We build too many walls and not enough bridges

pkg/config/preferences.go

@@ -0,0 +1,127 @@
+// Copyright (c) 2020 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package config
+
+import (
+	"encoding/json"
+	"errors"
+	"os"
+	"strconv"
+	"sync"
+)
+
+type Preferences struct {
+	cache map[string]string
+	path  string
+	lock  *sync.RWMutex
+}
+
+// NewPreferences returns loaded preferences.
+func NewPreferences(preferencesPath string) *Preferences {
+	p := &Preferences{
+		path: preferencesPath,
+		lock: &sync.RWMutex{},
+	}
+	if err := p.load(); err != nil {
+		log.Warn("Cannot load preferences: ", err)
+	}
+	return p
+}
+
+func (p *Preferences) load() error {
+	if p.cache != nil {
+		return nil
+	}
+
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	p.cache = map[string]string{}
+
+	f, err := os.Open(p.path)
+	if err != nil {
+		return err
+	}
+	defer f.Close() //nolint[errcheck]
+
+	return json.NewDecoder(f).Decode(&p.cache)
+}
+
+func (p *Preferences) save() error {
+	if p.cache == nil {
+		return errors.New("cannot save preferences: cache is nil")
+	}
+
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	f, err := os.Create(p.path)
+	if err != nil {
+		return err
+	}
+	defer f.Close() //nolint[errcheck]
+
+	return json.NewEncoder(f).Encode(p.cache)
+}
+
+func (p *Preferences) SetDefault(key, value string) {
+	if p.Get(key) == "" {
+		p.Set(key, value)
+	}
+}
+
+func (p *Preferences) Get(key string) string {
+	p.lock.RLock()
+	defer p.lock.RUnlock()
+
+	return p.cache[key]
+}
+
+func (p *Preferences) GetBool(key string) bool {
+	return p.Get(key) == "true"
+}
+
+func (p *Preferences) GetInt(key string) int {
+	value, err := strconv.Atoi(p.Get(key))
+	if err != nil {
+		log.Error("Cannot parse int: ", err)
+	}
+	return value
+}
+
+func (p *Preferences) Set(key, value string) {
+	p.lock.Lock()
+	p.cache[key] = value
+	p.lock.Unlock()
+
+	if err := p.save(); err != nil {
+		log.Warn("Cannot save preferences: ", err)
+	}
+}
+
+func (p *Preferences) SetBool(key string, value bool) {
+	if value {
+		p.Set(key, "true")
+	} else {
+		p.Set(key, "false")
+	}
+}
+
+func (p *Preferences) SetInt(key string, value int) {
+	p.Set(key, strconv.Itoa(value))
+}