feat: add CLI flags

README.md

@@ -146,6 +146,14 @@ Simply run `trmt` in your terminal to start a simulation.
 trmt
 ```
 
+You can also pass a rule and/or seed directly:
+```bash
+trmt --rule RL --seed abc123
+trmt -r 'R1>1,L0>2' -s myseed
+```
+> [!NOTE]
+> Quote rules containing special characters (`>`, `,`, `{`, `}`, etc.) to prevent shell interpretation.
+
 #### Examples
 Check out the [examples](/examples) to see some of the possibilities.
 

src/config/mod.rs

@@ -144,6 +144,15 @@ impl Config {
         Ok(())
     }
 
+    pub fn apply_cli_overrides(rule: Option<&str>, seed: Option<&str>) {
+        if let Some(rule) = rule {
+            let _ = Self::save_current_rule(rule);
+        }
+        if let Some(seed) = seed {
+            let _ = Self::save_current_seed(seed);
+        }
+    }
+
     pub fn validate(&self) -> Result<(), Vec<String>> {
         validation::validate_config(self)
     }

src/main.rs

@@ -21,6 +21,8 @@ use config::{Config, ConfigLoadResult};
 use render::{App, ui};
 
 fn main() -> Result<(), Box<dyn Error>> {
+    let (cli_rule, cli_seed) = parse_cli_args();
+
     let (config, error_message) = match Config::load() {
         ConfigLoadResult::Success(config) => (config, None),
         ConfigLoadResult::ValidationErrors(config, errors) => {
@@ -34,6 +36,8 @@ fn main() -> Result<(), Box<dyn Error>> {
         },
     };
 
+    Config::apply_cli_overrides(cli_rule.as_deref(), cli_seed.as_deref());
+
     enable_raw_mode()?;
     let mut stdout = io::stdout();
     execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
@@ -64,6 +68,55 @@ fn main() -> Result<(), Box<dyn Error>> {
     Ok(())
 }
 
+fn parse_cli_args() -> (Option<String>, Option<String>) {
+    let mut rule = None;
+    let mut seed = None;
+    let mut args = std::env::args().skip(1);
+
+    while let Some(arg) = args.next() {
+        match arg.as_str() {
+            "--help" | "-h" => {
+                println!("trmt {}", env!("CARGO_PKG_VERSION"));
+                println!();
+                println!("usage: trmt [options]");
+                println!();
+                println!("options:");
+                println!("  -r, --rule <RULE>  Override the simulation rule");
+                println!("  -s, --seed <SEED>  Override the simulation seed");
+                println!("  -h, --help         Show this help message");
+                println!("  -v, --version      Show version");
+                println!();
+                println!("note: quote rules with special characters: --rule 'R1>1,L0>2'");
+                std::process::exit(0);
+            }
+            "--version" | "-v" => {
+                println!("trmt {}", env!("CARGO_PKG_VERSION"));
+                std::process::exit(0);
+            }
+            "--rule" | "-r" => {
+                rule = Some(args.next().unwrap_or_else(|| {
+                    eprintln!("error: --rule requires a value");
+                    std::process::exit(1);
+                }));
+            }
+            "--seed" | "-s" => {
+                seed = Some(args.next().unwrap_or_else(|| {
+                    eprintln!("error: --seed requires a value");
+                    std::process::exit(1);
+                }));
+            }
+            other => {
+                eprintln!("error: unknown argument '{other}'");
+                eprintln!("usage: trmt [-r|--rule <RULE>] [-s|--seed <SEED>]");
+                eprintln!("note:  quote rules with special characters: --rule 'R1>1,L0>2'");
+                std::process::exit(1);
+            }
+        }
+    }
+
+    (rule, seed)
+}
+
 fn run_app(
     terminal: &mut Terminal<CrosstermBackend<io::Stdout>>,
     app: &mut App,