use std::{
    sync::{Arc, RwLock},
    time::Instant,
};

use winit::{
    dpi::LogicalSize,
    event::{Event, KeyEvent, WindowEvent},
    event_loop::{ActiveEventLoop, EventLoopProxy},
};

use crate::{
    emulator::{SimId, VBKey},
    input::InputMapper,
};

use super::{
    common::{ImguiState, UiExt, WindowState, WindowStateBuilder},
    AppWindow, UserEvent,
};

pub struct InputWindow {
    window: WindowState,
    imgui: ImguiState,
    input_mapper: Arc<RwLock<InputMapper>>,
    proxy: EventLoopProxy<UserEvent>,
    now_binding: Option<(SimId, VBKey)>,
}

const KEY_NAMES: [(VBKey, &str); 14] = [
    (VBKey::LU, "Up"),
    (VBKey::LD, "Down"),
    (VBKey::LL, "Left"),
    (VBKey::LR, "Right"),
    (VBKey::SEL, "Select"),
    (VBKey::STA, "Start"),
    (VBKey::B, "B"),
    (VBKey::A, "A"),
    (VBKey::LT, "L-Trigger"),
    (VBKey::RT, "R-Trigger"),
    (VBKey::RU, "R-Up"),
    (VBKey::RD, "R-Down"),
    (VBKey::RL, "R-Left"),
    (VBKey::RR, "R-Right"),
];

impl InputWindow {
    pub fn new(
        event_loop: &ActiveEventLoop,
        input_mapper: Arc<RwLock<InputMapper>>,
        proxy: EventLoopProxy<UserEvent>,
    ) -> Self {
        let window = WindowStateBuilder::new(event_loop)
            .with_title("Bind Inputs")
            .with_inner_size(LogicalSize::new(600, 400))
            .build();
        let imgui = ImguiState::new(&window);
        Self {
            window,
            imgui,
            input_mapper,
            now_binding: None,
            proxy,
        }
    }

    fn draw(&mut self) {
        let window = &mut self.window;
        let imgui = &mut self.imgui;
        let mut context = imgui.context.lock().unwrap();

        let now = Instant::now();
        context.io_mut().update_delta_time(now - imgui.last_frame);
        imgui.last_frame = now;

        let frame = match window.surface.get_current_texture() {
            Ok(frame) => frame,
            Err(e) => {
                if !self.window.minimized {
                    eprintln!("dropped frame: {e:?}");
                }
                return;
            }
        };
        imgui
            .platform
            .prepare_frame(context.io_mut(), &window.window)
            .expect("Failed to prepare frame");
        let ui = context.new_frame();

        let mut render_key_bindings = |sim_id: SimId| {
            if let Some(table) = ui.begin_table("controls", 2) {
                let binding_names = {
                    let mapper = self.input_mapper.read().unwrap();
                    mapper.binding_names(&sim_id)
                };
                ui.table_next_row();

                for (key, name) in KEY_NAMES {
                    let binding = binding_names.get(&key).map(|s| s.as_str());
                    ui.table_next_column();
                    let [space, _] = ui.content_region_avail();
                    ui.group(|| {
                        ui.right_align_text(name, space * 0.20);
                        ui.same_line();
                        let label_text = if self.now_binding == Some((sim_id, key)) {
                            "Press any input"
                        } else {
                            binding.unwrap_or("")
                        };
                        let label = format!("{}##{}", label_text, name);
                        if ui.button_with_size(label, [space * 0.60, 0.0]) {
                            self.now_binding = Some((sim_id, key));
                        }
                    });
                    ui.same_line();
                    if ui.button(format!("Clear##{name}")) {
                        let mut mapper = self.input_mapper.write().unwrap();
                        mapper.clear_binding(sim_id, key);
                    }
                }

                table.end();
            }
        };

        if let Some(window) = ui.fullscreen_window() {
            if let Some(tabs) = ui.tab_bar("tabs") {
                if let Some(tab) = ui.tab_item("Player 1") {
                    render_key_bindings(SimId::Player1);
                    tab.end();
                }
                if let Some(tab) = ui.tab_item("Player 2") {
                    render_key_bindings(SimId::Player2);
                    tab.end();
                }
                tabs.end();
            }
            window.end();
        }
        let mut encoder: wgpu::CommandEncoder = window
            .device
            .create_command_encoder(&wgpu::CommandEncoderDescriptor { label: None });

        if imgui.last_cursor != ui.mouse_cursor() {
            imgui.last_cursor = ui.mouse_cursor();
            imgui.platform.prepare_render(ui, &window.window);
        }

        let view = frame
            .texture
            .create_view(&wgpu::TextureViewDescriptor::default());
        let mut rpass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
            label: None,
            color_attachments: &[Some(wgpu::RenderPassColorAttachment {
                view: &view,
                resolve_target: None,
                ops: wgpu::Operations {
                    load: wgpu::LoadOp::Clear(imgui.clear_color),
                    store: wgpu::StoreOp::Store,
                },
            })],
            depth_stencil_attachment: None,
            timestamp_writes: None,
            occlusion_query_set: None,
        });

        // Draw the game
        imgui
            .renderer
            .render(context.render(), &window.queue, &window.device, &mut rpass)
            .expect("Rendering failed");

        drop(rpass);

        window.queue.submit(Some(encoder.finish()));

        frame.present();
    }

    fn try_bind_key(&mut self, event: &KeyEvent) {
        if !event.state.is_pressed() {
            return;
        }
        let Some((sim_id, vb)) = self.now_binding.take() else {
            return;
        };
        let mut mapper = self.input_mapper.write().unwrap();
        mapper.bind_key(sim_id, vb, event.physical_key);
    }
}

impl AppWindow for InputWindow {
    fn id(&self) -> winit::window::WindowId {
        self.window.window.id()
    }

    fn handle_event(&mut self, _: &ActiveEventLoop, event: &Event<UserEvent>) {
        match event {
            Event::WindowEvent { event, .. } => match event {
                WindowEvent::Resized(size) => self.window.handle_resize(size),
                WindowEvent::CloseRequested => {
                    self.proxy.send_event(UserEvent::Close(self.id())).unwrap()
                }
                WindowEvent::KeyboardInput { event, .. } => self.try_bind_key(event),
                WindowEvent::RedrawRequested => self.draw(),
                _ => (),
            },
            Event::AboutToWait => {
                self.window.window.request_redraw();
            }
            _ => (),
        }

        let window = &self.window;
        let imgui = &mut self.imgui;
        let mut context = imgui.context.lock().unwrap();
        imgui
            .platform
            .handle_event(context.io_mut(), &window.window, event);
    }
}