From 53640f33362d8d6dc65db403e3b31a6776b49796 Mon Sep 17 00:00:00 2001
From: n-peugnet <n.peugnet@free.fr>
Date: Mon, 27 Sep 2021 19:55:57 +0200
Subject: add CLI with subcommands

---
 TODO.md |  7 +++---
 main.go | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------
 repo.go |  7 ++++--
 3 files changed, 77 insertions(+), 15 deletions(-)

diff --git a/TODO.md b/TODO.md
index 0353b41..daa8120 100644
--- a/TODO.md
+++ b/TODO.md
@@ -17,7 +17,7 @@ priority 1
 - [x] remove errored files from `fileList`
 - [ ] **TODO: Priority 3** add superblock logic.
 - [ ] **TODO: Priority 2** add version blocks or journal logic.
-- [ ] command line with subcommands (like, hmm... git ? for instance).
+- [x] command line with subcommands (like, hmm... git ? for instance).
 
 priority 2
 ----------
@@ -48,6 +48,7 @@ priority 2
         listing could be another solution but with this approach we would have
         to think about what other metadata we want to store
     - [ ] use a symlink aware Walk function (easy enough)
+- [ ] add quick progress bar to CLI
 
 reunion 7/09
 ------------
@@ -65,8 +66,8 @@ ideas
 
 2. Implement the `fs` interface of Go? Not sure if this will be useful.
 
-3. If we don't need to reduce read amplification we could compress all chunks if
-    it reduces the space used.
+3. If we don't need to reduce read amplification we could compress all chunks 
+    together if it reduces the space used.
 
 mystical bug 22/09
 ------------------
diff --git a/main.go b/main.go
index c0e55d8..cf208c9 100644
--- a/main.go
+++ b/main.go
@@ -8,32 +8,90 @@ import (
 	"github.com/n-peugnet/dna-backup/logger"
 )
 
+type command struct {
+	Flag  *flag.FlagSet
+	Usage string
+	Help  string
+	Run   func([]string) error
+}
+
 const (
-	usage = "usage: dna-backup [<options>] [--] <source> <dest>\n\noptions:\n"
+	name         = "dna-backup"
+	baseUsage    = "<command> [<options>] [--] <args>"
+	commitUsage  = "[<options>] [--] <source> <dest>"
+	commitHelp   = "Create a new version of folder <source> into repo <dest>"
+	restoreUsage = "[<options>] [--] <source> <dest>"
+	restoreHelp  = "Restore the last version from repo <source> into folder <dest>"
 )
 
 var (
-	logLevel int
+	logLevel    int
+	commitCmd   = flag.NewFlagSet("commit", flag.ExitOnError)
+	restoreCmd  = flag.NewFlagSet("restore", flag.ExitOnError)
+	subcommands = map[string]command{
+		commitCmd.Name():  {commitCmd, commitUsage, commitHelp, commitMain},
+		restoreCmd.Name(): {restoreCmd, restoreUsage, restoreHelp, restoreMain},
+	}
 )
 
 func init() {
-	flag.IntVar(&logLevel, "v", 3, "log verbosity level (0-4)")
+	// init default help message
+	flag.Usage = func() {
+		fmt.Fprintf(flag.CommandLine.Output(), "usage: %s %s\n\ncommands:\n", name, baseUsage)
+		for _, s := range subcommands {
+			fmt.Printf("  %s	%s\n", s.Flag.Name(), s.Help)
+		}
+		os.Exit(1)
+	}
+	// setup subcommands
+	for _, s := range subcommands {
+		s.Flag.IntVar(&logLevel, "v", 3, "log verbosity level (0-4)")
+	}
 }
 
 func main() {
-	flag.Usage = func() {
-		fmt.Fprintf(flag.CommandLine.Output(), usage)
-		flag.PrintDefaults()
-	}
 	flag.Parse()
-	logger.Init(logLevel)
-	if len(flag.Args()) != 2 {
+
+	args := flag.Args()
+	if len(args) < 1 {
+		flag.Usage()
+	}
+	cmd, exists := subcommands[args[0]]
+	if !exists {
+		fmt.Fprintf(flag.CommandLine.Output(), "error: unknown command %s\n\n", args[0])
 		flag.Usage()
+	}
+	cmd.Flag.Usage = func() {
+		fmt.Fprintf(cmd.Flag.Output(), "usage: %s %s %s\n\noptions:\n", name, cmd.Flag.Name(), cmd.Usage)
+		cmd.Flag.PrintDefaults()
 		os.Exit(1)
 	}
-	args := flag.Args()
+	cmd.Flag.Parse(args[1:])
+	logger.Init(logLevel)
+	if err := cmd.Run(cmd.Flag.Args()); err != nil {
+		fmt.Fprintf(cmd.Flag.Output(), "error: %s\n\n", err)
+		cmd.Flag.Usage()
+	}
+}
+
+func commitMain(args []string) error {
+	if len(args) != 2 {
+		return fmt.Errorf("wrong number of args")
+	}
 	source := args[0]
 	dest := args[1]
 	repo := NewRepo(dest)
 	repo.Commit(source)
+	return nil
+}
+
+func restoreMain(args []string) error {
+	if len(args) != 2 {
+		return fmt.Errorf("wrong number args")
+	}
+	source := args[0]
+	dest := args[1]
+	repo := NewRepo(source)
+	repo.Restore(dest)
+	return nil
 }
diff --git a/repo.go b/repo.go
index 06524aa..d781b16 100644
--- a/repo.go
+++ b/repo.go
@@ -182,9 +182,12 @@ func (r *Repo) Commit(source string) {
 
 func (r *Repo) Restore(destination string) {
 	versions := r.loadVersions()
+	logger.Info("loading previous file lists")
 	r.loadFileLists(versions)
+	logger.Info("loading previous recipies")
 	r.loadRecipes(versions)
 	reader, writer := io.Pipe()
+	logger.Info("restoring latest version")
 	go r.restoreStream(writer, r.recipe)
 	bufReader := bufio.NewReaderSize(reader, r.chunkSize*2)
 	for _, file := range r.files {
@@ -353,7 +356,7 @@ func fileList2slice(l []File) (ret slice.Slice) {
 }
 
 func slice2fileList(s slice.Slice) (ret []File) {
-	ret = make([]File, len(s), len(s))
+	ret = make([]File, len(s))
 	for i := range s {
 		if f, ok := s[i].(File); ok {
 			ret[i] = f
@@ -721,7 +724,7 @@ func recipe2slice(r []Chunk) (ret slice.Slice) {
 }
 
 func slice2recipe(s slice.Slice) (ret []Chunk) {
-	ret = make([]Chunk, len(s), len(s))
+	ret = make([]Chunk, len(s))
 	for i := range s {
 		if c, ok := s[i].(Chunk); ok {
 			ret[i] = c
-- 
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