Long live Touhou

Signed-off-by: Izuru Yakumo <yakumo.izuru@chaotic.ninja>

git-svn-id: file:///srv/svn/repo/suwako/trunk@13 0b558ee1-521d-8b46-a41b-40029c97c055

version.go

@@ -0,0 +1,50 @@
+package suwako
+
+import (
+	"fmt"
+	"runtime/debug"
+	"strings"
+)
+
+const (
+	defaultVersion = "0.0.0"
+	defaultCommit  = "HEAD"
+	defaultBuild   = "0000-01-01:00:00+00:00"
+)
+
+var (
+	// Version is the tagged release version in the form <major>.<minor>.<patch>
+	// following semantic versioning and is overwritten by the build system.
+	Version = defaultVersion
+
+	// Commit is the commit sha of the build (normally from Git) and is overwritten
+	// by the build system.
+	Commit = defaultCommit
+
+	// Build is the date and time of the build as an RFC3339 formatted string
+	// and is overwritten by the build system.
+	Build = defaultBuild
+)
+
+// FullVersion display the full version and build
+func FullVersion() string {
+	var sb strings.Builder
+
+	isDefault := Version == defaultVersion && Commit == defaultCommit && Build == defaultBuild
+
+	if !isDefault {
+		sb.WriteString(fmt.Sprintf("%s@%s %s", Version, Commit, Build))
+	}
+
+	if info, ok := debug.ReadBuildInfo(); ok {
+		if isDefault {
+			sb.WriteString(fmt.Sprintf(" %s", info.Main.Version))
+		}
+		sb.WriteString(fmt.Sprintf(" %s", info.GoVersion))
+		if info.Main.Sum != "" {
+			sb.WriteString(fmt.Sprintf(" %s", info.Main.Sum))
+		}
+	}
+
+	return sb.String()
+}