roguelike-game/src/hunger_system.rs

use ::specs::prelude::*;

use crate::components::{HungerClock, HungerState, MyTurn, SufferDamage};
use crate::game_log::GameLog;

pub struct HungerSystem {}

impl<'a> System<'a> for HungerSystem {
    #[allow(clippy::type_complexity)]
    type SystemData = (
        Entities<'a>,
        WriteStorage<'a, HungerClock>,
        ReadExpect<'a, Entity>, // The player
        WriteStorage<'a, SufferDamage>,
        WriteExpect<'a, GameLog>,
        ReadStorage<'a, MyTurn>,
    );

    fn run(&mut self, data: Self::SystemData) {
        let (entities, mut hunger_clock, player_entity, mut inflict_damage, mut log, turns) = data;

        for (entity, mut clock, _myturn) in (&entities, &mut hunger_clock, &turns).join() {
            clock.duration -= 1;

            if clock.duration < 1 {
                match clock.state {
                    HungerState::WellFed => {
                        clock.state = HungerState::Normal;
                        clock.duration = 200;

                        if entity == *player_entity {
                            log.append("You are no longer well fed.");
                        }
                    }
                    HungerState::Normal => {
                        clock.state = HungerState::Hungry;
                        clock.duration = 200;

                        if entity == *player_entity {
                            log.append("You are hungry.");
                        }
                    }
                    HungerState::Hungry => {
                        clock.state = HungerState::Starving;
                        clock.duration = 200;

                        if entity == *player_entity {
                            log.append("You are starving!");
                        }
                    }
                    HungerState::Starving => {
                        // Inflict damage from hunger
                        if entity == *player_entity {
                            log.append("Your hunger pangs are getting painful!");
                        }

                        SufferDamage::new_damage(&mut inflict_damage, entity, 1, false);
                    }
                }
            }
        }
    }
}