use crate::state::GameState;

/**
 * This is the main game struct.
 * It takes care of stepping the game forward.
 * Changes are made to the state struct through the step function.
 */
pub struct Game {
    pub state: GameState,
}

impl Game {
    pub fn new(state: GameState) -> Game {
        Game {
            state: state,
        }
    }

    pub fn step(&mut self) {
        // get list of all people ids
        let ids: Vec<u32> = self.state.people.keys().map(|id| *id).collect();

        // step each person
        for id in ids {
            let person = self.state.people.get_mut(&id);
            match person {
                Some(p) => {
                    let mut p = p.clone();
                    p.step(&mut self.state);
                    self.state.people.insert(id, p);
                },
                // person is dead
                None => (),
            }

        }
        // increment time
        self.state.time.time += 1;
    }

}

#[cfg(test)]
mod tests {

    use crate::world::World;

    use super::*;

    #[test]
    fn test_step() {
        let state = GameState::new(World::new(100));
        let mut game = Game::new(state);
        game.step();
        assert_eq!(game.state.time.time, 1);
    }

}