Add docs for the CLI module

src/cli.rs

@@ -1,3 +1,43 @@
+//! Payphone's main entry point, which initializes the bot and starts the event loop.
+//!
+//! This module is responsible for parsing command line arguments, nothing else.
+//!
+//! # Command Line Arguments
+//!
+//! The command line arguments are parsed using the [`clap`] crate, and can be found in the
+//! [`Args`] struct. The arguments are:
+//!
+//! - `--token` or `-t`: The Discord bot token to run the bot with. This is required.
+//! - `--logging` or `-l`: The minimum level logs have to be to be outputted into the console, or
+//!   off for no logs. Defaults to `info`.
+//! - `--database-addr` or `-d`: The address of the database to connect to, a Scylla node.
+//!
+//! The CLI also supports setting argument values via environment variables. The environment
+//! variables are prefixed with `PAYPHONE_`, so for example, the `--token` argument can be set
+//! using the `PAYPHONE_TOKEN` environment variable. The environment variables are used to
+//! override the command line arguments. `.env` files are also supported by default, so you can
+//! create a `.env` file in the root of the project with the following content:
+//!
+//! ```env
+//! PAYPHONE_TOKEN="your_discord_bot_token"
+//! PAYPHONE_LOGGING="info"
+//! PAYPHONE_DATABASE_ADDR="your_database_addr"
+//! ```
+//! 
+//! # Parsing Arguments
+//! 
+//! The arguments are parsed using the [`Args::parse`] method, which returns an instance of the
+//! [`Args`] struct. This struct contains the parsed values of the command line arguments, and
+//! can be used to initialize the bot and start the event loop.
+//! 
+//! ```
+//! // Read the environment variables from the `.env` file, if it exists, and load them as proper
+//! // env variables.
+//! dotenvy::dotenv().ok();
+//! 
+//! let args = Args::parse();
+//! ```
+
 #[derive(clap::Parser)]
 pub struct Args {
     /// The Discord bot token to run the bot with.
@@ -18,11 +58,11 @@ pub struct Args {
     #[arg(
         long,
         short,
-        env = "PAYPHONE_DATABASE_URL",
+        env = "PAYPHONE_DATABASE_ADDR",
-        value_name = "URL",
+        value_name = "ADDR",
         default_value_t = String::from("127.0.0.1:9042"))
     ]
-    pub database_url: String,
+    pub database_addr: String,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, clap::ValueEnum)]

src/main.rs

@@ -1,78 +1,78 @@
 //! Payphone is a Discord bot that allows users to make calls to each other, similar to a phone
 //! system.
-//! 
+//!
 //! # Setting Up
-//! 
+//!
 //! First of all, clone the Git repository and navigate to the project directory:
-//! 
+//!
 //! ```shell
 //! $ git clone --branch rewrite https://git.nyeki.dev/payphone/payphone.git
 //! $ cd payphone
 //! ```
-//! 
+//!
 //! To boot up Payphone, you'll need both a Discord bot token and  a Scylla database cluster with
 //! at least 3 nodes.
-//! 
+//!
 //! - To get a Discord bot token, create a new bot application on the
 //!   [Discord Developer Portal](https://discord.com/developers/applications).
-//! 
+//!
 //! - To set up a Scylla database cluster, make sure to have Docker and Docker Compose installed
 //!   and run `docker compose up -d`. A development cluster will be created with 3 nodes, with one
 //!   of them listening at `127.0.0.1:9042`.
-//! 
+//!
 //! To stop the database cluster at any time, run `docker compose down`. To stop it and delete the
 //! volumes (resetting the database), run `docker compose down -v`.
-//! 
+//!
 //! ## Booting Up
-//! 
+//!
 //! Payphone has a CLI interface that allows you to pass the bot token and database URL as CLI
 //! arguments. To get all possible arguments, run the following command:
-//! 
+//!
 //! ```shell
 //! $ cargo run -- --help
 //! ```
-//! 
+//!
 //! Payphone also supports configuration via environment variables and `.env` files by default.
-//! 
+//!
 //! ```env
 //! PAYPHONE_TOKEN="your_discord_bot_token"
 //! ```
-//! 
+//!
 //! All environment variables are prefixed with `PAYPHONE_` and can be used to override the CLI
 //! arguments.
-//! 
+//!
 //! # Framework
-//! 
+//!
 //! Payphone has a custom framework that allows you to create commands, components, and event
 //! handlers easily. The framework is designed to be modular and extensible, allowing you to add
 //! new features and commands without modifying the core codebase. The documentation for the
 //! framework is all in the [`framework`] module.
-//! 
+//!
 //! # Database
-//! 
+//!
 //! The database Payphone runs on is ScyllaDB, a high-performance NoSQL database compatible with
-//! Apache Cassandra. For documentation on how to interact with the database, check the 
+//! Apache Cassandra. For documentation on how to interact with the database, check the
 //! [`database`] module's documentation.
-//! 
+//!
 //! # Application Code
-//! 
+//!
 //! Payphone's application code is under the [`groups`] module. It contains all commands, events,
 //! embeds, and other configurations for the bot grouped in submodules (e.g. [`groups::calls`],
 //! [`groups::about`], etc.), all which can be found at the [`groups`] module's documentation.
-//! 
+//!
 //! Each submodule contains files like `commands.rs`, `events.rs`, `embeds.rs`, and `components.rs`
 //! that define the commands, events, embeds, and components for that group. Some common file names
 //! are:
-//! 
+//!
 //! - `commands.rs`: Contains the commands for the group.
 //! - `events.rs`: Contains the event handlers for the group.
 //! - `embeds.rs`: Contains the embeds for the group.
 //! - `components.rs`: Contains the components for the group (action rows, buttons, soon also
 //!   select menus).
-//! 
+//!
 //! Always try to follow the same structure and patterns as the existing code to maintain
 //! consistency and readability.
-//! 
+//!
 //! More documentation about each group can be found in the respective submodule's documentation.
 
 use clap::Parser;
@@ -117,7 +117,7 @@ pub async fn main() {
         env!("CARGO_PKG_VERSION")
     );
 
-    let db = database::init(args.database_url)
+    let db = database::init(args.database_addr)
         .await
         .expect("Could not connect to the database!");