feat: implement language file loading

1. state.State implements Stringer, TextMarshaler and TextUnmarshaler
2. language can be loaded from translation file
3. add sample translation
4. Makefile and README

Author: JayceChant

Makefile

@@ -1,9 +1,12 @@
 APPNAME := commit-msg
 LDFLAGS += -s -w
 
-.PHONY: all build upx
+.PHONY: all gen build upx
 
-all: build upx
+all: gen build upx
+
+gen:
+	go generate ./...
 
 build:
 	go build -trimpath -ldflags "$(LDFLAGS) -X 'main.version=$(TAG)' -X 'main.goVersion=$(shell go version)' -X 'main.commitHash=$(shell git show -s --format=%H)' -X 'main.buildTime=$(shell date "+%Y-%m-%d %T%z")'"

README.md

@@ -101,6 +101,30 @@ If there are no configuration files, the program will use the following default
 }
 ```
 
+## Localization
+
+The program has built-in two languages: English (en) and Chinese (zh).
+
+You can add language support in two ways:
+
+### Contributing code
+
+The built-in languages are placed in the `lang` directory, with individual `.go` source file for each. You can copy `lang/english.go`, change the file name and translate the content, then commit it to launch a Pull Request. The language will be added in next release after the PR is approved.
+
+Of course, considering my limited English (my Chinese wording is not necessarily good either), you can also help improve the existing language support.
+
+### Add translation file
+
+However, committing code may not be the best way to go.
+
+Firstly , committing code is time-consuming. If you can't compile it yourself, but have to wait for next version release after the code merged in, it would be a long time until the version is ready. On the other hand, this is only a small tool after all, and to avoid the program becoming bloated, some languages may not be merged in, depending on the number of users.
+
+You can choose a quicker way: adding translation file.
+
+To do this, copy the [commit-msg.en.json.sample](./commit-msg.en.json.sample) file in the project root directory, remove `.sample` from the file name, and change `en` to the corresponding language (e.g., the abbreviation for language to be supported is `xx`) . Translate the contents of the file, keeping the formatting verb `%s` and the line break `\n`. Then put the file in the same directory as the configuration file (`home` directory or `hooks` directory). Afterwards, remember to change the language configuration to the corresponding language (`xx` in this case).
+
+Unlike the configuration file, if the translations for the same language exist in both `home` directory and `hooks` directory, the contents of both will not be merged, but the translation in `hooks` directory of the project will prevail. The contents of each language file must be a complete translation.
+
 ## More info
 
 The project was first inspired by [validate-commit-msg](https://github.com/conventional-changelog-archived-repos/validate-commit-msg) . ( It has now been moved to  [conventional-changelog/commitlint](https://github.com/conventional-changelog/commitlint) )

README_zh.md

@@ -101,6 +101,30 @@ the way to migrate:
 }
 ```
 
+## 本地化
+
+程序内置了两种语言的提示：英语（en） 和 中文（zh）。
+
+你可以通过以下两种方式增加支持的语言：
+
+### 提交代码
+
+内置的语言支持放在 `lang` 目录下，每种语言一个 `.go` 源文件。你可以拷贝 `lang/english.go` ，修改文件名并翻译内容，然后提交，发起 Pull Request。待 PR 通过后，下一个版本就可以支持对应的语言。
+
+当然，考虑到我的英语水平有限（中文的措辞也不见得很好），你也可以帮忙改进已有的语言支持。
+
+### 增加语言翻译文件
+
+但提交代码未必是最好的办法。
+
+一方面，提交代码耗时较多。如果你不能自行编译，而是要等代码合入之后发布下一个版本，还需要等待更多的时间。另一方面，这毕竟只是一个小工具，为了避免程序变得臃肿，视乎使用者的多寡，一些语言我可能不会选择合入。
+
+你可以选择更快捷的方式：增加语言文件。
+
+具体的做法是，拷贝项目根目录下的 [commit-msg.en.json.sample](./commit-msg.en.json.sample) 文件，去掉文件名里的 `.sample` ，把 `en` 改为对应的语言（举例说这种语言的缩写为 `xx`）。把文件内容翻译好，注意保留里面的格式化动词 `%s` 和换行符 `\n` 。然后把文件放到跟配置文件相同的目录（`home` 目录或者 `hooks` 目录）。之后记得修改语言配置为对应的语言（这里是 `xx`）。
+
+跟配置文件不同，如果相同语言的翻译在 `home` 目录和 `hooks` 目录同时存在，并不会合并两者的内容，而是直接以项目 `hooks` 目录的翻译为准。所以每一个语言文件里的内容，都必须是完整的翻译。
+
 ## 更多信息
 
 本项目最早受 [validate-commit-msg](https://github.com/conventional-changelog-archived-repos/validate-commit-msg) 启发。（该项目现已移至 [conventional-changelog/commitlint](https://github.com/conventional-changelog/commitlint)）

commit-msg.en.json.sample

@@ -0,0 +1,21 @@
+{
+    "hints":
+    {
+        "Validated": "Validated: commit message meet the rule.",
+        "Merge": "Merge: merge commit detected，skip check.",
+        "ArgumentMissing": "Error ArgumentMissing: commit message file argument missing.",
+        "FileMissing": "Error FileMissing: file %s not exists.",
+        "ReadError": "Error ReadError: read file %s error.",
+        "EmptyMessage": "Error EmptyMessage: commit message has no content except whitespaces.",
+        "EmptyHeader": "Error EmptyHeader: header (first line) has no content except whitespaces.",
+        "BadHeaderFormat": "Error BadHeaderFormat: header (first line) not following the rule:\n%s\nif you can not find any error after check, maybe you use full-width colon, or lack of whitespace after the colon.",
+        "WrongType": "Error WrongType: %s, type should be one of the keywords:\n%s",
+        "ScopeMissing": "Error ScopeMissing: (scope) is required right after type.",
+        "WrongScope": "Error WrongScope: %s, scope should be one of the keywords:\n%s",
+        "BodyMissing": "Error BodyMissing: body has no content except whitespaces.",
+        "NoBlankLineBeforeBody": "Error NoBlankLineBeforeBody: no empty line between header and body.",
+        "LineOverLong": "Error LineOverLong: the length of line is %d, exceed %d:\n%s",
+        "UndefindedError": "Error UndefindedError: unexpected error occurs, please raise an issue."
+    },
+    "rule": "Commit message rule as follow:\n<type>(<scope>): <subject>\n// empty line\n<body>\n// empty line\n<footer>\n\n(<scope>), <body> and <footer> are optional by default\n<type>  must be one of %s\nmore specific instructions, please refer to: https://github.com/JayceChant/commit-msg"
+}

dir/dir.go

@@ -0,0 +1,57 @@
+package dir
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/mitchellh/go-homedir"
+)
+
+const (
+	hookDir = "./.git/hooks/"
+)
+
+func FindFiles(file string) []string {
+	paths := make([]string, 0)
+	if home, err := homedir.Dir(); err == nil {
+		paths = append(paths, filepath.Join(home, file))
+	}
+
+	f, err := os.Stat(hookDir)
+	if (err == nil || os.IsExist(err)) && f.IsDir() {
+		// working dir is on project root
+		paths = append(paths, filepath.Join(hookDir, file))
+	} else {
+		// work around for test
+		paths = append(paths, file)
+	}
+	return paths
+}
+
+func FindFirstExist(file string) string {
+	if isFile(file) {
+		return file
+	}
+
+	hookFile := filepath.Join(hookDir, file)
+	if isFile(hookFile) {
+		return hookFile
+	}
+
+	if home, err := homedir.Dir(); err == nil {
+		homeFile := filepath.Join(home, file)
+		if isFile(homeFile) {
+			return homeFile
+		}
+	}
+
+	return ""
+}
+
+func isFile(path string) bool {
+	fi, err := os.Stat(path)
+	if err != nil && !os.IsExist(err) {
+		return false
+	}
+	return !fi.IsDir()
+}

lang/lang.go

@@ -1,22 +1,51 @@
 package lang
 
 import (
+	"encoding/json"
 	"fmt"
+	"log"
+	"os"
 
+	"github.com/JayceChant/commit-msg/dir"
 	. "github.com/JayceChant/commit-msg/state"
 )
 
+const (
+	langFile = "commit-msg.%s.json"
+)
+
 func LoadLanguage(language string) LangPack {
 	if l, ok := langs[language]; ok {
 		return l
 	}
-	return langEn
+
+	file := fmt.Sprintf(langFile, language)
+	path := dir.FindFirstExist(file)
+	if path == "" {
+		return langEn
+	}
+
+	f, err := os.Open(path)
+	if err != nil && !os.IsExist(err) {
+		log.Printf("open language %v error: %v\n", language, err)
+		return langEn
+	}
+	defer f.Close()
+
+	dec := json.NewDecoder(f)
+	l := &langPack{}
+	err = dec.Decode(l)
+	if err != nil {
+		log.Printf("decode language %v error: %v\n", language, err)
+		return langEn
+	}
+	return l
 }
 
 // langPack ...
 type langPack struct {
-	Hints map[State]string
-	Rule  string
+	Hints map[State]string `json:"hints"`
+	Rule  string           `json:"rule"`
 }
 
 func (l *langPack) GetHint(state State, v ...interface{}) string {

state/state.go

@@ -1,6 +1,9 @@
+//go:generate stringer -type=State
 package state
 
 import (
+	"encoding"
+	"fmt"
 	"log"
 	"os"
 )
@@ -21,6 +24,12 @@ type LangPack interface {
 	GetRule(types string) string
 }
 
+func _() {
+	// type check
+	var _ encoding.TextMarshaler = State(0)
+	var _ encoding.TextUnmarshaler = (*State)(nil)
+}
+
 // State indicate the state of a commit message
 type State int8
 
@@ -70,3 +79,18 @@ func (state State) IsNormal() bool {
 func (state State) IsFormatError() bool {
 	return state >= EmptyMessage
 }
+
+func (state State) MarshalText() (text []byte, err error) {
+	return []byte(state.String()), nil
+}
+
+func (state *State) UnmarshalText(text []byte) error {
+	str := string(text)
+	for s := Validated; s <= UndefindedError; s++ {
+		if s.String() == str {
+			*state = s
+			return nil
+		}
+	}
+	return fmt.Errorf("unknown state : %v", str)
+}

state/state_string.go

@@ -4,17 +4,15 @@ import (
 	"encoding/json"
 	"log"
 	"os"
-	"path/filepath"
 	"strings"
 
+	"github.com/JayceChant/commit-msg/dir"
 	"github.com/JayceChant/commit-msg/lang"
 	"github.com/JayceChant/commit-msg/state"
-	homedir "github.com/mitchellh/go-homedir"
 )
 
 const (
 	configFileName = ".commit-msg.json"
-	hookDir        = "./.git/hooks/"
 )
 
 type validateConfig struct {
@@ -51,23 +49,6 @@ var (
 	TypesStr string
 )
 
-func locateConfigs() []string {
-	paths := make([]string, 0)
-	if home, err := homedir.Dir(); err == nil {
-		paths = append(paths, filepath.Join(home, configFileName))
-	}
-
-	f, err := os.Stat(hookDir)
-	if (err == nil || os.IsExist(err)) && f.IsDir() {
-		// working dir is on project root
-		paths = append(paths, filepath.Join(hookDir, configFileName))
-	} else {
-		// work around for test
-		paths = append(paths, configFileName)
-	}
-	return paths
-}
-
 func loadConfig(path string, cfg *validateConfig) *validateConfig {
 	f, err := os.Open(path)
 	if err != nil && !os.IsExist(err) {
@@ -83,7 +64,7 @@ func loadConfig(path string, cfg *validateConfig) *validateConfig {
 }
 
 func init() {
-	paths := locateConfigs()
+	paths := dir.FindFiles(configFileName)
 	for _, p := range paths {
 		// TODO: fix json value overlaping
 		globalConfig = loadConfig(p, globalConfig)