package main

import (
	"fmt"
	"runtime"
	"strings"
)

// buildTime is stamped at build time via -ldflags "-X main.buildTime=..."
// (build.sh does this). A plain "go build" with no ldflags leaves it at
// "dev" — still a meaningful, comparable value: two "dev" builds are only
// ever the same binary bytes copied around (self-deploy), never two
// independently built ones landing on the same value by chance.
var buildTime = "dev"

// versionString is what `clonetool version` prints, and what a remote
// host's own `version` output is compared against (see remoteBuildTag) to
// tell whether it's running the same build as this binary.
func versionString() string {
	return fmt.Sprintf("clonetool %s/%s build=%s", runtime.GOOS, runtime.GOARCH, buildTime)
}

// remoteBuildTag extracts the "build=..." tag from a clonetool `version`
// line, ignoring its GOOS/GOARCH — those are expected to legitimately
// differ across a cross-compiled deploy — and any surrounding ssh/shell
// noise on other lines. Returns "" if the line isn't a clonetool version
// line at all (e.g. "command not found").
func remoteBuildTag(out string) string {
	line := firstLine(out)
	i := strings.Index(line, "build=")
	if i < 0 {
		return ""
	}
	return strings.TrimSpace(line[i+len("build="):])
}