initial version of the flake-info command

A tool to display information about a flake. For now we shows all the
inputs and when they were updated last.

1 files changed, 43 insertions, 0 deletions

diff --git a/cmd/flake-info/main.go b/cmd/flake-info/main.go
new file mode 100644
index 0000000..d41f321
--- /dev/null
+++ b/cmd/flake-info/main.go
@@ -0,0 +1,43 @@
+package main
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/fcuny/world/pkg/flake/lock"
+)
+
+func main() {
+	var flakeLockPath string
+
+	flag.StringVar(&flakeLockPath, "flake-lock", "flake.lock", "path to the flake lock file")
+
+	flag.Parse()
+
+	if _, err := os.Stat(flakeLockPath); err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			fmt.Fprintf(os.Stderr, "%s does not exists\n", flakeLockPath)
+		} else {
+			fmt.Fprintf(os.Stderr, "failed to check if %s exists: %v\n", flakeLockPath, err)
+		}
+		os.Exit(1)
+	}
+
+	lock, err := lock.New(flakeLockPath)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "failed to parse the lockfile for %s: %+v\n", flakeLockPath, err)
+		os.Exit(1)
+	}
+
+	fmt.Printf("%s info:\n", flakeLockPath)
+	fmt.Printf("version: %d\n", lock.Version)
+	fmt.Printf("all nodes:\n")
+	for nodeName, node := range lock.Nodes {
+		date := time.Unix(node.Locked.LastModified, 0)
+		unitTimeInRFC3339 := date.Format(time.RFC3339)
+		fmt.Printf("- %s was updated on %s\n", nodeName, unitTimeInRFC3339)
+	}
+}