feat(caldata): embed + parse the owned universal Roman calendar (initial coverage)

1 files changed, 69 insertions, 0 deletions

diff --git a/internal/caldata/caldata.go b/internal/caldata/caldata.go
new file mode 100644
index 0000000..5deb895
--- /dev/null
+++ b/internal/caldata/caldata.go
@@ -0,0 +1,69 @@
+// Package caldata embeds and parses lectio's owned universal General Roman
+// Calendar data into a calendar.Layer. It imports only internal/ini and
+// internal/calendar (types).
+package caldata
+
+import (
+	_ "embed"
+	"fmt"
+
+	"github.com/lukaszkasprzak/lectio/internal/calendar"
+	"github.com/lukaszkasprzak/lectio/internal/ini"
+)
+
+//go:embed roman-calendar.ini
+var romanCalendar []byte
+
+// Universal parses the embedded universal calendar. It panics on a malformed
+// embedded file (a build-time bug caught by tests), never at the request layer.
+func Universal() calendar.Layer {
+	l, err := parse(romanCalendar)
+	if err != nil {
+		panic(fmt.Sprintf("caldata: embedded roman-calendar.ini invalid: %v", err))
+	}
+	return l
+}
+
+func parse(data []byte) (calendar.Layer, error) {
+	secs, err := ini.Parse(data)
+	if err != nil {
+		return calendar.Layer{}, err
+	}
+	layer := calendar.Layer{Cels: map[string]calendar.RawCelebration{}}
+	for _, s := range secs {
+		fields := map[string]string{}
+		for _, p := range s.Pairs {
+			fields[p.Key] = p.Val
+		}
+		switch {
+		case s.Name == "" && len(fields) == 0:
+			continue
+		case s.Name == "layer":
+			layer.ID, layer.Name, layer.Type = fields["id"], fields["name"], fields["type"]
+		default:
+			base, variant, isVariant := cutVariant(s.Name)
+			rc := layer.Cels[base]
+			if rc.Fields == nil {
+				rc = calendar.RawCelebration{Fields: map[string]string{}, Variants: map[string]map[string]string{}}
+			}
+			if isVariant {
+				rc.Variants[variant] = fields
+			} else {
+				for k, v := range fields {
+					rc.Fields[k] = v
+				}
+			}
+			layer.Cels[base] = rc
+		}
+	}
+	return layer, nil
+}
+
+func cutVariant(name string) (base, variant string, ok bool) {
+	for i := 0; i < len(name); i++ {
+		if name[i] == '/' {
+			return name[:i], name[i+1:], true
+		}
+	}
+	return name, "", false
+}