use std::{
    path::PathBuf,
    sync::{
        mpsc::{self, Receiver, Sender},
        Arc, Mutex,
    },
};

use baseview::{Event, EventStatus, Size, Window, WindowEvent, WindowHandler, WindowOpenOptions};
use gb_emu_lib::{
    connect::{JoypadButtons, JoypadState, Renderer, ResolutionData, HEIGHT, WIDTH},
    renderer::{RendererBackend, RendererBackendManager, WindowOptions},
};
use keyboard_types::{Code, KeyState};
use nih_plug::prelude::*;

use crate::{access_config, Frame, FrameReceiver, JoypadInfo, JoypadSender, IS_CGB};

pub struct Emulator {
    frame_receiver: Arc<FrameReceiver>,
    joypad_sender: Arc<JoypadSender>,
    manager: Arc<Mutex<Option<Arc<RendererBackendManager>>>>,
    size: Size,
}

impl Emulator {
    pub fn new(
        frame_receiver: Arc<FrameReceiver>,
        joypad_sender: Arc<JoypadSender>,
        manager: Arc<Mutex<Option<Arc<RendererBackendManager>>>>,
        size: Size,
    ) -> Self {
        Self {
            frame_receiver,
            joypad_sender,
            manager,
            size,
        }
    }
}

impl Editor for Emulator {
    fn spawn(
        &self,
        parent: ParentWindowHandle,
        _context: Arc<dyn GuiContext>,
    ) -> Box<dyn std::any::Any + Send> {
        let fr_cloned = self.frame_receiver.clone();
        let js_cloned = self.joypad_sender.clone();

        // let (size, scale) = if cfg!(target_os = "macos") {
        //     (
        //         Size::new((WIDTH * EXTRA_SCALE) as f64, (HEIGHT * EXTRA_SCALE) as f64),
        //         baseview::WindowScalePolicy::SystemScaleFactor,
        //     )
        // } else {
        //     (
        //         Size::new(WIDTH as f64, HEIGHT as f64),
        //         baseview::WindowScalePolicy::ScaleFactor(EXTRA_SCALE as f64),
        //     )
        // };

        let config = access_config();

        #[cfg(feature = "vulkan")]
        let shader_path = if IS_CGB.get().is_some_and(|v| *v) {
            config.emu_config.vulkan_config.cgb_shader_path.as_ref()
        } else {
            config.emu_config.vulkan_config.dmg_shader_path.as_ref()
        }
        .map(|p| config.config_dir.join(p));

        let scale_factor = access_config().vst_config.scale_factor;

        let size = Size::new(
            (WIDTH * scale_factor) as f64,
            (HEIGHT * scale_factor) as f64,
        );

        let m = self.manager.clone();

        Window::open_parented(
            &parent,
            WindowOpenOptions {
                title: String::from("gb-emu"),
                size,
                scale: baseview::WindowScalePolicy::SystemScaleFactor,
            },
            move |w| {
                EmulatorWindow::new(
                    w,
                    fr_cloned,
                    js_cloned,
                    m,
                    size,
                    #[cfg(feature = "vulkan")]
                    shader_path,
                )
                .0
            },
        );
        Box::new(Self::new(
            self.frame_receiver.clone(),
            self.joypad_sender.clone(),
            self.manager.clone(),
            size,
        ))
    }

    fn size(&self) -> (u32, u32) {
        (self.size.width as u32, self.size.height as u32)
    }

    fn set_scale_factor(&self, _factor: f32) -> bool {
        true
    }

    fn param_value_changed(&self, _id: &str, _normalized_value: f32) {}

    fn param_modulation_changed(&self, _id: &str, _modulation_offset: f32) {}

    fn param_values_changed(&self) {}
}

pub struct EmulatorWindow {
    renderer: RendererBackend,
    manager: Arc<RendererBackendManager>,
    frame_receiver: Arc<FrameReceiver>,
    joypad_sender: Arc<JoypadSender>,
    current_resolution: ResolutionData,
}

impl EmulatorWindow {
    fn new(
        window: &mut Window,
        frame_receiver: Arc<FrameReceiver>,
        joypad_sender: Arc<JoypadSender>,
        manager: Arc<Mutex<Option<Arc<RendererBackendManager>>>>,
        size: Size,
        #[cfg(feature = "vulkan")] shader_path: Option<PathBuf>,
    ) -> (Self, Arc<RendererBackendManager>) {
        let current_resolution = ResolutionData {
            real_width: size.width as u32,
            real_height: size.height as u32,
            scaled_width: WIDTH as u32,
            scaled_height: HEIGHT as u32,
        };

        #[cfg(feature = "vulkan")]
        let window_options = WindowOptions { shader_path };
        #[cfg(feature = "pixels")]
        let window_options = WindowOptions {};

        let mut guard = manager.lock().unwrap();

        let m = guard.get_or_insert_with(|| {
            use raw_window_handle::HasRawDisplayHandle;
            Arc::new(RendererBackendManager::new(window.raw_display_handle()))
        });

        let renderer = RendererBackend::new(current_resolution, window, window_options, m.clone());

        (
            Self {
                renderer,
                manager: m.clone(),
                frame_receiver,
                joypad_sender,
                current_resolution,
            },
            m.clone(),
        )
    }
}

impl WindowHandler for EmulatorWindow {
    fn on_frame(&mut self, _window: &mut Window) {
        if let Some(ref mut receiver) = *self.frame_receiver.lock().expect("failed to lock mutex") {
            if let Some(ref buf) = receiver.try_iter().last() {
                self.renderer.new_frame(buf);
            }
        }

        self.renderer.render(self.current_resolution, &self.manager);
    }

    fn on_event(&mut self, window: &mut Window, event: baseview::Event) -> EventStatus {
        match event {
            Event::Window(WindowEvent::Resized(info)) => {
                let physical_size = info.physical_size();
                self.current_resolution = ResolutionData {
                    real_width: physical_size.width,
                    real_height: physical_size.height,
                    scaled_width: WIDTH as u32,
                    scaled_height: HEIGHT as u32,
                };
                self.renderer.resize(self.current_resolution, window);
                EventStatus::Captured
            }
            Event::Keyboard(event) => {
                let status = event.state == KeyState::Down;
                if let Some(button) = match event.code {
                    Code::Equal => Some(JoypadButtons::Start),
                    Code::Minus => Some(JoypadButtons::Select),
                    Code::Quote => Some(JoypadButtons::A),
                    Code::Semicolon => Some(JoypadButtons::B),
                    Code::KeyW | Code::ArrowUp => Some(JoypadButtons::Up),
                    Code::KeyA | Code::ArrowLeft => Some(JoypadButtons::Left),
                    Code::KeyS | Code::ArrowDown => Some(JoypadButtons::Down),
                    Code::KeyD | Code::ArrowRight => Some(JoypadButtons::Right),
                    _ => None,
                } {
                    if let Some(ref mut sender) =
                        *self.joypad_sender.lock().expect("failed to lock mutex")
                    {
                        sender.send((button, status)).unwrap();
                    }
                    EventStatus::Captured
                } else {
                    EventStatus::Ignored
                }
            }
            _ => EventStatus::Ignored,
        }
    }
}

pub struct EmulatorRenderer {
    tx: Sender<Frame>,
    joypad: JoypadState,
    keys: Receiver<JoypadInfo>,
}

impl EmulatorRenderer {
    pub(super) fn new() -> (Self, Receiver<Frame>, Sender<JoypadInfo>) {
        let (tx, rx) = mpsc::channel::<Frame>();
        let (keys_tx, keys) = mpsc::channel::<JoypadInfo>();
        (
            Self {
                tx,
                joypad: JoypadState::default(),
                keys,
            },
            rx,
            keys_tx,
        )
    }
}

impl Renderer<[u8; 4]> for EmulatorRenderer {
    fn prepare(&mut self, _width: usize, _height: usize) {}

    fn display(&mut self, buffer: &[[u8; 4]]) {
        let _ = self.tx.send(buffer.to_vec());
    }

    fn latest_joypad_state(&mut self) -> JoypadState {
        while let Ok((key, state)) = self.keys.try_recv() {
            match key {
                JoypadButtons::Down => self.joypad.down = state,
                JoypadButtons::Up => self.joypad.up = state,
                JoypadButtons::Left => self.joypad.left = state,
                JoypadButtons::Right => self.joypad.right = state,
                JoypadButtons::Start => self.joypad.start = state,
                JoypadButtons::Select => self.joypad.select = state,
                JoypadButtons::B => self.joypad.b = state,
                JoypadButtons::A => self.joypad.a = state,
            }
        }
        self.joypad
    }
}