badterm 0.4.1

//! The settings screen (Alt-O): display, sound and calling options, and the
//! interface colors, either a ready-made scheme or each part picked from a
//! grid of the 16 x 8 color combinations, as in QModem and Telix.

use std::path::PathBuf;

use badterm_core::screen::{Cell, Screen};

use super::macro_edit::{EditAction, MacroEditor};
use super::theme::{self, Attr, SCHEMES, Theme};
use super::*;
use crate::crt::{CrtMode, Curvature, Glow, Scanlines};
use crate::input::{Key, Mods};
use badterm_core::modem::FlowControl;

use crate::settings::{Aspect, BellMode, Music, ScaleMode, Settings};

pub const COLS: usize = 80;
pub const ROWS: usize = 25;

/// What the app should do after a key.
#[derive(Debug, PartialEq, Eq)]
pub enum Action {
    None,
    /// The settings changed: apply and save them.
    Changed,
    Close,
    /// Import the theme file at this path.
    Import(PathBuf),
    /// Save the current colors as a theme with this name.
    Export(String),
}

const ITEMS: [&str; 31] = [
    "Phosphor mode",
    "Scanlines",
    "Character cells",
    "Aspect ratio",
    "Monitor bezel",
    "Sound and music",
    "Redial busy BBSes",
    "Check for updates",
    "Keyboard macros...",
    "Color scheme",
    "Edit colors...",
    "Import a theme...",
    "Save as a theme...",
    "Downloads",
    "Captures",
    "Saved screens",
    "Uploads start in",
    "ANSI art starts in",
    "Curvature",
    "Scaling",
    "Splash screen",
    "Bell",
    "Serial port",
    "Speed",
    "Flow control",
    "Init string",
    "Dial command",
    "Glow",
    "Hotkeys...",
    "New entries' font",
    "New entries' screen",
];
const I_CRT: usize = 0;
const I_SCANLINES: usize = 1;
const I_NINE_DOT: usize = 2;
const I_ASPECT: usize = 3;
const I_BEZEL: usize = 4;
const I_MUSIC: usize = 5;
const I_REDIAL: usize = 6;
const I_UPDATES: usize = 7;
const I_MACROS: usize = 8;
const I_SCHEME: usize = 9;
const I_COLORS: usize = 10;
const I_IMPORT: usize = 11;
const I_EXPORT: usize = 12;
/// The folders, in `Folders::NAMES` order.
const I_FOLDER: usize = 13;
const I_CURVATURE: usize = 18;
const I_SCALING: usize = 19;
const I_SPLASH: usize = 20;
const I_BELL: usize = 21;
const I_PORT: usize = 22;
const I_SPEED: usize = 23;
const I_FLOW: usize = 24;
const I_INIT: usize = 25;
const I_DIAL: usize = 26;
const I_GLOW: usize = 27;
const I_HOTKEYS: usize = 28;
const I_ENTRY_FONT: usize = 29;
const I_ENTRY_SCREEN: usize = 30;
/// Items typed in, like the folders: Enter opens a prompt.
const TEXT_ITEMS: [usize; 3] = [I_PORT, I_INIT, I_DIAL];
/// Items that open something rather than having a value.
const ACTIONS: [usize; 5] = [I_MACROS, I_HOTKEYS, I_COLORS, I_IMPORT, I_EXPORT];

/// The tabs, and the items on each.
const TABS: [(&str, &[usize]); 5] = [
    ("Display", &[I_CRT, I_GLOW, I_SCANLINES, I_CURVATURE, I_NINE_DOT, I_ASPECT, I_SCALING, I_BEZEL]),
    ("General", &[I_SPLASH, I_MUSIC, I_BELL, I_REDIAL, I_UPDATES, I_ENTRY_FONT, I_ENTRY_SCREEN, I_MACROS, I_HOTKEYS]),
    ("Folders", &[I_FOLDER, I_FOLDER + 1, I_FOLDER + 2, I_FOLDER + 3, I_FOLDER + 4]),
    ("Colors", &[I_SCHEME, I_COLORS, I_IMPORT, I_EXPORT]),
    ("Modem", &[I_PORT, I_SPEED, I_FLOW, I_INIT, I_DIAL]),
];

fn is_folder(item: usize) -> bool {
    (I_FOLDER..I_FOLDER + 5).contains(&item)
}

/// Rows of the color grid: the eight background colors (bright ones blink
/// on a real VGA, so the interface leaves them out, as Telix did).
const GRID_BGS: u8 = 8;

#[derive(Default)]
enum Mode {
    #[default]
    Menu,
    /// Choosing which part to color.
    Parts,
    /// Choosing its colors on the grid; `before` is restored by Esc.
    Grid {
        before: Attr,
    },
    /// Asking for a theme file to import, or a name to save one as.
    Prompt(usize, TextField),
    /// Editing the keyboard macros: which one, and its text.
    Macros(MacroEditor),
    /// Moving the hotkeys: which action, and whether the next key is its
    /// new one.
    Hotkeys(usize, bool),
    Message(String),
}

#[derive(Default)]
pub struct SettingsUi {
    tab: usize,
    /// The item chosen on each tab (its position there).
    item_on: [usize; 5],
    /// The item chosen (its number), as `item_on` gives it.
    item: usize,
    part: usize,
    mode: Mode,
    /// The user's themes, after the built-in schemes in the list.
    themes: Vec<(String, Theme)>,
    /// The bezels to choose from, by name.
    bezels: Vec<String>,
    /// The folders BadTerm uses when none is chosen.
    folder_defaults: Vec<PathBuf>,
}

impl SettingsUi {
    /// Start at the menu, as the screen opens, with the themes and bezels
    /// there are now.
    pub fn open(&mut self, themes: Vec<(String, Theme)>, bezels: Vec<String>, folder_defaults: Vec<PathBuf>) {
        self.mode = Mode::Menu;
        self.themes = themes;
        self.bezels = bezels;
        self.folder_defaults = folder_defaults;
        self.item = TABS[self.tab].1[self.item_on[self.tab]];
    }

    fn select(&mut self, tab: usize, pos: usize) {
        self.tab = tab;
        self.item_on[tab] = pos;
        self.item = TABS[tab].1[pos];
    }

    /// Show the outcome of an import or export.
    pub fn show_message(&mut self, msg: String) {
        self.mode = Mode::Message(msg);
    }

    pub fn set_themes(&mut self, themes: Vec<(String, Theme)>) {
        self.themes = themes;
    }

    /// The name of the scheme or theme the colors are, if any.
    fn scheme_name<'a>(&'a self, colors: &Theme) -> Option<&'a str> {
        colors.scheme_name().or_else(|| self.themes.iter().find(|(_, t)| t == colors).map(|(n, _)| n.as_str()))
    }

    pub fn handle_key(&mut self, key: Key, mods: Mods, settings: &mut Settings) -> Action {
        match &mut self.mode {
            Mode::Menu => self.menu_key(key, mods, settings),
            Mode::Message(_) => {
                self.mode = Mode::Menu;
                Action::None
            }
            Mode::Macros(editor) => match editor.handle_key(key, mods, &mut settings.macros) {
                EditAction::None => Action::None,
                EditAction::Changed => Action::Changed,
                EditAction::Close => {
                    self.mode = Mode::Menu;
                    Action::None
                }
            },
            Mode::Hotkeys(sel, waiting) => {
                let n = crate::hotkeys::ALL.len();
                let half = n.div_ceil(2);
                let usual = crate::hotkeys::ALL[*sel].0;
                if *waiting {
                    *waiting = false;
                    let to = match key {
                        Key::Enter => Some("Enter".to_string()),
                        Key::Char(c) if c.is_ascii_alphabetic() => Some(c.to_ascii_uppercase().to_string()),
                        _ => None,
                    };
                    if let Some(to) = to {
                        crate::hotkeys::assign(&mut settings.hotkeys, usual, &to);
                        return Action::Changed;
                    }
                    return Action::None;
                }
                match key {
                    Key::Escape => self.mode = Mode::Menu,
                    Key::Up => *sel = (*sel + n - 1) % n,
                    Key::Down => *sel = (*sel + 1) % n,
                    Key::Left | Key::Right => *sel = (*sel + half) % (half * 2),
                    Key::Enter | Key::Char(' ') => *waiting = true,
                    Key::Delete | Key::Backspace => {
                        crate::hotkeys::assign(&mut settings.hotkeys, usual, usual);
                        return Action::Changed;
                    }
                    _ => {}
                }
                if let Mode::Hotkeys(sel, _) = &mut self.mode {
                    *sel = (*sel).min(n - 1);
                }
                Action::None
            }
            Mode::Prompt(item, field) => match key {
                Key::Escape => {
                    self.mode = Mode::Menu;
                    Action::None
                }
                Key::Enter => {
                    let value = field.value.trim().to_string();
                    let item = *item;
                    self.mode = Mode::Menu;
                    match item {
                        // An empty folder is the default one.
                        _ if is_folder(item) => self.set_folder(item, &value, settings),
                        I_PORT => {
                            settings.modem.device = value;
                            Action::Changed
                        }
                        I_INIT => {
                            settings.modem.init = value;
                            Action::Changed
                        }
                        I_DIAL => {
                            settings.modem.dial = value;
                            Action::Changed
                        }
                        _ if value.is_empty() => Action::None,
                        I_IMPORT => Action::Import(PathBuf::from(value)),
                        _ => Action::Export(value),
                    }
                }
                _ => {
                    field.handle_key(key, mods);
                    Action::None
                }
            },
            Mode::Parts => {
                let n = Theme::NAMES.len();
                match key {
                    Key::Up => self.part = (self.part + n - 1) % n,
                    Key::Down => self.part = (self.part + 1) % n,
                    Key::Home => self.part = 0,
                    Key::End => self.part = n - 1,
                    Key::Enter | Key::Right => self.mode = Mode::Grid { before: settings.colors.get(self.part) },
                    Key::Escape | Key::Left => self.mode = Mode::Menu,
                    _ => {}
                }
                Action::None
            }
            Mode::Grid { before } => {
                let before = *before;
                let mut a = settings.colors.get(self.part);
                match key {
                    Key::Left => a.fg = (a.fg + 15) % 16,
                    Key::Right => a.fg = (a.fg + 1) % 16,
                    Key::Up => a.bg = (a.bg + GRID_BGS - 1) % GRID_BGS,
                    Key::Down => a.bg = (a.bg + 1) % GRID_BGS,
                    Key::Enter => {
                        self.mode = Mode::Parts;
                        return Action::None;
                    }
                    Key::Escape => {
                        a = before;
                        self.mode = Mode::Parts;
                    }
                    _ => return Action::None,
                }
                settings.colors.set(self.part, a);
                theme::set_current(settings.colors);
                Action::Changed
            }
        }
    }

    /// Choose a folder: a path, or empty for the default. It is created
    /// if it does not exist.
    fn set_folder(&mut self, item: usize, value: &str, settings: &mut Settings) -> Action {
        let i = item - I_FOLDER;
        if value.is_empty() {
            settings.folders.set(i, None);
            return Action::Changed;
        }
        let path = expand_home(value);
        match std::fs::create_dir_all(&path) {
            Ok(()) => {
                settings.folders.set(i, Some(path));
                Action::Changed
            }
            Err(e) => {
                self.mode = Mode::Message(format!("Could not use {}: {e}", path.display()));
                Action::None
            }
        }
    }

    /// The folder an item shows: the chosen one, or the default.
    fn folder(&self, item: usize, settings: &Settings) -> (PathBuf, bool) {
        let i = item - I_FOLDER;
        match settings.folders.get(i) {
            Some(p) => (p.clone(), true),
            None => (self.folder_defaults.get(i).cloned().unwrap_or_default(), false),
        }
    }

    fn menu_key(&mut self, key: Key, mods: Mods, settings: &mut Settings) -> Action {
        let items = TABS[self.tab].1;
        let n = items.len();
        let pos = self.item_on[self.tab];
        let back = key == Key::Left;
        match key {
            Key::Up => self.select(self.tab, (pos + n - 1) % n),
            Key::Down => self.select(self.tab, (pos + 1) % n),
            Key::Home => self.select(self.tab, 0),
            Key::End => self.select(self.tab, n - 1),
            // Tabs: Tab and Shift-Tab, or PgUp and PgDn.
            Key::Tab | Key::PageDown | Key::PageUp => {
                let t = TABS.len();
                let tab = if key == Key::PageUp || mods.shift { (self.tab + t - 1) % t } else { (self.tab + 1) % t };
                self.select(tab, self.item_on[tab]);
            }
            Key::Escape => return Action::Close,
            Key::Enter if is_folder(self.item) => {
                let (path, _) = self.folder(self.item, settings);
                self.mode = Mode::Prompt(self.item, TextField::new(&path.to_string_lossy(), 1000));
            }
            Key::Delete | Key::Backspace if is_folder(self.item) => {
                settings.folders.set(self.item - I_FOLDER, None);
                return Action::Changed;
            }
            _ if is_folder(self.item) => {}
            Key::Enter if TEXT_ITEMS.contains(&self.item) => {
                let m = &settings.modem;
                let value = match self.item {
                    I_PORT => m.device.clone(),
                    I_INIT => m.init.clone(),
                    _ => m.dial.clone(),
                };
                self.mode = Mode::Prompt(self.item, TextField::new(&value, 200));
            }
            // The serial port also steps through the ports the system lists.
            Key::Left | Key::Right if self.item == I_PORT => {
                let ports = badterm_core::modem::ports();
                if !ports.is_empty() {
                    let i = ports.iter().position(|p| *p == settings.modem.device);
                    let n = ports.len();
                    let next = match (i, back) {
                        (None, _) => 0,
                        (Some(i), true) => (i + n - 1) % n,
                        (Some(i), false) => (i + 1) % n,
                    };
                    settings.modem.device = ports[next].clone();
                    return Action::Changed;
                }
            }
            _ if TEXT_ITEMS.contains(&self.item) => {}
            Key::Enter if self.item == I_COLORS => self.mode = Mode::Parts,
            Key::Enter if self.item == I_MACROS => {
                self.mode = Mode::Macros(MacroEditor::new(&settings.macros));
            }
            Key::Enter if self.item == I_HOTKEYS => self.mode = Mode::Hotkeys(0, false),
            Key::Enter if self.item == I_IMPORT => self.mode = Mode::Prompt(I_IMPORT, TextField::new("", 400)),
            Key::Enter if self.item == I_EXPORT => {
                let name = self.scheme_name(&settings.colors).unwrap_or("My colors").to_string();
                let name = if settings.colors.scheme_name().is_some() { format!("My {name}") } else { name };
                self.mode = Mode::Prompt(I_EXPORT, TextField::new(&name, 60));
            }
            _ if ACTIONS.contains(&self.item) => {}
            Key::Left | Key::Right | Key::Char(' ') | Key::Enter => {
                self.change(back, settings);
                return Action::Changed;
            }
            _ => {}
        }
        Action::None
    }

    /// Step the current item to its next (or, `back`, previous) value.
    fn change(&self, back: bool, s: &mut Settings) {
        let step = |i: usize, n: usize| if back { (i + n - 1) % n } else { (i + 1) % n };
        match self.item {
            I_CRT => {
                let all = CrtMode::ALL;
                let i = all.iter().position(|&m| m == s.crt).unwrap_or(0);
                s.crt = all[step(i, all.len())];
            }
            I_GLOW => {
                let all = Glow::ALL;
                let i = all.iter().position(|&g| g == s.glow).unwrap_or(0);
                s.glow = all[step(i, all.len())];
            }
            I_SCANLINES => {
                let all = Scanlines::ALL;
                let i = all.iter().position(|&m| m == s.scanlines).unwrap_or(0);
                s.scanlines = all[step(i, all.len())];
            }
            I_CURVATURE => {
                let all = Curvature::ALL;
                let i = all.iter().position(|&m| m == s.curvature).unwrap_or(0);
                s.curvature = all[step(i, all.len())];
            }
            I_NINE_DOT => s.nine_dot = !s.nine_dot,
            I_ASPECT => {
                let all = Aspect::ALL;
                let i = all.iter().position(|&a| a == s.aspect).unwrap_or(0);
                s.aspect = all[step(i, all.len())];
            }
            I_SCALING => {
                let all = ScaleMode::ALL;
                let i = all.iter().position(|&m| m == s.scaling).unwrap_or(0);
                s.scaling = all[step(i, all.len())];
            }
            I_BEZEL => {
                // "None", then each bezel.
                let i = self.bezels.iter().position(|b| *b == s.bezel).map_or(0, |i| i + 1);
                let next = step(i, self.bezels.len() + 1);
                s.bezel = if next == 0 { String::new() } else { self.bezels[next - 1].clone() };
            }
            I_MUSIC => {
                let all = [Music::Off, Music::On, Music::All];
                let i = all.iter().position(|&m| m == s.music).unwrap_or(0);
                s.music = all[step(i, all.len())];
            }
            I_BELL => {
                let all = BellMode::ALL;
                let i = all.iter().position(|&m| m == s.bell).unwrap_or(0);
                s.bell = all[step(i, all.len())];
            }
            I_SPEED => {
                let all = badterm_core::modem::SPEEDS;
                let i = all.iter().position(|&v| v == s.modem.speed).unwrap_or(all.len() - 2);
                s.modem.speed = all[step(i, all.len())];
            }
            I_FLOW => {
                let all = FlowControl::ALL;
                let i = all.iter().position(|&f| f == s.modem.flow).unwrap_or(0);
                s.modem.flow = all[step(i, all.len())];
            }
            I_ENTRY_FONT => {
                let all = crate::ui::dialer::fonts();
                let i = all.iter().position(|&f| f == s.entry_font).unwrap_or(0);
                s.entry_font = all[step(i, all.len())];
            }
            I_ENTRY_SCREEN => {
                let all = badterm_core::dialer::SCREEN_MODES;
                let i = all.iter().position(|&m| m == s.entry_screen).unwrap_or(0);
                s.entry_screen = all[step(i, all.len())];
            }
            I_REDIAL => s.redial = !s.redial,
            I_SPLASH => s.splash = !s.splash,
            I_UPDATES => s.check_updates = !s.check_updates,
            I_SCHEME => {
                // The built-in schemes, then the user's themes; from custom
                // colors, the first step goes to the first scheme.
                let all: Vec<Theme> =
                    SCHEMES.iter().map(|(_, t)| *t).chain(self.themes.iter().map(|(_, t)| *t)).collect();
                s.colors = match all.iter().position(|t| *t == s.colors) {
                    Some(i) => all[step(i, all.len())],
                    None => all[0],
                };
                theme::set_current(s.colors);
            }
            _ => {}
        }
    }

    /// Draw the screen; returns the text cursor, if a prompt shows one.
    /// `own_crt`: the connected BBS's own phosphor mode; `update`: a newer
    /// version, if a check found one.
    pub fn draw(
        &self,
        s: &mut Screen,
        settings: &Settings,
        own_crt: Option<&str>,
        update: Option<&str>,
    ) -> Option<(usize, usize)> {
        let t = theme::current();
        s.fill_rect(0, 0, COLS, ROWS, Cell::new(b' ', t.help.fg(), t.help.bg()));
        let title = format!(" BadTerm {} \u{2502} Settings", env!("CARGO_PKG_VERSION"));
        text(s, 0, 0, COLS, &title, t.title_bar.fg(), t.title_bar.bg());
        let mut cursor = None;
        match &self.mode {
            Mode::Menu => self.draw_menu(s, settings, own_crt, update),
            Mode::Parts | Mode::Grid { .. } => self.draw_colors(s, settings),
            Mode::Prompt(item, field) => {
                self.draw_menu(s, settings, own_crt, update);
                let (title, hint) = match *item {
                    I_IMPORT => ("Import a Theme", "A BadTerm theme file (.toml), from anywhere"),
                    I_PORT => ("Serial Port", "/dev/ttyUSB0, /dev/cu.usbmodem1101, COM3..."),
                    I_INIT => ("Init String", "Sent before dialing, e.g. ATZ or AT&F E1 V1 X4"),
                    I_DIAL => ("Dial Command", "Before the number: ATDT for tone, ATDP for pulse"),
                    i if is_folder(i) => ("Folder", "Empty for the default"),
                    _ => ("Save as a Theme", "A name for these colors, to share or keep"),
                };
                let (x, y, w) = (6, 9, 68);
                frame(s, x, y, w, 6, title, t.window.fg(), t.window.bg());
                label(s, x + 2, y + 1, hint, t.window_text.fg(), t.window_text.bg());
                cursor = Some(field.draw(s, x + 2, y + 3, w - 4, false, t.input.fg(), t.input.bg()));
            }
            Mode::Macros(editor) => cursor = Some(editor.draw(s, "Keyboard Macros", &settings.macros, None)),
            Mode::Hotkeys(sel, waiting) => self.draw_hotkeys(s, *sel, *waiting),
            Mode::Message(msg) => {
                self.draw_menu(s, settings, own_crt, update);
                let lines = wrap(msg, 60);
                let w = lines.iter().map(|l| l.chars().count()).max().unwrap_or(0) + 6;
                let (x, y) = ((COLS - w) / 2, 10);
                frame(s, x, y, w, lines.len() + 4, "Themes", t.window.fg(), t.window.bg());
                for (i, l) in lines.iter().enumerate() {
                    label(s, x + 3, y + 2 + i, l, t.window.fg(), t.window.bg());
                }
            }
        }
        let help = match self.mode {
            Mode::Menu => "Tab Next tab   \u{2191}\u{2193} Choose   \u{2190}\u{2192} Change   Enter Open   Esc Done",
            Mode::Parts => "\u{2191}\u{2193} Choose a part   Enter Pick its colors   Esc Back",
            Mode::Grid { .. } => "\u{2190}\u{2192} Foreground   \u{2191}\u{2193} Background   Enter Keep   Esc Undo",
            Mode::Prompt(..) => "Enter OK   Esc Cancel",
            Mode::Macros(..) => "\u{2191}\u{2193} Choose   Type to change (saved as you go)   Esc Done",
            Mode::Hotkeys(_, true) => "Press a letter, or Enter, for it   Any other key keeps it",
            Mode::Hotkeys(..) => {
                "\u{2191}\u{2193}\u{2190}\u{2192} Choose   Enter Change   Del Its usual key   Esc Done"
            }
            Mode::Message(_) => "Press any key",
        };
        text(s, 1, 24, COLS - 2, help, t.help.fg(), t.help.bg());
        cursor
    }

    fn draw_hotkeys(&self, s: &mut Screen, sel: usize, waiting: bool) {
        let t = theme::current();
        let (x, y, w) = (3, 2, COLS - 6);
        frame(s, x, y, w, 19, "Hotkeys", t.window.fg(), t.window.bg());
        let half = crate::hotkeys::ALL.len().div_ceil(2);
        for (i, (usual, what)) in crate::hotkeys::ALL.iter().enumerate() {
            let (cx, yy) = (x + 2 + (i / half) * 37, y + 2 + i % half);
            let focused = i == sel;
            let key = if focused && waiting { "?".to_string() } else { crate::hotkeys::label(usual) };
            let a = if focused { t.input } else { t.keys };
            text(s, cx, yy, 10, &format!(" {key:<9}"), a.fg(), a.bg());
            label(s, cx + 11, yy, what, t.window_text.fg(), t.window_text.bg());
        }
        let moved = crate::hotkeys::ALL.iter().filter(|(k, _)| crate::hotkeys::key(k) != *k).count();
        let note = match moved {
            0 => "Each is where it usually is.".to_string(),
            1 => "One is moved from its usual key; Del puts it back.".to_string(),
            n => format!("{n} are moved from their usual keys; Del puts one back."),
        };
        label(s, x + 2, y + 3 + half, &note, t.note.fg(), t.window.bg());
        label(s, x + 2, y + 4 + half, "Macros stay on 1 to 0.", t.note.fg(), t.window.bg());
    }

    fn draw_menu(&self, s: &mut Screen, settings: &Settings, own_crt: Option<&str>, update: Option<&str>) {
        let t = theme::current();
        let (w, h) = (72, 16);
        let (x, y) = ((COLS - w) / 2, 3);
        frame(s, x, y, w, h, "Settings", t.window.fg(), t.window.bg());
        // The tabs, along the top as in NetRunner.
        let mut tx = x + 2;
        for (i, (name, _)) in TABS.iter().enumerate() {
            let a = if i == self.tab { t.selected } else { t.window_text };
            let label_text = format!(" {name} ");
            text(s, tx, y + 1, label_text.len(), &label_text, a.fg(), a.bg());
            tx += label_text.len() + 1;
        }
        divider(s, x, y + 2, w, t.window.fg(), t.window.bg());
        for (pos, &item) in TABS[self.tab].1.iter().enumerate() {
            let yy = y + 4 + pos;
            let focused = item == self.item;
            let name_attr = if focused { t.keys } else { t.field_name };
            text(s, x + 2, yy, 20, &format!("{:>19}", ITEMS[item]), name_attr.fg(), name_attr.bg());
            let a = if focused { t.input } else { t.field_value };
            if is_folder(item) {
                let (path, chosen) = self.folder(item, settings);
                let shown = path.to_string_lossy().into_owned();
                let room = w - 26;
                let shown = if shown.chars().count() > room {
                    format!("\u{2026}{}", shown.chars().skip(shown.chars().count() + 1 - room).collect::<String>())
                } else {
                    shown
                };
                text(s, x + 23, yy, room, &shown, a.fg(), a.bg());
                if !chosen {
                    let d = t.note;
                    label(s, x + w - 11, yy, "(default)", d.fg(), if focused { a.bg() } else { d.bg() });
                }
                continue;
            }
            if ACTIONS.contains(&item) {
                continue;
            }
            let v = format!("\u{25C4} {:<22} \u{25BA}", self.value(item, settings));
            text(s, x + 23, yy, 26, &v, a.fg(), a.bg());
        }
        let note = match (self.item, own_crt, update) {
            (I_UPDATES, _, Some(v)) => format!("BadTerm {v} is out: {}", badterm_core::update::DOWNLOAD_PAGE),
            (I_UPDATES, _, None) => "When on, asks git.badcluster.dev for the newest version".to_string(),
            (I_ENTRY_FONT | I_ENTRY_SCREEN, ..) => "For entries added from now on; each can change its own".to_string(),
            (I_HOTKEYS, ..) => format!("Which {HOTKEY} key does what"),
            (I_BELL, ..) => "Ctrl-G from the BBS; an entry in the directory can have its own".to_string(),
            (I_PORT, ..) => "Enter to type it; \u{2190}\u{2192} step through the ports found".to_string(),
            (I_SPEED, ..) => "Between the computer and the modem, not the call's speed".to_string(),
            (I_FLOW, ..) => "RTS/CTS for almost every modem".to_string(),
            (I_INIT | I_DIAL, ..) => "For directory entries whose protocol is Modem".to_string(),
            (I_CRT, Some(own), _) => format!("This BBS has its own phosphor mode: {own}"),
            (I_GLOW, ..) => "How much bright text glows onto the dark around it".to_string(),
            (I_SCANLINES, ..) => "In phosphor mode; they show from twice the size up".to_string(),
            (I_CURVATURE, ..) => "How much phosphor mode's glass bulges".to_string(),
            (I_ASPECT, ..) => "The text area's shape; Alt-A cycles through them".to_string(),
            (I_SCALING, ..) => match settings.scaling {
                ScaleMode::Auto => "Whole numbers in a window, fit when full screen".to_string(),
                ScaleMode::Integer => "Every pixel exact; a border fills the rest".to_string(),
                ScaleMode::Fit => "As large as fits, keeping the shape".to_string(),
                ScaleMode::Stretch => "Fills the window; the shape follows it".to_string(),
            },
            (I_BEZEL, ..) => "Your own: a PNG with a see-through screen, in bezels/".to_string(),
            (I_SCHEME | I_IMPORT | I_EXPORT, ..) => {
                "Themes are kept in the themes folder (badterm --paths)".to_string()
            }
            (i, ..) if is_folder(i) => "Enter to change (created if need be); Del for the default".to_string(),
            _ => String::new(),
        };
        label(s, x + 2, y + h - 2, &note, t.note.fg(), t.note.bg());
    }

    /// An item's current value, as shown.
    fn value(&self, item: usize, s: &Settings) -> String {
        match item {
            I_CRT => s.crt.name().to_string(),
            I_GLOW => s.glow.name().into(),
            I_SCANLINES => s.scanlines.name().into(),
            I_CURVATURE => s.curvature.name().into(),
            I_NINE_DOT => if s.nine_dot { "9 dots, as on a VGA" } else { "8 dots" }.into(),
            I_ASPECT => s.aspect.name().into(),
            I_SCALING => s.scaling.name().into(),
            I_BEZEL if s.bezel.is_empty() => "None".into(),
            I_BEZEL => s.bezel.clone(),
            I_MUSIC => match s.music {
                Music::Off => "Off",
                Music::On => "On",
                Music::All => "On, including ESC [ M",
            }
            .into(),
            I_REDIAL => if s.redial { "On" } else { "Off" }.into(),
            I_BELL => s.bell.name().into(),
            I_PORT if s.modem.device.is_empty() => "None chosen".into(),
            I_PORT => s.modem.device.clone(),
            I_SPEED => format!("{} bps", s.modem.speed),
            I_FLOW => s.modem.flow.name().into(),
            I_INIT => s.modem.init.clone(),
            I_DIAL => s.modem.dial.clone(),
            I_SPLASH => if s.splash { "On, 2 seconds" } else { "Off" }.into(),
            I_UPDATES => if s.check_updates { "On, at each start" } else { "Off" }.into(),
            I_SCHEME => self.scheme_name(&s.colors).unwrap_or("Custom").into(),
            I_ENTRY_FONT => crate::ui::dialer::font_name(s.entry_font).into(),
            I_ENTRY_SCREEN => format!("{}x{}", s.entry_screen.0, s.entry_screen.1),
            _ => String::new(),
        }
    }

    fn draw_colors(&self, s: &mut Screen, settings: &Settings) {
        let t = theme::current();
        let picking = matches!(self.mode, Mode::Grid { .. });

        // The parts, each named in its own colors.
        let (lx, ly, lw) = (1, 2, 36);
        frame(s, lx, ly, lw, Theme::NAMES.len() + 2, "Parts", t.window.fg(), t.window.bg());
        for (i, name) in Theme::NAMES.iter().enumerate() {
            let a = settings.colors.get(i);
            let yy = ly + 1 + i;
            let mark = if i == self.part { '\u{25BA}' } else { ' ' };
            label(s, lx + 1, yy, &mark.to_string(), t.keys.fg(), t.window.bg());
            text(s, lx + 3, yy, 24, &format!(" {name}"), a.fg(), a.bg());
            label(s, lx + 28, yy, &format!("{:>2}/{}", a.fg, a.bg), t.window_text.fg(), t.window_text.bg());
        }

        // The grid: foreground across, background down.
        let (gx, gy) = (40, 2);
        let title = if picking { "Pick colors" } else { "Colors" };
        frame(s, gx, gy, 16 * 2 + 4, GRID_BGS as usize + 2, title, t.window.fg(), t.window.bg());
        let chosen = settings.colors.get(self.part);
        for bg in 0..GRID_BGS {
            for fg in 0..16u8 {
                let a = Attr::new(fg, bg);
                let glyph = if a == chosen { "\u{25C4}\u{25BA}" } else { "Aa" };
                label(s, gx + 2 + fg as usize * 2, gy + 1 + bg as usize, glyph, a.fg(), a.bg());
            }
        }

        // A sample window in the colors as they are now.
        let (px, py, pw) = (40, 13, 36);
        frame(s, px, py, pw, 9, "Sample", t.window.fg(), t.window.bg());
        label(s, px + 2, py + 1, "Window text", t.window_text.fg(), t.window_text.bg());
        text(s, px + 2, py + 3, 10, "     Name", t.field_name.fg(), t.field_name.bg());
        text(s, px + 13, py + 3, 18, "The Vortex BBS", t.field_value.fg(), t.field_value.bg());
        text(s, px + 2, py + 4, 10, "  Address", t.keys.fg(), t.keys.bg());
        text(s, px + 13, py + 4, 18, "vortexbbs.com_", t.input.fg(), t.input.bg());
        label(s, px + 2, py + 5, "(a note)", t.note.fg(), t.note.bg());
        label(s, px + 2, py + 6, "Address is required", t.error.fg(), t.error.bg());
        label(s, px + 2, py + 7, "Enter save   Esc cancel", t.keys.fg(), t.keys.bg());
        let name = self.scheme_name(&settings.colors).unwrap_or("custom");
        label(s, 1, 23, &format!(" Scheme: {name}"), t.info.fg(), t.info.bg());
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    impl SettingsUi {
        fn handle_key_test(&mut self, key: Key, s: &mut Settings) -> Action {
            self.handle_key(key, Mods::default(), s)
        }
    }

    #[test]
    fn tabs_and_folders() {
        let mut ui = SettingsUi::default();
        let dir = std::env::temp_dir().join(format!("badterm-folders-{}", std::process::id()));
        ui.open(Vec::new(), Vec::new(), vec![PathBuf::from("/default"); 5]);
        let mut s = Settings::default();
        // Shift-Tab goes back, round to the last tab.
        ui.handle_key(Key::Tab, Mods { shift: true, ..Mods::default() }, &mut s);
        assert_eq!((ui.tab, ui.item), (4, I_PORT));
        // The modem: a speed to step through, a port to type.
        ui.handle_key_test(Key::Down, &mut s);
        assert_eq!(ui.handle_key_test(Key::Right, &mut s), Action::Changed);
        assert_eq!(s.modem.speed, 230_400);
        ui.handle_key_test(Key::Up, &mut s);
        ui.handle_key_test(Key::Enter, &mut s);
        let Mode::Prompt(_, field) = &mut ui.mode else { panic!() };
        *field = TextField::new("/dev/ttyS0", 200);
        assert_eq!(ui.handle_key_test(Key::Enter, &mut s), Action::Changed);
        assert_eq!(s.modem.device, "/dev/ttyS0");
        ui.handle_key_test(Key::PageUp, &mut s);
        assert_eq!((ui.tab, ui.item), (3, I_SCHEME));
        ui.handle_key_test(Key::PageUp, &mut s);
        assert_eq!((ui.tab, ui.item), (2, I_FOLDER));
        // Each tab remembers its place.
        ui.handle_key_test(Key::Down, &mut s);
        ui.handle_key_test(Key::Tab, &mut s);
        ui.handle_key_test(Key::PageUp, &mut s);
        assert_eq!(ui.item, I_FOLDER + 1);
        // Choose a folder (made if missing), then go back to the default.
        ui.handle_key_test(Key::Enter, &mut s);
        let Mode::Prompt(_, field) = &mut ui.mode else { panic!() };
        *field = TextField::new(&dir.to_string_lossy(), 1000);
        assert_eq!(ui.handle_key_test(Key::Enter, &mut s), Action::Changed);
        assert_eq!(s.folders.captures.as_deref(), Some(dir.as_path()));
        assert!(dir.is_dir());
        let mut screen = Screen::new(COLS, ROWS, 0);
        ui.draw(&mut screen, &s, None, None);
        assert_eq!(ui.handle_key_test(Key::Delete, &mut s), Action::Changed);
        assert_eq!(s.folders.captures, None);
        ui.draw(&mut screen, &s, None, None);
        let rows: Vec<String> = (0..ROWS).map(|y| Screen::row_text(screen.row(y))).collect();
        assert!(rows.iter().any(|r| r.contains("Captures") && r.contains("(default)")), "{rows:#?}");
        let _ = std::fs::remove_dir_all(&dir);
    }

    #[test]
    fn macro_editor() {
        let mut ui = SettingsUi { item: I_MACROS, ..SettingsUi::default() };
        let mut s = Settings::default();
        ui.handle_key_test(Key::Enter, &mut s);
        ui.handle_key_test(Key::Down, &mut s);
        for c in "hi^M".chars() {
            assert_eq!(ui.handle_key_test(Key::Char(c), &mut s), Action::Changed);
        }
        assert_eq!(s.macros[1], "hi^M");
        let mut screen = Screen::new(COLS, ROWS, 0);
        assert!(ui.draw(&mut screen, &s, None, None).is_some());
        // Back to the first, then out.
        ui.handle_key_test(Key::Up, &mut s);
        ui.handle_key_test(Key::Escape, &mut s);
        assert_eq!(ui.handle_key_test(Key::Escape, &mut s), Action::Close);
    }

    #[test]
    fn themes_bezels_import_and_export() {
        let mut ui = SettingsUi::default();
        let mut mine = Theme::default();
        mine.window.bg = 2;
        ui.open(vec![("Mine".into(), mine)], vec!["Beige".into(), "Platinum".into()], vec![PathBuf::from("/dl"); 5]);
        let mut s = Settings::default();
        ui.item = I_BEZEL;
        ui.handle_key_test(Key::Right, &mut s);
        assert_eq!(s.bezel, "Beige");
        ui.handle_key_test(Key::Left, &mut s);
        ui.handle_key_test(Key::Left, &mut s);
        assert_eq!(s.bezel, "Platinum");
        // The user's theme comes after the built-in schemes.
        ui.item = I_SCHEME;
        ui.handle_key_test(Key::Left, &mut s);
        assert_eq!(s.colors, mine);
        assert_eq!(ui.value(I_SCHEME, &s), "Mine");
        // Export offers the theme's name; import takes a path.
        ui.item = I_EXPORT;
        ui.handle_key_test(Key::Enter, &mut s);
        assert_eq!(ui.handle_key_test(Key::Enter, &mut s), Action::Export("Mine".into()));
        ui.item = I_IMPORT;
        ui.handle_key_test(Key::Enter, &mut s);
        for c in "a.toml".chars() {
            ui.handle_key_test(Key::Char(c), &mut s);
        }
        let mut screen = Screen::new(COLS, ROWS, 0);
        assert!(ui.draw(&mut screen, &s, None, None).is_some());
        assert_eq!(ui.handle_key_test(Key::Enter, &mut s), Action::Import("a.toml".into()));
        ui.show_message("Imported".into());
        ui.draw(&mut screen, &s, None, None);
        assert_eq!(ui.handle_key_test(Key::Char('x'), &mut s), Action::None);
        assert_eq!(ui.handle_key_test(Key::Escape, &mut s), Action::Close);
        theme::set_current(Theme::default());
    }

    #[test]
    fn menu_changes_settings() {
        let mut ui = SettingsUi::default();
        let mut s = Settings::default();
        assert_eq!(ui.handle_key_test(Key::Right, &mut s), Action::Changed);
        assert_eq!(s.crt, CrtMode::Color);
        assert_eq!(ui.handle_key_test(Key::Left, &mut s), Action::Changed);
        assert_eq!(s.crt, CrtMode::Off);
        // Tab to the colors.
        for _ in 0..3 {
            ui.handle_key_test(Key::Tab, &mut s);
        }
        assert_eq!(ui.item, I_SCHEME);
        ui.handle_key_test(Key::Right, &mut s);
        assert_eq!(s.colors, SCHEMES[1].1);
        assert_eq!(theme::current(), SCHEMES[1].1);
        assert_eq!(ui.handle_key_test(Key::Escape, &mut s), Action::Close);
        theme::set_current(Theme::default());
    }

    #[test]
    fn color_editor_picks_and_undoes() {
        let mut ui = SettingsUi { item: I_COLORS, ..SettingsUi::default() };
        let mut s = Settings::default();
        ui.handle_key_test(Key::Enter, &mut s);
        ui.handle_key_test(Key::Down, &mut s); // the directory border
        ui.handle_key_test(Key::Enter, &mut s);
        let before = s.colors.border;
        assert_eq!(ui.handle_key_test(Key::Right, &mut s), Action::Changed);
        assert_eq!(s.colors.border.fg, (before.fg + 1) % 16);
        ui.handle_key_test(Key::Up, &mut s);
        assert_eq!(s.colors.border.bg, (before.bg + 7) % 8);
        assert_eq!(s.colors.scheme_name(), None);
        let mut screen = Screen::new(COLS, ROWS, 0);
        ui.draw(&mut screen, &s, None, None);
        // Esc puts it back; then Esc leaves the editor, and the screen.
        ui.handle_key_test(Key::Escape, &mut s);
        assert_eq!(s.colors.border, before);
        ui.handle_key_test(Key::Escape, &mut s);
        assert_eq!(ui.handle_key_test(Key::Escape, &mut s), Action::Close);
        ui.draw(&mut screen, &s, Some("Amber screen"), Some("9.9.9"));
        theme::set_current(Theme::default());
    }
}