Refactor snapshot module into subcommands.

cmd/snapshot_list.go

@@ -0,0 +1,60 @@
+package cmd
+
+import (
+	"fmt"
+	"github.com/gonuts/commander"
+	"github.com/gonuts/flag"
+	"github.com/smira/aptly/debian"
+	"sort"
+)
+
+func aptlySnapshotList(cmd *commander.Command, args []string) error {
+	var err error
+	if len(args) != 0 {
+		cmd.Usage()
+		return err
+	}
+
+	snapshotCollection := debian.NewSnapshotCollection(context.database)
+
+	if snapshotCollection.Len() > 0 {
+		fmt.Printf("List of snapshots:\n")
+
+		snapshots := make([]string, snapshotCollection.Len())
+
+		i := 0
+		snapshotCollection.ForEach(func(snapshot *debian.Snapshot) error {
+			snapshots[i] = snapshot.String()
+			i++
+			return nil
+		})
+
+		sort.Strings(snapshots)
+		for _, snapshot := range snapshots {
+			fmt.Printf(" * %s\n", snapshot)
+		}
+
+		fmt.Printf("\nTo get more information about snapshot, run `aptly snapshot show <name>`.\n")
+	} else {
+		fmt.Printf("\nNo snapshots found, create one with `aptly snapshot create...`.\n")
+	}
+	return err
+
+}
+
+func makeCmdSnapshotList() *commander.Command {
+	cmd := &commander.Command{
+		Run:       aptlySnapshotList,
+		UsageLine: "list",
+		Short:     "lists snapshots",
+		Long: `
+Command list shows full list of snapshots created.
+
+ex:
+  $ aptly snapshot list
+`,
+		Flag: *flag.NewFlagSet("aptly-snapshot-list", flag.ExitOnError),
+	}
+
+	return cmd
+}