增加配置文件

config.go

@@ -0,0 +1,219 @@
+package main
+
+import (
+	cryptotls "crypto/tls"
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+
+	"gopkg.in/yaml.v3"
+)
+
+const configFileName = "config.yaml"
+
+type config struct {
+	MQTT       mqttConfig       `yaml:"mqtt"`
+	Meshtastic meshtasticConfig `yaml:"meshtastic"`
+	key        []byte
+}
+
+type mqttConfig struct {
+	Host string    `yaml:"host"`
+	Port int       `yaml:"port"`
+	TLS  tlsConfig `yaml:"tls"`
+}
+
+type tlsConfig struct {
+	Enabled  bool   `yaml:"enabled"`
+	CertFile string `yaml:"cert_file"`
+	KeyFile  string `yaml:"key_file"`
+}
+
+type meshtasticConfig struct {
+	PSK string `yaml:"psk"`
+}
+
+type rawConfig struct {
+	MQTT       *rawMQTTConfig       `yaml:"mqtt"`
+	Meshtastic *rawMeshtasticConfig `yaml:"meshtastic"`
+}
+
+type rawMQTTConfig struct {
+	Host *string       `yaml:"host"`
+	Port *int          `yaml:"port"`
+	TLS  *rawTLSConfig `yaml:"tls"`
+}
+
+type rawTLSConfig struct {
+	Enabled  *bool   `yaml:"enabled"`
+	CertFile *string `yaml:"cert_file"`
+	KeyFile  *string `yaml:"key_file"`
+}
+
+type rawMeshtasticConfig struct {
+	PSK *string `yaml:"psk"`
+}
+
+// defaultConfig 返回内置默认配置。
+func defaultConfig() *config {
+	return &config{
+		MQTT: mqttConfig{
+			Host: "0.0.0.0",
+			Port: 1883,
+			TLS: tlsConfig{
+				Enabled:  false,
+				CertFile: "",
+				KeyFile:  "",
+			},
+		},
+		Meshtastic: meshtasticConfig{
+			PSK: "AQ==",
+		},
+	}
+}
+
+// defaultConfigDir 根据操作系统返回配置目录。
+func defaultConfigDir() string {
+	if runtime.GOOS == "windows" {
+		return filepath.Join(".", "win", "etc", "mesh_mqtt_go")
+	}
+	return filepath.Join(string(filepath.Separator), "etc", "mesh_mqtt_go")
+}
+
+// defaultConfigPath 返回默认配置文件路径。
+func defaultConfigPath() string {
+	return filepath.Join(defaultConfigDir(), configFileName)
+}
+
+// loadConfig 加载配置文件；文件不存在时生成，字段缺失时自动补全并写回。
+func loadConfig(path string) (*config, error) {
+	if path == "" {
+		path = defaultConfigPath()
+	}
+	if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
+		return nil, fmt.Errorf("create config directory %s: %w", filepath.Dir(path), err)
+	}
+
+	if _, err := os.Stat(path); err != nil {
+		if !os.IsNotExist(err) {
+			return nil, fmt.Errorf("stat config file %s: %w", path, err)
+		}
+		cfg := defaultConfig()
+		if err := writeConfig(path, cfg); err != nil {
+			return nil, err
+		}
+		return cfg, nil
+	}
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("read config file %s: %w", path, err)
+	}
+
+	var raw rawConfig
+	if err := yaml.Unmarshal(data, &raw); err != nil {
+		return nil, fmt.Errorf("parse config file %s: %w", path, err)
+	}
+
+	cfg, changed := normalizeConfig(raw)
+	if err := validateConfig(cfg); err != nil {
+		return nil, err
+	}
+	if changed {
+		if err := writeConfig(path, cfg); err != nil {
+			return nil, err
+		}
+	}
+	return cfg, nil
+}
+
+// normalizeConfig 将原始配置合并到默认配置，并标记是否补齐了缺失项。
+func normalizeConfig(raw rawConfig) (*config, bool) {
+	cfg := defaultConfig()
+	changed := false
+
+	if raw.MQTT == nil {
+		changed = true
+	} else {
+		if raw.MQTT.Host == nil {
+			changed = true
+		} else {
+			cfg.MQTT.Host = *raw.MQTT.Host
+		}
+		if raw.MQTT.Port == nil {
+			changed = true
+		} else {
+			cfg.MQTT.Port = *raw.MQTT.Port
+		}
+		if raw.MQTT.TLS == nil {
+			changed = true
+		} else {
+			if raw.MQTT.TLS.Enabled == nil {
+				changed = true
+			} else {
+				cfg.MQTT.TLS.Enabled = *raw.MQTT.TLS.Enabled
+			}
+			if raw.MQTT.TLS.CertFile == nil {
+				changed = true
+			} else {
+				cfg.MQTT.TLS.CertFile = *raw.MQTT.TLS.CertFile
+			}
+			if raw.MQTT.TLS.KeyFile == nil {
+				changed = true
+			} else {
+				cfg.MQTT.TLS.KeyFile = *raw.MQTT.TLS.KeyFile
+			}
+		}
+	}
+
+	if raw.Meshtastic == nil {
+		changed = true
+	} else if raw.Meshtastic.PSK == nil {
+		changed = true
+	} else {
+		cfg.Meshtastic.PSK = *raw.Meshtastic.PSK
+	}
+
+	return cfg, changed
+}
+
+func validateConfig(cfg *config) error {
+	if cfg.MQTT.Port <= 0 || cfg.MQTT.Port > 65535 {
+		return fmt.Errorf("invalid mqtt port %d: must be 1-65535", cfg.MQTT.Port)
+	}
+	return nil
+}
+
+func writeConfig(path string, cfg *config) error {
+	data, err := yaml.Marshal(cfg)
+	if err != nil {
+		return fmt.Errorf("encode config file %s: %w", path, err)
+	}
+	if err := os.WriteFile(path, data, 0644); err != nil {
+		return fmt.Errorf("write config file %s: %w", path, err)
+	}
+	return nil
+}
+
+// buildTLSConfig 根据配置构造 mochi listener 使用的 TLS 设置。
+func buildTLSConfig(cfg tlsConfig) (*cryptotls.Config, error) {
+	if !cfg.Enabled {
+		return nil, nil
+	}
+	if cfg.CertFile == "" {
+		return nil, fmt.Errorf("mqtt tls cert_file is required when tls is enabled")
+	}
+	if cfg.KeyFile == "" {
+		return nil, fmt.Errorf("mqtt tls key_file is required when tls is enabled")
+	}
+
+	cert, err := cryptotls.LoadX509KeyPair(cfg.CertFile, cfg.KeyFile)
+	if err != nil {
+		return nil, fmt.Errorf("load mqtt tls certificate: %w", err)
+	}
+	return &cryptotls.Config{
+		MinVersion:   cryptotls.VersionTLS12,
+		Certificates: []cryptotls.Certificate{cert},
+	}, nil
+}