Add restoring config file

pkg/modules/dump/restore.go

@@ -16,7 +16,68 @@
 
 package dump
 
+import (
+	"archive/zip"
+	"bufio"
+	"code.vikunja.io/api/pkg/log"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+)
+
 // Restore takes a zip file name and restores it
 func Restore(filename string) error {
+
+	r, err := zip.OpenReader(filename)
+	if err != nil {
+		return fmt.Errorf("could not open zip file: %s", err)
+	}
+
+	log.Warning("Restoring a dump will wipe your current installation!")
+	log.Warning("To confirm, please type 'Yes, I understand' and confirm with enter:")
+	cr := bufio.NewReader(os.Stdin)
+	text, err := cr.ReadString('\n')
+	if err != nil {
+		return fmt.Errorf("could not read confirmation message: %s", err)
+	}
+	if text != "Yes, I understand\n" {
+		return fmt.Errorf("invalid confirmation message")
+	}
+
+	// Find the config file
+	var config *zip.File
+	for _, file := range r.File {
+		if strings.HasPrefix(file.Name, "config") {
+			config = file
+			break
+		}
+	}
+	if config == nil {
+		return fmt.Errorf("dump does not contain a config file")
+	}
+
+	if err := writeFile(config, config.Name); err != nil {
+		return fmt.Errorf("could not create config file: %s", err)
+	}
+
 	return nil
 }
+
+func writeFile(file *zip.File, path string) error {
+
+	outFile, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, file.Mode())
+	if err != nil {
+		return err
+	}
+	defer outFile.Close()
+
+	rc, err := file.Open()
+	if err != nil {
+		return err
+	}
+	defer rc.Close()
+
+	_, err = io.Copy(outFile, rc)
+	return err
+}