use sdl2::{

    keyboard::Scancode,

    event::EventType,

    surface::Surface,

    pixels::{

        PixelFormatEnum, Color

    }

};

use rand::{

    thread_rng, RngCore, Rng,

    distributions::uniform::SampleUniform

};

use landgen::{

    LandGenerator,

    LandGenerationParameters

};

use land2d::Land2D;

use lfprng::LaggedFibonacciPRNG;

struct LandSource<T> {

    rnd: LaggedFibonacciPRNG,

    generator: T

}

impl <T: LandGenerator> LandSource<T> {

    fn new(generator: T) -> Self {

        let mut init = [0u8; 64];

        thread_rng().fill_bytes(&mut init);

        LandSource {

            rnd: LaggedFibonacciPRNG::new(&init),

            generator

        }

    }

    fn next(&mut self, parameters: LandGenerationParameters<u32>) -> Land2D<u32> {

        self.generator.generate_land(parameters, &mut self.rnd)

    }

}

fn fill_pixels(pixels: &mut [u8], land: &Land2D<u32>) {

    for (surf_row, land_row) in pixels.chunks_mut(land.width() * 4).zip(land.rows()) {

        for (surf_pixel, land_pixel) in surf_row.chunks_mut(4).zip(land_row) {

            if let [b, g, r, a] = surf_pixel {

                *a = 255; *r = *land_pixel as u8;

            }

        }

    }

}

fn fill_texture(surface: &mut Surface, land: &Land2D<u32>) {

    if surface.must_lock() {

        surface.with_lock_mut(|data| fill_pixels(data, land));

    } else {

        surface.without_lock_mut().map(|data| fill_pixels(data, land));

    }

}

fn rnd<T: Default + SampleUniform + Ord>(max: T) -> T {

    thread_rng().gen_range(T::default(), max)

}

const WIDTH: u32 = 512;

const HEIGHT: u32 = 512;

fn main() {

    let sdl = sdl2::init().unwrap();

    let _image = sdl2::image::init(sdl2::image::INIT_PNG).unwrap();

    let events = sdl.event().unwrap();

    let mut pump = sdl.event_pump().unwrap();

    let video = sdl.video().unwrap();

    let window = video.window("Theme Editor", WIDTH, HEIGHT)

        .position_centered()

        .build().unwrap();

    let mut land_surf = Surface::new(WIDTH, HEIGHT, PixelFormatEnum::ARGB8888).unwrap();

    fn point() -> Point {

        Point::new(rnd(WIDTH as i32), rnd(HEIGHT as i32))

    }

    for i in 0..32 {

        land.draw_thick_line(point(), point(), rnd(5), u32::max_value());

        land.fill_circle(point(), rnd(60), u32::max_value());

    }

    fill_texture(&mut land_surf, &land);

    let mut win_surf = window.surface(&pump).unwrap();

    let win_rect = win_surf.rect();

    land_surf.blit(land_surf.rect(), &mut win_surf, win_rect).unwrap();

    win_surf.update_window();

    'pool: loop {

        use sdl2::event::Event::*;

        pump.pump_events();

        while let Some(event) = pump.poll_event() {

            match event {

                Quit{ .. } => break 'pool,

                _ => ()

            }

        }

    }

}