use egui::{
    Button, CentralPanel, Context, Label, Layout, TopBottomPanel, Ui, ViewportBuilder, ViewportId,
};
use egui_extras::{Column, TableBuilder};

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

use super::AppWindow;

pub struct InputWindow {
    mappings: MappingProvider,
    now_binding: Option<(SimId, VBKey)>,
    active_tab: InputTab,
}

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(mappings: MappingProvider) -> Self {
        Self {
            mappings,
            now_binding: None,
            active_tab: InputTab::Player1,
        }
    }

    fn render_key_bindings(&mut self, ui: &mut Ui, sim_id: SimId) {
        let mappings = self.mappings.for_sim(sim_id);
        let binding_names = {
            let mapping = mappings.read().unwrap();
            mapping.keyboard_mapping_names()
        };
        TableBuilder::new(ui)
            .column(Column::remainder())
            .column(Column::remainder())
            .cell_layout(Layout::left_to_right(egui::Align::Center))
            .body(|mut body| {
                for keys in KEY_NAMES.chunks_exact(2) {
                    body.row(20.0, |mut row| {
                        for (key, name) in keys {
                            let binding = binding_names.get(key).map(|s| s.as_str());
                            row.col(|ui| {
                                let size = ui.available_size_before_wrap();
                                let width = size.x;
                                let height = size.y;
                                ui.add_sized((width * 0.2, height), Label::new(*name));
                                let label_text = if self.now_binding == Some((sim_id, *key)) {
                                    "Press any input"
                                } else {
                                    binding.unwrap_or("")
                                };
                                if ui
                                    .add_sized((width * 0.6, height), Button::new(label_text))
                                    .clicked()
                                {
                                    self.now_binding = Some((sim_id, *key))
                                }
                                if ui
                                    .add_sized(ui.available_size(), Button::new("Clear"))
                                    .clicked()
                                {
                                    let mut mapping = mappings.write().unwrap();
                                    mapping.clear_keyboard_mappings(*key);
                                }
                            });
                        }
                    });
                }
            });
    }
}

impl AppWindow for InputWindow {
    fn viewport_id(&self) -> ViewportId {
        ViewportId::from_hash_of("input")
    }

    fn initial_viewport(&self) -> ViewportBuilder {
        ViewportBuilder::default()
            .with_title("Bind Inputs")
            .with_inner_size((600.0, 400.0))
    }

    fn show(&mut self, ctx: &Context) {
        TopBottomPanel::top("options").show(ctx, |ui| {
            ui.horizontal(|ui| {
                ui.selectable_value(&mut self.active_tab, InputTab::Player1, "Player 1");
                ui.selectable_value(&mut self.active_tab, InputTab::Player2, "Player 2");
            });
        });
        CentralPanel::default().show(ctx, |ui| {
            match self.active_tab {
                InputTab::Player1 => self.render_key_bindings(ui, SimId::Player1),
                InputTab::Player2 => self.render_key_bindings(ui, SimId::Player2),
            };
        });
    }

    fn handle_key_event(&mut self, event: &winit::event::KeyEvent) {
        if !event.state.is_pressed() {
            return;
        }
        let Some((sim_id, vb)) = self.now_binding.take() else {
            return;
        };
        let mut mappings = self.mappings.for_sim(sim_id).write().unwrap();
        mappings.add_keyboard_mapping(vb, event.physical_key);
    }
}

#[derive(Clone, Copy, PartialEq, Eq)]
enum InputTab {
    Player1,
    Player2,
}