package main

import (
	"log"
	"os"
	"strings"

	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing"
)

const prefLocalBranch = `refs/heads/`

type branchInfo struct {
	hash string
	name string
}

func checkIfError(err error) {
	if err != nil {
		log.Fatal(err)
	}
}

func main() {
	dir, err := os.Getwd()
	checkIfError(err)

	log.Printf("Opening %s…", dir)
	r, err := git.PlainOpen(dir)
	checkIfError(err)

	refs, err := r.References()
	checkIfError(err)

	branches := []branchInfo{}
	addIfBranch := func(cr *plumbing.Reference) {
		if cr.Type() == plumbing.HashReference {
			rn := cr.Name()
			if strings.HasPrefix(rn.String(), prefLocalBranch) {
				branches = append(
					branches,
					branchInfo{
						hash: cr.Hash().String(),
						name: rn.Short(),
					},
				)
			}
		}
	}
	refs.ForEach(
		func(ref *plumbing.Reference) error {
			addIfBranch(ref)
			return nil
		},
	)

	log.Println(branches)
}