1 files changed, 360 insertions, 0 deletions
diff --git a/modules/setting/config_provider.go b/modules/setting/config_provider.go
new file mode 100644
index 0000000..12cf36a
--- /dev/null
+++ b/modules/setting/config_provider.go
@@ -0,0 +1,360 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package setting
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/util"
+
+	"gopkg.in/ini.v1" //nolint:depguard
+)
+
+type ConfigKey interface {
+	Name() string
+	Value() string
+	SetValue(v string)
+
+	In(defaultVal string, candidates []string) string
+	String() string
+	Strings(delim string) []string
+
+	MustString(defaultVal string) string
+	MustBool(defaultVal ...bool) bool
+	MustInt(defaultVal ...int) int
+	MustInt64(defaultVal ...int64) int64
+	MustDuration(defaultVal ...time.Duration) time.Duration
+}
+
+type ConfigSection interface {
+	Name() string
+	MapTo(any) error
+	HasKey(key string) bool
+	NewKey(name, value string) (ConfigKey, error)
+	Key(key string) ConfigKey
+	Keys() []ConfigKey
+	ChildSections() []ConfigSection
+}
+
+// ConfigProvider represents a config provider
+type ConfigProvider interface {
+	Section(section string) ConfigSection
+	Sections() []ConfigSection
+	NewSection(name string) (ConfigSection, error)
+	GetSection(name string) (ConfigSection, error)
+	Save() error
+	SaveTo(filename string) error
+
+	GetFile() string
+	DisableSaving()
+	PrepareSaving() (ConfigProvider, error)
+	IsLoadedFromEmpty() bool
+}
+
+type iniConfigProvider struct {
+	file string
+	ini  *ini.File
+
+	disableSaving   bool // disable the "Save" method because the config options could be polluted
+	loadedFromEmpty bool // whether the file has not existed previously
+}
+
+type iniConfigSection struct {
+	sec *ini.Section
+}
+
+var (
+	_ ConfigProvider = (*iniConfigProvider)(nil)
+	_ ConfigSection  = (*iniConfigSection)(nil)
+	_ ConfigKey      = (*ini.Key)(nil)
+)
+
+// ConfigSectionKey only searches the keys in the given section, but it is O(n).
+// ini package has a special behavior:  with "[sec] a=1" and an empty "[sec.sub]",
+// then in "[sec.sub]", Key()/HasKey() can always see "a=1" because it always tries parent sections.
+// It returns nil if the key doesn't exist.
+func ConfigSectionKey(sec ConfigSection, key string) ConfigKey {
+	if sec == nil {
+		return nil
+	}
+	for _, k := range sec.Keys() {
+		if k.Name() == key {
+			return k
+		}
+	}
+	return nil
+}
+
+func ConfigSectionKeyString(sec ConfigSection, key string, def ...string) string {
+	k := ConfigSectionKey(sec, key)
+	if k != nil && k.String() != "" {
+		return k.String()
+	}
+	if len(def) > 0 {
+		return def[0]
+	}
+	return ""
+}
+
+func ConfigSectionKeyBool(sec ConfigSection, key string, def ...bool) bool {
+	k := ConfigSectionKey(sec, key)
+	if k != nil && k.String() != "" {
+		b, _ := strconv.ParseBool(k.String())
+		return b
+	}
+	if len(def) > 0 {
+		return def[0]
+	}
+	return false
+}
+
+// ConfigInheritedKey works like ini.Section.Key(), but it always returns a new key instance, it is O(n) because NewKey is O(n)
+// and the returned key is safe to be used with "MustXxx", it doesn't change the parent's values.
+// Otherwise, ini.Section.Key().MustXxx would pollute the parent section's keys.
+// It never returns nil.
+func ConfigInheritedKey(sec ConfigSection, key string) ConfigKey {
+	k := sec.Key(key)
+	if k != nil && k.String() != "" {
+		newKey, _ := sec.NewKey(k.Name(), k.String())
+		return newKey
+	}
+	newKey, _ := sec.NewKey(key, "")
+	return newKey
+}
+
+func ConfigInheritedKeyString(sec ConfigSection, key string, def ...string) string {
+	k := sec.Key(key)
+	if k != nil && k.String() != "" {
+		return k.String()
+	}
+	if len(def) > 0 {
+		return def[0]
+	}
+	return ""
+}
+
+func (s *iniConfigSection) Name() string {
+	return s.sec.Name()
+}
+
+func (s *iniConfigSection) MapTo(v any) error {
+	return s.sec.MapTo(v)
+}
+
+func (s *iniConfigSection) HasKey(key string) bool {
+	return s.sec.HasKey(key)
+}
+
+func (s *iniConfigSection) NewKey(name, value string) (ConfigKey, error) {
+	return s.sec.NewKey(name, value)
+}
+
+func (s *iniConfigSection) Key(key string) ConfigKey {
+	return s.sec.Key(key)
+}
+
+func (s *iniConfigSection) Keys() (keys []ConfigKey) {
+	for _, k := range s.sec.Keys() {
+		keys = append(keys, k)
+	}
+	return keys
+}
+
+func (s *iniConfigSection) ChildSections() (sections []ConfigSection) {
+	for _, s := range s.sec.ChildSections() {
+		sections = append(sections, &iniConfigSection{s})
+	}
+	return sections
+}
+
+func configProviderLoadOptions() ini.LoadOptions {
+	return ini.LoadOptions{
+		KeyValueDelimiterOnWrite: " = ",
+		IgnoreContinuation:       true,
+	}
+}
+
+// NewConfigProviderFromData this function is mainly for testing purpose
+func NewConfigProviderFromData(configContent string) (ConfigProvider, error) {
+	cfg, err := ini.LoadSources(configProviderLoadOptions(), strings.NewReader(configContent))
+	if err != nil {
+		return nil, err
+	}
+	cfg.NameMapper = ini.SnackCase
+	return &iniConfigProvider{
+		ini:             cfg,
+		loadedFromEmpty: true,
+	}, nil
+}
+
+// NewConfigProviderFromFile load configuration from file.
+// NOTE: do not print any log except error.
+func NewConfigProviderFromFile(file string) (ConfigProvider, error) {
+	cfg := ini.Empty(configProviderLoadOptions())
+	loadedFromEmpty := true
+
+	if file != "" {
+		isFile, err := util.IsFile(file)
+		if err != nil {
+			return nil, fmt.Errorf("unable to check if %q is a file. Error: %v", file, err)
+		}
+		if isFile {
+			if err = cfg.Append(file); err != nil {
+				return nil, fmt.Errorf("failed to load config file %q: %v", file, err)
+			}
+			loadedFromEmpty = false
+		}
+	}
+
+	cfg.NameMapper = ini.SnackCase
+	return &iniConfigProvider{
+		file:            file,
+		ini:             cfg,
+		loadedFromEmpty: loadedFromEmpty,
+	}, nil
+}
+
+func (p *iniConfigProvider) Section(section string) ConfigSection {
+	return &iniConfigSection{sec: p.ini.Section(section)}
+}
+
+func (p *iniConfigProvider) Sections() (sections []ConfigSection) {
+	for _, s := range p.ini.Sections() {
+		sections = append(sections, &iniConfigSection{s})
+	}
+	return sections
+}
+
+func (p *iniConfigProvider) NewSection(name string) (ConfigSection, error) {
+	sec, err := p.ini.NewSection(name)
+	if err != nil {
+		return nil, err
+	}
+	return &iniConfigSection{sec: sec}, nil
+}
+
+func (p *iniConfigProvider) GetSection(name string) (ConfigSection, error) {
+	sec, err := p.ini.GetSection(name)
+	if err != nil {
+		return nil, err
+	}
+	return &iniConfigSection{sec: sec}, nil
+}
+
+var errDisableSaving = errors.New("this config can't be saved, developers should prepare a new config to save")
+
+func (p *iniConfigProvider) GetFile() string {
+	return p.file
+}
+
+// Save saves the content into file
+func (p *iniConfigProvider) Save() error {
+	if p.disableSaving {
+		return errDisableSaving
+	}
+	filename := p.file
+	if filename == "" {
+		return fmt.Errorf("config file path must not be empty")
+	}
+	if p.loadedFromEmpty {
+		if err := os.MkdirAll(filepath.Dir(filename), os.ModePerm); err != nil {
+			return fmt.Errorf("failed to create %q: %v", filename, err)
+		}
+	}
+	if err := p.ini.SaveTo(filename); err != nil {
+		return fmt.Errorf("failed to save %q: %v", filename, err)
+	}
+
+	// Change permissions to be more restrictive
+	fi, err := os.Stat(filename)
+	if err != nil {
+		return fmt.Errorf("failed to determine current conf file permissions: %v", err)
+	}
+
+	if fi.Mode().Perm() > 0o600 {
+		if err = os.Chmod(filename, 0o600); err != nil {
+			log.Warn("Failed changing conf file permissions to -rw-------. Consider changing them manually.")
+		}
+	}
+	return nil
+}
+
+func (p *iniConfigProvider) SaveTo(filename string) error {
+	if p.disableSaving {
+		return errDisableSaving
+	}
+	return p.ini.SaveTo(filename)
+}
+
+// DisableSaving disables the saving function, use PrepareSaving to get clear config options.
+func (p *iniConfigProvider) DisableSaving() {
+	p.disableSaving = true
+}
+
+// PrepareSaving loads the ini from file again to get clear config options.
+// Otherwise, the "MustXxx" calls would have polluted the current config provider,
+// it makes the "Save" outputs a lot of garbage options
+// After the INI package gets refactored, no "MustXxx" pollution, this workaround can be dropped.
+func (p *iniConfigProvider) PrepareSaving() (ConfigProvider, error) {
+	if p.file == "" {
+		return nil, errors.New("no config file to save")
+	}
+	return NewConfigProviderFromFile(p.file)
+}
+
+func (p *iniConfigProvider) IsLoadedFromEmpty() bool {
+	return p.loadedFromEmpty
+}
+
+func mustMapSetting(rootCfg ConfigProvider, sectionName string, setting any) {
+	if err := rootCfg.Section(sectionName).MapTo(setting); err != nil {
+		log.Fatal("Failed to map %s settings: %v", sectionName, err)
+	}
+}
+
+// DeprecatedWarnings contains the warning message for various deprecations, including: setting option, file/folder, etc
+var DeprecatedWarnings []string
+
+func deprecatedSetting(rootCfg ConfigProvider, oldSection, oldKey, newSection, newKey, version string) {
+	if rootCfg.Section(oldSection).HasKey(oldKey) {
+		msg := fmt.Sprintf("Deprecated config option `[%s]` `%s` present. Use `[%s]` `%s` instead. This fallback will be/has been removed in %s", oldSection, oldKey, newSection, newKey, version)
+		log.Error("%v", msg)
+		DeprecatedWarnings = append(DeprecatedWarnings, msg)
+	}
+}
+
+// deprecatedSettingDB add a hint that the configuration has been moved to database but still kept in app.ini
+func deprecatedSettingDB(rootCfg ConfigProvider, oldSection, oldKey string) {
+	if rootCfg.Section(oldSection).HasKey(oldKey) {
+		log.Error("Deprecated `[%s]` `%s` present which has been copied to database table sys_setting", oldSection, oldKey)
+	}
+}
+
+// NewConfigProviderForLocale loads locale configuration from source and others. "string" if for a local file path, "[]byte" is for INI content
+func NewConfigProviderForLocale(source any, others ...any) (ConfigProvider, error) {
+	iniFile, err := ini.LoadSources(ini.LoadOptions{
+		IgnoreInlineComment:         true,
+		UnescapeValueCommentSymbols: true,
+		IgnoreContinuation:          true,
+	}, source, others...)
+	if err != nil {
+		return nil, fmt.Errorf("unable to load locale ini: %w", err)
+	}
+	iniFile.BlockMode = false
+	return &iniConfigProvider{
+		ini:             iniFile,
+		loadedFromEmpty: true,
+	}, nil
+}
+
+func init() {
+	ini.PrettyFormat = false
+}