1 files changed, 110 insertions, 0 deletions

diff --git a/src/client/shell.rs b/src/client/shell.rs
new file mode 100644
index 0000000..73843c8
--- /dev/null
+++ b/src/client/shell.rs
@@ -0,0 +1,110 @@
+//! Parser for the terminal's command line.
+//!
+//! The core speaks `Command`; this module turns one typed line into either a
+//! core command or an action only an interactive frontend can perform
+//! (connecting, prompting for a password, listing hosts).
+
+use crate::client::ui::parse_bet_arg;
+use crate::client::view::Command;
+use crate::history::{DEFAULT_HISTORY, MAX_HISTORY};
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Shell {
+    /// A command the core can run on its own.
+    Run(Command),
+    Login,
+    Register,
+    SetCred,
+    Connect(Option<String>),
+    Disconnect,
+    Hosts,
+    ForgetHost(Option<String>),
+    ForgetLogin(Option<String>),
+    Help,
+    Quit,
+    Empty,
+    Usage(String),
+}
+
+/// Split off the first whitespace-delimited word.
+///
+/// The remainder keeps its internal spacing (so `send` can echo a message
+/// verbatim) but loses the separator run before it.
+fn split_word(line: &str) -> (&str, &str) {
+    match line.find(char::is_whitespace) {
+        Some(index) => (&line[..index], line[index..].trim_start()),
+        None => (line, ""),
+    }
+}
+
+pub fn parse(line: &str) -> Shell {
+    let line = line.trim();
+    if line.is_empty() {
+        return Shell::Empty;
+    }
+
+    let (word, rest) = split_word(line);
+    match word {
+        "play" => {
+            let (game, bet) = split_word(rest);
+            if game.is_empty() {
+                return Shell::Usage("Usage: play <game> [bet]".to_string());
+            }
+            let bet = if bet.is_empty() {
+                None
+            } else {
+                match parse_bet_arg(bet) {
+                    Ok(bet) => Some(bet),
+                    Err(message) => return Shell::Usage(message),
+                }
+            };
+            Shell::Run(Command::Play {
+                game: game.to_string(),
+                bet,
+            })
+        }
+        "history" => {
+            let (raw, _) = split_word(rest);
+            let limit = if raw.is_empty() {
+                DEFAULT_HISTORY
+            } else {
+                match raw.parse::<u32>() {
+                    Ok(count) if (1..=MAX_HISTORY).contains(&count) => count,
+                    _ => return Shell::Usage(format!("Usage: history [1-{MAX_HISTORY}]")),
+                }
+            };
+            Shell::Run(Command::History { limit })
+        }
+        "games" => Shell::Run(Command::Games),
+        "logout" => Shell::Run(Command::Logout),
+        "ping" => Shell::Run(Command::Ping),
+        "send" => {
+            if rest.is_empty() {
+                Shell::Usage("Usage: send <message>".to_string())
+            } else {
+                Shell::Run(Command::Echo(rest.to_string()))
+            }
+        }
+        "info" => Shell::Run(Command::Info),
+        "help" => Shell::Help,
+        "connect" => Shell::Connect(optional_word(rest)),
+        "login" => Shell::Login,
+        "register" => Shell::Register,
+        "setcred" => Shell::SetCred,
+        "disconnect" => Shell::Disconnect,
+        "hosts" => Shell::Hosts,
+        "forget-host" => Shell::ForgetHost(optional_word(rest)),
+        "forget-login" => Shell::ForgetLogin(optional_word(rest)),
+        "quit" => Shell::Quit,
+        _ => Shell::Help,
+    }
+}
+
+fn optional_word(rest: &str) -> Option<String> {
+    let (word, _) = split_word(rest);
+    if word.is_empty() {
+        None
+    } else {
+        Some(word.to_string())
+    }
+}