48,7 +48,7 @@ func (state *State) LoadCache(fileName string, forceNew bool) error {
 	if forceNew {
 		cache, err = newCache()
 	} else {
-		cache, err = loadCache(fileName)
+		cache, err = LoadCache(fileName)
 	}
 
 	if err != nil {
diff --git a/tools/print-cache/print-cache.go b/tools/print-cache/print-cache.go
new file mode 100644
index 0000000..d20963a
--- /dev/null
+++ b/tools/print-cache/print-cache.go
@@ -0,0 +1,36 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+
+	"github.com/Necoro/feed2imap-go/internal/feed"
+)
+
+// flags
+var (
+	cacheFile string = "feed.cache"
+	feedId    string = ""
+)
+
+func init() {
+	flag.StringVar(&cacheFile, "c", cacheFile, "cache file")
+	flag.StringVar(&feedId, "i", feedId, "id of the feed")
+}
+
+func main() {
+	flag.Parse()
+
+	cache, err := feed.LoadCache(cacheFile)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Printf("Cache version %d\n", cache.Version())
+	if feedId != "" {
+		fmt.Print(cache.SpecificInfo(feedId))
+	} else {
+		fmt.Print(cache.Info())
+	}
+}