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

use crate::input::{Command, ShortcutProvider};

use super::AppWindow;

pub struct ShortcutsWindow {
    shortcuts: ShortcutProvider,
    now_binding: Option<Command>,
}

impl ShortcutsWindow {
    pub fn new(shortcuts: ShortcutProvider) -> Self {
        Self {
            shortcuts,
            now_binding: None,
        }
    }

    fn show_shortcuts(&mut self, ui: &mut Ui) {
        ui.horizontal(|ui| {
            if ui.button("Use defaults").clicked() {
                self.shortcuts.reset();
            }
        });
        ui.separator();
        let row_height = ui.spacing().interact_size.y;
        let width = ui.available_width() - 20.0;
        TableBuilder::new(ui)
            .column(Column::exact(width * 0.3))
            .column(Column::exact(width * 0.5))
            .column(Column::exact(width * 0.2))
            .cell_layout(Layout::left_to_right(egui::Align::Center))
            .body(|mut body| {
                for command in Command::all() {
                    body.row(row_height, |mut row| {
                        row.col(|ui| {
                            ui.add_sized(ui.available_size(), Label::new(command.name()));
                        });
                        row.col(|ui| {
                            let button = if self.now_binding == Some(command) {
                                Button::new("Binding...")
                            } else if let Some(shortcut) = self.shortcuts.shortcut_for(command) {
                                Button::new(ui.ctx().format_shortcut(&shortcut))
                            } else {
                                Button::new("")
                            };
                            if ui.add_sized(ui.available_size(), button).clicked() {
                                self.now_binding = Some(command);
                            }
                        });
                        row.col(|ui| {
                            if ui
                                .add_sized(ui.available_size(), Button::new("Clear"))
                                .clicked()
                            {
                                self.shortcuts.unset(command);
                                self.now_binding = None;
                            }
                        });
                    });
                }
            });
        if let Some(command) = self.now_binding {
            if let Some(shortcut) = ui.input_mut(|i| {
                i.events.iter().find_map(|event| match event {
                    Event::Key {
                        key,
                        pressed: true,
                        modifiers,
                        ..
                    } => Some(KeyboardShortcut::new(*modifiers, *key)),
                    _ => None,
                })
            }) {
                self.shortcuts.set(command, shortcut);
                self.now_binding = None;
            }
        }
    }
}

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

    fn initial_viewport(&self) -> ViewportBuilder {
        ViewportBuilder::default()
            .with_title("Keyboard Shortcuts")
            .with_inner_size((400.0, 400.0))
    }

    fn show(&mut self, ctx: &Context) {
        CentralPanel::default().show(ctx, |ui| {
            self.show_shortcuts(ui);
        });
    }
}