//! The desktop shell: header, roulette table, and betting sidebar.
//!
//! Phase 3 is a style spike. The table is painted from a demo `RouletteView`
//! built with the core's own types, but no command is sent yet: Phase 4 wires
//! the transport and replaces the demo state with `ClientCore`.

use std::f32::consts::TAU;

use eframe::egui::{
    self, Align, Button, CentralPanel, Color32, Context, Frame, Key, Layout, Margin, Panel,
    RichText, Sense, Stroke, Ui, Vec2, vec2,
};
use zagan_bet::client::games::roulette::{Cursor, Direction};
use zagan_bet::client::view::{RoulettePhase, RouletteView};
use zagan_bet::roulette::{BetTarget, Bets, Outside, WHEEL, color as wheel_color};
use zagan_bet::version::VERSION;

use crate::{roulette, theme};

const HEADER_HEIGHT: f32 = 64.0;
const SIDEBAR_WIDTH: f32 = 336.0;
const SPIN_SECONDS: f64 = 2.4;
/// Demo winners, cycled: a red, a zero, a red, a black, a black, a black.
const DEMO_TARGETS: [u8; 6] = [17, 0, 32, 26, 8, 11];
const CHIP_SIZES: [u64; 4] = [10, 25, 50, 100];

pub struct ZaganApp {
    demo: Demo,
}

impl ZaganApp {
    pub fn new(cc: &eframe::CreationContext<'_>) -> Self {
        theme::install(&cc.egui_ctx);
        Self { demo: Demo::new() }
    }
}

impl eframe::App for ZaganApp {
    fn ui(&mut self, ui: &mut Ui, _frame: &mut eframe::Frame) {
        self.demo.tick(ui.ctx());
        self.demo.keys(ui.ctx());

        Panel::top("header")
            .exact_size(HEADER_HEIGHT)
            .frame(
                Frame::new()
                    .fill(theme::SURFACE)
                    .inner_margin(Margin::symmetric(theme::SPACE_5 as i8, 0)),
            )
            .show(ui, |ui| header(ui, &self.demo));

        Panel::right("sidebar")
            .exact_size(SIDEBAR_WIDTH)
            .frame(
                Frame::new()
                    .fill(theme::SURFACE)
                    .inner_margin(Margin::symmetric(theme::SPACE_5 as i8, 20)),
            )
            .show(ui, |ui| {
                egui::ScrollArea::vertical()
                    .auto_shrink([false, false])
                    .show(ui, |ui| sidebar(ui, &mut self.demo));
            });

        CentralPanel::default()
            .frame(
                Frame::new()
                    .fill(theme::BG)
                    .inner_margin(Margin::same(theme::SPACE_5 as i8)),
            )
            .show(ui, |ui| table(ui, &mut self.demo));
    }
}

// ---------------------------------------------------------------------------
// Header
// ---------------------------------------------------------------------------

fn header(ui: &mut Ui, demo: &Demo) {
    ui.with_layout(Layout::left_to_right(Align::Center), |ui| {
        let (mark, _) = ui.allocate_exact_size(Vec2::splat(10.0), Sense::hover());
        ui.painter().rect_filled(mark, theme::RADIUS_SM, theme::WIN);
        ui.add_space(theme::SPACE_2);
        ui.label(
            RichText::new("ZAGAN")
                .font(theme::mono(18.0))
                .color(theme::TEXT),
        );
        ui.label(
            RichText::new("BET")
                .font(theme::mono(18.0))
                .color(theme::WIN),
        );
        ui.add_space(theme::SPACE_3);
        pill(ui, &format!("v{VERSION}"), theme::TEXT_FAINT);
        ui.add_space(theme::SPACE_1);
        pill(ui, "PREVIEW", theme::GOLD);
        ui.add_space(theme::SPACE_5);
        connection_pill(ui, demo);

        ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
            stat_block(
                ui,
                150.0,
                "Balance",
                &theme::money(demo.balance),
                theme::mono(20.0),
                theme::TEXT,
                None,
            );
            ui.add_space(theme::SPACE_5);
            stat_block(
                ui,
                190.0,
                "Account",
                demo.user,
                theme::sans(theme::FONT_BODY),
                theme::TEXT,
                Some(demo.account),
            );
        });
    });
}

fn pill(ui: &mut Ui, text: &str, color: Color32) {
    Frame::new()
        .fill(theme::SURFACE_RAISED)
        .corner_radius(theme::RADIUS_SM)
        .inner_margin(Margin::symmetric(theme::SPACE_2 as i8, 3))
        .show(ui, |ui| {
            ui.label(RichText::new(text).font(theme::mono(10.0)).color(color));
        });
}

fn connection_pill(ui: &mut Ui, demo: &Demo) {
    Frame::new()
        .fill(theme::SURFACE_RAISED)
        .corner_radius(theme::RADIUS_SM)
        .inner_margin(Margin::symmetric(theme::SPACE_3 as i8, 5))
        .show(ui, |ui| {
            ui.horizontal(|ui| {
                let (dot, _) = ui.allocate_exact_size(Vec2::splat(8.0), Sense::hover());
                ui.painter().circle_filled(dot.center(), 3.0, theme::WIN);
                ui.label(
                    RichText::new("ONLINE")
                        .font(theme::mono(10.0))
                        .color(theme::WIN),
                );
                ui.label(
                    RichText::new(demo.host)
                        .font(theme::mono(12.0))
                        .color(theme::TEXT_DIM),
                );
                ui.label(
                    RichText::new(format!("{} ms", demo.ping_ms))
                        .font(theme::mono(12.0))
                        .color(theme::TEXT_FAINT),
                );
            });
        });
}

/// A label over a value, right-aligned in a fixed slot so the header's right
/// edge stays put as the numbers change.
fn stat_block(
    ui: &mut Ui,
    width: f32,
    label: &str,
    value: &str,
    value_font: egui::FontId,
    value_color: Color32,
    detail: Option<&str>,
) {
    ui.allocate_ui_with_layout(vec2(width, 44.0), Layout::top_down(Align::Max), |ui| {
        ui.spacing_mut().item_spacing.y = 0.0;
        ui.label(theme::label(label));
        ui.label(RichText::new(value).font(value_font).color(value_color));
        if let Some(detail) = detail {
            ui.label(
                RichText::new(detail)
                    .font(theme::mono(10.0))
                    .color(theme::TEXT_FAINT),
            );
        }
    });
}

// ---------------------------------------------------------------------------
// Sidebar
// ---------------------------------------------------------------------------

fn sidebar(ui: &mut Ui, demo: &mut Demo) {
    ui.label(
        RichText::new("Roulette")
            .font(theme::sans(22.0))
            .color(theme::TEXT),
    );
    ui.label(
        RichText::new("European  ·  single zero")
            .font(theme::sans(12.0))
            .color(theme::TEXT_DIM),
    );

    ui.add_space(theme::SPACE_4);
    let view = demo.view();
    let wheel_size = ui.available_width().min(210.0);
    ui.horizontal(|ui| {
        let pad = ((ui.available_width() - wheel_size) * 0.5).max(0.0);
        ui.add_space(pad);
        roulette::wheel(ui, wheel_size, &view, demo.rotation);
    });
    ui.add_space(theme::SPACE_1);
    result_line(ui, demo);

    ui.add_space(theme::SPACE_3);
    ui.separator();
    ui.add_space(theme::SPACE_3);

    ui.label(theme::label("Chip"));
    ui.add_space(theme::SPACE_2);
    ui.horizontal(|ui| {
        ui.spacing_mut().item_spacing.x = theme::SPACE_2;
        for amount in CHIP_SIZES {
            if chip_button(ui, amount, demo.chip == amount).clicked() {
                demo.chip = amount;
            }
        }
    });

    ui.add_space(theme::SPACE_3);
    ui.label(theme::label("Bets"));
    ui.add_space(theme::SPACE_1);
    if demo.bets.chips.is_empty() {
        ui.label(
            RichText::new("No chips on the felt")
                .font(theme::sans(12.0))
                .color(theme::TEXT_FAINT),
        );
    } else {
        for chip in &demo.bets.chips {
            bet_row(ui, &roulette::target_name(&chip.target), chip.amount);
        }
    }

    ui.add_space(theme::SPACE_3);
    ui.separator();
    ui.add_space(theme::SPACE_2);
    bet_row(ui, "Total", demo.bets.total());

    ui.add_space(theme::SPACE_3);
    let spinning = demo.phase == RoulettePhase::Spinning;
    let spin = Button::new(
        RichText::new("SPIN")
            .font(theme::mono(theme::FONT_MONO))
            .color(theme::BG),
    )
    .fill(if spinning {
        theme::WIN.gamma_multiply(0.45)
    } else {
        theme::WIN
    })
    .corner_radius(theme::RADIUS_MD)
    .min_size(vec2(ui.available_width(), 44.0));
    if ui.add_enabled(!spinning, spin).clicked() {
        demo.start_spin(ui.ctx());
    }

    ui.add_space(theme::SPACE_2);
    let clear = Button::new(
        RichText::new("Clear bets")
            .font(theme::sans(12.0))
            .color(theme::TEXT_DIM),
    )
    .frame(false);
    if ui
        .add_enabled(!demo.bets.is_empty() && !spinning, clear)
        .clicked()
    {
        demo.bets = Bets::default();
    }
}

fn result_line(ui: &mut Ui, demo: &Demo) {
    ui.horizontal(|ui| {
        match (demo.phase, demo.number) {
            (RoulettePhase::Result, Some(number)) => {
                ui.label(theme::label("Result"));
                ui.label(
                    RichText::new(number.to_string())
                        .font(theme::mono(15.0))
                        .color(color_of(number)),
                );
                ui.label(
                    RichText::new(wheel_color(number).to_uppercase())
                        .font(theme::mono(12.0))
                        .color(theme::TEXT_DIM),
                );
            }
            (RoulettePhase::Spinning, _) => {
                ui.label(
                    RichText::new("SPINNING…")
                        .font(theme::mono(12.0))
                        .color(theme::GOLD),
                );
            }
            _ => {
                ui.label(
                    RichText::new("Place your bets")
                        .font(theme::sans(12.0))
                        .color(theme::TEXT_DIM),
                );
            }
        }
        ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
            ui.label(
                RichText::new(format!("{} chips", demo.bets.chips.len()))
                    .font(theme::mono(10.0))
                    .color(theme::TEXT_FAINT),
            );
        });
    });
}

fn bet_row(ui: &mut Ui, name: &str, amount: u64) {
    ui.horizontal(|ui| {
        ui.label(
            RichText::new(name)
                .font(theme::sans(13.0))
                .color(theme::TEXT_DIM),
        );
        ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
            ui.label(
                RichText::new(theme::money(amount as i64))
                    .font(theme::mono(13.0))
                    .color(theme::GOLD),
            );
        });
    });
}

fn chip_button(ui: &mut Ui, amount: u64, selected: bool) -> egui::Response {
    let (rect, response) = ui.allocate_exact_size(Vec2::splat(46.0), Sense::click());
    let center = rect.center();
    let radius = 20.0;
    let painter = ui.painter();
    if selected || response.hovered() {
        painter.circle_stroke(
            center,
            radius + 3.0,
            Stroke::new(if selected { 2.0 } else { 1.0 }, theme::ACCENT),
        );
    }
    roulette::paint_chip(painter, center, radius, amount);
    response
}

fn color_of(number: u8) -> Color32 {
    match wheel_color(number) {
        "red" => theme::ROULETTE_RED,
        "green" => theme::WIN,
        _ => theme::TEXT,
    }
}

// ---------------------------------------------------------------------------
// Table
// ---------------------------------------------------------------------------

fn table(ui: &mut Ui, demo: &mut Demo) {
    ui.horizontal(|ui| {
        ui.label(
            RichText::new("Table 01")
                .font(theme::sans(15.0))
                .color(theme::TEXT),
        );
        ui.label(
            RichText::new("European  ·  single zero")
                .font(theme::sans(12.0))
                .color(theme::TEXT_DIM),
        );
        ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
            ui.label(
                RichText::new("Limits 10 – 500 Kr")
                    .font(theme::mono(12.0))
                    .color(theme::TEXT_FAINT),
            );
        });
    });
    ui.add_space(theme::SPACE_4);

    let view = demo.view();
    let strip_height = 104.0;
    let available = ui.available_size();
    let size = roulette::size_for(vec2(available.x, (available.y - strip_height).max(220.0)));
    let side_pad = ((available.x - size.x) * 0.5).max(0.0);
    let top_pad = ((available.y - size.y - strip_height) * 0.5).max(0.0);
    let chip = demo.chip;
    ui.add_space(top_pad);
    ui.horizontal(|ui| {
        ui.add_space(side_pad);
        if let Some(target) = roulette::felt(ui, size, &view) {
            demo.bets.add(target, chip);
        }
    });

    ui.add_space(theme::SPACE_4);
    ui.horizontal(|ui| {
        ui.label(theme::label("Last"));
        if demo.last.is_empty() {
            ui.label(
                RichText::new("No spins yet")
                    .font(theme::sans(12.0))
                    .color(theme::TEXT_FAINT),
            );
        }
        for number in &demo.last {
            let (dot, _) = ui.allocate_exact_size(Vec2::splat(26.0), Sense::hover());
            roulette::paint_result_dot(ui.painter(), dot.center(), 11.0, *number);
            ui.add_space(theme::SPACE_1);
        }
    });
    ui.add_space(theme::SPACE_2);
    ui.label(
        RichText::new(
            "Click a pocket to place a chip  ·  arrow keys move the cursor  ·  space spins",
        )
        .font(theme::sans(12.0))
        .color(theme::TEXT_FAINT),
    );
}

// ---------------------------------------------------------------------------
// Demo state
// ---------------------------------------------------------------------------

struct Spin {
    started: f64,
    from: f32,
    delta: f32,
    target: u8,
}

struct Demo {
    bets: Bets,
    cursor: Cursor,
    chip: u64,
    phase: RoulettePhase,
    number: Option<u8>,
    rotation: f32,
    spin: Option<Spin>,
    spins: usize,
    last: Vec<u8>,
    balance: i64,
    host: &'static str,
    ping_ms: u32,
    user: &'static str,
    account: &'static str,
}

impl Demo {
    fn new() -> Self {
        let mut bets = Bets::default();
        bets.add(BetTarget::Straight { number: 17 }, 50);
        bets.add(
            BetTarget::Corner {
                numbers: [17, 18, 20, 21],
            },
            25,
        );
        bets.add(BetTarget::Outside { kind: Outside::Red }, 25);

        Self {
            bets,
            // A split with no chip on it, so the fine lattice cursor shows.
            cursor: Cursor::Lattice { x: 18, y: 3 },
            chip: 25,
            phase: RoulettePhase::Placing,
            number: None,
            rotation: 0.0,
            spin: None,
            spins: 0,
            last: Vec::new(),
            balance: 1000,
            host: "127.0.0.1:11525",
            ping_ms: 41,
            user: "alice",
            account: "#4161673306",
        }
    }

    fn view(&self) -> RouletteView {
        RouletteView {
            bet_amount: 10,
            balance: Some(self.balance),
            chip: self.chip,
            bets: self.bets.clone(),
            cursor: self.cursor,
            phase: self.phase,
            number: self.number,
            color: self.number.map(|number| wheel_color(number).to_string()),
            winnings: None,
            error: None,
        }
    }

    fn tick(&mut self, ctx: &Context) {
        let now = ctx.input(|input| input.time);
        let mut finished = None;
        if let Some(spin) = &self.spin {
            let t = (((now - spin.started) / SPIN_SECONDS) as f32).clamp(0.0, 1.0);
            let eased = 1.0 - (1.0 - t).powi(3);
            self.rotation = spin.from + spin.delta * eased;
            if t >= 1.0 {
                finished = Some(spin.target);
            }
            ctx.request_repaint();
        }
        if let Some(number) = finished {
            self.spin = None;
            self.phase = RoulettePhase::Result;
            self.number = Some(number);
            self.last.insert(0, number);
            self.last.truncate(12);
        }
    }

    fn keys(&mut self, ctx: &Context) {
        if self.phase == RoulettePhase::Spinning {
            return;
        }
        let (left, right, up, down) = ctx.input(|input| {
            (
                input.key_pressed(Key::ArrowLeft),
                input.key_pressed(Key::ArrowRight),
                input.key_pressed(Key::ArrowUp),
                input.key_pressed(Key::ArrowDown),
            )
        });
        for (pressed, direction) in [
            (left, Direction::Left),
            (right, Direction::Right),
            (up, Direction::Up),
            (down, Direction::Down),
        ] {
            if pressed {
                self.cursor = self.cursor.moved(direction);
            }
        }
        if ctx.memory(|memory| memory.focused().is_none()) {
            if ctx.input(|input| input.key_pressed(Key::Enter)) {
                if let Some(target) = self.cursor.target() {
                    let chip = self.chip;
                    self.bets.add(target, chip);
                }
            }
            if ctx.input(|input| input.key_pressed(Key::Space)) {
                self.start_spin(ctx);
            }
        }
    }

    fn start_spin(&mut self, ctx: &Context) {
        if self.phase == RoulettePhase::Spinning {
            return;
        }
        let target = DEMO_TARGETS[self.spins % DEMO_TARGETS.len()];
        self.spins += 1;

        let segment = TAU / WHEEL.len() as f32;
        let index = WHEEL
            .iter()
            .position(|number| *number == target)
            .unwrap_or(0) as f32;
        let desired = -index * segment;
        let delta = (desired - self.rotation).rem_euclid(TAU) + 3.0 * TAU;

        self.spin = Some(Spin {
            started: ctx.input(|input| input.time),
            from: self.rotation,
            delta,
            target,
        });
        self.phase = RoulettePhase::Spinning;
        self.number = None;
        ctx.request_repaint();
    }
}