/*extern crate sdl2;

use sdl2::pixels::PixelFormatEnum;
use sdl2::rect::Rect;
use sdl2::event::Event;
use sdl2::keyboard::Keycode;

pub fn main() -> Result<(), String> {
    let sdl_context = sdl2::init()?;
    let video_subsystem = sdl_context.video()?;

    let window = video_subsystem.window("rust-sdl2 demo: Video", 800, 600)
        .position_centered()
        .opengl()
        .build()
        .map_err(|e| e.to_string())?;

    let mut canvas = window.into_canvas().build().map_err(|e| e.to_string())?;
    let texture_creator = canvas.texture_creator();

    let mut texture = texture_creator.create_texture_streaming(PixelFormatEnum::RGB24, 256, 256)
        .map_err(|e| e.to_string())?;
    // Create a red-green gradient
    texture.with_lock(None, |buffer: &mut [u8], pitch: usize| {
        for y in 0..256 {
            for x in 0..256 {
                let offset = y*pitch + x*3;
                buffer[offset] = x as u8;
                buffer[offset + 1] = y as u8;
                buffer[offset + 2] = 0;
            }
        }
    })?;

    canvas.clear();
    canvas.copy(&texture, None, Some(Rect::new(100, 100, 256, 256)))?;
    canvas.copy_ex(&texture, None,
        Some(Rect::new(450, 100, 256, 256)), 30.0, None, false, false)?;
    canvas.present();

    let mut event_pump = sdl_context.event_pump()?;

    'running: loop {
        for event in event_pump.poll_iter() {
            match event {
                Event::Quit {..}
                | Event::KeyDown { keycode: Some(Keycode::Escape), .. } => {
                    break 'running
                },
                _ => {}
            }
        }
        // The rest of the game loop goes here...
    }

    Ok(())
}

*/
extern crate rustro;
extern crate sdl2;

use rustro::retro;
use rustro::retro::ffi::GameGeometry;
use rustro::retro::ffi::SystemAvInfo;

use std::ffi::CStr;
use std::path::{PathBuf, Path};
use std::time::Duration;

use structopt::StructOpt;

use sdl2::render::{WindowCanvas, Texture, TextureCreator};
use sdl2::rect::Rect;
use sdl2::event::Event;
use sdl2::keyboard::Keycode;
use sdl2::video::WindowContext;
use std::io::Write;

struct MyEmulator {
    retro: retro::wrapper::LibretroWrapper,
    av_info: SystemAvInfo,
    pixel_format: sdl2::pixels::PixelFormatEnum,
    texture: Option<Texture>,
}

impl MyEmulator {
    pub fn with_core(core: impl AsRef<Path>) -> Self {
        let lib = libloading::Library::new(core.as_ref()).unwrap();
        let raw_retro = retro::loading::LibretroApi::from_library(lib).unwrap();
        let retro = retro::wrapper::LibretroWrapper::from(raw_retro);
        println!("api version: {}", retro.as_ref().api_version());
        println!("name: {}", unsafe { CStr::from_ptr(retro.as_ref().get_system_info().library_name) }.to_string_lossy());

        let av_info = retro.as_ref().get_system_av_info();

        let pixel_format = sdl2::pixels::PixelFormatEnum::ABGR1555;
        let mut result = MyEmulator { retro, av_info, pixel_format, texture: None };

        retro::wrapper::register_handler(&mut result);
        result.retro.as_ref().init();
        result
    }

    pub fn run(&self) {
        self.retro.as_ref().run();
    }

    pub fn base_dimensions(&self) -> (u32, u32) {
        (self.av_info.geometry.base_width, self.av_info.geometry.base_height)
    }

    pub fn load_game(&self, rom: impl AsRef<Path>) {
        self.retro.as_ref().load_game(Some(rom.as_ref()), None, None);
    }
}

impl retro::convert::Handler for MyEmulator {
    fn video_refresh(&mut self, data: &[u8], width: u32, height: u32, pitch: u32) {
        //println!("video_refresh {}x{}", width, height);
        //let rect = Rect::new(0, 0, width, height);
        println!("{:?}", self.texture.is_some());
        if let Some(ref mut tex) = self.texture {
            tex.update(None, data, pitch as usize).unwrap();
        }
    }

    fn set_pixel_format(&mut self, pix_fmt: retro::ffi::PixelFormat) -> bool {
        self.pixel_format = match pix_fmt {
            retro::ffi::PixelFormat::ARGB1555 => sdl2::pixels::PixelFormatEnum::RGB555,
            retro::ffi::PixelFormat::ARGB8888 => sdl2::pixels::PixelFormatEnum::ARGB8888,
            retro::ffi::PixelFormat::RGB565 => sdl2::pixels::PixelFormatEnum::RGB565,
        };
        true
    }
}

pub fn main() -> failure::Fallible<()> {
    let opt: Opt = Opt::from_args();
    let mut emu = MyEmulator::with_core(&opt.core);
    emu.load_game(&opt.rom);

    let sdl_context = sdl2::init().map_err(failure::err_msg)?;
    let video_subsystem = sdl_context.video().map_err(failure::err_msg)?;

    let (width, height) = emu.base_dimensions();
    let window = video_subsystem.window("rust libretro", width, height)
        .position_centered()
        .opengl()
        .build()?;

    let mut canvas = window.into_canvas().build()?;
    let texture_creator = canvas.texture_creator();
    emu.texture = texture_creator.create_texture_streaming(emu.pixel_format, width, height).ok();
    println!("{:?}", emu.texture.is_some());

    let mut event_pump = sdl_context.event_pump().map_err(failure::err_msg)?;
    'running: loop {
        for event in event_pump.poll_iter() {
            match event {
                Event::Quit {..}
                | Event::KeyDown { keycode: Some(Keycode::Escape), .. } => {
                    break 'running
                },
                _ => {}
            }
        }
        // The rest of the game loop goes here...
        emu.run();
        canvas.clear();
        canvas.copy(emu.texture.as_ref().unwrap(), None, Some(Rect::new(0, 0, width, height))).map_err(failure::err_msg)?;
        canvas.present();
        ::std::thread::sleep(Duration::new(0, 1_000_000_000u32 / 60));
    }
    Ok(())
}

#[derive(StructOpt)]
struct Opt {
    /// Core module to use.
    #[structopt(short, long, parse(from_os_str))]
    core: PathBuf,
    /// Rom to load using the core.
    #[structopt(short, long, parse(from_os_str))]
    rom: PathBuf,
}