feat: add the command getSchema

This command is handy to retrieve the schema used on the device. This
provides the information about the available parameters and the minimum
and maximum value ranges. As well as their defaults.

Signed-off-by: Christian Ege <[email protected]>

cmd/ovp8xx/cmd/getSchema.go

@@ -0,0 +1,41 @@
+/*
+Copyright © 2023 Christian Ege <[email protected]>
+*/
+package cmd
+
+import (
+	"fmt"
+
+	"github.com/graugans/go-ovp8xx/pkg/ovp8xx"
+	"github.com/spf13/cobra"
+)
+
+func getSchemaCommand(cmd *cobra.Command, args []string) error {
+
+	host, err := rootCmd.PersistentFlags().GetString("ip")
+	if err != nil {
+		return err
+	}
+
+	o3r := ovp8xx.NewClient(
+		ovp8xx.WithHost(host),
+	)
+
+	if result, err := o3r.GetSchema(); err != nil {
+		return err
+	} else {
+		fmt.Printf("%s\n", result)
+	}
+	return nil
+}
+
+// getCmd represents the get command
+var getSchemaCmd = &cobra.Command{
+	Use:   "getSchema",
+	Short: "Retrieve the currently used JSON schema from the device",
+	RunE:  getSchemaCommand,
+}
+
+func init() {
+	rootCmd.AddCommand(getSchemaCmd)
+}

pkg/ovp8xx/rpc.go

@@ -94,3 +94,20 @@ func (device *Client) FactoryReset(keepNetworkSettings bool) error {
 	}
 	return client.Call("factoryReset", arg, nil)
 }
+
+func (device *Client) GetSchema() (string, error) {
+	client, err := xmlrpc.NewClient(device.url)
+	if err != nil {
+		return "", err
+	}
+	defer client.Close()
+
+	result := &struct {
+		JSON string
+	}{}
+
+	if err := client.Call("getSchema", nil, result); err != nil {
+		return "", err
+	}
+	return result.JSON, nil
+}