#[macro_use] extern crate specs_derive;

use ggez::{Context, ContextBuilder, GameResult};
use ggez::event::{self, EventHandler};
use ggez::graphics;

use specs::RunNow;

use sdl2::keyboard as sdl;

pub mod consts;
pub mod components;
pub mod res;
pub mod sys;

struct MyGame {
    world: specs::World,
    sprites: graphics::spritebatch::SpriteBatch,
}

impl EventHandler for MyGame {

    fn update(&mut self, _ctx: &mut Context) -> GameResult<()> {
        Ok(())
    }

    fn draw(&mut self, ctx: &mut Context) -> GameResult<()> {
        ggez::graphics::set_background_color(ctx, ggez::graphics::BLACK);
        ggez::graphics::clear(ctx);

        sys::Draw {
            ctx,
            sprites: &mut self.sprites,
            _phase: components::Background,
        }.run_now(&self.world.res);
        sys::Draw {
            ctx,
            sprites: &mut self.sprites,
            _phase: components::Foreground,
        }.run_now(&self.world.res);
        sys::Draw {
            ctx,
            sprites: &mut self.sprites,
            _phase: components::Decoration,
        }.run_now(&self.world.res);

        ggez::graphics::draw(
            ctx,
            &self.sprites,
            ggez::nalgebra::Point2::new(0.0, 0.0),
            0.0
        )?;
        self.sprites.clear();
        ggez::graphics::present(ctx);
        Ok(())
    }

    fn key_down_event(
        &mut self,
        ctx: &mut Context,
        keycode: sdl::Keycode,
        _keymod: sdl::Mod,
        _repeat: bool,
    ) {
        if keycode == sdl::Keycode::Escape {
            ctx.quit().expect("Should never fail");
        }
        sys::Move { keycode }.run_now(&self.world.res);
    }
}

fn main() -> Result<(), ggez::error::GameError> {
    let mut world = specs::World::new();
    components::register(&mut world);

    res::world_from_file(&mut world, "assets/main.tmx");

    // Make a Context and an EventLoop.
    let mut ctx = ContextBuilder::new("game", "me")
        .add_resource_path({
            let base = std::env::var("CARGO_MANIFEST_DIR").unwrap();
            let mut path = std::path::PathBuf::from(base);
            path.push("assets");
            path
        })
        .window_mode(ggez::conf::WindowMode {
            width: consts::WINDOW_WIDTH,
            height: consts::WINDOW_HEIGHT,
            ..Default::default()
        })
        .build()?;
    let image = graphics::Image::new(&mut ctx, "/spritesheet.png")?;
    let mut sprites = graphics::spritebatch::SpriteBatch::new(image);
    sprites.set_filter(ggez::graphics::FilterMode::Nearest);

    let mut my_game = MyGame {
        world,
        sprites,
    };

    event::run(&mut ctx, &mut my_game)
}