Add loading yaml label template files (#22976)

Extract from #11669 and enhancement to #22585 to support exclusive
scoped labels in label templates

* Move label template functionality to label module
* Fix handling of color codes
* Add Advanced label template

6 files changed, 308 insertions, 117 deletions

diff --git a/modules/label/label.go b/modules/label/label.go
new file mode 100644
index 000000000..d3ef0e1dc
--- /dev/null
+++ b/modules/label/label.go
@@ -0,0 +1,46 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package label
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+// colorPattern is a regexp which can validate label color
+var colorPattern = regexp.MustCompile("^#?(?:[0-9a-fA-F]{6}|[0-9a-fA-F]{3})$")
+
+// Label represents label information loaded from template
+type Label struct {
+	Name        string `yaml:"name"`
+	Color       string `yaml:"color"`
+	Description string `yaml:"description,omitempty"`
+	Exclusive   bool   `yaml:"exclusive,omitempty"`
+}
+
+// NormalizeColor normalizes a color string to a 6-character hex code
+func NormalizeColor(color string) (string, error) {
+	// normalize case
+	color = strings.TrimSpace(strings.ToLower(color))
+
+	// add leading hash
+	if len(color) == 6 || len(color) == 3 {
+		color = "#" + color
+	}
+
+	if !colorPattern.MatchString(color) {
+		return "", fmt.Errorf("bad color code: %s", color)
+	}
+
+	// convert 3-character shorthand into 6-character version
+	if len(color) == 4 {
+		r := color[1]
+		g := color[2]
+		b := color[3]
+		color = fmt.Sprintf("#%c%c%c%c%c%c", r, r, g, g, b, b)
+	}
+
+	return color, nil
+}
diff --git a/modules/label/parser.go b/modules/label/parser.go
new file mode 100644
index 000000000..768c72a61
--- /dev/null
+++ b/modules/label/parser.go
@@ -0,0 +1,126 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package label
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"code.gitea.io/gitea/modules/options"
+
+	"gopkg.in/yaml.v3"
+)
+
+type labelFile struct {
+	Labels []*Label `yaml:"labels"`
+}
+
+// ErrTemplateLoad represents a "ErrTemplateLoad" kind of error.
+type ErrTemplateLoad struct {
+	TemplateFile  string
+	OriginalError error
+}
+
+// IsErrTemplateLoad checks if an error is a ErrTemplateLoad.
+func IsErrTemplateLoad(err error) bool {
+	_, ok := err.(ErrTemplateLoad)
+	return ok
+}
+
+func (err ErrTemplateLoad) Error() string {
+	return fmt.Sprintf("Failed to load label template file '%s': %v", err.TemplateFile, err.OriginalError)
+}
+
+// GetTemplateFile loads the label template file by given name,
+// then parses and returns a list of name-color pairs and optionally description.
+func GetTemplateFile(name string) ([]*Label, error) {
+	data, err := options.GetRepoInitFile("label", name+".yaml")
+	if err == nil && len(data) > 0 {
+		return parseYamlFormat(name+".yaml", data)
+	}
+
+	data, err = options.GetRepoInitFile("label", name+".yml")
+	if err == nil && len(data) > 0 {
+		return parseYamlFormat(name+".yml", data)
+	}
+
+	data, err = options.GetRepoInitFile("label", name)
+	if err != nil {
+		return nil, ErrTemplateLoad{name, fmt.Errorf("GetRepoInitFile: %w", err)}
+	}
+
+	return parseLegacyFormat(name, data)
+}
+
+func parseYamlFormat(name string, data []byte) ([]*Label, error) {
+	lf := &labelFile{}
+
+	if err := yaml.Unmarshal(data, lf); err != nil {
+		return nil, err
+	}
+
+	// Validate label data and fix colors
+	for _, l := range lf.Labels {
+		l.Color = strings.TrimSpace(l.Color)
+		if len(l.Name) == 0 || len(l.Color) == 0 {
+			return nil, ErrTemplateLoad{name, errors.New("label name and color are required fields")}
+		}
+		color, err := NormalizeColor(l.Color)
+		if err != nil {
+			return nil, ErrTemplateLoad{name, fmt.Errorf("bad HTML color code '%s' in label: %s", l.Color, l.Name)}
+		}
+		l.Color = color
+	}
+
+	return lf.Labels, nil
+}
+
+func parseLegacyFormat(name string, data []byte) ([]*Label, error) {
+	lines := strings.Split(string(data), "\n")
+	list := make([]*Label, 0, len(lines))
+	for i := 0; i < len(lines); i++ {
+		line := strings.TrimSpace(lines[i])
+		if len(line) == 0 {
+			continue
+		}
+
+		parts, description, _ := strings.Cut(line, ";")
+
+		color, name, ok := strings.Cut(parts, " ")
+		if !ok {
+			return nil, ErrTemplateLoad{name, fmt.Errorf("line is malformed: %s", line)}
+		}
+
+		color, err := NormalizeColor(color)
+		if err != nil {
+			return nil, ErrTemplateLoad{name, fmt.Errorf("bad HTML color code '%s' in line: %s", color, line)}
+		}
+
+		list = append(list, &Label{
+			Name:        strings.TrimSpace(name),
+			Color:       color,
+			Description: strings.TrimSpace(description),
+		})
+	}
+
+	return list, nil
+}
+
+// LoadFormatted loads the labels' list of a template file as a string separated by comma
+func LoadFormatted(name string) (string, error) {
+	var buf strings.Builder
+	list, err := GetTemplateFile(name)
+	if err != nil {
+		return "", err
+	}
+
+	for i := 0; i < len(list); i++ {
+		if i > 0 {
+			buf.WriteString(", ")
+		}
+		buf.WriteString(list[i].Name)
+	}
+	return buf.String(), nil
+}
diff --git a/modules/label/parser_test.go b/modules/label/parser_test.go
new file mode 100644
index 000000000..5c8042f66
--- /dev/null
+++ b/modules/label/parser_test.go
@@ -0,0 +1,72 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package label
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestYamlParser(t *testing.T) {
+	data := []byte(`labels:
+  - name: priority/low
+    exclusive: true
+    color: "#0000ee"
+    description: "Low priority"
+  - name: priority/medium
+    exclusive: true
+    color: "0e0"
+    description: "Medium priority"
+  - name: priority/high
+    exclusive: true
+    color: "#ee0000"
+    description: "High priority"
+  - name: type/bug
+    color: "#f00"
+    description: "Bug"`)
+
+	labels, err := parseYamlFormat("test", data)
+	require.NoError(t, err)
+	require.Len(t, labels, 4)
+	assert.Equal(t, "priority/low", labels[0].Name)
+	assert.True(t, labels[0].Exclusive)
+	assert.Equal(t, "#0000ee", labels[0].Color)
+	assert.Equal(t, "Low priority", labels[0].Description)
+	assert.Equal(t, "priority/medium", labels[1].Name)
+	assert.True(t, labels[1].Exclusive)
+	assert.Equal(t, "#00ee00", labels[1].Color)
+	assert.Equal(t, "Medium priority", labels[1].Description)
+	assert.Equal(t, "priority/high", labels[2].Name)
+	assert.True(t, labels[2].Exclusive)
+	assert.Equal(t, "#ee0000", labels[2].Color)
+	assert.Equal(t, "High priority", labels[2].Description)
+	assert.Equal(t, "type/bug", labels[3].Name)
+	assert.False(t, labels[3].Exclusive)
+	assert.Equal(t, "#ff0000", labels[3].Color)
+	assert.Equal(t, "Bug", labels[3].Description)
+}
+
+func TestLegacyParser(t *testing.T) {
+	data := []byte(`#ee0701 bug   ;   Something is not working
+#cccccc   duplicate ; This issue or pull request already exists
+#84b6eb enhancement`)
+
+	labels, err := parseLegacyFormat("test", data)
+	require.NoError(t, err)
+	require.Len(t, labels, 3)
+	assert.Equal(t, "bug", labels[0].Name)
+	assert.False(t, labels[0].Exclusive)
+	assert.Equal(t, "#ee0701", labels[0].Color)
+	assert.Equal(t, "Something is not working", labels[0].Description)
+	assert.Equal(t, "duplicate", labels[1].Name)
+	assert.False(t, labels[1].Exclusive)
+	assert.Equal(t, "#cccccc", labels[1].Color)
+	assert.Equal(t, "This issue or pull request already exists", labels[1].Description)
+	assert.Equal(t, "enhancement", labels[2].Name)
+	assert.False(t, labels[2].Exclusive)
+	assert.Equal(t, "#84b6eb", labels[2].Color)
+	assert.Empty(t, labels[2].Description)
+}
diff --git a/modules/options/repo.go b/modules/options/repo.go
new file mode 100644
index 000000000..1480f7808
--- /dev/null
+++ b/modules/options/repo.go
@@ -0,0 +1,44 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package options
+
+import (
+	"fmt"
+	"os"
+	"path"
+	"strings"
+
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
+)
+
+// GetRepoInitFile returns repository init files
+func GetRepoInitFile(tp, name string) ([]byte, error) {
+	cleanedName := strings.TrimLeft(path.Clean("/"+name), "/")
+	relPath := path.Join("options", tp, cleanedName)
+
+	// Use custom file when available.
+	customPath := path.Join(setting.CustomPath, relPath)
+	isFile, err := util.IsFile(customPath)
+	if err != nil {
+		log.Error("Unable to check if %s is a file. Error: %v", customPath, err)
+	}
+	if isFile {
+		return os.ReadFile(customPath)
+	}
+
+	switch tp {
+	case "readme":
+		return Readme(cleanedName)
+	case "gitignore":
+		return Gitignore(cleanedName)
+	case "license":
+		return License(cleanedName)
+	case "label":
+		return Labels(cleanedName)
+	default:
+		return []byte{}, fmt.Errorf("Invalid init file type")
+	}
+}
diff --git a/modules/repository/create.go b/modules/repository/create.go
index 1704ea792..6a1fa41b6 100644
--- a/modules/repository/create.go
+++ b/modules/repository/create.go
@@ -23,6 +23,7 @@ import (
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/models/webhook"
 	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/label"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
@@ -189,7 +190,7 @@ func CreateRepository(doer, u *user_model.User, opts CreateRepoOptions) (*repo_m
 
 	// Check if label template exist
 	if len(opts.IssueLabels) > 0 {
-		if _, err := GetLabelTemplateFile(opts.IssueLabels); err != nil {
+		if _, err := label.GetTemplateFile(opts.IssueLabels); err != nil {
 			return nil, err
 		}
 	}
diff --git a/modules/repository/init.go b/modules/repository/init.go
index 771b68a49..49c8d2a90 100644
--- a/modules/repository/init.go
+++ b/modules/repository/init.go
@@ -18,6 +18,7 @@ import (
 	repo_model "code.gitea.io/gitea/models/repo"
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/label"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/options"
 	"code.gitea.io/gitea/modules/setting"
@@ -40,114 +41,6 @@ var (
 	LabelTemplates map[string]string
 )
 
-// ErrIssueLabelTemplateLoad represents a "ErrIssueLabelTemplateLoad" kind of error.
-type ErrIssueLabelTemplateLoad struct {
-	TemplateFile  string
-	OriginalError error
-}
-
-// IsErrIssueLabelTemplateLoad checks if an error is a ErrIssueLabelTemplateLoad.
-func IsErrIssueLabelTemplateLoad(err error) bool {
-	_, ok := err.(ErrIssueLabelTemplateLoad)
-	return ok
-}
-
-func (err ErrIssueLabelTemplateLoad) Error() string {
-	return fmt.Sprintf("Failed to load label template file '%s': %v", err.TemplateFile, err.OriginalError)
-}
-
-// GetRepoInitFile returns repository init files
-func GetRepoInitFile(tp, name string) ([]byte, error) {
-	cleanedName := strings.TrimLeft(path.Clean("/"+name), "/")
-	relPath := path.Join("options", tp, cleanedName)
-
-	// Use custom file when available.
-	customPath := path.Join(setting.CustomPath, relPath)
-	isFile, err := util.IsFile(customPath)
-	if err != nil {
-		log.Error("Unable to check if %s is a file. Error: %v", customPath, err)
-	}
-	if isFile {
-		return os.ReadFile(customPath)
-	}
-
-	switch tp {
-	case "readme":
-		return options.Readme(cleanedName)
-	case "gitignore":
-		return options.Gitignore(cleanedName)
-	case "license":
-		return options.License(cleanedName)
-	case "label":
-		return options.Labels(cleanedName)
-	default:
-		return []byte{}, fmt.Errorf("Invalid init file type")
-	}
-}
-
-// GetLabelTemplateFile loads the label template file by given name,
-// then parses and returns a list of name-color pairs and optionally description.
-func GetLabelTemplateFile(name string) ([][3]string, error) {
-	data, err := GetRepoInitFile("label", name)
-	if err != nil {
-		return nil, ErrIssueLabelTemplateLoad{name, fmt.Errorf("GetRepoInitFile: %w", err)}
-	}
-
-	lines := strings.Split(string(data), "\n")
-	list := make([][3]string, 0, len(lines))
-	for i := 0; i < len(lines); i++ {
-		line := strings.TrimSpace(lines[i])
-		if len(line) == 0 {
-			continue
-		}
-
-		parts := strings.SplitN(line, ";", 2)
-
-		fields := strings.SplitN(parts[0], " ", 2)
-		if len(fields) != 2 {
-			return nil, ErrIssueLabelTemplateLoad{name, fmt.Errorf("line is malformed: %s", line)}
-		}
-
-		color := strings.Trim(fields[0], " ")
-		if len(color) == 6 {
-			color = "#" + color
-		}
-		if !issues_model.LabelColorPattern.MatchString(color) {
-			return nil, ErrIssueLabelTemplateLoad{name, fmt.Errorf("bad HTML color code in line: %s", line)}
-		}
-
-		var description string
-
-		if len(parts) > 1 {
-			description = strings.TrimSpace(parts[1])
-		}
-
-		fields[1] = strings.TrimSpace(fields[1])
-		list = append(list, [3]string{fields[1], color, description})
-	}
-
-	return list, nil
-}
-
-func loadLabels(labelTemplate string) ([]string, error) {
-	list, err := GetLabelTemplateFile(labelTemplate)
-	if err != nil {
-		return nil, err
-	}
-
-	labels := make([]string, len(list))
-	for i := 0; i < len(list); i++ {
-		labels[i] = list[i][0]
-	}
-	return labels, nil
-}
-
-// LoadLabelsFormatted loads the labels' list of a template file as a string separated by comma
-func LoadLabelsFormatted(labelTemplate string) (string, error) {
-	labels, err := loadLabels(labelTemplate)
-	return strings.Join(labels, ", "), err
-}
-
 // LoadRepoConfig loads the repository config
 func LoadRepoConfig() {
 	// Load .gitignore and license files and readme templates.
@@ -158,6 +51,14 @@ func LoadRepoConfig() {
 		if err != nil {
 			log.Fatal("Failed to get %s files: %v", t, err)
 		}
+		if t == "label" {
+			for i, f := range files {
+				ext := strings.ToLower(filepath.Ext(f))
+				if ext == ".yaml" || ext == ".yml" {
+					files[i] = f[:len(f)-len(ext)]
+				}
+			}
+		}
 		customPath := path.Join(setting.CustomPath, "options", t)
 		isDir, err := util.IsDir(customPath)
 		if err != nil {
@@ -190,7 +91,7 @@ func LoadRepoConfig() {
 	// Load label templates
 	LabelTemplates = make(map[string]string)
 	for _, templateFile := range LabelTemplatesFiles {
-		labels, err := LoadLabelsFormatted(templateFile)
+		labels, err := label.LoadFormatted(templateFile)
 		if err != nil {
 			log.Error("Failed to load labels: %v", err)
 		}
@@ -235,7 +136,7 @@ func prepareRepoCommit(ctx context.Context, repo *repo_model.Repository, tmpDir,
 	}
 
 	// README
-	data, err := GetRepoInitFile("readme", opts.Readme)
+	data, err := options.GetRepoInitFile("readme", opts.Readme)
 	if err != nil {
 		return fmt.Errorf("GetRepoInitFile[%s]: %w", opts.Readme, err)
 	}
@@ -263,7 +164,7 @@ func prepareRepoCommit(ctx context.Context, repo *repo_model.Repository, tmpDir,
 		var buf bytes.Buffer
 		names := strings.Split(opts.Gitignores, ",")
 		for _, name := range names {
-			data, err = GetRepoInitFile("gitignore", name)
+			data, err = options.GetRepoInitFile("gitignore", name)
 			if err != nil {
 				return fmt.Errorf("GetRepoInitFile[%s]: %w", name, err)
 			}
@@ -281,7 +182,7 @@ func prepareRepoCommit(ctx context.Context, repo *repo_model.Repository, tmpDir,
 
 	// LICENSE
 	if len(opts.License) > 0 {
-		data, err = GetRepoInitFile("license", opts.License)
+		data, err = options.GetRepoInitFile("license", opts.License)
 		if err != nil {
 			return fmt.Errorf("GetRepoInitFile[%s]: %w", opts.License, err)
 		}
@@ -443,7 +344,7 @@ func initRepository(ctx context.Context, repoPath string, u *user_model.User, re
 
 // InitializeLabels adds a label set to a repository using a template
 func InitializeLabels(ctx context.Context, id int64, labelTemplate string, isOrg bool) error {
-	list, err := GetLabelTemplateFile(labelTemplate)
+	list, err := label.GetTemplateFile(labelTemplate)
 	if err != nil {
 		return err
 	}
@@ -451,9 +352,10 @@ func InitializeLabels(ctx context.Context, id int64, labelTemplate string, isOrg
 	labels := make([]*issues_model.Label, len(list))
 	for i := 0; i < len(list); i++ {
 		labels[i] = &issues_model.Label{
-			Name:        list[i][0],
-			Description: list[i][2],
-			Color:       list[i][1],
+			Name:        list[i].Name,
+			Exclusive:   list[i].Exclusive,
+			Description: list[i].Description,
+			Color:       list[i].Color,
 		}
 		if isOrg {
 			labels[i].OrgID = id