Index functions

xmlmodels/meta.go

@@ -3,6 +3,7 @@ package xmlmodels
 import (
 	"encoding/json"
 	"encoding/xml"
+	"iter"
 
 	xmlparsing "github.com/Theodor-Springmann-Stiftung/lenz-web/xml"
 )
@@ -17,6 +18,28 @@ type Meta struct {
 	Recieved    []Action                `xml:"recieved"`
 }
 
+func (m *Meta) Earliest() *Date {
+	var earliest *Date
+
+	for _, action := range m.Sent {
+		if earliest == nil || action.Earliest().Sort().Before(*earliest.Sort()) {
+			earliest = action.Earliest()
+		}
+	}
+
+	if earliest != nil {
+		return earliest
+	}
+
+	for _, action := range m.Recieved {
+		if earliest == nil || action.Earliest().Sort().Before(*earliest.Sort()) {
+			earliest = action.Earliest()
+		}
+	}
+
+	return earliest
+}
+
 func (m Meta) Keys() []any {
 	return []any{m.Letter}
 }
@@ -33,8 +56,30 @@ func (m Meta) String() string {
 	return string(json)
 }
 
+func (m Meta) SendRecieved() iter.Seq2[*Action, *Action] {
+	return func(yield func(*Action, *Action) bool) {
+		for i, sent := range m.Sent {
+			var rec *Action
+			if i < len(m.Recieved) {
+				rec = &m.Recieved[i]
+			}
+			if !yield(&sent, rec) {
+				return
+			}
+		}
+	}
+}
+
 type Action struct {
-	Dates   []Date       `xml:"date,attr"`
+	Dates   []Date       `xml:"date"`
 	Places  []RefElement `xml:"place"`
 	Persons []RefElement `xml:"person"`
 }
+
+func (a *Action) Earliest() *Date {
+	if len(a.Dates) == 0 {
+		return nil
+	}
+
+	return &a.Dates[0]
+}