use std::path::PathBuf;

use structopt::StructOpt;

use ferretro_components::prelude::*;
use ferretro_components::provided::stdlib::*;

use anime_telnet::encoding::Encoder as AnsiArtEncoder;
use anime_telnet::encoding::ProcessorPipeline;
use anime_telnet::metadata::ColorMode;
use fast_image_resize::FilterType;

use image::RgbaImage;
use sdl2::pixels::PixelFormatEnum;
use sdl2::surface::Surface;
use ferretro_components::base::ControlFlow;

#[derive(StructOpt)]
struct Opt {
    /// Emulator core to use.
    #[structopt(short, long, parse(from_os_str))]
    core: PathBuf,
    /// Path to ROM.
    #[structopt(parse(from_os_str))]
    rom: PathBuf,
    /// Directory containing BIOS files
    #[structopt(short, long, parse(from_os_str))]
    system: Option<PathBuf>,
}

struct RetroFrameEncoder {
    terminal_width: u32,
    terminal_height: u32,
    color_mode: ColorMode,
}

impl Default for RetroFrameEncoder {
    fn default() -> Self {
        use terminal_size::*;
        let (Width(w), Height(h)) = terminal_size()
            .unwrap_or((Width(80), Height(24)));
        RetroFrameEncoder {
            terminal_width: w as u32,
            terminal_height: h as u32,
            color_mode: ColorMode::EightBit,
        }
    }
}

impl AnsiArtEncoder for RetroFrameEncoder {
    fn needs_width(&self) -> u32 {
        self.terminal_width
    }

    fn needs_height(&self) -> u32 {
        self.terminal_height * 2 // half-blocks?
    }

    fn needs_color(&self) -> ColorMode {
        self.color_mode
    }
}

struct AnsiVideoComponent {
    processor: ProcessorPipeline,
    encoder: RetroFrameEncoder,
}

impl Default for AnsiVideoComponent {
    fn default() -> Self {
        let encoder = RetroFrameEncoder::default();
        let processor = ProcessorPipeline {
            filter: FilterType::Hamming,
            width: encoder.needs_width(),
            height: encoder.needs_height(),
            color_modes: Some(encoder.needs_color()).into_iter().collect(),
        };
        AnsiVideoComponent {
            processor,
            encoder,
        }
    }
}

impl RetroCallbacks for AnsiVideoComponent {
    fn video_refresh(&mut self, frame: &VideoFrame) {
        match frame {
            VideoFrame::XRGB1555 { width, height, .. }
            | VideoFrame::RGB565 { width, height, .. }
            | VideoFrame::XRGB8888 { width, height, .. } => {
                // dirty, but must be &mut for SDL API.
                // safe as long as we don't leak the Surface we construct here.
                let (bytes, pitch) = frame.data_pitch_as_bytes().unwrap();
                let pitch = pitch as u32;
                let format = match frame.pixel_format().unwrap() {
                    PixelFormat::ARGB1555 => sdl2::pixels::PixelFormatEnum::RGB555,
                    PixelFormat::ARGB8888 => sdl2::pixels::PixelFormatEnum::ARGB8888,
                    PixelFormat::RGB565 => sdl2::pixels::PixelFormatEnum::RGB565,
                };
                let data = unsafe {
                    core::slice::from_raw_parts_mut(bytes.as_ptr() as *mut u8, bytes.len())
                };
                if let Ok(surf) = Surface::from_data(data, *width, *height, pitch, format) {
                    let rgba_raw = surf.into_canvas().unwrap().read_pixels(None, PixelFormatEnum::ABGR8888).unwrap();
                    let rgba_img = RgbaImage::from_raw(*width, *height, rgba_raw).unwrap();
                    let processed = self.processor.process(&rgba_img).into_iter().next().unwrap().1;
                    println!("\x1B[0m\x1B[0J{}", self.encoder.encode_frame(&processed));
                }
            }
            _ => {}
        }
    }
}

impl RetroComponent for AnsiVideoComponent {}

fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    let opt: Opt = Opt::from_args();
    let mut emu = RetroComponentBase::new(&opt.core);
    emu.register_component(AnsiVideoComponent::default())?;
    emu.register_component(StatefulInputComponent::default())?;
    emu.register_component(PathBufComponent {
        sys_path: opt.system.clone(),
        libretro_path: Some(opt.core.to_path_buf()),
        core_assets_path: None,
        save_path: Some(std::env::temp_dir()),
    })?;
    let mut vars_comp = VariableStoreComponent::default();
    vars_comp.insert("mgba_skip_bios", "ON");
    vars_comp.insert("mgba_sgb_borders", "OFF");
    vars_comp.insert("parallel-n64-gfxplugin", "angrylion");
    emu.register_component(vars_comp)?;
    emu.register_component(SleepFramerateLimitComponent::default())?;

    emu.init()?;
    emu.load_game(&opt.rom)?;

    while let ControlFlow::Continue = emu.run() {
    }

    Ok(())
}