add comments to the repl package

pkg/cli/repl/repl.go

@@ -1,3 +1,4 @@
+// Package repl implements the Read-Eval-Print Loop (REPL) for the PM CLI.
 package repl
 
 import (
@@ -14,45 +15,63 @@ import (
 	"golang.org/x/term"
 )
 
+const (
+	ReplHelp = `Type 'pm help' for available PM commands.
+You can also run shell commands directly. Type 'exit' or 'quit' to leave.`
+
+	ReplTitle = "Welcome to Project Management CLI! " + ReplHelp
+)
+
+// RunREPL starts the interactive Read-Eval-Print Loop for the PM CLI.
 func RunREPL(ctx context.Context, config cli.CLIConfig) error {
+	// Set terminal to raw mode to capture input properly in the REPL.
+	// This allows us to handle input character by character and provide a better user experience.
+	// We also ensure that the terminal state is restored when the REPL exits, even if an error occurs.
 	oldState, err := term.GetState(int(os.Stdin.Fd()))
 	if err != nil {
 		return fmt.Errorf("failed to get terminal state: %w", err)
 	}
 	defer term.Restore(int(os.Stdin.Fd()), oldState)
 
+	// Initialize services for beads, config and stats.
 	svc, cleanup, err := service.NewServices(ctx, config)
 	if err != nil {
 		return fmt.Errorf("failed to initialize services: %w", err)
 	}
 	defer cleanup()
 
+	// Make sure to set services, to ensure they are available.
 	commands.SetServices(svc)
 
-	fmt.Println(styles.TitleStyle.Render(ReplTitle))
+	fmt.Println(styles.TitleStyle.Render(ReplTitle)) // Print REPL title.
 
+	// history keeps track of command history.
+	// This enables navigating through previous commands.
 	var history []string
 
+	// Start the REPL loop, which continues until the user types "exit" or "quit".
 	for {
+		// Prompt the user for input, and provide suggestions.
 		input := prompt.Input(
 			PromptPrefix,
 			completer,
 			promptOptions(history)...,
 		)
 
+		// Trim whitespace from the input to ensure consistent command processing.
 		input = strings.TrimSpace(input)
 
+		// If the user types "exit" or "quit", break the loop and exit the REPL.
 		if input == "exit" || input == "quit" {
 			fmt.Println("Goodbye!")
 			break
 		}
 
+		// Add the input to the history for future navigation.
 		history = append(history, input)
 
-		// Ignore errors for now, gives better ux
-		output, _ := execute(input)
-
-		fmt.Println(styles.CommandStyle.Render(output))
+		output, _ := execute(input)                     // Ignore errors for now, gives better ux
+		fmt.Println(styles.CommandStyle.Render(output)) // Print the output of the command in a styled format.
 	}
 
 	return nil