refactor: redistribute main.rs into new modules for app & service initialization

src/cli.rs

@@ -0,0 +1,104 @@
+use clap::Parser;
+
+/// Banner Discord Bot - Course availability monitoring
+///
+/// This application runs multiple services that can be controlled via CLI arguments:
+/// - bot: Discord bot for course monitoring commands
+/// - web: HTTP server for web interface and API
+/// - scraper: Background service for scraping course data
+///
+/// Use --services to specify which services to run, or --disable-services to exclude specific services.
+#[derive(Parser, Debug)]
+#[command(author, version, about, long_about = None)]
+pub struct Args {
+    /// Log formatter to use
+    #[arg(long, value_enum, default_value_t = default_tracing_format())]
+    pub tracing: TracingFormat,
+
+    /// Services to run (comma-separated). Default: all services
+    ///
+    /// Examples:
+    ///   --services bot,web    # Run only bot and web services
+    ///   --services scraper    # Run only the scraper service
+    #[arg(long, value_delimiter = ',', conflicts_with = "disable_services")]
+    pub services: Option<Vec<ServiceName>>,
+
+    /// Services to disable (comma-separated)
+    ///
+    /// Examples:
+    ///   --disable-services bot        # Run web and scraper only
+    ///   --disable-services bot,web    # Run only the scraper service
+    #[arg(long, value_delimiter = ',', conflicts_with = "services")]
+    pub disable_services: Option<Vec<ServiceName>>,
+}
+
+#[derive(clap::ValueEnum, Clone, Debug)]
+pub enum TracingFormat {
+    /// Use pretty formatter (default in debug mode)
+    Pretty,
+    /// Use JSON formatter (default in release mode)
+    Json,
+}
+
+#[derive(clap::ValueEnum, Clone, Debug, PartialEq)]
+pub enum ServiceName {
+    /// Discord bot for course monitoring commands
+    Bot,
+    /// HTTP server for web interface and API
+    Web,
+    /// Background service for scraping course data
+    Scraper,
+}
+
+impl ServiceName {
+    /// Get all available services
+    pub fn all() -> Vec<ServiceName> {
+        vec![ServiceName::Bot, ServiceName::Web, ServiceName::Scraper]
+    }
+
+    /// Convert to string for service registration
+    pub fn as_str(&self) -> &'static str {
+        match self {
+            ServiceName::Bot => "bot",
+            ServiceName::Web => "web",
+            ServiceName::Scraper => "scraper",
+        }
+    }
+}
+
+/// Determine which services should be enabled based on CLI arguments
+pub fn determine_enabled_services(args: &Args) -> Result<Vec<ServiceName>, anyhow::Error> {
+    match (&args.services, &args.disable_services) {
+        (Some(services), None) => {
+            // User specified which services to run
+            Ok(services.clone())
+        }
+        (None, Some(disabled)) => {
+            // User specified which services to disable
+            let enabled: Vec<ServiceName> = ServiceName::all()
+                .into_iter()
+                .filter(|s| !disabled.contains(s))
+                .collect();
+            Ok(enabled)
+        }
+        (None, None) => {
+            // Default: run all services
+            Ok(ServiceName::all())
+        }
+        (Some(_), Some(_)) => {
+            // This should be prevented by clap's conflicts_with, but just in case
+            Err(anyhow::anyhow!(
+                "Cannot specify both --services and --disable-services"
+            ))
+        }
+    }
+}
+
+#[cfg(debug_assertions)]
+const DEFAULT_TRACING_FORMAT: TracingFormat = TracingFormat::Pretty;
+#[cfg(not(debug_assertions))]
+const DEFAULT_TRACING_FORMAT: TracingFormat = TracingFormat::Json;
+
+fn default_tracing_format() -> TracingFormat {
+    DEFAULT_TRACING_FORMAT
+}