generator.go

package main

import (
	_ "embed"
	"fmt"
	"io"
	"os"
	"runtime/debug"
	"strings"
	"text/template"
)

//go:embed stub.tmpl.bash
var stubTemplateText string
var stubTemplate = template.Must(template.New("toolstub").Parse(stubTemplateText))

type Generator struct {
	ToolImport string
	Exe        string
	ModDir     string
}

func (g *Generator) GoToolImportPath() string {
	value, version, found := strings.Cut(g.ToolImport, "@")
	if found {
		fmt.Fprintf(os.Stderr, "[WARN] toolstub does not currently support version directive, ignoring version directive %q\n", "@"+version)
	}
	return value
}

func (g *Generator) WriteTo(w io.Writer) (int64, error) {
	// Is there a point to conform with io.WriterTo interface?
	// Kinda silly since template.(*Template).Execute doesn't return the written size...
	if err := stubTemplate.Execute(w, g); err != nil {
		return 0, err
	}
	return 1, nil
}

func (t *Generator) ToolstubInfo() string {
	bi, ok := debug.ReadBuildInfo()
	if !ok {
		return "toolstub"
	}

	version := bi.Main.Version
	rev := ""

	for _, i := range bi.Settings {
		switch i.Key {
		case "vcs.revision":
			rev = i.Value
		}
	}

	if rev != "" {
		if version == "(devel)" {
			version = rev
		} else {
			version = fmt.Sprintf("%s-%s", version, rev)
		}
	}

	return fmt.Sprintf("%s@%s", bi.Path, version)
}

func (t *Generator) ToolstubCmd() string {
	// This is gross and should probably be an attribute set by caller.
	args := os.Args[1:len(os.Args)]
	args = append([]string{"toolstub"}, args...)
	return strings.Join(args, " ")
}