mill_game/src/simple_ai.rs

use crate::{
    board::{Board, BoardSlot, BoardSlotState},
    game::{GameState, LogSeverity, MillGame, MillState, PlayerColor, Stone, StoneState},
};

use anyhow::Result;
use engine::prelude::*;

pub struct SimpleAI {
    pub player_color: PlayerColor,
}

impl SimpleAI {
    pub fn new(player_color: PlayerColor) -> Self {
        Self { player_color }
    }

    pub fn step(
        &self,
        stones: &mut [Stone; 9],
        board: &mut [[[BoardSlot; 3]; 3]; 3],
        scene: &mut SceneHandle,
        state: &mut GameState,
    ) -> Result<()> {
        MillGame::log(&format!("AI at state {:?}", *state), LogSeverity::Debug);

        let mut found_a_mill = false;

        match *state {
            GameState::Placing => {
                if let Some(placable) = stones
                    .iter_mut()
                    .find(|stone| stone.state == StoneState::ReadyToBePlaced)
                {
                    let (x, y, z) = {
                        let free_slots: Vec<&BoardSlot> = board
                            .iter()
                            .flatten()
                            .flatten()
                            .filter(|slot| slot.state() == BoardSlotState::Empty)
                            .collect();

                        let len = free_slots.len();

                        let slot = &free_slots[Random::range(0, len as u32) as usize];

                        (slot.x, slot.y, slot.z)
                    };

                    scene.on_scene(|scene| {
                        if MillGame::place_stone(
                            placable,
                            (x, y, z),
                            board,
                            self.player_color,
                            scene,
                            state,
                        )? != MillState::None
                        {
                            found_a_mill = true;
                        }

                        Ok(())
                    })?;
                }
            }
            GameState::Removing => {
                let mut other_color: Vec<&mut BoardSlot> = board
                    .iter_mut()
                    .flatten()
                    .flatten()
                    .filter(|slot| match (slot.state(), self.player_color) {
                        (BoardSlotState::Black(_), PlayerColor::White) => true,
                        (BoardSlotState::White(_), PlayerColor::Black) => true,
                        _ => false,
                    })
                    .collect();

                let len = other_color.len();

                let slot: &mut &mut BoardSlot =
                    &mut other_color[Random::range(0, len as u32) as usize];

                let stone = stones
                    .iter_mut()
                    .find(|s| {
                        s.stone
                            == match slot.state() {
                                BoardSlotState::Black(e) => e,
                                BoardSlotState::White(e) => e,
                                _ => unreachable!(),
                            }
                    })
                    .unwrap();

                MillGame::log("[AI] remove stone", LogSeverity::Debug);

                scene.on_scene(|scene| {
                    MillGame::remove_stone(stone, slot, scene)?;

                    Ok(())
                })?;
            }
            GameState::Main => {
                scene.on_scene(|scene| {
                    loop {
                        let same_color: Vec<&BoardSlot> = board
                            .iter()
                            .flatten()
                            .flatten()
                            .filter(|slot| match (slot.state(), self.player_color) {
                                (BoardSlotState::White(_), PlayerColor::White) => true,
                                (BoardSlotState::Black(_), PlayerColor::Black) => true,
                                _ => false,
                            })
                            .collect();

                        let len = same_color.len();
                        let slot = &same_color[Random::range(0, len as u32) as usize];
                        let n = Board::get_neighbours(slot, board);
                        let neighbours: Vec<&&BoardSlot> = n
                            .iter()
                            .filter(|n| n.state() == BoardSlotState::Empty)
                            .collect();

                        if !neighbours.is_empty() {
                            let neighbour =
                                &neighbours[Random::range(0, neighbours.len() as u32) as usize];

                            if neighbour.state() == BoardSlotState::Empty {
                                let (x, y, z) = (slot.x, slot.y, slot.z);
                                let (tx, ty, tz) = (neighbour.x, neighbour.y, neighbour.z);

                                let mut successful_move = false;

                                MillGame::log("[AI] going to make a move", LogSeverity::Debug);

                                if let Some(millstate) = MillGame::move_stone(
                                    (x, y, z),
                                    (tx, ty, tz),
                                    scene,
                                    board,
                                    state,
                                )? {
                                    MillGame::log("[AI] successful move", LogSeverity::Debug);

                                    if MillState::None != millstate {
                                        MillGame::log("[AI] found a mill", LogSeverity::Debug);

                                        found_a_mill = true;
                                    }

                                    successful_move = true;
                                } else {
                                    MillGame::log("[AI] move failed", LogSeverity::Debug);
                                }

                                if successful_move {
                                    break;
                                }
                            }
                        }
                    }

                    Ok(())
                })?;
            }
            GameState::Waiting => unreachable!(),
        }

        if found_a_mill {
            self.step(stones, board, scene, state)?;
        }

        MillGame::log("finish AI", LogSeverity::Debug);

        Ok(())
    }
}