feat: initial implementation of distro interface

distro/distro.go

@@ -1,6 +1,47 @@
 package distro
 
+import (
+	"sync"
+)
+
+var mu sync.Mutex
+var distros []distribution
+
+type distribution interface {
+	ID() ID
+	Equal(Distro) bool
+	Packages() (packages []string, err error)
+}
+
+func Register(d distribution) {
+	mu.Lock()
+	defer mu.Unlock()
+
+	distros = append(distros, d)
+}
+
 type Distro struct {
 	ID      ID
 	Release string
 }
+
+func (d Distro) Packages() (packages []string, err error) {
+	for _, dd := range distros {
+		if d.ID != None && d.ID != dd.ID() {
+			continue
+		}
+
+		if d.Release != "" && !dd.Equal(d) {
+			continue
+		}
+
+		var pkgs []string
+		pkgs, err = dd.Packages()
+		if err != nil {
+			return
+		}
+
+		packages = append(packages, pkgs...)
+	}
+	return
+}