minimax/src/main.rs

use anyhow::Result;
use std::io::{stdin, stdout, StdoutLock, Write};
use termion::{
	color::{self},
	cursor::HideCursor,
	event::Key,
	input::TermRead,
	raw::IntoRawMode,
};

mod agents;
mod board;
mod util;
use board::Board;
use util::{Player, Symb};

fn play(
	stdout: &mut StdoutLock,
	player_max: bool,
	computer: &mut dyn agents::PlayerAgent,
) -> Result<Board> {
	let mut cursor = 0usize;
	let cursor_offset = 10usize - 1;
	let cursor_max = 10usize;

	let mut board = Board::new(if player_max {
		Player::Human
	} else {
		Player::Computer
	});

	let mut is_first = true;
	let mut print_board = true;

	// For human player UI
	let symbols = [
		'1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '+', '-', '×', '÷',
	];
	let mut selected_symbol = 0;

	'outer: loop {
		// Computer turn
		if board.current_player() == Player::Computer && !board.is_done() {
			computer.step(&mut board);
		}

		let min_color = if !player_max {
			Player::Human.color()
		} else {
			Player::Computer.color()
		};

		let max_color = if player_max {
			Player::Human.color()
		} else {
			Player::Computer.color()
		};

		if print_board {
			println!(
				"\r{}\r{}Min{}/{}Max{}  {}{}{}",
				" ".repeat(cursor_max + cursor_offset),
				color::Fg(min_color),
				color::Fg(color::Reset),
				color::Fg(max_color),
				color::Fg(color::Reset),
				if is_first { '╓' } else { '║' },
				board,
				if is_first { '╖' } else { '║' },
			);
			is_first = false;
		}

		while board.contains(Symb::from_char(&symbols[selected_symbol]).unwrap()) {
			if selected_symbol == symbols.len() - 1 {
				selected_symbol = 0;
			} else {
				selected_symbol += 1;
			}
		}

		print!(
			"\r{}╙{}{}{}{}{}╜",
			" ".repeat(cursor_offset),
			" ".repeat(cursor),
			color::Fg(board.current_player().color()),
			if board.is_done() {
				' '
			} else {
				symbols[selected_symbol]
			},
			color::Fg(color::Reset),
			" ".repeat(cursor_max - cursor),
		);
		stdout.flush()?;

		if board.is_done() {
			break;
		}

		// Player turn
		let stdin = stdin();
		for c in stdin.keys() {
			print_board = match c.unwrap() {
				Key::Char('q') => break 'outer,
				Key::Right => {
					cursor = cursor_max.min(cursor + 1);
					false
				}
				Key::Left => {
					if cursor != 0 {
						cursor -= 1
					}
					false
				}
				Key::Up => {
					if selected_symbol == 0 {
						selected_symbol = symbols.len() - 1;
					} else {
						selected_symbol -= 1;
					}

					while board.contains(Symb::from_char(&symbols[selected_symbol]).unwrap()) {
						if selected_symbol == 0 {
							selected_symbol = symbols.len() - 1;
						} else {
							selected_symbol -= 1;
						}
					}
					false
				}
				Key::Down => {
					if selected_symbol == symbols.len() - 1 {
						selected_symbol = 0;
					} else {
						selected_symbol += 1;
					}

					while board.contains(Symb::from_char(&symbols[selected_symbol]).unwrap()) {
						if selected_symbol == symbols.len() - 1 {
							selected_symbol = 0;
						} else {
							selected_symbol += 1;
						}
					}
					false
				}
				Key::Char('\n') => {
					let s = Symb::from_char(&symbols[selected_symbol]);
					if let Some(s) = s {
						board.play(cursor, s)
					} else {
						false
					}
				}
				Key::Char(c) => {
					let s = Symb::from_char(&c);
					if let Some(s) = s {
						board.play(cursor, s)
					} else {
						false
					}
				}
				_ => false,
			};
			continue 'outer;
		}
	}

	return Ok(board);
}

fn main() -> Result<()> {
	let stdout = HideCursor::from(stdout().into_raw_mode().unwrap());
	let mut stdout = stdout.lock();

	let mut agent = agents::MinMaxTree {};
	let a = play(&mut stdout, true, &mut agent)?;
	if a.is_done() {
		println!(
			"\r\n{}Your score:{} {:.2}\n\n",
			color::Fg(Player::Human.color()),
			color::Fg(color::Reset),
			a.evaluate().unwrap()
		);
	} else {
		println!(
			"\r\n{}Quitting{}\r\n",
			color::Fg(color::Red),
			color::Fg(color::Reset),
		);
		return Ok(());
	}

	let mut agent = agents::RandomAgent {};
	let b = play(&mut stdout, false, &mut agent)?;
	if b.is_done() {
		println!(
			"\r\n{}Computer score:{} {:.2}\n\n",
			color::Fg(Player::Computer.color()),
			color::Fg(color::Reset),
			b.evaluate().unwrap()
		);
	} else {
		println!(
			"\r\n{}Quitting{}\r\n",
			color::Fg(color::Red),
			color::Fg(color::Reset),
		);
		return Ok(());
	}

	Ok(())
}