//! Blackjack screen: cards painted from `BlackjackView`.

use eframe::egui::{
    Align2, Color32, CornerRadius, Painter, Pos2, Rect, Sense, Shape, Stroke, StrokeKind, Ui, Vec2,
    pos2, vec2,
};
use zagan_bet::blackjack::is_red_suit;
use zagan_bet::client::view::{BlackjackView, Command};

use crate::{theme, widgets};

const CARD: Vec2 = vec2(92.0, 128.0);

pub fn show(ui: &mut Ui, view: &BlackjackView) -> Option<Command> {
    let mut command = None;
    eframe::egui::CentralPanel::default()
        .frame(eframe::egui::Frame::new().fill(theme::BG))
        .show(ui, |ui| {
            let full = ui.max_rect();
            let sidebar_rect = eframe::egui::Rect::from_min_max(
                eframe::egui::pos2(full.right() - 336.0, full.top()),
                full.right_bottom(),
            );
            let board_rect = eframe::egui::Rect::from_min_max(
                full.min,
                eframe::egui::pos2(sidebar_rect.left(), full.bottom()),
            );
            ui.painter().rect_filled(
                sidebar_rect,
                eframe::egui::CornerRadius::ZERO,
                theme::SURFACE,
            );
            ui.scope_builder(
                eframe::egui::UiBuilder::new()
                    .max_rect(board_rect.shrink2(eframe::egui::vec2(24.0, 24.0)))
                    .layout(eframe::egui::Layout::top_down(eframe::egui::Align::Min)),
                |ui| board(ui, view),
            );
            ui.scope_builder(
                eframe::egui::UiBuilder::new()
                    .max_rect(sidebar_rect.shrink2(eframe::egui::vec2(24.0, 20.0)))
                    .layout(eframe::egui::Layout::top_down(eframe::egui::Align::Min)),
                |ui| {
                    command = sidebar(ui, view);
                },
            );
        });
    command
}

fn live(view: &BlackjackView) -> bool {
    view.status == "player"
}

fn sidebar(ui: &mut Ui, view: &BlackjackView) -> Option<Command> {
    let mut command = None;
    let betting = !live(view) && view.status != "dealing" && view.status != "forfeiting";
    let (content, actions) = widgets::sidebar_layout(ui, 200.0);

    ui.scope_builder(
        eframe::egui::UiBuilder::new()
            .max_rect(content)
            .layout(eframe::egui::Layout::top_down(eframe::egui::Align::Min)),
        |ui| {
            eframe::egui::ScrollArea::vertical()
                .auto_shrink([false, false])
                .show(ui, |ui| {
                    ui.label(
                        eframe::egui::RichText::new("Blackjack")
                            .font(theme::sans(22.0))
                            .color(theme::TEXT),
                    );
                    widgets::note(ui, "Get close to 21 without going over.");

                    ui.add_space(theme::SPACE_5);
                    ui.label(theme::label("Bet"));
                    ui.add_space(theme::SPACE_2);
                    if let Some(delta) = widgets::bet_control(ui, view.bet, betting) {
                        command = Some(Command::AdjustBet(delta));
                    }

                    ui.add_space(theme::SPACE_4);
                    match view.status.as_str() {
                        "player" => widgets::note(ui, "Hit, stand or double."),
                        "done" => {
                            if let Some(hand) = &view.hand {
                                let (text, color) = result_text(&hand.result, hand.winnings);
                                ui.label(
                                    eframe::egui::RichText::new(text)
                                        .font(theme::mono(15.0))
                                        .color(color),
                                );
                            }
                        }
                        "dealing" => widgets::note(ui, "Dealing…"),
                        _ => widgets::note(ui, "Press DEAL to start a hand."),
                    }

                    if let Some(error) = &view.error {
                        ui.add_space(theme::SPACE_3);
                        widgets::error(ui, error);
                    }
                });
        },
    );

    ui.scope_builder(
        eframe::egui::UiBuilder::new()
            .max_rect(actions)
            .layout(eframe::egui::Layout::bottom_up(eframe::egui::Align::Min)),
        |ui| {
            if live(view) {
                if widgets::ghost(ui, "Forfeit hand") {
                    command = Some(Command::Leave);
                }
            } else if widgets::ghost(ui, "Leave table") {
                command = Some(Command::Leave);
            }

            match view.status.as_str() {
                "player" => {
                    if view
                        .hand
                        .as_ref()
                        .is_some_and(|hand| hand.actions.iter().any(|action| action == "double"))
                    {
                        ui.add_space(theme::SPACE_2);
                        if widgets::secondary(ui, "DOUBLE", true, ui.available_width(), 38.0) {
                            command = Some(Command::Double);
                        }
                    }
                    ui.add_space(theme::SPACE_2);
                    if widgets::secondary(ui, "STAND", true, ui.available_width(), 38.0) {
                        command = Some(Command::Stand);
                    }
                    ui.add_space(theme::SPACE_2);
                    if widgets::primary(ui, "HIT", true, ui.available_width(), 44.0) {
                        command = Some(Command::Hit);
                    }
                }
                "dealing" | "forfeiting" => {
                    ui.label(
                        eframe::egui::RichText::new(if view.status == "dealing" {
                            "DEALING…"
                        } else {
                            "FORFEITING…"
                        })
                        .font(theme::mono(12.0))
                        .color(theme::GOLD),
                    );
                }
                _ => {
                    if widgets::primary(ui, "DEAL", true, ui.available_width(), 46.0) {
                        command = Some(Command::Deal);
                    }
                }
            }
        },
    );

    command
}

fn result_text(result: &str, winnings: u64) -> (String, Color32) {
    match result {
        "win" => (
            format!("YOU WIN  {}", theme::money(winnings as i64)),
            theme::WIN,
        ),
        "blackjack" => (
            format!("BLACKJACK  {}", theme::money(winnings as i64)),
            theme::GOLD,
        ),
        "push" => ("PUSH".to_string(), theme::TEXT),
        "bust" => ("BUST".to_string(), theme::LOSS),
        "forfeit" => ("FORFEITED".to_string(), theme::TEXT_DIM),
        _ => ("DEALER WINS".to_string(), theme::LOSS),
    }
}

fn board(ui: &mut Ui, view: &BlackjackView) {
    ui.add_space(theme::SPACE_2);

    let Some(hand) = &view.hand else {
        centered_note(ui, "Place a bet and deal a hand.");
        return;
    };

    let width = ui.available_width();
    let hidden = hand.dealer.iter().any(|card| card == "?");
    hand_header(ui, "Dealer", hand.dealer_total, hidden);
    paint_hand(ui, &hand.dealer, width);
    ui.add_space(theme::SPACE_5);

    let (line, _) = ui.allocate_exact_size(vec2(width, 1.0), Sense::hover());
    ui.painter()
        .rect_filled(line, CornerRadius::ZERO, theme::LINE);
    ui.add_space(theme::SPACE_5);

    hand_header(ui, "You", hand.player_total, false);
    paint_hand(ui, &hand.player, width);

    ui.add_space(theme::SPACE_4);
    ui.label(
        eframe::egui::RichText::new(match view.status.as_str() {
            "player" => "Your move.",
            "dealing" => "Dealing…",
            "done" => "Hand complete.",
            _ => "Place your bet.",
        })
        .font(theme::sans(13.0))
        .color(theme::TEXT_DIM),
    );
}

fn hand_header(ui: &mut Ui, label: &str, total: u8, hidden: bool) {
    ui.horizontal(|ui| {
        ui.label(theme::label(label));
        ui.label(
            eframe::egui::RichText::new(if hidden {
                format!("{total} + ?")
            } else {
                total.to_string()
            })
            .font(theme::mono(15.0))
            .color(if label == "You" {
                theme::TEXT
            } else {
                theme::TEXT_DIM
            }),
        );
    });
    ui.add_space(theme::SPACE_2);
}

fn paint_hand(ui: &mut Ui, cards: &[String], width: f32) {
    if cards.is_empty() {
        ui.add_space(CARD.y);
        return;
    }
    let step = CARD.x * 0.74;
    let hand_width = CARD.x + step * (cards.len() as f32 - 1.0);
    let (rect, _) = ui.allocate_exact_size(vec2(width.max(hand_width), CARD.y), Sense::hover());
    let left = rect.left() + ((rect.width() - hand_width) * 0.5).max(0.0);
    let painter = ui.painter();
    for (index, card) in cards.iter().enumerate() {
        let rect = Rect::from_min_size(pos2(left + step * index as f32, rect.top()), CARD);
        if card == "?" {
            paint_back(painter, rect);
        } else {
            paint_card(painter, rect, card);
        }
    }
}

fn paint_card(painter: &Painter, rect: Rect, card: &str) {
    painter.rect_filled(rect, theme::RADIUS_MD, Color32::from_rgb(0xe8, 0xe4, 0xd8));
    painter.rect_stroke(
        rect,
        theme::RADIUS_MD,
        Stroke::new(1.0, Color32::from_rgb(0x9a, 0x94, 0x86)),
        StrokeKind::Inside,
    );
    let color = if is_red_suit(card) {
        Color32::from_rgb(0xb0, 0x31, 0x3a)
    } else {
        Color32::from_rgb(0x15, 0x1b, 0x21)
    };
    let suit = card.chars().last().unwrap_or('?');
    let rank = &card[..card.len().saturating_sub(suit.len_utf8())];
    painter.text(
        rect.left_top() + vec2(9.0, 6.0),
        Align2::LEFT_TOP,
        rank,
        theme::mono(20.0),
        color,
    );
    painter.text(
        rect.right_bottom() - vec2(9.0, 6.0),
        Align2::RIGHT_BOTTOM,
        rank,
        theme::mono(20.0),
        color,
    );
    paint_suit(painter, rect.center(), rect.width() * 0.55, suit, color);
}

/// Card suits are drawn, not typed: neither embedded font carries the glyphs.
///
/// The circles must overlap the stem, or the shape reads as three dots above a
/// detached bar.
fn paint_suit(painter: &Painter, center: Pos2, size: f32, suit: char, color: Color32) {
    let s = size;
    match suit {
        'H' => {
            painter.circle_filled(center + vec2(-s * 0.22, -s * 0.12), s * 0.31, color);
            painter.circle_filled(center + vec2(s * 0.22, -s * 0.12), s * 0.31, color);
            painter.add(Shape::convex_polygon(
                vec![
                    center + vec2(-s * 0.50, 0.0),
                    center + vec2(s * 0.50, 0.0),
                    center + vec2(0.0, s * 0.56),
                ],
                color,
                Stroke::NONE,
            ));
        }
        'D' => {
            painter.add(Shape::convex_polygon(
                vec![
                    center + vec2(0.0, -s * 0.56),
                    center + vec2(s * 0.42, 0.0),
                    center + vec2(0.0, s * 0.56),
                    center + vec2(-s * 0.42, 0.0),
                ],
                color,
                Stroke::NONE,
            ));
        }
        'S' => {
            painter.circle_filled(center + vec2(-s * 0.24, s * 0.10), s * 0.32, color);
            painter.circle_filled(center + vec2(s * 0.24, s * 0.10), s * 0.32, color);
            painter.add(Shape::convex_polygon(
                vec![
                    center + vec2(-s * 0.50, s * 0.02),
                    center + vec2(s * 0.50, s * 0.02),
                    center + vec2(0.0, -s * 0.56),
                ],
                color,
                Stroke::NONE,
            ));
            painter.add(Shape::convex_polygon(
                vec![
                    center + vec2(-s * 0.11, s * 0.08),
                    center + vec2(s * 0.11, s * 0.08),
                    center + vec2(s * 0.05, s * 0.52),
                    center + vec2(-s * 0.05, s * 0.52),
                ],
                color,
                Stroke::NONE,
            ));
        }
        'C' => {
            painter.circle_filled(center + vec2(0.0, -s * 0.26), s * 0.33, color);
            painter.circle_filled(center + vec2(-s * 0.30, s * 0.10), s * 0.33, color);
            painter.circle_filled(center + vec2(s * 0.30, s * 0.10), s * 0.33, color);
            painter.add(Shape::convex_polygon(
                vec![
                    center + vec2(-s * 0.13, s * 0.08),
                    center + vec2(s * 0.13, s * 0.08),
                    center + vec2(s * 0.05, s * 0.52),
                    center + vec2(-s * 0.05, s * 0.52),
                ],
                color,
                Stroke::NONE,
            ));
        }
        _ => {}
    }
}

fn paint_back(painter: &Painter, rect: Rect) {
    painter.rect_filled(rect, theme::RADIUS_MD, Color32::from_rgb(0x1b, 0x3a, 0x2c));
    painter.rect_stroke(
        rect,
        theme::RADIUS_MD,
        Stroke::new(1.0, Color32::from_rgb(0x2b, 0x5a, 0x43)),
        StrokeKind::Inside,
    );
    let inner = rect.shrink(8.0);
    painter.rect_stroke(
        inner,
        theme::RADIUS_SM,
        Stroke::new(1.0, Color32::from_rgb(0x2b, 0x5a, 0x43)),
        StrokeKind::Inside,
    );
    painter.text(
        rect.center(),
        Align2::CENTER_CENTER,
        "Z",
        theme::mono(30.0),
        Color32::from_rgb(0x4e, 0x8a, 0x68),
    );
}

fn centered_note(ui: &mut Ui, text: &str) {
    let available = ui.available_size();
    ui.add_space(available.y * 0.35);
    ui.vertical_centered(|ui| {
        ui.label(
            eframe::egui::RichText::new(text)
                .font(theme::sans(15.0))
                .color(theme::TEXT_DIM),
        );
    });
}