From c166c473525e7f16e2c2f2914e22cb58bfbdb5fe Mon Sep 17 00:00:00 2001
From: Etienne Samson <samson.etienne@gmail.com>
Date: Mon, 29 Jul 2024 18:17:17 +0200
Subject: [PATCH] fix: Add help messages to the cli and clarify some options
 (#27)

---
 README.md        |  8 +++----
 src/clientApp.ts | 58 +++++++++++++++++++++++++++++++++++++++---------
 2 files changed, 51 insertions(+), 15 deletions(-)

diff --git a/README.md b/README.md
index c49f690..e23314e 100644
--- a/README.md
+++ b/README.md
@@ -42,12 +42,12 @@ Steam OpenId support is required on your local server. Enable it with [screepsmo
 
 All of the command line arguments are optional.
 
-- `--package` &mdash; Used to set the path to the Screeps package.nw file. Use this if the path isn't automatically detected.
+- `--package` &mdash; Path to the Screeps package.nw file. Use this if the path isn't automatically detected.
 - `--host` &mdash; Changes the host address. (default: localhost)
 - `--port` &mdash; Changes the port. (default: 8080)
-- `--backend` &mdash; Used to configure a backend url. If provided, the client app proxies this endpoint and the server list page is disabled.
-- `--internal_backend` &mdash; Used to configure an internal backend url. If provided, the client app uses this address to reference the internal server endpoint.
-- `--server_list` &mdash; Used to set the path to a custom server list json config file.
+- `--backend` &mdash; Set the backend url. When provided, the app will directly proxy this server and disable the server list page.
+- `--internal_backend` &mdash; Set the backend's internal url. Requires --backend to be set. When provided, the app will use this url to connect to the server while still using its --backend name externally.
+- `--server_list` &mdash; Path to a custom server list json config file.
 - `--beautify` &mdash; Formats .js files loaded in the client for debugging.
 - `--debug` &mdash; Display verbose errors for development.
 - `-v` , `--version` &mdash; Display the version number.
diff --git a/src/clientApp.ts b/src/clientApp.ts
index 987827a..1956dd1 100644
--- a/src/clientApp.ts
+++ b/src/clientApp.ts
@@ -38,18 +38,55 @@ const packageJson = JSON.parse(await fs.readFile(packageJsonPath, 'utf8'));
 const version = packageJson.version || '1.0.0';
 const arrow = '\u2192';
 
+const DEFAULT_HOST = 'localhost';
+const DEFAULT_PORT = 8080;
+
 // Parse program arguments
 const argv = (() => {
-    const parser = new ArgumentParser();
+    const parser = new ArgumentParser({ description: 'Web proxy for the Screeps World game client.' });
     parser.add_argument('-v', '--version', { action: 'version', version: `v${version}` });
-    parser.add_argument('--package', { nargs: '?', type: 'str' });
-    parser.add_argument('--host', { nargs: '?', type: 'str' });
-    parser.add_argument('--port', { nargs: '?', type: 'int' });
-    parser.add_argument('--backend', { nargs: '?', type: 'str' });
-    parser.add_argument('--internal_backend', { nargs: '?', type: 'str' });
-    parser.add_argument('--server_list', { nargs: '?', type: 'str' });
-    parser.add_argument('--beautify', { action: 'store_true', default: false });
-    parser.add_argument('--debug', { action: 'store_true', default: false });
+    parser.add_argument('--package', {
+        nargs: '?',
+        type: 'str',
+        help: "Path to the Screeps package.nw file. Use this if the path isn't automatically detected.",
+    });
+    parser.add_argument('--host', {
+        nargs: '?',
+        type: 'str',
+        default: DEFAULT_HOST,
+        help: `Changes the host address. (default: ${DEFAULT_HOST})`,
+    });
+    parser.add_argument('--port', {
+        nargs: '?',
+        type: 'int',
+        default: DEFAULT_PORT,
+        help: `Changes the port. (default: ${DEFAULT_PORT})`,
+    });
+    parser.add_argument('--backend', {
+        nargs: '?',
+        type: 'str',
+        help: 'Set the backend url. When provided, the app will directly proxy this server and disable the server list page.',
+    });
+    parser.add_argument('--internal_backend', {
+        nargs: '?',
+        type: 'str',
+        help: "Set the backend's internal url. Requires --backend to be set. When provided, the app will use this url to connect to the server while still using its --backend name externally.",
+    });
+    parser.add_argument('--server_list', {
+        nargs: '?',
+        type: 'str',
+        help: 'Path to a custom server list json config file.',
+    });
+    parser.add_argument('--beautify', {
+        action: 'store_true',
+        default: false,
+        help: 'Formats .js files loaded in the client for debugging.',
+    });
+    parser.add_argument('--debug', {
+        action: 'store_true',
+        default: false,
+        help: 'Display verbose errors for development.',
+    });
     return parser.parse_args();
 })();
 
@@ -88,8 +125,7 @@ const lastModified = stat.mtime;
 
 // Set up web server
 const koa = new Koa();
-const port = argv.port ?? 8080;
-const host = argv.host ?? 'localhost';
+const { host, port } = argv;
 const server = koa.listen(port, host);
 server.on('error', (err) => handleServerError(err, argv.debug));
 server.on('listening', () => console.log('🌐', chalk.dim('Ready', arrow), chalk.white(`http://${host}:${port}/`)));