From c82e3b3b2de0633317ec8fc85925e91422820597 Mon Sep 17 00:00:00 2001
From: "Benjamin J. Culkin" <bjculkin@mix.wvu.edu>
Date: Sun, 8 Oct 2017 22:39:59 -0300
Subject: Start splitting into maven modules

---
 base/src/main/java/bjc/utils/cli/CLICommander.java | 134 +++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 base/src/main/java/bjc/utils/cli/CLICommander.java

(limited to 'base/src/main/java/bjc/utils/cli/CLICommander.java')

diff --git a/base/src/main/java/bjc/utils/cli/CLICommander.java b/base/src/main/java/bjc/utils/cli/CLICommander.java
new file mode 100644
index 0000000..cccb255
--- /dev/null
+++ b/base/src/main/java/bjc/utils/cli/CLICommander.java
@@ -0,0 +1,134 @@
+package bjc.utils.cli;
+
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.PrintStream;
+import java.util.Arrays;
+import java.util.Scanner;
+
+/**
+ * Runs a CLI interface from the provided set of streams.
+ *
+ * @author ben
+ *
+ */
+public class CLICommander {
+	/*
+	 * The streams used for input and normal/error output.
+	 */
+	private final InputStream	input;
+	private final OutputStream	output;
+	private final OutputStream	error;
+
+	/*
+	 * The command mode to start execution in.
+	 */
+	private CommandMode initialMode;
+
+	/**
+	 * Create a new CLI interface powered by streams.
+	 *
+	 * @param input
+	 *                The stream to get user input from.
+	 * @param output
+	 *                The stream to send normal output to.
+	 * @param error
+	 *                The stream to send error output to.
+	 */
+	public CLICommander(final InputStream input, final OutputStream output, final OutputStream error) {
+		if (input == null)
+			throw new NullPointerException("Input stream must not be null");
+		else if (output == null)
+			throw new NullPointerException("Output stream must not be null");
+		else if (error == null) throw new NullPointerException("Error stream must not be null");
+
+		this.input = input;
+		this.output = output;
+		this.error = error;
+	}
+
+	/**
+	 * Start handling commands from the given input stream.
+	 */
+	public void runCommands() {
+		/*
+		 * Setup output streams.
+		 */
+		final PrintStream normalOutput = new PrintStream(output);
+		final PrintStream errorOutput = new PrintStream(error);
+
+		/*
+		 * Set up input streams.
+		 *
+		 * We're suppressing the warning because we might use the input
+		 * stream multiple times.
+		 */
+		@SuppressWarnings("resource")
+		final Scanner inputSource = new Scanner(input);
+
+		/*
+		 * The mode currently being used to handle commands.
+		 *
+		 * Used to preserve the initial mode.
+		 */
+		CommandMode currentMode = initialMode;
+
+		/*
+		 * Process commands until we're told to stop.
+		 */
+		while (currentMode != null) {
+			/*
+			 * Print out the command prompt, using a custom prompt
+			 * if one is specified.
+			 */
+			if (currentMode.isCustomPromptEnabled()) {
+				normalOutput.print(currentMode.getCustomPrompt());
+			} else {
+				normalOutput.print(currentMode.getName() + ">> ");
+			}
+
+			/*
+			 * Read in a command.
+			 */
+			final String currentLine = inputSource.nextLine();
+
+			/*
+			 * Handle commands we can handle.
+			 */
+			if (currentMode.canHandle(currentLine)) {
+				final String[] commandTokens = currentLine.split(" ");
+				String[] commandArgs = null;
+
+				final int argCount = commandTokens.length;
+
+				/*
+				 * Parse args if they are present.
+				 */
+				if (argCount > 1) {
+					commandArgs = Arrays.copyOfRange(commandTokens, 1, argCount);
+				}
+
+				/*
+				 * Process command.
+				 */
+				currentMode = currentMode.process(commandTokens[0], commandArgs);
+			} else {
+				errorOutput.print("Error: Unrecognized command " + currentLine);
+			}
+		}
+
+		normalOutput.print("Exiting now.");
+	}
+
+	/**
+	 * Set the initial command mode to use.
+	 *
+	 * @param initialMode
+	 *                The initial command mode to use.
+	 */
+	public void setInitialCommandMode(final CommandMode initialMode) {
+		if (initialMode == null) throw new NullPointerException("Initial mode must be non-zero");
+
+		this.initialMode = initialMode;
+	}
+}
-- 
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