Allow document update via CLI (#66)

Here we simply expose `outline` package's document update facility via
the cli.

This time after gaining more knowledge about the cobra module, the way
I added new command is a bit different. This approach IMO is simpler and
easier with better organization and less verbose.

---------

Co-authored-by: Stefan M. <StefMa@users.noreply.github.com>

internal/cli/cli.go

@@ -4,7 +4,9 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
+	"os"
 
 	"github.com/ioki-mobility/go-outline"
 	"github.com/ioki-mobility/go-outline/internal/common"
@@ -123,6 +125,7 @@ func parseCmd() *cobra.Command {
 	rootCmd.AddCommand(documentCmd)
 	documentCmd.AddCommand(documentCreateCmd)
 	documentCmd.AddCommand(documentGetCmd)
+	documentCmd.AddCommand(documentUpdate())
 
 	return rootCmd
 }
@@ -233,9 +236,68 @@ func documentGet(serverURL string, apiKey string, id string, idIsShareID bool) e
 
 	b, err := json.MarshalIndent(doc, "", "  ")
 	if err != nil {
-		return fmt.Errorf("failed marshalling document with id '%s: %w", id, err)
+		return fmt.Errorf("failed marshalling document with id '%s': %w", id, err)
 	}
 	fmt.Println(string(b))
 
 	return nil
 }
+
+func documentUpdate() *cobra.Command {
+	var title string
+	var append, publish, readText bool
+
+	cmd := &cobra.Command{
+		Use:   "update",
+		Short: "Update an existing document",
+		Long:  "Update an existing document's title, text etc. properties",
+		Args:  cobra.MinimumNArgs(1),
+		RunE: func(c *cobra.Command, args []string) error {
+			id := args[0]
+			errBase := fmt.Sprintf("failed updating document with ID '%s'", id)
+
+			// Extract value of global flags
+			key, err := c.Flags().GetString(flagApiKey)
+			if err != nil {
+				return fmt.Errorf("%s: %w", errBase, err)
+			}
+			url, err := c.Flags().GetString(flagServerURL)
+			if err != nil {
+				return fmt.Errorf("%s: %w", errBase, err)
+			}
+
+			cl := outline.New(url, &http.Client{}, key).Documents().Update(outline.DocumentID(id)).
+				Append(append).Publish(publish).Title(title)
+
+			if readText {
+				b, err := io.ReadAll(os.Stdin)
+				if err != nil {
+					return fmt.Errorf("%s: %w", errBase, err)
+				}
+				cl.Text(string(b))
+			}
+
+			doc, err := cl.Do(context.Background())
+			if err != nil {
+				return fmt.Errorf("%s: %w", errBase, err)
+			}
+
+			b, err := json.MarshalIndent(doc, "", "  ")
+			if err != nil {
+				return fmt.Errorf("failed marshalling document with ID '%s': %w", id, err)
+			}
+			fmt.Println(string(b))
+
+			return nil
+		},
+	}
+
+	cmd.Flags().StringVar(&title, "title", "", "The title of the document")
+	cmd.Flags().BoolVar(&readText, "text", false, "Read document text from stdin")
+	cmd.Flags().BoolVar(&append, "append", false, "Append new text to existing rather than replacing it")
+	cmd.Flags().BoolVar(&publish, "publish", false,
+		"Whether this document should be published and made visible to other team members, if a draft",
+	)
+
+	return cmd
+}