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

use sepax2d::{Shape, sat_collision, contains_point};
use sepax2d::polygon::Polygon;
use sepax2d::circle::Circle;
use sepax2d::aabb::AABB;
use sepax2d::capsule::Capsule;

mod dynamic;
use dynamic::DrawableShape;

struct MainState
{

    shapes: Vec<(Box<dyn DrawableShape>, bool)>,

    mouse: (f32, f32),
    selected: Option<usize>

}

const SPEED: f32 = 2.0;

impl MainState
{

    fn new() -> GameResult<MainState>
    {

        let hexagon = Polygon::from_vertices((600.0, 100.0), vec![(0.0, 0.0), (50.0, 50.0), (50.0, 100.0), (0.0, 150.0), (-50.0, 100.0), (-50.0, 50.0)]);
        let triangle = Polygon::from_vertices((150.0, 150.0), vec![(0.0, 0.0), (100.0, 50.0), (0.0, 50.0)]);
    
        let circle = Circle::new((400.0, 200.0), 80.0);
        let small_circle = Circle::new((700.0, 300.0), 40.0);
    
        let rectangle = AABB::new((550.0, 400.0), 100.0, 50.0);
        let square = AABB::new((100.0, 350.0), 50.0, 50.0);
    
        let vertical_capsule = Capsule::new((250.0, 400.0), (0.0, 30.0), 40.0);
        let rotated_capsule = Capsule::new((400.0, 500.0), (30.0, 20.0), 50.0);

        let s = MainState { shapes: vec!
        [

            (Box::new(hexagon), false),
            (Box::new(triangle), false),
            (Box::new(circle), false),
            (Box::new(small_circle), false),
            (Box::new(rectangle), false),
            (Box::new(square), false),
            (Box::new(vertical_capsule), false),
            (Box::new(rotated_capsule), false)

        ], mouse: (0.0, 0.0), selected: None };

        return Ok(s);

    }

}

impl event::EventHandler<ggez::GameError> for MainState
{

    fn update(&mut self, _context: &mut Context) -> GameResult
    {

        if let Some(i) = self.selected
        {


            let position = self.shapes[i].0.position();
            let new_position = (position.0 + SPEED * self.mouse.0, position.1 + SPEED * self.mouse.1);

            self.shapes[i].0.set_position(new_position);

            let mut resolution = (0.0, 0.0);

            for (j, (shape, _collides)) in self.shapes.iter().enumerate()
            {

                if j != i
                {

                    let single_resolution = sat_collision(shape, &self.shapes[i].0);

                    resolution = (resolution.0 + single_resolution.0, resolution.1 + single_resolution.1);

                }

            }

            self.shapes[i].0.set_position((new_position.0 + resolution.0, new_position.1 + resolution.1));

        }

        return Ok(());

    }

    fn draw(&mut self, context: &mut Context) -> GameResult 
    {

        graphics::clear(context, [0.6, 0.6, 0.6, 1.0].into());

        for (shape, collides) in self.shapes.iter()
        {

            let mesh = shape.draw(*collides, context)?;
            let position = shape.position();

            graphics::draw(context, &mesh, ([position.0, position.1],))?;

        }

        let font = graphics::Font::new(context, "/PolandCanInto.otf")?;
        let text = graphics::Text::new(graphics::TextFragment
        {
            text: "Click and hold to move a shape! \n \n Shapes will be stopped from overlapping.".to_string(), 
            font: Some(font),
            color: Some(graphics::Color::new(0.0, 0.0, 0.0, 1.0)),
            ..Default::default()
        
        });

        graphics::draw(context, &text, ([25.0, 25.0],))?;

        graphics::present(context)?;

        return Ok(());

    }

    fn mouse_button_down_event(&mut self, _ctx: &mut Context, _button: ggez::input::mouse::MouseButton, x: f32, y: f32)
    {

        for (i, (shape, _overlap)) in self.shapes.iter().enumerate()
        {

            if contains_point(shape, (x, y))
            {

                self.selected = Some(i);
                return;

            }

        }

    }

    fn mouse_button_up_event(&mut self, _ctx: &mut Context, _button: ggez::input::mouse::MouseButton, _x: f32, _y: f32)
    {

        self.selected = None;

    }

    fn mouse_motion_event(&mut self, _ctx: &mut Context, _x: f32, _y: f32, dx: f32, dy: f32)
    {

        self.mouse = (dx, dy);

    }

}

fn main() -> GameResult
{

    let cb = ContextBuilder::new("collision", "Meowitzher")
    .add_resource_path("./examples/resources/")
    .window_setup(ggez::conf::WindowSetup::default().title("Collision Example!"));

    let (context, event_loop) = cb.build()?;
    let state = MainState::new()?;

    //Ommitted explicit return due to clippy complaining of unreachable code
    event::run(context, event_loop, state)

}