//! Shared slots rules used by both the server engine and the client board.

pub const REELS: usize = 5;
pub const ROWS: usize = 3;
pub const SYMBOLS: [char; 6] = ['C', 'L', 'O', 'G', 'D', 'S'];

/// Five paylines, each entry is the row used on reel 0..4.
pub const PAYLINES: [[usize; REELS]; 5] = [
    [0, 0, 0, 0, 0], // line 1: top
    [1, 1, 1, 1, 1], // line 2: middle
    [2, 2, 2, 2, 2], // line 3: bottom
    [0, 1, 2, 1, 0], // line 4: V
    [2, 1, 0, 1, 2], // line 5: inverted V
];

/// (symbol, 3-of-a-kind, 4-of-a-kind, 5-of-a-kind) multipliers of total bet.
pub const PAYTABLE: [(char, u64, u64, u64); 6] = [
    ('C', 2, 5, 15),
    ('L', 3, 7, 20),
    ('O', 3, 8, 25),
    ('G', 4, 12, 40),
    ('D', 6, 18, 70),
    ('S', 9, 30, 150),
];

/// Paytable rendered under the reels, split so it fits a narrow terminal.
pub fn paytable_lines() -> Vec<String> {
    let entries: Vec<String> = PAYTABLE
        .iter()
        .map(|(symbol, three, four, five)| format!("{symbol} {three}/{four}/{five}"))
        .collect();

    entries
        .chunks(3)
        .enumerate()
        .map(|(index, chunk)| {
            let prefix = if index == 0 {
                "Pays 3/4/5 x bet: "
            } else {
                ""
            };
            format!("{}{}", prefix, chunk.join(" "))
        })
        .collect()
}