4 files changed, 679 insertions, 0 deletions
diff --git a/repository/gogit.go b/repository/gogit.go
new file mode 100644
index 00000000..71a7e6d0
--- /dev/null
+++ b/repository/gogit.go
@@ -0,0 +1,378 @@
+package repository
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	stdpath "path"
+	"path/filepath"
+	"sync"
+
+	gogit "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/MichaelMure/git-bug/util/lamport"
+)
+
+var _ ClockedRepo = &GoGitRepo{}
+
+type GoGitRepo struct {
+	r    *gogit.Repository
+	path string
+
+	clocksMutex sync.Mutex
+	clocks      map[string]lamport.Clock
+}
+
+func NewGoGitRepo(path string, clockLoaders []ClockLoader) (*GoGitRepo, error) {
+	path, err := detectGitPath(path)
+	if err != nil {
+		return nil, err
+	}
+
+	r, err := gogit.PlainOpen(path)
+	if err != nil {
+		return nil, err
+	}
+
+	repo := &GoGitRepo{
+		r:      r,
+		path:   path,
+		clocks: make(map[string]lamport.Clock),
+	}
+
+	for _, loader := range clockLoaders {
+		allExist := true
+		for _, name := range loader.Clocks {
+			if _, err := repo.getClock(name); err != nil {
+				allExist = false
+			}
+		}
+
+		if !allExist {
+			err = loader.Witnesser(repo)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	return repo, nil
+}
+
+func detectGitPath(path string) (string, error) {
+	// normalize the path
+	path, err := filepath.Abs(path)
+	if err != nil {
+		return "", err
+	}
+
+	for {
+		fi, err := os.Stat(stdpath.Join(path, ".git"))
+		if err == nil {
+			if !fi.IsDir() {
+				return "", fmt.Errorf(".git exist but is not a directory")
+			}
+			return stdpath.Join(path, ".git"), nil
+		}
+		if !os.IsNotExist(err) {
+			// unknown error
+			return "", err
+		}
+
+		// detect bare repo
+		ok, err := isGitDir(path)
+		if err != nil {
+			return "", err
+		}
+		if ok {
+			return path, nil
+		}
+
+		if parent := filepath.Dir(path); parent == path {
+			return "", fmt.Errorf(".git not found")
+		} else {
+			path = parent
+		}
+	}
+}
+
+func isGitDir(path string) (bool, error) {
+	markers := []string{"HEAD", "objects", "refs"}
+
+	for _, marker := range markers {
+		_, err := os.Stat(stdpath.Join(path, marker))
+		if err == nil {
+			continue
+		}
+		if !os.IsNotExist(err) {
+			// unknown error
+			return false, err
+		} else {
+			return false, nil
+		}
+	}
+
+	return true, nil
+}
+
+// InitGoGitRepo create a new empty git repo at the given path
+func InitGoGitRepo(path string) (*GoGitRepo, error) {
+	r, err := gogit.PlainInit(path, false)
+	if err != nil {
+		return nil, err
+	}
+
+	return &GoGitRepo{
+		r:      r,
+		path:   path + "/.git",
+		clocks: make(map[string]lamport.Clock),
+	}, nil
+}
+
+// InitBareGoGitRepo create a new --bare empty git repo at the given path
+func InitBareGoGitRepo(path string) (*GoGitRepo, error) {
+	r, err := gogit.PlainInit(path, true)
+	if err != nil {
+		return nil, err
+	}
+
+	return &GoGitRepo{
+		r:      r,
+		path:   path,
+		clocks: make(map[string]lamport.Clock),
+	}, nil
+}
+
+func (repo *GoGitRepo) LocalConfig() Config {
+	return newGoGitConfig(repo.r)
+}
+
+func (repo *GoGitRepo) GlobalConfig() Config {
+	panic("go-git doesn't support writing global config")
+}
+
+// GetPath returns the path to the repo.
+func (repo *GoGitRepo) GetPath() string {
+	return repo.path
+}
+
+// GetUserName returns the name the the user has used to configure git
+func (repo *GoGitRepo) GetUserName() (string, error) {
+	cfg, err := repo.r.Config()
+	if err != nil {
+		return "", err
+	}
+
+	return cfg.User.Name, nil
+}
+
+// GetUserEmail returns the email address that the user has used to configure git.
+func (repo *GoGitRepo) GetUserEmail() (string, error) {
+	cfg, err := repo.r.Config()
+	if err != nil {
+		return "", err
+	}
+
+	return cfg.User.Email, nil
+}
+
+// GetCoreEditor returns the name of the editor that the user has used to configure git.
+func (repo *GoGitRepo) GetCoreEditor() (string, error) {
+
+	panic("implement me")
+}
+
+// GetRemotes returns the configured remotes repositories.
+func (repo *GoGitRepo) GetRemotes() (map[string]string, error) {
+	cfg, err := repo.r.Config()
+	if err != nil {
+		return nil, err
+	}
+
+	result := make(map[string]string, len(cfg.Remotes))
+	for name, remote := range cfg.Remotes {
+		if len(remote.URLs) > 0 {
+			result[name] = remote.URLs[0]
+		}
+	}
+
+	return result, nil
+}
+
+// FetchRefs fetch git refs from a remote
+func (repo *GoGitRepo) FetchRefs(remote string, refSpec string) (string, error) {
+	buf := bytes.NewBuffer(nil)
+
+	err := repo.r.Fetch(&gogit.FetchOptions{
+		RemoteName: remote,
+		RefSpecs:   []config.RefSpec{config.RefSpec(refSpec)},
+		Progress:   buf,
+	})
+	if err != nil {
+		return "", err
+	}
+
+	return buf.String(), nil
+}
+
+// PushRefs push git refs to a remote
+func (repo *GoGitRepo) PushRefs(remote string, refSpec string) (string, error) {
+	buf := bytes.NewBuffer(nil)
+
+	err := repo.r.Push(&gogit.PushOptions{
+		RemoteName: remote,
+		RefSpecs:   []config.RefSpec{config.RefSpec(refSpec)},
+		Progress:   buf,
+	})
+	if err != nil {
+		return "", err
+	}
+
+	return buf.String(), nil
+}
+
+// StoreData will store arbitrary data and return the corresponding hash
+func (repo *GoGitRepo) StoreData(data []byte) (Hash, error) {
+	obj := repo.r.Storer.NewEncodedObject()
+	obj.SetType(plumbing.BlobObject)
+
+	w, err := obj.Writer()
+	if err != nil {
+		return "", err
+	}
+
+	_, err = w.Write(data)
+	if err != nil {
+		return "", err
+	}
+
+	h, err := repo.r.Storer.SetEncodedObject(obj)
+	if err != nil {
+		return "", err
+	}
+
+	return Hash(h.String()), nil
+}
+
+// ReadData will attempt to read arbitrary data from the given hash
+func (repo *GoGitRepo) ReadData(hash Hash) ([]byte, error) {
+	obj, err := repo.r.BlobObject(plumbing.NewHash(hash.String()))
+	if err != nil {
+		return nil, err
+	}
+
+	r, err := obj.Reader()
+	if err != nil {
+		return nil, err
+	}
+
+	return ioutil.ReadAll(r)
+}
+
+func (repo *GoGitRepo) StoreTree(mapping []TreeEntry) (Hash, error) {
+	panic("implement me")
+}
+
+func (repo *GoGitRepo) ReadTree(hash Hash) ([]TreeEntry, error) {
+	panic("implement me")
+}
+
+func (repo *GoGitRepo) StoreCommit(treeHash Hash) (Hash, error) {
+	panic("implement me")
+}
+
+func (repo *GoGitRepo) StoreCommitWithParent(treeHash Hash, parent Hash) (Hash, error) {
+	panic("implement me")
+}
+
+func (repo *GoGitRepo) GetTreeHash(commit Hash) (Hash, error) {
+	panic("implement me")
+}
+
+func (repo *GoGitRepo) FindCommonAncestor(commit1 Hash, commit2 Hash) (Hash, error) {
+	panic("implement me")
+}
+
+func (repo *GoGitRepo) UpdateRef(ref string, hash Hash) error {
+	panic("implement me")
+}
+
+func (repo *GoGitRepo) RemoveRef(ref string) error {
+	panic("implement me")
+}
+
+func (repo *GoGitRepo) ListRefs(refspec string) ([]string, error) {
+	panic("implement me")
+}
+
+func (repo *GoGitRepo) RefExist(ref string) (bool, error) {
+	panic("implement me")
+}
+
+func (repo *GoGitRepo) CopyRef(source string, dest string) error {
+	panic("implement me")
+}
+
+func (repo *GoGitRepo) ListCommits(ref string) ([]Hash, error) {
+	panic("implement me")
+}
+
+// GetOrCreateClock return a Lamport clock stored in the Repo.
+// If the clock doesn't exist, it's created.
+func (repo *GoGitRepo) GetOrCreateClock(name string) (lamport.Clock, error) {
+	c, err := repo.getClock(name)
+	if err == nil {
+		return c, nil
+	}
+	if err != ErrClockNotExist {
+		return nil, err
+	}
+
+	repo.clocksMutex.Lock()
+	defer repo.clocksMutex.Unlock()
+
+	p := clockPath + name + "-clock"
+
+	c, err = lamport.NewPersistedClock(p)
+	if err != nil {
+		return nil, err
+	}
+
+	repo.clocks[name] = c
+	return c, nil
+}
+
+func (repo *GoGitRepo) getClock(name string) (lamport.Clock, error) {
+	repo.clocksMutex.Lock()
+	defer repo.clocksMutex.Unlock()
+
+	if c, ok := repo.clocks[name]; ok {
+		return c, nil
+	}
+
+	p := clockPath + name + "-clock"
+
+	c, err := lamport.LoadPersistedClock(p)
+	if err == nil {
+		repo.clocks[name] = c
+		return c, nil
+	}
+	if err == lamport.ErrClockNotExist {
+		return nil, ErrClockNotExist
+	}
+	return nil, err
+}
+
+// AddRemote add a new remote to the repository
+// Not in the interface because it's only used for testing
+func (repo *GoGitRepo) AddRemote(name string, url string) error {
+	_, err := repo.r.CreateRemote(&config.RemoteConfig{
+		Name: name,
+		URLs: []string{url},
+	})
+
+	return err
+}
diff --git a/repository/gogit_config.go b/repository/gogit_config.go
new file mode 100644
index 00000000..0f91b092
--- /dev/null
+++ b/repository/gogit_config.go
@@ -0,0 +1,175 @@
+package repository
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+
+	gogit "github.com/go-git/go-git/v5"
+	"github.com/go-git/go-git/v5/plumbing/format/config"
+)
+
+var _ Config = &goGitConfig{}
+
+type goGitConfig struct {
+	repo *gogit.Repository
+}
+
+func newGoGitConfig(repo *gogit.Repository) *goGitConfig {
+	return &goGitConfig{repo: repo}
+}
+
+func (ggc *goGitConfig) StoreString(key, value string) error {
+	cfg, err := ggc.repo.Config()
+	if err != nil {
+		return err
+	}
+
+	split := strings.Split(key, ".")
+
+	switch {
+	case len(split) <= 1:
+		return fmt.Errorf("invalid key")
+	case len(split) == 2:
+		cfg.Raw.Section(split[0]).SetOption(split[1], value)
+	default:
+		section := split[0]
+		subsection := strings.Join(split[1:len(split)-2], ".")
+		option := split[len(split)-1]
+		cfg.Raw.Section(section).Subsection(subsection).SetOption(option, value)
+	}
+
+	return ggc.repo.SetConfig(cfg)
+}
+
+func (ggc *goGitConfig) StoreTimestamp(key string, value time.Time) error {
+	return ggc.StoreString(key, strconv.Itoa(int(value.Unix())))
+}
+
+func (ggc *goGitConfig) StoreBool(key string, value bool) error {
+	return ggc.StoreString(key, strconv.FormatBool(value))
+}
+
+func (ggc *goGitConfig) ReadAll(keyPrefix string) (map[string]string, error) {
+	cfg, err := ggc.repo.Config()
+	if err != nil {
+		return nil, err
+	}
+
+	split := strings.Split(keyPrefix, ".")
+
+	var opts config.Options
+
+	switch {
+	case len(split) < 1:
+		return nil, fmt.Errorf("invalid key prefix")
+	case len(split) == 1:
+		opts = cfg.Raw.Section(split[0]).Options
+	default:
+		section := split[0]
+		subsection := strings.Join(split[1:len(split)-1], ".")
+		opts = cfg.Raw.Section(section).Subsection(subsection).Options
+	}
+
+	if len(opts) == 0 {
+		return nil, fmt.Errorf("invalid section")
+	}
+
+	if keyPrefix[len(keyPrefix)-1:] != "." {
+		keyPrefix += "."
+	}
+
+	result := make(map[string]string, len(opts))
+	for _, opt := range opts {
+		result[keyPrefix+opt.Key] = opt.Value
+	}
+
+	return result, nil
+}
+
+func (ggc *goGitConfig) ReadBool(key string) (bool, error) {
+	val, err := ggc.ReadString(key)
+	if err != nil {
+		return false, err
+	}
+
+	return strconv.ParseBool(val)
+}
+
+func (ggc *goGitConfig) ReadString(key string) (string, error) {
+	cfg, err := ggc.repo.Config()
+	if err != nil {
+		return "", err
+	}
+
+	split := strings.Split(key, ".")
+
+	// TODO: return ErrNoConfigEntry and ErrMultipleConfigEntry
+	// Can use forked go-git: https://github.com/go-git/go-git/pull/112
+
+	switch {
+	case len(split) <= 1:
+		return "", fmt.Errorf("invalid key")
+	case len(split) == 2:
+		return cfg.Raw.Section(split[0]).Option(split[1]), nil
+	default:
+		section := split[0]
+		subsection := strings.Join(split[1:len(split)-2], ".")
+		option := split[len(split)-1]
+		return cfg.Raw.Section(section).Subsection(subsection).Option(option), nil
+	}
+}
+
+func (ggc *goGitConfig) ReadTimestamp(key string) (time.Time, error) {
+	value, err := ggc.ReadString(key)
+	if err != nil {
+		return time.Time{}, err
+	}
+	return ParseTimestamp(value)
+}
+
+func (ggc *goGitConfig) RemoveAll(keyPrefix string) error {
+	cfg, err := ggc.repo.Config()
+	if err != nil {
+		return err
+	}
+
+	split := strings.Split(keyPrefix, ".")
+
+	// missing in go-git
+	hasOption := func(options config.Options, key string) bool {
+		for _, option := range options {
+			if option.IsKey(key) {
+				return true
+			}
+		}
+		return false
+	}
+
+	switch {
+	case len(split) < 1:
+		return fmt.Errorf("invalid key prefix")
+	case len(split) == 1:
+		if len(cfg.Raw.Section(split[0]).Options) > 0 {
+			cfg.Raw.RemoveSection(split[0])
+		} else {
+			return fmt.Errorf("invalid key prefix")
+		}
+	default:
+		section := split[0]
+		rest := strings.Join(split[1:], ".")
+
+		if cfg.Raw.Section(section).HasSubsection(rest) {
+			cfg.Raw.RemoveSubsection(section, rest)
+		} else {
+			if hasOption(cfg.Raw.Section(section).Options, rest) {
+				cfg.Raw.Section(section).RemoveOption(rest)
+			} else {
+				return fmt.Errorf("invalid key prefix")
+			}
+		}
+	}
+
+	return ggc.repo.SetConfig(cfg)
+}
diff --git a/repository/gogit_test.go b/repository/gogit_test.go
new file mode 100644
index 00000000..9dcf109f
--- /dev/null
+++ b/repository/gogit_test.go
@@ -0,0 +1,68 @@
+package repository
+
+import (
+	"io/ioutil"
+	"os"
+	"path"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewGoGitRepo(t *testing.T) {
+	// Plain
+	plainRoot, err := ioutil.TempDir("", "")
+	require.NoError(t, err)
+	defer os.RemoveAll(plainRoot)
+
+	_, err = InitGoGitRepo(plainRoot)
+	require.NoError(t, err)
+	plainGitDir := path.Join(plainRoot, ".git")
+
+	// Bare
+	bareRoot, err := ioutil.TempDir("", "")
+	require.NoError(t, err)
+	defer os.RemoveAll(bareRoot)
+
+	_, err = InitBareGoGitRepo(bareRoot)
+	require.NoError(t, err)
+	bareGitDir := bareRoot
+
+	tests := []struct {
+		inPath  string
+		outPath string
+		err     bool
+	}{
+		// errors
+		{"/", "", true},
+		// parent dir of a repo
+		{filepath.Dir(plainRoot), "", true},
+
+		// Plain repo
+		{plainRoot, plainGitDir, false},
+		{plainGitDir, plainGitDir, false},
+		{path.Join(plainGitDir, "objects"), plainGitDir, false},
+
+		// Bare repo
+		{bareRoot, bareGitDir, false},
+		{bareGitDir, bareGitDir, false},
+		{path.Join(bareGitDir, "objects"), bareGitDir, false},
+	}
+
+	for i, tc := range tests {
+		r, err := NewGoGitRepo(tc.inPath, nil)
+
+		if tc.err {
+			require.Error(t, err, i)
+		} else {
+			require.NoError(t, err, i)
+			assert.Equal(t, tc.outPath, r.GetPath(), i)
+		}
+	}
+}
+
+func TestGoGitRepo(t *testing.T) {
+	RepoTest(t, CreateGoGitTestRepo, CleanupTestRepos)
+}
diff --git a/repository/gogit_testing.go b/repository/gogit_testing.go
new file mode 100644
index 00000000..f20ff6be
--- /dev/null
+++ b/repository/gogit_testing.go
@@ -0,0 +1,58 @@
+package repository
+
+import (
+	"io/ioutil"
+	"log"
+)
+
+// This is intended for testing only
+
+func CreateGoGitTestRepo(bare bool) TestedRepo {
+	dir, err := ioutil.TempDir("", "")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	var creator func(string) (*GoGitRepo, error)
+
+	if bare {
+		creator = InitBareGoGitRepo
+	} else {
+		creator = InitGoGitRepo
+	}
+
+	repo, err := creator(dir)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	config := repo.LocalConfig()
+	if err := config.StoreString("user.name", "testuser"); err != nil {
+		log.Fatal("failed to set user.name for test repository: ", err)
+	}
+	if err := config.StoreString("user.email", "testuser@example.com"); err != nil {
+		log.Fatal("failed to set user.email for test repository: ", err)
+	}
+
+	return repo
+}
+
+func SetupGoGitReposAndRemote() (repoA, repoB, remote TestedRepo) {
+	repoA = CreateGoGitTestRepo(false)
+	repoB = CreateGoGitTestRepo(false)
+	remote = CreateGoGitTestRepo(true)
+
+	remoteAddr := "file://" + remote.GetPath()
+
+	err := repoA.AddRemote("origin", remoteAddr)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	err = repoB.AddRemote("origin", remoteAddr)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return repoA, repoB, remote
+}