feat: add completion for output flag

cmd/root.go

@@ -4,8 +4,12 @@ import (
 	"context"
 	"fmt"
 	"log/slog"
+	"maps"
 	"os"
+	"slices"
+	"strings"
 
+	"git.bissendorf.co/bissendorf/unifood/m/v2/core/output"
 	"git.bissendorf.co/bissendorf/unifood/m/v2/core/services/jlog"
 	"github.com/spf13/cobra"
 )
@@ -15,6 +19,7 @@ var rootCmd = &cobra.Command{
 	Short: "Unifood is a CLI for retrieving restaurant information",
 	Long:  ``,
 	Run: func(cmd *cobra.Command, args []string) {
+		_ = cmd.Help()
 	},
 }
 
@@ -30,11 +35,20 @@ func Execute() {
 func initRootCmd() {
 	var appConfig AppConfig
 
+	// Compile list of available formatters
+	formatters := slices.AppendSeq([]string{}, maps.Keys(output.Formatters))
+	formattersList := fmt.Sprintf("(available: %s)", strings.Join(formatters, ", "))
+
+	// Add persistent flags
 	rootCmd.PersistentFlags().BoolVarP(&appConfig.OutputVerbose, "verbose", "v", false, "Enable verbose output")
-	rootCmd.PersistentFlags().StringVarP(&appConfig.OutputFormatter, "output", "o", "table", "Set output format")
+	rootCmd.PersistentFlags().StringVarP(&appConfig.OutputFormatter, "output", "o", "table", "Set output format "+formattersList)
 	rootCmd.PersistentFlags().BoolVar(&appConfig.OutputOrderReverse, "reverse", false, "Reverses output item order")
 	rootCmd.PersistentFlags().BoolVar(&appConfig.PrintConfig, "print-config", false, "Enable printing the application config")
 
+	// Add flag completions
+	rootCmd.RegisterFlagCompletionFunc("output", cobra.FixedCompletions(formatters, cobra.ShellCompDirectiveNoFileComp))
+
+	// Create logger and add child commands
 	logger := jlog.New(slog.LevelDebug)
 	ctx := jlog.ContextWith(context.Background(), logger)
 

core/output/formatter.go

@@ -12,4 +12,5 @@ var Formatters = map[string]interfaces.Formatter{
 	"csv":      &TableFormatter{HideSummary: true, RenderFormat: tableFormatCSV},
 	"html":     &TableFormatter{HideSummary: true, RenderFormat: tableFormatHTML},
 	"markdown": &TableFormatter{HideSummary: true, RenderFormat: tableFormatMarkdown},
+	"name":     &NameFormatter{},
 }

core/output/name.go

@@ -0,0 +1,21 @@
+package output
+
+import (
+	"bytes"
+	"io"
+
+	"git.bissendorf.co/bissendorf/unifood/m/v2/core/interfaces"
+)
+
+type NameFormatter struct{}
+
+func (f *NameFormatter) Format(list *interfaces.ResourceList) (io.Reader, error) {
+	var buffer = make([]byte, 0, 1024)
+	outputBuffer := bytes.NewBuffer(buffer)
+
+	for _, item := range list.Items {
+		outputBuffer.WriteString(item.ItemName() + "\r\n")
+	}
+
+	return outputBuffer, nil
+}