//go:build ignore

package main

import (
	"bufio"
	"flag"
	"fmt"
	"log"
	"os"

	"github.com/mdomke/git-semver/v6/version"
)

func fetchVersion() string {
	repoPath, err := os.Getwd()
	if err != nil {
		log.Fatal(err)
	}
	v, err := version.NewFromRepo(repoPath)
	if err != nil {
		log.Fatal(err)
	}
	s, err := v.Format(version.FullFormat)
	if err != nil {
		log.Fatal(err)
	}
	return s
}

func main() {
	var pkgName string
	var varName string
	var fileName string
	flag.StringVar(&pkgName, "p", "main", "Specify package name.")
	flag.StringVar(&varName, "v", "gitVersion", "Specify variable name.")
	flag.StringVar(&fileName, "f", "./version.go", "Specify filename.")
	flag.Usage = func() {
		fmt.Printf("gen_version")
		flag.PrintDefaults()
	}
	flag.Parse()
	versionStr := fetchVersion()
	lines := []string{
		fmt.Sprintf("package %s", pkgName),
		"// Code generated automatically. DO NOT EDIT",
		"",
		fmt.Sprintf(
			"// %s is the generated version based on the current git revision",
			varName),
		fmt.Sprintf("const %s = \"%s\"", varName, versionStr),
	}
	file, err := os.Create(fileName)
	if err != nil {
		log.Fatal(err)
	}
	writer := bufio.NewWriter(file)
	for _, line := range lines {
		_, err := writer.WriteString(line + "\n")
		if err != nil {
			log.Fatalf("Error while writing to file: %s", err.Error())
		}
	}
	writer.Flush()
	fmt.Printf("Wrote version %s to %s, variable %s in package %s\n",
		versionStr, fileName, varName, pkgName)
}