package main

import (
	"flag"
	"fmt"
	"os"

	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/config"
	"gopkg.in/yaml.v2"
)

func main() {
	dir := flag.String("dir", "repo", "path to local git repo")
	configFile := flag.String("config", "config.yaml", "path to configuration")
	flag.Parse()

	file, err := os.Open(*configFile)
	if err != nil {
		panic(fmt.Sprintf("Could not open '%s': %s", *configFile, err))
	}
	defer file.Close()

	cfg := new(configFormat)

	configDecoder := yaml.NewDecoder(file)
	err = configDecoder.Decode(&cfg)
	if err != nil {
		panic(fmt.Sprintf("Failed parsing '%s': %s", *configFile, err))
	}

	_, err = git.PlainClone(*dir, true, &git.CloneOptions{
		URL:          cfg.Sites.Upstream.FullURL(),
		Auth:         nil,
		RemoteName:   "upstream",
		SingleBranch: false,
		NoCheckout:   true,
	})
	if err != nil && err != git.ErrRepositoryAlreadyExists {
		panic(err)
	}

	repo, err := git.PlainOpen(*dir)
	if err != nil {
		panic(err)
	}

	_, err = repo.CreateRemote(&config.RemoteConfig{
		Name: "downstream",
		URLs: []string{cfg.Sites.Downstream.FullURL()},
	})
	if err != nil && err != git.ErrRemoteExists {
		panic(err)
	}

	err = repo.Fetch(&git.FetchOptions{
		RemoteName: "upstream",
	})
	if err != nil && err != git.NoErrAlreadyUpToDate {
		panic(err)
	}

	err = repo.Fetch(&git.FetchOptions{
		RemoteName: "downstream",
	})
	if err != nil && err != git.NoErrAlreadyUpToDate {
		panic(err)
	}

	fmt.Println(repo)
}