use eframe::egui;
use egui::{Align2, FontId, Key, Pos2, Rect, vec2};

mod game;
use game::{GameState, Glyph};

const CELL_W: f32 = 14.0;
const CELL_H: f32 = 20.0;

fn main() -> eframe::Result<()> {
    let options = eframe::NativeOptions::default();
    eframe::run_native(
        "Viberogue",
        options,
        Box::new(|_cc| Ok(Box::new(App::new()))),
    )
}

struct App {
    state: GameState,
}

impl App {
    fn new() -> Self {
        Self { state: GameState::new() }
    }
}

impl eframe::App for App {
    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
        ctx.input(|i| {
            if i.key_pressed(Key::ArrowUp)    { self.state.try_move( 0, -1); }
            if i.key_pressed(Key::ArrowDown)  { self.state.try_move( 0,  1); }
            if i.key_pressed(Key::ArrowLeft)  { self.state.try_move(-1,  0); }
            if i.key_pressed(Key::ArrowRight) { self.state.try_move( 1,  0); }
        });

        egui::TopBottomPanel::top("menu_bar").show(ctx, |ui| {
            egui::MenuBar::new().ui(ui, |ui| {
                ui.menu_button("File", |ui| {
                    if ui.button("Exit").clicked() {
                        ctx.send_viewport_cmd(egui::ViewportCommand::Close);
                    }
                });
            });
        });

        egui::CentralPanel::default().show(ctx, |ui| {
            let board = &self.state.board;
            let origin = ui.available_rect_before_wrap().min;
            let painter = ui.painter();

            for y in 0..board.height {
                for x in 0..board.width {
                    let (glyph, _) = board.get(x, y);
                    draw_glyph(painter, origin, x, y, glyph);
                }
            }

            let player_glyph = Glyph::player();
            draw_glyph(
                painter,
                origin,
                self.state.player.x as usize,
                self.state.player.y as usize,
                &player_glyph,
            );
        });

        ctx.request_repaint();
    }
}

fn draw_glyph(painter: &egui::Painter, origin: Pos2, x: usize, y: usize, glyph: &Glyph) {
    let tl = origin + vec2(x as f32 * CELL_W, y as f32 * CELL_H);
    let rect = Rect::from_min_size(tl, vec2(CELL_W, CELL_H));
    let center = rect.center();
    painter.rect_filled(rect, 0.0, glyph.bg);
    painter.text(center, Align2::CENTER_CENTER, glyph.ch, FontId::monospace(CELL_H), glyph.fg);
}