Write a first version of the ROLIE feed.

csaf/rolie.go

@@ -1,5 +1,12 @@
 package csaf
 
+import (
+	"encoding/json"
+	"io"
+	"sort"
+	"time"
+)
+
 type Link struct {
 	Rel  string `json:"rel"`
 	HRef string `json:"href"`
@@ -30,7 +37,7 @@ type Entry struct {
 	Link      []Link    `json:"link"`
 	Published TimeStamp `json:"published"`
 	Updated   TimeStamp `json:"updated"`
-	Summary   Summary   `json:"summary"`
+	Summary   *Summary  `json:"summary,omitempty"`
 	Content   Content   `json:"content"`
 	Format    Format    `json:"format"`
 }
@@ -38,8 +45,39 @@ type Entry struct {
 type ROLIEFeed struct {
 	ID       string     `json:"id"`
 	Title    string     `json:"title"`
-	Link     []Link     `json:"link"`
-	Category []Category `json:"category"`
+	Link     []Link     `json:"link,omitempty"`
+	Category []Category `json:"category,omitempty"`
 	Updated  TimeStamp  `json:"updated"`
-	Entry    []*Entry   `json:"entry"`
+	Entry    []*Entry   `json:"entry,omitempty"`
+}
+
+func LoadROLIEFeed(r io.Reader) (*ROLIEFeed, error) {
+	dec := json.NewDecoder(r)
+	var rf ROLIEFeed
+	if err := dec.Decode(&rf); err != nil {
+		return nil, err
+	}
+	return &rf, nil
+}
+
+func (rf *ROLIEFeed) Save(w io.Writer) error {
+	enc := json.NewEncoder(w)
+	enc.SetIndent("", "  ")
+	return enc.Encode(rf)
+}
+
+func (rf *ROLIEFeed) EntryByID(id string) *Entry {
+	for _, entry := range rf.Entry {
+		if entry.ID == id {
+			return entry
+		}
+	}
+	return nil
+}
+
+func (rf *ROLIEFeed) SortEntriesByUpdated() {
+	entries := rf.Entry
+	sort.Slice(entries, func(i, j int) bool {
+		return time.Time(entries[j].Updated).Before(time.Time(entries[i].Updated))
+	})
 }