Added create data file if not exist

1 files changed, 34 insertions, 23 deletions

diff --git a/main.go b/main.go
index 8bd2d5c..329fc34 100644
--- a/main.go
+++ b/main.go
@@ -3,6 +3,7 @@ package main
 import (
 	_ "embed"
 	"encoding/gob"
+	"errors"
 	"html/template"
 	"io"
 	"log"
@@ -77,39 +78,49 @@ func main() {
 	// If the .data file does not exist, create it in the cache directory
 	{
 		p := os.Getenv("XDG_CACHE_HOME")
-		// TODO: remove for testing
-		p = ""
 		if p == "" {
 			p = "."
 		}
 		DataFilename = p + "/" + DataFilename
 
-		f, err := os.OpenFile(DataFilename, os.O_RDONLY|os.O_CREATE, 0666)
-		if err != nil {
-			log.Fatalln("Error while opening data file:", err)
-		}
-
-		// Decode the data and import it into Ideas
+		f, err := os.Open(DataFilename)
+		if errors.Is(err, os.ErrNotExist) {
+			// The file does not exist, so create one with only Version encoded
+			log.Println("File does not exist, creating", DataFilename)
+			f, err = os.Create(DataFilename)
+			if err != nil {
+				log.Fatalln("Error while creating data file:", err)
+			}
 
-		dec := gob.NewDecoder(f)
-		var v string
-		if err := dec.Decode(&v); err != io.EOF && err != nil {
-			log.Fatalln("Error while decoding version:", err)
-		}
+			enc := gob.NewEncoder(f)
+			if err := enc.Encode(Version); err != nil {
+				log.Fatalln("Error while encoding Version:", err)
+			}
+		} else if err != nil {
+			log.Fatalln("Error while opening data file:", err)
+		} else {
+			dec := gob.NewDecoder(f)
 
-		if v != Version {
-			log.Fatalf("Version mismatch for datafile@%s != package@%s\n", v, Version)
-		}
+			// Check the version
+			var v string
+			if err := dec.Decode(&v); err != io.EOF && err != nil {
+				log.Fatalln("Error while decoding version:", err)
+			}
+			if v != Version {
+				log.Fatalf("Version mismatch for datafile@%s != package@%s\n", v, Version)
+			}
 
-		err = dec.Decode(&Ideas)
-		if err != nil && err != io.EOF {
-			log.Fatalln("Error while decoding ideas:", err)
+			// Decode the data and import it into Ideas
+			err = dec.Decode(&Ideas)
+			if err != nil && err != io.EOF {
+				log.Fatalln("Error while decoding ideas:", err)
+			}
+			log.Printf("Imported @%s: %d ideas\n", v, len(Ideas))
+			if err := f.Close(); err != nil {
+				log.Fatalln("Error while closing file:", err)
+			}
 		}
 
-		log.Printf("Imported @%s: %d ideas\n", v, len(Ideas))
-		if err := f.Close(); err != nil {
-			log.Fatalln("Error while closing file:", err)
-		}
 	}
 
 	// Handle SIGINT