1 files changed, 143 insertions, 0 deletions

diff --git a/src/client/ui.rs b/src/client/ui.rs
new file mode 100644
index 0000000..036c36a
--- /dev/null
+++ b/src/client/ui.rs
@@ -0,0 +1,143 @@
+//! Pure text/history helpers for the client TUI.
+//!
+//! Nothing here touches the terminal, so it is unit-tested from `tests/`
+//! without a PTY.
+
+struct CommandHelp {
+    name: &'static str,
+    usage: &'static str,
+    description: &'static str,
+}
+
+const COMMANDS: &[CommandHelp] = &[
+    CommandHelp {
+        name: "connect",
+        usage: "connect <ip>:<port>",
+        description: "connect to the server",
+    },
+    CommandHelp {
+        name: "send",
+        usage: "send <message>",
+        description: "send a message to the server",
+    },
+    CommandHelp {
+        name: "disconnect",
+        usage: "disconnect",
+        description: "disconnect from the server",
+    },
+    CommandHelp {
+        name: "ping",
+        usage: "ping",
+        description: "ping the server",
+    },
+    CommandHelp {
+        name: "login",
+        usage: "login",
+        description: "login to the server",
+    },
+    CommandHelp {
+        name: "register",
+        usage: "register",
+        description: "register a new user",
+    },
+    CommandHelp {
+        name: "setcred",
+        usage: "setcred",
+        description: "set credentials for a host",
+    },
+    CommandHelp {
+        name: "logout",
+        usage: "logout",
+        description: "logout from the server",
+    },
+    CommandHelp {
+        name: "info",
+        usage: "info",
+        description: "show account and connection info",
+    },
+    CommandHelp {
+        name: "play",
+        usage: "play <game> [bet]",
+        description: "start a game (e.g. play slots 50)",
+    },
+    CommandHelp {
+        name: "games",
+        usage: "games",
+        description: "list available games",
+    },
+    CommandHelp {
+        name: "help",
+        usage: "help",
+        description: "show this message",
+    },
+    CommandHelp {
+        name: "forget-host",
+        usage: "forget-host [ip:port]",
+        description: "clear saved trust fingerprint and credentials",
+    },
+    CommandHelp {
+        name: "hosts",
+        usage: "hosts",
+        description: "list remembered hosts",
+    },
+    CommandHelp {
+        name: "quit",
+        usage: "quit",
+        description: "quit the program",
+    },
+];
+
+pub fn command_names() -> Vec<&'static str> {
+    COMMANDS.iter().map(|command| command.name).collect()
+}
+
+pub fn help_lines() -> Vec<String> {
+    let mut lines = vec!["Available commands:".to_string()];
+    for command in COMMANDS {
+        lines.push(format!(
+            "  {:<28} - {}",
+            command.usage, command.description
+        ));
+    }
+    lines
+}
+
+/// Add a command to the history, skipping blanks and consecutive duplicates.
+pub fn record_history(history: &mut Vec<String>, line: &str) {
+    let line = line.trim();
+    if line.is_empty() {
+        return;
+    }
+    if history.last().is_some_and(|last| last == line) {
+        return;
+    }
+    history.push(line.to_string());
+}
+
+/// Parse the optional bet argument of `play <game> [bet]`.
+pub fn parse_bet_arg(raw: &str) -> Result<u64, String> {
+    let bet = raw
+        .trim()
+        .parse::<u64>()
+        .map_err(|_| format!("Invalid bet: {raw}"))?;
+    if bet < 10 {
+        return Err("Bet must be at least 10 PLN".to_string());
+    }
+    Ok(bet)
+}
+
+/// Lines to move the cursor up to reach the first line of a region that ends
+/// on the current line. `render()` has no trailing newline, so a 7-line board
+/// needs `MoveUp(6)`.
+pub fn lines_to_move_up(previous_lines: usize) -> u16 {
+    previous_lines
+        .saturating_sub(1)
+        .min(u16::MAX as usize) as u16
+}
+
+/// Column (0-based) to move to after the given prompt and input text.
+pub fn input_cursor_column(prompt_len: usize, input_len: usize) -> u16 {
+    prompt_len
+        .saturating_add(input_len)
+        .min(u16::MAX as usize) as u16
+}