package main

import (
	"fmt"
	"log"
	"os"
	"sort"

	"github.com/go-git/go-billy/v5/memfs"
	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing"
	"github.com/go-git/go-git/v5/storage/memory"

	"github.com/spf13/cobra"
	flags "github.com/spf13/pflag"

	"github.com/Masterminds/semver/v3"
)

var (
	clonedRepo = &git.Repository{}
	localRepo  = &git.Repository{}
	repoDir    string
	rootCmd    = &cobra.Command{
		Use:       "semverbump part [major|minor|patch]",
		Short:     "A tool for bumping semver git tags.",
		ValidArgs: []string{"major", "minor", "patch"},
		Args:      cobra.MatchAll(cobra.ExactArgs(1), cobra.OnlyValidArgs),
		Long:      `Inspired by the python bumpversion tool.`,
		RunE: func(cmd *cobra.Command, args []string) error {
			part := args[0]
			localRepo, err := git.PlainOpen(repoDir)
			if err != nil {
				return err
			}

			remoteURL := getRemoteURL(localRepo)
			fs := memfs.New()
			storer := memory.NewStorage()
			remoteRepo, err := git.Clone(storer, fs, &git.CloneOptions{
				URL: remoteURL,
			})
			if err != nil {
				log.Fatal(err)
			}

			tags := findTags(remoteRepo)
			latestVersion := latestTag(tags)
			if latestVersion == nil {
				fmt.Println("No tags found. Not doing anything")
				return nil
			}
			nextVersion := semver.Version{}
			switch part {
			case "major":
				nextVersion = latestVersion.IncMajor()
			case "minor":
				nextVersion = latestVersion.IncMinor()
			case "patch":
				nextVersion = latestVersion.IncPatch()
			}
			fmt.Println(nextVersion)
			return err
		},
	}
)

// TODO this only works for a single remote
func getRemoteURL(repo *git.Repository) string {
	_, err := repo.Config()
	if err != nil {
		log.Fatal(err)
	}
	remotes, err := repo.Remotes()
	if err != nil {
		log.Fatalf("error getting remotes %s", err)
	}
	if len(remotes) == 0 {
		return ""

	}
	primaryConfig := remotes[0].Config()
	return primaryConfig.URLs[0]
}

func latestTag(tags []*semver.Version) *semver.Version {
	numTags := len(tags)
	if numTags == 0 {
		return nil
	}
	return tags[numTags-1]
}

func findTags(repo *git.Repository) []*semver.Version {
	repoTagsIter, err := repo.Tags()
	if err != nil {
		log.Fatal(err)
	}
	repoTags := []*semver.Version{}
	if err := repoTagsIter.ForEach(func(ref *plumbing.Reference) error {
		if err != nil {
			log.Fatal(err)
		}
		rn := plumbing.ReferenceName(ref.Name())
		version, err := semver.NewVersion(rn.Short())
		if err != nil {
			// not a semver
			return nil
		}
		repoTags = append(repoTags, version)
		return nil
	}); err != nil {
		// log.error
		fmt.Printf("Iteration Error %s", err)
	}
	sort.Sort(semver.Collection(repoTags))
	return repoTags
}

func main() {
	// Clone the given repository to the given directory

	//repo, err := git.PlainClone("/tmp/foo", false, &git.CloneOptions{
	//	URL:      "https://github.com/grumps/selector",
	//	Progress: os.Stdout,
	//})
	//if err != nil {
	//	log.Fatal(err)
	//}
	if err := rootCmd.Execute(); err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
}

func init() {
	// global flags
	cwd, err := os.Getwd()
	if err != nil {
		log.Fatalf("couldn't get cwd %s", err)
	}
	repoDir = *flags.String("repoDir", cwd, "repo to examine")
	//pflag
}