1 files changed, 60 insertions, 0 deletions
diff --git a/src/cli.rs b/src/cli.rs
new file mode 100644
index 0000000..f1563b3
--- /dev/null
+++ b/src/cli.rs
@@ -0,0 +1,60 @@
+use std::env;
+
+#[derive(Debug, PartialEq)]
+pub enum Action {
+    NewConfig,
+    NewState,
+    DumpTrajectory,
+    DumpLearner,
+    DumpAlbums,
+    Run,
+}
+
+const NAME: &str = env!("CARGO_PKG_NAME");
+const VERSION: &str = env!("CARGO_PKG_VERSION");
+const DESCRIPTION: &str = env!("CARGO_PKG_DESCRIPTION");
+
+fn print_help() {
+    println!(
+        "\
+        {NAME}: {DESCRIPTION}
+Usage: {NAME} [OPTION]
+
+Options:
+  --help            Show this help message.
+  --version         Show version information.
+  --new-config      Write a default config file and exit.
+  --new-state       Write a default state file and exit.
+  --dump-trajectory Dump the play trajectory as JSON to stdout.
+  --dump-learner    Dump learner weights as JSON to stdout.
+  --dump-albums     Dump album list from state as JSON to stdout.
+<no option>       Suggest and play the next album"
+    );
+}
+
+pub fn parse() -> Option<Action> {
+    let mut args = env::args();
+
+    let _binary_name = args.next();
+
+    match args.next().as_deref() {
+        None => Some(Action::Run),
+        Some("--help") | Some("-h") => {
+            print_help();
+            None
+        }
+        Some("--version") | Some("-V") | Some("-v") => {
+            println!("{NAME} {VERSION}");
+            None
+        }
+        Some("--new-config") => Some(Action::NewConfig),
+        Some("--new-state") => Some(Action::NewState),
+        Some("--dump-trajectory") => Some(Action::DumpTrajectory),
+        Some("--dump-learner") => Some(Action::DumpLearner),
+        Some("--dump-albums") => Some(Action::DumpAlbums),
+        Some(unknown) => {
+            eprintln!("Unknown option: {unknown}");
+            std::process::exit(1);
+        }
+    }
+}