1 files changed, 221 insertions, 0 deletions
diff --git a/repository/git_config.go b/repository/git_config.go
new file mode 100644
index 00000000..987cf195
--- /dev/null
+++ b/repository/git_config.go
@@ -0,0 +1,221 @@
+package repository
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/blang/semver"
+	"github.com/pkg/errors"
+)
+
+var _ Config = &gitConfig{}
+
+type gitConfig struct {
+	repo         *GitRepo
+	localityFlag string
+}
+
+func newGitConfig(repo *GitRepo, global bool) *gitConfig {
+	localityFlag := "--local"
+	if global {
+		localityFlag = "--global"
+	}
+	return &gitConfig{
+		repo:         repo,
+		localityFlag: localityFlag,
+	}
+}
+
+// StoreString store a single key/value pair in the config of the repo
+func (gc *gitConfig) StoreString(key string, value string) error {
+	_, err := gc.repo.runGitCommand("config", gc.localityFlag, "--replace-all", key, value)
+	return err
+}
+
+func (gc *gitConfig) StoreBool(key string, value bool) error {
+	return gc.StoreString(key, strconv.FormatBool(value))
+}
+
+func (gc *gitConfig) StoreTimestamp(key string, value time.Time) error {
+	return gc.StoreString(key, strconv.Itoa(int(value.Unix())))
+}
+
+// ReadAll read all key/value pair matching the key prefix
+func (gc *gitConfig) ReadAll(keyPrefix string) (map[string]string, error) {
+	stdout, err := gc.repo.runGitCommand("config", gc.localityFlag, "--includes", "--get-regexp", keyPrefix)
+
+	//   / \
+	//  / ! \
+	// -------
+	//
+	// There can be a legitimate error here, but I see no portable way to
+	// distinguish them from the git error that say "no matching value exist"
+	if err != nil {
+		return nil, nil
+	}
+
+	lines := strings.Split(stdout, "\n")
+
+	result := make(map[string]string, len(lines))
+
+	for _, line := range lines {
+		if strings.TrimSpace(line) == "" {
+			continue
+		}
+
+		parts := strings.SplitN(line, " ", 2)
+		result[parts[0]] = parts[1]
+	}
+
+	return result, nil
+}
+
+func (gc *gitConfig) ReadString(key string) (string, error) {
+	stdout, err := gc.repo.runGitCommand("config", gc.localityFlag, "--includes", "--get-all", key)
+
+	//   / \
+	//  / ! \
+	// -------
+	//
+	// There can be a legitimate error here, but I see no portable way to
+	// distinguish them from the git error that say "no matching value exist"
+	if err != nil {
+		return "", ErrNoConfigEntry
+	}
+
+	lines := strings.Split(stdout, "\n")
+
+	if len(lines) == 0 {
+		return "", ErrNoConfigEntry
+	}
+	if len(lines) > 1 {
+		return "", ErrMultipleConfigEntry
+	}
+
+	return lines[0], nil
+}
+
+func (gc *gitConfig) ReadBool(key string) (bool, error) {
+	val, err := gc.ReadString(key)
+	if err != nil {
+		return false, err
+	}
+
+	return strconv.ParseBool(val)
+}
+
+func (gc *gitConfig) ReadTimestamp(key string) (time.Time, error) {
+	value, err := gc.ReadString(key)
+	if err != nil {
+		return time.Time{}, err
+	}
+	return ParseTimestamp(value)
+}
+
+func (gc *gitConfig) rmSection(keyPrefix string) error {
+	_, err := gc.repo.runGitCommand("config", gc.localityFlag, "--remove-section", keyPrefix)
+	return err
+}
+
+func (gc *gitConfig) unsetAll(keyPrefix string) error {
+	_, err := gc.repo.runGitCommand("config", gc.localityFlag, "--unset-all", keyPrefix)
+	return err
+}
+
+// return keyPrefix section
+// example: sectionFromKey(a.b.c.d) return a.b.c
+func sectionFromKey(keyPrefix string) string {
+	s := strings.Split(keyPrefix, ".")
+	if len(s) == 1 {
+		return keyPrefix
+	}
+
+	return strings.Join(s[:len(s)-1], ".")
+}
+
+// rmConfigs with git version lesser than 2.18
+func (gc *gitConfig) rmConfigsGitVersionLT218(keyPrefix string) error {
+	// try to remove key/value pair by key
+	err := gc.unsetAll(keyPrefix)
+	if err != nil {
+		return gc.rmSection(keyPrefix)
+	}
+
+	m, err := gc.ReadAll(sectionFromKey(keyPrefix))
+	if err != nil {
+		return err
+	}
+
+	// if section doesn't have any left key/value remove the section
+	if len(m) == 0 {
+		return gc.rmSection(sectionFromKey(keyPrefix))
+	}
+
+	return nil
+}
+
+// RmConfigs remove all key/value pair matching the key prefix
+func (gc *gitConfig) RemoveAll(keyPrefix string) error {
+	// starting from git 2.18.0 sections are automatically deleted when the last existing
+	// key/value is removed. Before 2.18.0 we should remove the section
+	// see https://github.com/git/git/blob/master/Documentation/RelNotes/2.18.0.txt#L379
+	lt218, err := gc.gitVersionLT218()
+	if err != nil {
+		return errors.Wrap(err, "getting git version")
+	}
+
+	if lt218 {
+		return gc.rmConfigsGitVersionLT218(keyPrefix)
+	}
+
+	err = gc.unsetAll(keyPrefix)
+	if err != nil {
+		return gc.rmSection(keyPrefix)
+	}
+
+	return nil
+}
+
+func (gc *gitConfig) gitVersion() (*semver.Version, error) {
+	versionOut, err := gc.repo.runGitCommand("version")
+	if err != nil {
+		return nil, err
+	}
+	return parseGitVersion(versionOut)
+}
+
+func parseGitVersion(versionOut string) (*semver.Version, error) {
+	// extract the version and truncate potential bad parts
+	// ex: 2.23.0.rc1 instead of 2.23.0-rc1
+	r := regexp.MustCompile(`(\d+\.){1,2}\d+`)
+
+	extracted := r.FindString(versionOut)
+	if extracted == "" {
+		return nil, fmt.Errorf("unreadable git version %s", versionOut)
+	}
+
+	version, err := semver.Make(extracted)
+	if err != nil {
+		return nil, err
+	}
+
+	return &version, nil
+}
+
+func (gc *gitConfig) gitVersionLT218() (bool, error) {
+	version, err := gc.gitVersion()
+	if err != nil {
+		return false, err
+	}
+
+	version218string := "2.18.0"
+	gitVersion218, err := semver.Make(version218string)
+	if err != nil {
+		return false, err
+	}
+
+	return version.LT(gitVersion218), nil
+}