add generic ConfigLoad()

3 files changed, 180 insertions, 3 deletions

diff --git a/findFilename.go b/findFilename.go
new file mode 100644
index 0000000..d69b538
--- /dev/null
+++ b/findFilename.go
@@ -0,0 +1,70 @@
+package config
+
+import (
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/reflect/protoreflect"
+)
+
+// Gemini AI can help author some pretty good protobuf code.
+// I never remember the syntax for 'reflect' on these things.
+
+// returns "Filename" if it exists in the protobuf
+func GetFilename(pb proto.Message) (string, bool) {
+	// 1. Get the protoreflect.Message interface from the message.
+	// This is the entry point to the reflection API.
+	msg := pb.ProtoReflect()
+
+	// 2. Get the message's descriptor, which contains metadata about its fields.
+	descriptor := msg.Descriptor()
+
+	// 3. Find the specific field descriptor by its protobuf name ("Filename").
+	// Note: The field name must match the name in the .proto file.
+	fieldName := protoreflect.Name("Filename")
+	fieldDescriptor := descriptor.Fields().ByName(fieldName)
+
+	// 4. Check if the field was found. If not, return false.
+	if fieldDescriptor == nil {
+		return "", false
+	}
+
+	// 5. (Optional but recommended) Verify the field is a string type.
+	if fieldDescriptor.Kind() != protoreflect.StringKind {
+		// The field exists but is not a string, so we can't return it as one.
+		return "", false
+	}
+
+	// 6. If the field exists and is a string, get its value.
+	// The value is returned as a protoreflect.Value.
+	value := msg.Get(fieldDescriptor)
+
+	// 7. Convert the protoreflect.Value to a native Go string.
+	return value.String(), true
+}
+
+// sets "Filename" if it exists in the protobuf
+func SetFilename(pb proto.Message, filename string) bool {
+	msg := pb.ProtoReflect() // This is the entry point to the reflection API.
+
+	descriptor := msg.Descriptor() // Get the message's descriptor, which contains metadata about its fields.
+
+	fieldName := protoreflect.Name("Filename")
+	fieldDescriptor := descriptor.Fields().ByName(fieldName)
+
+	if fieldDescriptor == nil {
+		return false
+	}
+
+	if fieldDescriptor.Kind() != protoreflect.StringKind {
+		// The field exists but is not a string, so we can't return it as one.
+		return false
+	}
+
+	valueToSet := protoreflect.ValueOfString(filename)
+
+	// 6. If the field exists and is a string, get its value.
+	// The value is returned as a protoreflect.Value.
+	msg.Set(fieldDescriptor, valueToSet)
+
+	// 7. Convert the protoreflect.Value to a native Go string.
+	return true
+}
diff --git a/load.go b/load.go
index 31e169a..1568968 100644
--- a/load.go
+++ b/load.go
@@ -1,14 +1,71 @@
 package config
 
+// functions to import and export the protobuf
+// data to and from config files
+
 import (
+	"errors"
 	"os"
-	"strings"
-	"unicode"
+	"path/filepath"
 
 	"go.wit.com/log"
-	"golang.org/x/term"
+	"google.golang.org/protobuf/encoding/prototext"
+	"google.golang.org/protobuf/proto"
 )
 
+/*
 // loads a file from ~/.config/<argname>/
 func Load(argname string) ([]byte, string) {
 }
+*/
+
+var ErrEmpty error = log.Errorf("file was empty")
+
+// returns:
+//   - Full path to the config file. usually: ~/.config/<argname>
+//   - []byte  : the contents of the file
+//   - error on read
+func ConfigLoad(pb proto.Message, argname string, protoname string) error {
+	var data []byte
+	var fullname string
+	homeDir, err := os.UserHomeDir()
+	if err != nil {
+		return err
+	}
+
+	fullname = filepath.Join(homeDir, ".config", argname, protoname+".text")
+	if data, err = loadFile(fullname); err != nil {
+		log.Warn("config file failed to load", err)
+		// something went wrong loading the file
+		return err
+	}
+
+	// don't even bother with Marshal()
+	if data == nil {
+		return ErrEmpty // file is empty
+	}
+
+	//	Unmarshal()
+	if err = prototext.Unmarshal(data, pb); err != nil {
+		return err
+	}
+
+	// set pb.Filename if it is there in the .proto file
+	SetFilename(pb, fullname)
+
+	log.Infof("ConfigLoad() arg=%s, proto=%s\n", argname, protoname)
+	return nil
+}
+
+func loadFile(fullname string) ([]byte, error) {
+	data, err := os.ReadFile(fullname)
+	if errors.Is(err, os.ErrNotExist) {
+		// if file does not exist, just return nil. this
+		return nil, err
+	}
+	if err != nil {
+		// log.Info("open config file :", err)
+		return nil, err
+	}
+	return data, nil
+}
diff --git a/save.go b/save.go
new file mode 100644
index 0000000..35c5bab
--- /dev/null
+++ b/save.go
@@ -0,0 +1,50 @@
+package config
+
+// functions to import and export the protobuf
+// data to and from config files
+
+/*
+
+func (e *Events) Save() {
+	var fullname string
+	base, _ := filepath.Split(argv.Config)
+	fullname = filepath.Join(base, "events.pb")
+
+	data, err := e.Marshal()
+	if err != nil {
+		log.Info("proto.Marshal() failed", err)
+		return
+	}
+	log.Info("proto.Marshal() worked len", len(data))
+	configWrite(fullname, data)
+}
+
+
+func configWrite(fullname string, data []byte) error {
+	if _, base := filepath.Split(fullname); base == "" {
+		return fmt.Errorf("--config option not set")
+	}
+	cfgfile, err := os.OpenFile(fullname, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
+	defer cfgfile.Close()
+	if err != nil {
+		log.Warn("open config file :", err)
+		return err
+	}
+	cfgfile.Write(data)
+	return nil
+}
+
+func (m *Portmaps) configWrite(fullname string, data []byte) error {
+	if _, base := filepath.Split(fullname); base == "" {
+		return fmt.Errorf("--config option not set")
+	}
+	cfgfile, err := os.OpenFile(fullname, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
+	defer cfgfile.Close()
+	if err != nil {
+		log.Warn("open config file :", err)
+		return err
+	}
+	cfgfile.Write(data)
+	return nil
+}
+*/