package main

import (
	"fmt"
	"io"
	"runtime"
	"runtime/debug"
)

// version is overridden at build time:
//
//	go build -ldflags "-X main.version=$(git describe --tags --always --dirty)"
//
// It stays "dev" for a plain `go build`. See the Makefile.
var version = "dev"

// commit and date are optional build-time stamps, also set with -X.
var (
	commit = ""
	date   = ""
)

// buildVersion resolves the version string, preferring the ldflags value and
// falling back to the VCS revision the Go toolchain embeds for `go install`.
func buildVersion() string {
	v := version
	c := commit
	if c == "" {
		if info, ok := debug.ReadBuildInfo(); ok {
			for _, s := range info.Settings {
				if s.Key == "vcs.revision" {
					c = s.Value
				}
				if s.Key == "vcs.time" && date == "" {
					date = s.Value
				}
			}
		}
	}
	if len(c) > 12 {
		c = c[:12]
	}
	if c != "" {
		v += " (" + c + ")"
	}
	return v
}

func printVersion(w io.Writer) {
	fmt.Fprintf(w, "rip %s\n", buildVersion())
	if date != "" {
		fmt.Fprintf(w, "built:  %s\n", date)
	}
	fmt.Fprintf(w, "go:     %s\n", runtime.Version())
	fmt.Fprintf(w, "target: %s/%s\n", runtime.GOOS, runtime.GOARCH)
}