From c8297534cc0c98307338aa4c00412b7aa550dd90 Mon Sep 17 00:00:00 2001
From: David Allen <allend@lanl.gov>
Date: Wed, 28 Aug 2024 12:34:49 -0600
Subject: [PATCH] Added version command and corresponding implementation

---
 cmd/version.go      | 24 ++++++++++++++++++++++++
 internal/version.go | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)
 create mode 100644 cmd/version.go
 create mode 100644 internal/version.go

diff --git a/cmd/version.go b/cmd/version.go
new file mode 100644
index 0000000..be17843
--- /dev/null
+++ b/cmd/version.go
@@ -0,0 +1,24 @@
+package cmd
+
+import (
+	"fmt"
+
+	magellan "github.com/OpenCHAMI/magellan/internal"
+	"github.com/spf13/cobra"
+)
+
+var versionCmd = &cobra.Command{
+	Use: "version",
+	Run: func(cmd *cobra.Command, args []string) {
+		if cmd.Flag("rev").Value.String() == "true" {
+			fmt.Println(magellan.VersionCommit())
+		} else {
+			fmt.Println(magellan.VersionTag())
+		}
+	},
+}
+
+func init() {
+	versionCmd.Flags().Bool("rev", false, "show the version commit")
+	rootCmd.AddCommand(versionCmd)
+}
diff --git a/internal/version.go b/internal/version.go
new file mode 100644
index 0000000..f11b47a
--- /dev/null
+++ b/internal/version.go
@@ -0,0 +1,42 @@
+package magellan
+
+import (
+	"fmt"
+	"os/exec"
+	"strings"
+)
+
+// VersionCommit() returns a string with 'r{commit_count}.{commit_version}' format.
+func VersionCommit() string {
+	var (
+		version  string
+		revlist  []byte
+		revparse []byte
+		err      error
+	)
+	revlist, err = exec.Command("git", "rev-list", "--count", "HEAD").Output()
+	if err != nil {
+		return ""
+	}
+
+	revparse, err = exec.Command("git", "rev-parse", "--short", "HEAD").Output()
+	if err != nil {
+		return ""
+	}
+	version = fmt.Sprintf("r%s.%s", strings.TrimRight(string(revlist), "\n"), string(revparse))
+	return strings.TrimRight(version, "\n")
+}
+
+// VersionTag() returns  a string with format '{git_tag}' using the `git describe` command.
+func VersionTag() string {
+	var (
+		describe []byte
+		err      error
+	)
+	describe, err = exec.Command("git", "describe", "--long", "HEAD").Output()
+	if err != nil {
+		return ""
+	}
+
+	return strings.TrimRight(string(describe), "\n")
+}