non-functional wip state

app/utils.go

@@ -0,0 +1,47 @@
+package app
+
+import (
+	"encoding/json"
+	"os"
+
+	"git.blackforestbytes.com/BlackForestBytes/goext/cryptext"
+	"git.blackforestbytes.com/BlackForestBytes/goext/exerr"
+)
+
+func fileExists(p string) bool {
+	_, err := os.Stat(p)
+	if os.IsNotExist(err) {
+		return false
+	}
+	return true
+}
+
+type State struct {
+	ETag     string `json:"etag"`
+	Size     int64  `json:"size"`
+	Checksum string `json:"checksum"`
+}
+
+func (app *Application) readState() *State {
+	bin, err := os.ReadFile(app.stateFile)
+	if err != nil {
+		return nil
+	}
+
+	var state State
+	err = json.Unmarshal(bin, &state)
+	if err != nil {
+		return nil
+	}
+
+	return &state
+}
+
+func (app *Application) calcLocalChecksum() (string, error) {
+	bin, err := os.ReadFile(app.dbFile)
+	if err != nil {
+		return "", exerr.Wrap(err, "").Build()
+	}
+
+	return cryptext.BytesSha256(bin), nil
+}