path: root/src/game.rs

use crate::geometry::*;
use crate::command::Command;
use crate::json;

mod player;
use player::*;

mod powerup;
use powerup::*;

mod map;
use map::*;

use arrayvec::ArrayVec;

#[derive(Debug, PartialEq, Eq, Clone)]
pub struct GameBoard {
    pub round: u16,
    pub max_rounds: u16,
    pub players: [Player; 2],
    pub powerups: ArrayVec<[Powerup; 2]>,
    pub map: Map,
    pub outcome: SimulationOutcome
}

#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub enum SimulationOutcome {
    PlayerWon(usize),
    Draw,
    Continue,
}

impl GameBoard {
    pub fn new(json: json::State) -> GameBoard {
        let commando_damage = json.my_player.worms[0].weapon.damage;
        let commando_range = json.my_player.worms[0].weapon.range;

        let player = Player {
            active_worm: json.active_worm_index().unwrap(),
            worms: json.my_player.worms.iter().map(|w| Worm {
                id: w.id,
                health: w.health,
                position: Point2d::new(w.position.x, w.position.y),
                weapon_damage: commando_damage,
                weapon_range: commando_range
            }).collect()
        };

        let opponent = Player {
            active_worm: 0,
            worms: json.opponents.iter().flat_map(|o| &o.worms).map(|w| Worm {
                id: w.id,
                health: w.health,
                position: Point2d::new(w.position.x, w.position.y),
                weapon_damage: commando_damage,
                weapon_range: commando_range
            }).collect()
        };

        let mut map = Map::default();
        for cell in json.map.iter().flatten() {
            if cell.cell_type == json::CellType::Dirt {
                map.set(Point2d::new(cell.x, cell.y))
            }
        }
            
        GameBoard {
            round: json.current_round,
            max_rounds: json.max_rounds,
            players: [player, opponent],
            powerups: json.map.iter().flatten().filter_map(|c| {
                c.powerup.as_ref().map(|p| Powerup {
                    position: Point2d::new(c.x, c.y),
                    value: p.value
                })
            }).collect(),
            map,
            outcome: SimulationOutcome::Continue
        }
    }

    pub fn update(&mut self, json: json::State) {
        for w in json.my_player.worms {
            if let Some(worm) = self.players[0].find_worm_mut(w.id) {
                worm.health = w.health;
                worm.position = Point2d::new(w.position.x, w.position.y);
            }
        }
        for w in json.opponents.iter().flat_map(|o| &o.worms) {
            if let Some(worm) = self.players[1].find_worm_mut(w.id) {
                worm.health = w.health;
                worm.position = Point2d::new(w.position.x, w.position.y);
            }
        }

        self.powerups = json.map.iter().flatten().filter_map(|c| {
            c.powerup.as_ref().map(|p| Powerup {
                position: Point2d::new(c.x, c.y),
                value: p.value
            })
        }).collect();

        for cell in json.map.iter().flatten() {
            if cell.cell_type == json::CellType::Air {
                self.map.clear(Point2d::new(cell.x, cell.y))
            }
        }
        
        self.round += 1;
        debug_assert_eq!(json.current_round, self.round);
        
        // Remove dead worms and update active worm
        for player in &mut self.players {
            player.clear_dead_worms();
            player.next_active_worm();
        }
    }

    pub fn simulate(&mut self, moves: [Command; 2]) {
        self.simulate_moves(moves);
        self.simulate_digs(moves);
        self.simulate_shoots(moves);

        for player in &mut self.players {
            player.clear_dead_worms();
            player.next_active_worm();
        }

        self.round += 1;

        self.outcome = match (self.players[0].worms.len(), self.players[1].worms.len(), self.round > self.max_rounds) {
            (0, 0, _) => SimulationOutcome::Draw,
            (_, 0, _) => SimulationOutcome::PlayerWon(0),
            (0, _, _) => SimulationOutcome::PlayerWon(1),
            (_, _, true) => SimulationOutcome::Draw,
            _ => SimulationOutcome::Continue
        };
    }

    fn simulate_moves(&mut self, moves: [Command; 2]) {
        match moves {
            [Command::Move(p1), Command::Move(p2)] if p1.x == p2.x && p1.y == p2.y => {
                // TODO: Get this from some sort of config rather
                let damage = 20;


                debug_assert_eq!(Some(false), self.map.at(Point2d::new(p1.x, p1.y)), "Movement target wasn't empty, ({}, {})", p1.x, p1.y);
                // Worms have a 50% chance of swapping places
                // here. I'm treating that as an edge case that I
                // don't need to handle for now.
                for player in &mut self.players {
                    let worm = player.active_worm_mut();
                    worm.health = worm.health.saturating_sub(damage);
                }
            },
            _ => {
                for player_index in 0..moves.len() {
                    if let Command::Move(p) = moves[player_index] {
                        debug_assert_eq!(Some(false), self.map.at(p), "Movement target wasn't empty, ({}, {})", p.x, p.y);

                        let worm = self.players[player_index].active_worm_mut();

                        debug_assert!(
                            (worm.position.x - p.x).abs() <= 1 &&
                                (worm.position.y - p.y).abs() <= 1,
                            "Tried to move too far away, ({}, {})", p.x, p.y
                        );

                        worm.position = p;
                        
                        self.powerups.retain(|power| {
                            if power.position == worm.position {
                                worm.health += power.value;
                                false
                            } else {
                                true
                            }
                        });
                    }
                }
            }
        }
    }
    
    fn simulate_digs(&mut self, moves: [Command; 2]) {
        for player_index in 0..moves.len() {
            if let Command::Dig(p) = moves[player_index] {
                debug_assert!(
                    Some(true) == self.map.at(p) ||
                        (player_index == 1 && moves[0] == Command::Dig(p)),
                    "Tried to dig through air, ({}, {})", p.x, p.y
                );
                debug_assert!{
                    (self.players[player_index].active_worm().position.x - p.x).abs() <= 1 &&
                        (self.players[player_index].active_worm().position.y - p.y).abs() <= 1,
                    "Tried to dig too far away, ({}, {})", p.x, p.y
                };

                self.map.clear(p);
            }
        }
    }
    
    fn simulate_shoots(&mut self, moves: [Command; 2]) {
        for player_index in 0..moves.len() {
            if let Command::Shoot(dir) = moves[player_index] {
                let (center, weapon_range, weapon_damage) = {
                    let worm = self.players[player_index].active_worm();
                    (worm.position, worm.weapon_range, worm.weapon_damage)
                };
                let diff = dir.as_vec();

                let range = if dir.is_diagonal() {
                    ((weapon_range as f32 + 1.) / 2f32.sqrt()).floor() as i8
                } else {
                    weapon_range as i8
                };

                for distance in 1..=range {
                    let target = center + diff * distance;
                    match self.map.at(target) {
                        Some(false) => {
                            let target_worm: Option<&mut Worm> = self.players.iter_mut()
                                .flat_map(|p| p.worms.iter_mut())
                                .find(|w| w.position == target);
                            if let Some(target_worm) = target_worm {
                                target_worm.health -= weapon_damage;
                                break;
                            }
                        },
                        _ => break
                    }
                }
            }
        }
    }

    pub fn opponent(player_index: usize) -> usize {
        (player_index + 1)%2
    }


    pub fn valid_move_commands(&self, player_index: usize) -> ArrayVec<[Command;8]> {
        let worm = self.players[player_index].active_worm();
        let taken_positions = self.players.iter()
            .flat_map(|p| p.worms.iter())
            .map(|w| w.position)
            .collect::<ArrayVec<[Point2d<i8>; 6]>>();
        
        Direction::all()
            .iter()
            .map(Direction::as_vec)
            .map(|d| worm.position + d)
            .filter(|p| !taken_positions.contains(p))
            .filter_map(|p| match self.map.at(p) {
                Some(false) => Some(Command::Move(p)),
                Some(true) => Some(Command::Dig(p)),
                _ => None,
            })
            .collect()
    }
    
    pub fn valid_shoot_commands(&self, player_index: usize, center: Point2d<i8>, weapon_range: u8) -> ArrayVec<[Command;8]> {
        let range = weapon_range as i8;
        let dir_range = ((weapon_range as f32 + 1.) / 2f32.sqrt()).floor() as i8;

        self.players[GameBoard::opponent(player_index)].worms
            .iter()
            .filter_map(|w| {
                let diff = w.position - center;
                if diff.x == 0 && diff.y.abs() <= range {
                    if diff.y > 0 {
                        Some((Direction::South, diff.y))
                    } else {
                        Some((Direction::North, -diff.y))
                    }
                } else if diff.y == 0 && diff.x.abs() <= range {
                    if diff.x > 0 {
                        Some((Direction::East, diff.x))
                    } else {
                        Some((Direction::West, -diff.x))
                    }
                } else if diff.x.abs() == diff.y.abs() && diff.x.abs() <= dir_range {
                    match (diff.x > 0, diff.y > 0) {
                        (true, true) => Some((Direction::SouthEast, diff.x)),
                        (false, true) => Some((Direction::SouthWest, -diff.x)),
                        (true, false) => Some((Direction::NorthEast, diff.x)),
                        (false, false) => Some((Direction::NorthWest, -diff.x)),
                    }
                } else {
                    None
                }
            })
            .filter(|(dir, range)| {
                // TODO if this filtered all players, I don't  need to dedup
                let diff = dir.as_vec();
                !(1..*range).any(|distance|
                                 self.map.at(center + diff * distance) != Some(false) &&
                                 !self.players[player_index].worms.iter().any(|w| w.position == center + diff * distance))
            })
            .map(|(dir, _range)| Command::Shoot(dir))
            .collect()
    }
}

#[cfg(test)]
mod test {
    
}