use std::rc::Rc;

use rand::prelude::*;
use crate::person::Person;
use crate::time::Time;
use crate::world::{World, Terrain, Town};
use crate::events::{FoundTown, WorldGenesis, PersonGenesis};
pub struct GameState {
    pub time: Time,
    pub world: World,
    pub events: Vec<Box<Event>>
}

pub struct Event {
    pub time: Time,
    pub effect: Box<dyn Effect>,
}

pub trait Effect {
    fn apply(&self, state: &mut GameState);
    fn description(&self) -> String;
}

impl Event {
    pub fn description(&self) -> String {
        format!("{}: {}", self.time, self.effect.description())
    }
}


impl GameState {
    pub fn new(world: World) -> GameState {
        let mut events = Vec::new();
        events.push(Box::new(Event {
            time: Time { time: 0 },
            effect: Box::new(WorldGenesis),
        }));

        GameState {
            time: Time { time: 0 },
            world: world,
            events: events,
        }
    }

    pub fn add_event(&mut self, event: Event) {
        event.effect.apply(self);
        self.events.push(Box::new(event));
    }

    pub fn step(&mut self) {
        self.time.time += 1;
    }

    pub fn step_n(&mut self, n: u32) {
        for _ in 0..n {
            self.step();
        }
    }

    pub fn step_year(&mut self) {
        for _ in 0..360 {
            self.step();
        }
    }

    pub fn found_town(&mut self) {  
        let mut rng = rand::thread_rng();  
        loop {
            let x = rng.gen_range(0..self.world.size);
            let y = rng.gen_range(0..self.world.size);
            if 
                self.world.map[x][y].terrain == Terrain::Flats ||
                self.world.map[x][y].terrain == Terrain::Hills
            {
                let town = Rc::new(Town::new());
                self.add_event(Event {
                    time: self.time,
                    effect: Box::new(FoundTown {
                        x: x,
                        y: y,
                        town: town.clone(),
                    })
                });

                let pop_size = rng.gen_range(20..200);

                for _ in 0..pop_size {
                    self.add_event(Event {
                        time: self.time,
                        effect: Box::new(PersonGenesis {
                            town: town.clone(),
                            person: Rc::new(Person::new(
                                self.time.substract_years(rng.gen_range(18..30)),
                                town.clone(),
                                self.world.get_town_location(&town)
                            )),
                        })
                    });
                }
                break;
            }
        }
    }

    pub fn add_person(&mut self, person: Rc<Person>) {
        
    }
}