lib/config is now using this

1 files changed, 93 insertions, 0 deletions

diff --git a/identify.go b/identify.go
index 0de53a2..c27dd51 100644
--- a/identify.go
+++ b/identify.go
@@ -1,9 +1,19 @@
 package filepb
 
 import (
+	"errors"
+	"fmt"
 	"os"
+	"strings"
+
+	"google.golang.org/protobuf/encoding/protojson"
+	"google.golang.org/protobuf/encoding/prototext"
+	"google.golang.org/protobuf/proto"
 )
 
+var ErrEmpty error = fmt.Errorf("config file was empty")
+var ErrMarshal error = fmt.Errorf("protobuf parse error")
+
 // print the protobuf in human form
 func IdentifyPB(filename string) (string, string, error) {
 	data, err := os.ReadFile(filename)
@@ -20,3 +30,86 @@ func IdentifyPB(filename string) (string, string, error) {
 	// log.Info("Identify protobuf file uuid =", pb.Uuid, "version =", pb.Version)
 	return pb.Uuid, pb.Version, nil
 }
+
+func (pb *FakeFile) loadFromFilename(fullname string) error {
+	if strings.HasSuffix(fullname, ".text") {
+		return loadTEXT(pb, fullname)
+	}
+	if strings.HasSuffix(fullname, ".json") {
+		return loadJSON(pb, fullname)
+	}
+	if strings.HasSuffix(fullname, ".pb") {
+		return loadPB(pb, fullname)
+	}
+
+	return fmt.Errorf("unknown filetype '%s'", fullname)
+}
+
+func loadPB(pb proto.Message, fullname string) error {
+	data, err := loadFile(fullname)
+	if err != nil {
+		// set pb.Filename that was attempted
+		return err
+	}
+
+	if err = proto.Unmarshal(data, pb); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func loadTEXT(pb proto.Message, fullname string) error {
+	var data []byte
+	var err error
+	if data, err = loadFile(fullname); err != nil {
+		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 ErrMarshal
+	}
+	return nil
+}
+
+// json files are backup Marshal() data in case .text Unmarshal() fails
+// they always should have the ".text" filename in them
+func loadJSON(pb proto.Message, fullname string) error {
+	var data []byte
+	var err error
+	if data, err = loadFile(fullname); err != nil {
+		return err
+	}
+
+	// don't even bother with Marshal()
+	if data == nil {
+		return ErrEmpty // file is empty
+	}
+
+	// Unmarshal()
+	if err = protojson.Unmarshal(data, pb); err != nil {
+		return ErrMarshal
+	}
+	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 {
+		return nil, err
+	}
+	if len(data) == 0 {
+		return data, ErrEmpty
+	}
+	return data, nil
+}