From a81f0432e9e5188b88d45a298dd802200fe0058d Mon Sep 17 00:00:00 2001
From: Michael Eischer <michael.eischer@fau.de>
Date: Mon, 3 Oct 2022 14:16:33 +0200
Subject: [PATCH] restic: Add unified method to resolve a single snapshot

---
 cmd/restic/cmd_dump.go           | 15 +++------------
 cmd/restic/cmd_restore.go        | 15 +++------------
 internal/restic/snapshot_find.go | 16 ++++++++++++++++
 3 files changed, 22 insertions(+), 24 deletions(-)

diff --git a/cmd/restic/cmd_dump.go b/cmd/restic/cmd_dump.go
index fdb6b0b91..4f2827b02 100644
--- a/cmd/restic/cmd_dump.go
+++ b/cmd/restic/cmd_dump.go
@@ -139,18 +139,9 @@ func runDump(ctx context.Context, opts DumpOptions, gopts GlobalOptions, args []
 		}
 	}
 
-	var id restic.ID
-
-	if snapshotIDString == "latest" {
-		id, err = restic.FindLatestSnapshot(ctx, repo.Backend(), repo, opts.Paths, opts.Tags, opts.Hosts, nil)
-		if err != nil {
-			Exitf(1, "latest snapshot for criteria not found: %v Paths:%v Hosts:%v", err, opts.Paths, opts.Hosts)
-		}
-	} else {
-		id, err = restic.FindSnapshot(ctx, repo.Backend(), snapshotIDString)
-		if err != nil {
-			Exitf(1, "invalid id %q: %v", snapshotIDString, err)
-		}
+	id, err := restic.FindFilteredSnapshot(ctx, repo.Backend(), repo, opts.Paths, opts.Tags, opts.Hosts, snapshotIDString)
+	if err != nil {
+		Exitf(1, "failed to find snapshot: %v", err)
 	}
 
 	sn, err := restic.LoadSnapshot(ctx, repo, id)
diff --git a/cmd/restic/cmd_restore.go b/cmd/restic/cmd_restore.go
index 1254174d7..33a12b441 100644
--- a/cmd/restic/cmd_restore.go
+++ b/cmd/restic/cmd_restore.go
@@ -131,18 +131,9 @@ func runRestore(ctx context.Context, opts RestoreOptions, gopts GlobalOptions, a
 		}
 	}
 
-	var id restic.ID
-
-	if snapshotIDString == "latest" {
-		id, err = restic.FindLatestSnapshot(ctx, repo.Backend(), repo, opts.Paths, opts.Tags, opts.Hosts, nil)
-		if err != nil {
-			Exitf(1, "latest snapshot for criteria not found: %v Paths:%v Hosts:%v", err, opts.Paths, opts.Hosts)
-		}
-	} else {
-		id, err = restic.FindSnapshot(ctx, repo.Backend(), snapshotIDString)
-		if err != nil {
-			Exitf(1, "invalid id %q: %v", snapshotIDString, err)
-		}
+	id, err := restic.FindFilteredSnapshot(ctx, repo.Backend(), repo, opts.Hosts, opts.Tags, opts.Paths, snapshotIDString)
+	if err != nil {
+		Exitf(1, "failed to find snapshot %q: %v", snapshotIDString, err)
 	}
 
 	err = repo.LoadIndex(ctx)
diff --git a/internal/restic/snapshot_find.go b/internal/restic/snapshot_find.go
index f472ccfaa..088b920ec 100644
--- a/internal/restic/snapshot_find.go
+++ b/internal/restic/snapshot_find.go
@@ -88,6 +88,22 @@ func FindSnapshot(ctx context.Context, be Lister, s string) (ID, error) {
 	return ParseID(name)
 }
 
+func FindFilteredSnapshot(ctx context.Context, be Lister, loader LoaderUnpacked, hosts []string, tags []TagList, paths []string, snapshotID string) (ID, error) {
+	if snapshotID == "latest" {
+		id, err := FindLatestSnapshot(ctx, be, loader, paths, tags, hosts, nil)
+		if err == ErrNoSnapshotFound {
+			err = errors.Errorf("no snapshot matched given filter (Paths:%v Tags:%v Hosts:%v)", paths, tags, hosts)
+		}
+		return id, err
+	} else {
+		id, err := FindSnapshot(ctx, be, snapshotID)
+		if err != nil {
+			return ID{}, err
+		}
+		return id, err
+	}
+}
+
 type SnapshotFindCb func(string, *Snapshot, error) error
 
 // FindFilteredSnapshots yields Snapshots, either given explicitly by `snapshotIDs` or filtered from the list of all snapshots.