Port "Refactor node creation"

Signed-off-by: Vasyl Gello <vasek.gello@gmail.com>

src/config/config.go

@@ -33,6 +33,7 @@ import (
 	"time"
 
 	"github.com/hjson/hjson-go/v4"
+	"github.com/mitchellh/mapstructure"
 	"golang.org/x/text/encoding/unicode"
 )
 
@@ -89,6 +90,22 @@ func GenerateConfig() *NodeConfig {
 	return cfg
 }
 
+func GenerateConfigJSON(isjson bool) []byte {
+	// Generates a new configuration and returns it in HJSON or JSON format.
+	cfg := GenerateConfig()
+	var bs []byte
+	var err error
+	if isjson {
+		bs, err = json.MarshalIndent(cfg, "", "  ")
+	} else {
+		bs, err = hjson.Marshal(cfg)
+	}
+	if err != nil {
+		panic(err)
+	}
+	return bs
+}
+
 func (cfg *NodeConfig) ReadFrom(r io.Reader) (int64, error) {
 	conf, err := io.ReadAll(r)
 	if err != nil {
@@ -258,3 +275,68 @@ func (k *KeyBytes) UnmarshalJSON(b []byte) error {
 	*k, err = hex.DecodeString(s)
 	return err
 }
+
+func ReadConfig(conf []byte) *NodeConfig {
+	// Generate a new configuration - this gives us a set of sane defaults -
+	// then parse the configuration we loaded above on top of it. The effect
+	// of this is that any configuration item that is missing from the provided
+	// configuration will use a sane default.
+	cfg := GenerateConfig()
+	var dat map[string]interface{}
+	if err := hjson.Unmarshal(conf, &dat); err != nil {
+		panic(err)
+	}
+	// Check if we have old field names
+	if old, ok := dat["SigningPrivateKey"]; ok {
+		if _, ok := dat["PrivateKey"]; !ok {
+			if privstr, err := hex.DecodeString(old.(string)); err == nil {
+				priv := ed25519.PrivateKey(privstr)
+				pub := priv.Public().(ed25519.PublicKey)
+				dat["PrivateKey"] = hex.EncodeToString(priv[:])
+				dat["PublicKey"] = hex.EncodeToString(pub[:])
+			}
+		}
+	}
+	if oldmc, ok := dat["MulticastInterfaces"]; ok {
+		if oldmcvals, ok := oldmc.([]interface{}); ok {
+			var newmc []MulticastInterfaceConfig
+			for _, oldmcval := range oldmcvals {
+				if str, ok := oldmcval.(string); ok {
+					newmc = append(newmc, MulticastInterfaceConfig{
+						Regex:  str,
+						Beacon: true,
+						Listen: true,
+					})
+				}
+			}
+			if newmc != nil {
+				if oldport, ok := dat["LinkLocalTCPPort"]; ok {
+					// numbers parse to float64 by default
+					if port, ok := oldport.(float64); ok {
+						for idx := range newmc {
+							newmc[idx].Port = uint16(port)
+						}
+					}
+				}
+				dat["MulticastInterfaces"] = newmc
+			}
+		}
+	}
+	// Sanitise the config
+	confJson, err := json.Marshal(dat)
+	if err != nil {
+		panic(err)
+	}
+	if err := json.Unmarshal(confJson, &cfg); err != nil {
+		panic(err)
+	}
+	// Overlay our newly mapped configuration onto the autoconf node config that
+	// we generated above.
+	if err = mapstructure.Decode(dat, &cfg); err != nil {
+		panic(err)
+	}
+	if err := cfg.postprocessConfig(); err != nil {
+		panic(err)
+	}
+	return cfg
+}