1 files changed, 116 insertions, 0 deletions
diff --git a/internal/feed/cache_v1.go b/internal/feed/cache_v1.go
new file mode 100644
index 0000000..3d46084
--- /dev/null
+++ b/internal/feed/cache_v1.go
@@ -0,0 +1,116 @@
+package feed
+
+import (
+	"crypto/sha256"
+	"time"
+
+	"github.com/Necoro/feed2imap-go/pkg/log"
+)
+
+const (
+	v1Version   Version = 1
+	startFeedId uint64  = 1
+)
+
+type feedId uint64
+
+type v1Cache struct {
+	Ids    map[feedDescriptor]feedId
+	NextId uint64
+	Feeds  map[feedId]*cachedFeed
+}
+
+type cachedFeed struct {
+	LastCheck   time.Time
+	NumFailures uint // can't be named `Failures` b/c it'll collide with the interface
+	Items       []cachedItem
+}
+
+type itemHash [sha256.Size]byte
+
+type cachedItem struct {
+	Uid     string
+	Title   string
+	Link    string
+	Date    time.Time
+	Updated time.Time
+	Creator string
+	Hash    itemHash
+}
+
+func (cf *cachedFeed) Checked(withFailure bool) {
+	cf.LastCheck = time.Now()
+	if withFailure {
+		cf.NumFailures++
+	} else {
+		cf.NumFailures = 0
+	}
+}
+
+func (cf *cachedFeed) Failures() uint {
+	return cf.NumFailures
+}
+
+func (cache *v1Cache) Version() Version {
+	return v1Version
+}
+
+func newV1Cache() *v1Cache {
+	cache := v1Cache{
+		Ids:    map[feedDescriptor]feedId{},
+		Feeds:  map[feedId]*cachedFeed{},
+		NextId: startFeedId,
+	}
+	return &cache
+}
+
+func (cache *v1Cache) transformToCurrent() (Cache, error) {
+	return cache, nil
+}
+
+func (cache *v1Cache) getItem(id feedId) CachedFeed {
+	feed, ok := cache.Feeds[id]
+	if !ok {
+		feed = &cachedFeed{}
+		cache.Feeds[id] = feed
+	}
+	return feed
+}
+
+func (cache *v1Cache) findItem(feed *Feed) CachedFeed {
+	if feed.cached != nil {
+		return feed.cached.(*cachedFeed)
+	}
+
+	fDescr := feed.descriptor()
+	id, ok := cache.Ids[fDescr]
+	if !ok {
+		var otherId feedDescriptor
+		changed := false
+		for otherId, id = range cache.Ids {
+			if otherId.Name == fDescr.Name {
+				log.Warnf("Feed %s seems to have changed URLs: newCache '%s', old '%s'. Updating.",
+					fDescr.Name, fDescr.Url, otherId.Url)
+				changed = true
+				break
+			} else if otherId.Url == fDescr.Url {
+				log.Warnf("Feed with URL '%s' seems to have changed its name: newCache '%s', old '%s'. Updating",
+					fDescr.Url, fDescr.Name, otherId.Name)
+				changed = true
+				break
+			}
+		}
+		if changed {
+			delete(cache.Ids, otherId)
+		} else {
+			id = feedId(cache.NextId)
+			cache.NextId++
+		}
+
+		cache.Ids[fDescr] = id
+	}
+
+	item := cache.getItem(id)
+	feed.cached = item
+	return item
+}