client cli

1 files changed, 86 insertions, 0 deletions

diff --git a/src/main/java/derms/client/CLI.java b/src/main/java/derms/client/CLI.java
new file mode 100644
index 0000000..05f4e35
--- /dev/null
+++ b/src/main/java/derms/client/CLI.java
@@ -0,0 +1,86 @@
+package derms.client;
+
+import java.util.*;
+
+abstract class CLI implements Runnable {
+	protected Map<String, Command> commands = new HashMap<String, Command>();
+	protected List<Description> cmdDescriptions = new ArrayList<Description>();
+	protected List<Description> argDescriptions = new ArrayList<Description>();
+
+	protected CLI() {
+		commands.put("quit", new Quit());
+		cmdDescriptions.add(new Description("quit", "Exit the program"));
+
+		commands.put("help", new Help());
+		cmdDescriptions.add(new Description("help", "List commands"));
+	}
+
+	@Override
+	public void run() {
+		Scanner scanner = new Scanner(System.in);
+		System.out.println("Type 'help' for a list of commands.");
+		for (;;) {
+			System.out.print("Command: ");
+			String input = scanner.nextLine();
+			String[] fields = input.split(" ");
+			if (fields.length < 1 || fields[0] == "") {
+				continue;
+			}
+			Command cmd = commands.get(fields[0]);
+			if (cmd == null) {
+				System.out.println("Invalid command '"+fields[0]+"'");
+				System.out.println("Type 'help' for a list of commands.");
+				continue;
+			}
+			String[] args = null;
+			if (fields.length < 2) {
+				args = new String[0];
+			} else {
+				args = Arrays.copyOfRange(fields, 1, fields.length);
+			}
+			cmd.exec(args);
+		}
+	}
+
+	protected interface Command {
+		public void exec(String[] args);
+	}
+
+	protected class Quit implements Command {
+		@Override
+		public void exec(String[] args) {
+			System.out.println("Shutting down...");
+			System.exit(1);
+		}
+	}
+
+	protected class Help implements Command {
+		@Override
+		public void exec(String[] args) {
+			System.out.println("\nCommands:");
+			for (Description d : cmdDescriptions) {
+				System.out.println(d);
+			}
+			System.out.println("\nArguments:");
+			for (Description d : argDescriptions) {
+				System.out.println(d);
+			}
+			System.out.println();
+		}
+	}
+
+	protected class Description {
+		String object; /// The thing being described
+		String description;
+
+		protected Description(String object, String description) {
+			this.object = object;
+			this.description = description;
+		}
+
+		@Override
+		public String toString() {
+			return object+"\n\t"+description;
+		}
+	}
+}