package githelper

import (
	"errors"
	"os"

	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/config"
	"github.com/go-git/go-git/v5/plumbing"
	"github.com/go-git/go-git/v5/plumbing/transport/ssh"
	"github.com/sirupsen/logrus"
)

type Git struct {
	SshPrivateKeyPath string
}

func NewGit(sshPrivateKeyPath string) Githelper {
	return &Git{
		SshPrivateKeyPath: sshPrivateKeyPath,
	}
}

func (g *Git) CloneRepo(workdir, gitURL string, dry bool) error {
	// TODO(@allanger): Support ssh keys with passwords
	publicKeys, err := ssh.NewPublicKeysFromFile("git", g.SshPrivateKeyPath, "")
	if err != nil {
		return err
	}
	_, err = git.PlainClone(workdir, false, &git.CloneOptions{URL: gitURL, Auth: publicKeys})
	if err != nil && !errors.Is(err, git.ErrEmptyUrls) {
		logrus.Info("the repo seems to be empty, I'll try to bootsrap it")
		// Initialize the repo
		err := os.Mkdir(workdir, 0077700)
		if err != nil {
			return err
		}
		r, err := git.PlainInit(workdir, false)
		if err != nil {
			return err
		}

		logrus.Infof("adding an origin remote: %s", gitURL)
		if _, err := r.CreateRemote(&config.RemoteConfig{Name: "origin", URLs: []string{gitURL}}); err != nil {
			return err
		}

		logrus.Info("getting the worktree")
		w, err := r.Worktree()
		if err != nil {
			return err
		}

		if err := r.Storer.SetReference(plumbing.NewHashReference(plumbing.Main, plumbing.ZeroHash)); err != nil {
			return err
		}

		logrus.Info("creating an empty 'Init Commit'")
		if _, err := w.Commit("Init Commit", &git.CommitOptions{
			AllowEmptyCommits: true,
		}); err != nil {
			return err
		}
		if !dry {
			if err := r.Push(&git.PushOptions{RemoteName: "origin"}); err != nil {
				return err
			}
		}
	} else if err != nil {
		return err
	}

	return nil
}

func (g *Git) AddAllAndCommit(workdir, message string) (string, error) {
	r, err := git.PlainOpen(workdir)
	if err != nil {
		return "", err
	}

	w, err := r.Worktree()
	if err != nil {
		return "", err
	}
	if _, err := w.Add("."); err != nil {
		return "", err
	}

	sha, err := w.Commit(message, &git.CommitOptions{})
	if err != nil {
		return "", err
	}

	return sha.String(), nil
}

func (g *Git) Push(workdir string) error {
	r, err := git.PlainOpen(workdir)
	if err != nil {
		return err
	}
	publicKeys, err := ssh.NewPublicKeysFromFile("git", g.SshPrivateKeyPath, "")
	if err != nil {
		return err
	}

	if err := r.Push(&git.PushOptions{
		RemoteName: "origin",
		Auth:       publicKeys,
	}); err != nil {
		return err
	}
	return nil
}