contributing: Get owner and project from git

Signed-off-by: Ce Gao <ce.gao@outlook.com>

CONTRIBUTING.md

@@ -61,4 +61,4 @@ For the why part, if no specific reason for the change,
 you can use one of some generic reasons like "Improve documentation.",
 "Improve performance.", "Improve robustness.", "Improve test coverage."
 
-###### Auto generated by [gaocegege/maintainer](https://github.com/gaocegege/maintainer) on 2017-04-27
+###### Auto generated by [gaocegege/maintainer](https://github.com/gaocegege/maintainer) on 2017-05-01

cmd/contributing.go

@@ -17,6 +17,7 @@ package cmd
 import (
 	"log"
 
+	"github.com/gaocegege/maintainer/repo"
 	"github.com/gaocegege/maintainer/util"
 	"github.com/spf13/cobra"
 )
@@ -49,6 +50,11 @@ func init() {
 
 // contributingRun runs the real logic to generate CONTRIBUTING.md.
 func contributingRun() error {
+	repo, err := repo.NewRepository()
+	if err != nil {
+		log.Panicf("Error when read the information from local repository: %s\n", err)
+	}
+	log.Print(repo.String())
 	// Output results to AUTHORS.md.
 	f, err := util.OpenFile(contributingFile)
 	if err != nil {

cmd/root.go

@@ -20,13 +20,19 @@ import (
 
 	"log"
 
+	"github.com/gaocegege/maintainer/repo"
+
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 )
 
-var cfgFile string
+var (
+	cfgFile string
+	// Repo stores the information in the local repository.
+	Repo *repo.Repository
+)
 
-// This represents the base command when called without any subcommands
+// RootCmd represents the base command when called without any subcommands
 var RootCmd = &cobra.Command{
 	Use:   "maintainer",
 	Short: "Help you to be a qualified maintainer.",
@@ -61,5 +67,7 @@ func initConfig() {
 	// If a config file is found, read it in.
 	if err := viper.ReadInConfig(); err == nil {
 		log.Println("Using config file:", viper.ConfigFileUsed())
+	} else {
+		log.Println("There is no config file defined.")
 	}
 }

repo/repo.go

@@ -0,0 +1,117 @@
+// Copyright © 2017 Maintainer Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package repo
+
+import (
+	"errors"
+	"fmt"
+	"os/exec"
+	"regexp"
+)
+
+const (
+	gitCmd                 string = "git"
+	gitConfigArgs          string = "config"
+	gitConfigGetArgs       string = "--get"
+	gitConfigGetRemoteArgs string = "remote.origin.url"
+)
+
+var (
+	gitRemotePattern = []string{
+		`.*(?:[:\/])(?P<user>(?:-|\w|\.)*)\/(?P<project>(?:-|\w|\.)*)(?:\.git).*`,
+		`.*\/(?P<user>(?:-|\w|\.)*)\/(?P<project>(?:-|\w|\.)*).*`,
+	}
+
+	errNameOrProjectNotExists = errors.New("Couldn't get the URL of this repository")
+
+	singleton *Repository
+)
+
+// Repository is the type for the local repository.
+type Repository struct {
+	Owner string
+	Name  string
+}
+
+// NewRepository returns a new Repository.
+func NewRepository() (*Repository, error) {
+	if singleton != nil {
+		return singleton, nil
+	}
+
+	name, project, err := getNameAndRepoName()
+	if err != nil {
+		return nil, err
+	}
+
+	singleton = &Repository{
+		Owner: name,
+		Name:  project,
+	}
+	return singleton, nil
+}
+
+// String returns the information of a local repository.
+func (r *Repository) String() string {
+	return fmt.Sprintf("Local Repository Information: \n\tOwner: %s\n\tName: %s\n", r.Owner, r.Name)
+}
+
+// See https://github.com/skywinder/github-changelog-generator/blob/master/lib/github_changelog_generator/parser.rb#L312.
+func getNameAndRepoName() (string, string, error) {
+	cmd := exec.Command(gitCmd, gitConfigArgs, gitConfigGetArgs, gitConfigGetRemoteArgs)
+	output, err := cmd.Output()
+	if err != nil {
+		return "", "", err
+	}
+	outputStr := string(output)
+
+	// get the name and project.
+	name, project, err := getNameAndRepoNameFromRemote(outputStr)
+	if err != nil {
+		return "", "", err
+	}
+
+	return name, project, nil
+}
+
+// getNameAndRepoName gets the name and project from local repository.
+func getNameAndRepoNameFromRemote(remoteStr string) (string, string, error) {
+	for _, regEx := range gitRemotePattern {
+		paramsMap := getParams(regEx, remoteStr)
+		name, ok1 := paramsMap["user"]
+		project, ok2 := paramsMap["project"]
+		if ok1 != true || ok2 != true {
+			continue
+		}
+		return name, project, nil
+	}
+	return "", "", errNameOrProjectNotExists
+}
+
+// getParams get the params from regexp.
+// See http://stackoverflow.com/questions/30483652/how-to-get-capturing-group-functionality-in-golang-regular-expressions.
+func getParams(regEx, url string) (paramsMap map[string]string) {
+
+	var compRegEx = regexp.MustCompile(regEx)
+	match := compRegEx.FindStringSubmatch(url)
+
+	paramsMap = make(map[string]string)
+	for i, name := range compRegEx.SubexpNames() {
+		if i > 0 && i <= len(match) {
+			paramsMap[name] = match[i]
+		}
+	}
+	return
+}